qemu-system(1)



QEMU.1(1)                                                            QEMU.1(1)

NAME
       qemu-doc - QEMU version 2.10.0 User Documentation

SYNOPSIS
       qemu-system-i386 [options] [disk_image]

DESCRIPTION
       The QEMU PC System emulator simulates the following peripherals:

       -   i440FX host PCI bridge and PIIX3 PCI to ISA bridge

       -   Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
           extensions (hardware level, including all non standard modes).

       -   PS/2 mouse and keyboard

       -   2 PCI IDE interfaces with hard disk and CD-ROM support

       -   Floppy disk

       -   PCI and ISA network adapters

       -   Serial ports

       -   IPMI BMC, either and internal or external one

       -   Creative SoundBlaster 16 sound card

       -   ENSONIQ AudioPCI ES1370 sound card

       -   Intel 82801AA AC97 Audio compatible sound card

       -   Intel HD Audio Controller and HDA codec

       -   Adlib (OPL2) - Yamaha YM3812 compatible chip

       -   Gravis Ultrasound GF1 sound card

       -   CS4231A compatible sound card

       -   PCI UHCI, OHCI, EHCI or XHCI USB controller and a virtual USB-1.1
           hub.

       SMP is supported with up to 255 CPUs.

       QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs
       LGPL VGA BIOS.

       QEMU uses YM3812 emulation by Tatsuyuki Satoh.

       QEMU uses GUS emulation (GUSEMU32 <http://www.deinmeister.de/gusemu/>)
       by Tibor "TS" Schutz.

       Note that, by default, GUS shares IRQ(7) with parallel ports and so
       QEMU must be told to not have parallel ports to have working GUS.

               qemu-system-i386 dos.img -soundhw gus -parallel none

       Alternatively:

               qemu-system-i386 dos.img -device gus,irq=5

       Or some other unclaimed IRQ.

       CS4231A is the chip used in Windows Sound System and GUSMAX products

OPTIONS
       disk_image is a raw hard disk image for IDE hard disk 0. Some targets
       do not need a disk image.

       Standard options

       -h  Display help and exit

       -version
           Display version information and exit

       -machine [type=]name[,prop=value[,...]]
           Select the emulated machine by name. Use "-machine help" to list
           available machines.

           For architectures which aim to support live migration compatibility
           across releases, each release will introduce a new versioned
           machine type. For example, the 2.8.0 release introduced machine
           types "pc-i440fx-2.8" and "pc-q35-2.8" for the x86_64/i686
           architectures.

           To allow live migration of guests from QEMU version 2.8.0, to QEMU
           version 2.9.0, the 2.9.0 version must support the "pc-i440fx-2.8"
           and "pc-q35-2.8" machines too. To allow users live migrating VMs to
           skip multiple intermediate releases when upgrading, new releases of
           QEMU will support machine types from many previous versions.

           Supported machine properties are:

           accel=accels1[:accels2[:...]]
               This is used to enable an accelerator. Depending on the target
               architecture, kvm, xen, hax or tcg can be available. By
               default, tcg is used. If there is more than one accelerator
               specified, the next one is used if the previous one fails to
               initialize.

           kernel_irqchip=on|off
               Controls in-kernel irqchip support for the chosen accelerator
               when available.

           gfx_passthru=on|off
               Enables IGD GFX passthrough support for the chosen machine when
               available.

           vmport=on|off|auto
               Enables emulation of VMWare IO port, for vmmouse etc. auto says
               to select the value based on accel. For accel=xen the default
               is off otherwise the default is on.

           kvm_shadow_mem=size
               Defines the size of the KVM shadow MMU.

           dump-guest-core=on|off
               Include guest memory in a core dump. The default is on.

           mem-merge=on|off
               Enables or disables memory merge support. This feature, when
               supported by the host, de-duplicates identical memory pages
               among VMs instances (enabled by default).

           aes-key-wrap=on|off
               Enables or disables AES key wrapping support on s390-ccw hosts.
               This feature controls whether AES wrapping keys will be created
               to allow execution of AES cryptographic functions.  The default
               is on.

           dea-key-wrap=on|off
               Enables or disables DEA key wrapping support on s390-ccw hosts.
               This feature controls whether DEA wrapping keys will be created
               to allow execution of DEA cryptographic functions.  The default
               is on.

           nvdimm=on|off
               Enables or disables NVDIMM support. The default is off.

           s390-squash-mcss=on|off
               Enables or disables squashing subchannels into the default css.
               The default is off.

           enforce-config-section=on|off
               If enforce-config-section is set to on, force migration code to
               send configuration section even if the machine-type sets the
               migration.send-configuration property to off.  NOTE: this
               parameter is deprecated. Please use -global
               migration.send-configuration=on|off instead.

       -cpu model
           Select CPU model ("-cpu help" for list and additional feature
           selection)

       -accel name[,prop=value[,...]]
           This is used to enable an accelerator. Depending on the target
           architecture, kvm, xen, hax or tcg can be available. By default,
           tcg is used. If there is more than one accelerator specified, the
           next one is used if the previous one fails to initialize.

           thread=single|multi
               Controls number of TCG threads. When the TCG is multi-threaded
               there will be one thread per vCPU therefor taking advantage of
               additional host cores. The default is to enable multi-threading
               where both the back-end and front-ends support it and no
               incompatible TCG features have been enabled (e.g.
               icount/replay).

       -smp
       [cpus=]n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus]
           Simulate an SMP system with n CPUs. On the PC target, up to 255
           CPUs are supported. On Sparc32 target, Linux limits the number of
           usable CPUs to 4.  For the PC target, the number of cores per
           socket, the number of threads per cores and the total number of
           sockets can be specified. Missing values will be computed. If any
           on the three values is given, the total number of CPUs n can be
           omitted. maxcpus specifies the maximum number of hotpluggable CPUs.

       -numa node[,mem=size][,cpus=firstcpu[-lastcpu]][,nodeid=node]
       -numa node[,memdev=id][,cpus=firstcpu[-lastcpu]][,nodeid=node]
       -numa dist,src=source,dst=destination,val=distance
       -numa cpu,node-id=node[,socket-id=x][,core-id=y][,thread-id=z]
           Define a NUMA node and assign RAM and VCPUs to it.  Set the NUMA
           distance from a source node to a destination node.

           Legacy VCPU assignment uses cpus option where firstcpu and lastcpu
           are CPU indexes. Each cpus option represent a contiguous range of
           CPU indexes (or a single VCPU if lastcpu is omitted). A non-
           contiguous set of VCPUs can be represented by providing multiple
           cpus options. If cpus is omitted on all nodes, VCPUs are
           automatically split between them.

           For example, the following option assigns VCPUs 0, 1, 2 and 5 to a
           NUMA node:

                   -numa node,cpus=0-2,cpus=5

           cpu option is a new alternative to cpus option which uses
           socket-id|core-id|thread-id properties to assign CPU objects to a
           node using topology layout properties of CPU.  The set of
           properties is machine specific, and depends on used machine
           type/smp options. It could be queried with hotpluggable-cpus
           monitor command.  node-id property specifies node to which CPU
           object will be assigned, it's required for node to be declared with
           node option before it's used with cpu option.

           For example:

                   -M pc \
                   -smp 1,sockets=2,maxcpus=2 \
                   -numa node,nodeid=0 -numa node,nodeid=1 \
                   -numa cpu,node-id=0,socket-id=0 -numa cpu,node-id=1,socket-id=1

           mem assigns a given RAM amount to a node. memdev assigns RAM from a
           given memory backend device to a node. If mem and memdev are
           omitted in all nodes, RAM is split equally between them.

           mem and memdev are mutually exclusive. Furthermore, if one node
           uses memdev, all of them have to use it.

           source and destination are NUMA node IDs.  distance is the NUMA
           distance from source to destination.  The distance from a node to
           itself is always 10. If any pair of nodes is given a distance, then
           all pairs must be given distances. Although, when distances are
           only given in one direction for each pair of nodes, then the
           distances in the opposite directions are assumed to be the same.
           If, however, an asymmetrical pair of distances is given for even
           one node pair, then all node pairs must be provided distance values
           for both directions, even when they are symmetrical. When a node is
           unreachable from another node, set the pair's distance to 255.

           Note that the -numa option doesn't allocate any of the specified
           resources, it just assigns existing resources to NUMA nodes. This
           means that one still has to use the -m, -smp options to allocate
           RAM and VCPUs respectively.

       -add-fd fd=fd,set=set[,opaque=opaque]
           Add a file descriptor to an fd set.  Valid options are:

           fd=fd
               This option defines the file descriptor of which a duplicate is
               added to fd set.  The file descriptor cannot be stdin, stdout,
               or stderr.

           set=set
               This option defines the ID of the fd set to add the file
               descriptor to.

           opaque=opaque
               This option defines a free-form string that can be used to
               describe fd.

           You can open an image using pre-opened file descriptors from an fd
           set:

                   qemu-system-i386
                   -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
                   -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
                   -drive file=/dev/fdset/2,index=0,media=disk

       -set group.id.arg=value
           Set parameter arg for item id of type group

       -global driver.prop=value
       -global driver=driver,property=property,value=value
           Set default value of driver's property prop to value, e.g.:

                   qemu-system-i386 -global ide-hd.physical_block_size=4096 disk-image.img

           In particular, you can use this to set driver properties for
           devices which are created automatically by the machine model. To
           create a device which is not created automatically and set
           properties on it, use -device.

           -global driver.prop=value is shorthand for -global
           driver=driver,property=prop,value=value.  The longhand syntax works
           even when driver contains a dot.

       -boot
       [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_timeout][,strict=on|off]
           Specify boot order drives as a string of drive letters. Valid drive
           letters depend on the target architecture. The x86 PC uses: a, b
           (floppy 1 and 2), c (first hard disk), d (first CD-ROM), n-p
           (Etherboot from network adapter 1-4), hard disk boot is the
           default. To apply a particular boot order only on the first
           startup, specify it via once. Note that the order or once parameter
           should not be used together with the bootindex property of devices,
           since the firmware implementations normally do not support both at
           the same time.

           Interactive boot menus/prompts can be enabled via menu=on as far as
           firmware/BIOS supports them. The default is non-interactive boot.

           A splash picture could be passed to bios, enabling user to show it
           as logo, when option splash=sp_name is given and menu=on, If
           firmware/BIOS supports them. Currently Seabios for X86 system
           support it.  limitation: The splash file could be a jpeg file or a
           BMP file in 24 BPP format(true color). The resolution should be
           supported by the SVGA mode, so the recommended is 320x240, 640x480,
           800x640.

           A timeout could be passed to bios, guest will pause for rb_timeout
           ms when boot failed, then reboot. If rb_timeout is '-1', guest will
           not reboot, qemu passes '-1' to bios by default. Currently Seabios
           for X86 system support it.

           Do strict boot via strict=on as far as firmware/BIOS supports it.
           This only effects when boot priority is changed by bootindex
           options. The default is non-strict boot.

                   # try to boot from network first, then from hard disk
                   qemu-system-i386 -boot order=nc
                   # boot from CD-ROM first, switch back to default order after reboot
                   qemu-system-i386 -boot once=d
                   # boot with a splash picture for 5 seconds.
                   qemu-system-i386 -boot menu=on,splash=/root/boot.bmp,splash-time=5000

           Note: The legacy format '-boot drives' is still supported but its
           use is discouraged as it may be removed from future versions.

       -m [size=]megs[,slots=n,maxmem=size]
           Sets guest startup RAM size to megs megabytes. Default is 128 MiB.
           Optionally, a suffix of "M" or "G" can be used to signify a value
           in megabytes or gigabytes respectively. Optional pair slots, maxmem
           could be used to set amount of hotpluggable memory slots and
           maximum amount of memory. Note that maxmem must be aligned to the
           page size.

           For example, the following command-line sets the guest startup RAM
           size to 1GB, creates 3 slots to hotplug additional memory and sets
           the maximum memory the guest can reach to 4GB:

                   qemu-system-x86_64 -m 1G,slots=3,maxmem=4G

           If slots and maxmem are not specified, memory hotplug won't be
           enabled and the guest startup RAM will never increase.

       -mem-path path
           Allocate guest RAM from a temporarily created file in path.

       -mem-prealloc
           Preallocate memory when using -mem-path.

       -k language
           Use keyboard layout language (for example "fr" for French). This
           option is only needed where it is not easy to get raw PC keycodes
           (e.g. on Macs, with some X11 servers or with a VNC or curses
           display). You don't normally need to use it on PC/Linux or
           PC/Windows hosts.

           The available layouts are:

                   ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
                   da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
                   de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr

           The default is "en-us".

       -audio-help
           Will show the audio subsystem help: list of drivers, tunable
           parameters.

       -soundhw card1[,card2,...] or -soundhw all
           Enable audio and selected sound hardware. Use 'help' to print all
           available sound hardware.

                   qemu-system-i386 -soundhw sb16,adlib disk.img
                   qemu-system-i386 -soundhw es1370 disk.img
                   qemu-system-i386 -soundhw ac97 disk.img
                   qemu-system-i386 -soundhw hda disk.img
                   qemu-system-i386 -soundhw all disk.img
                   qemu-system-i386 -soundhw help

           Note that Linux's i810_audio OSS kernel (for AC97) module might
           require manually specifying clocking.

                   modprobe i810_audio clocking=48000

       -balloon none
           Disable balloon device.

       -balloon virtio[,addr=addr]
           Enable virtio balloon device (default), optionally with PCI address
           addr.

       -device driver[,prop[=value][,...]]
           Add device driver.  prop=value sets driver properties.  Valid
           properties depend on the driver.  To get help on possible drivers
           and properties, use "-device help" and "-device driver,help".

           Some drivers are:

       -device
       ipmi-bmc-sim,id=id[,slave_addr=val][,sdrfile=file][,furareasize=val][,furdatafile=file]
           Add an IPMI BMC.  This is a simulation of a hardware management
           interface processor that normally sits on a system.  It provides a
           watchdog and the ability to reset and power control the system.
           You need to connect this to an IPMI interface to make it useful

           The IPMI slave address to use for the BMC.  The default is 0x20.
           This address is the BMC's address on the I2C network of management
           controllers.  If you don't know what this means, it is safe to
           ignore it.

           bmc=id
               The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
               above.

           slave_addr=val
               Define slave address to use for the BMC.  The default is 0x20.

           sdrfile=file
               file containing raw Sensor Data Records (SDR) data. The default
               is none.

           fruareasize=val
               size of a Field Replaceable Unit (FRU) area.  The default is
               1024.

           frudatafile=file
               file containing raw Field Replaceable Unit (FRU) inventory
               data. The default is none.

       -device ipmi-bmc-extern,id=id,chardev=id[,slave_addr=val]
           Add a connection to an external IPMI BMC simulator.  Instead of
           locally emulating the BMC like the above item, instead connect to
           an external entity that provides the IPMI services.

           A connection is made to an external BMC simulator.  If you do this,
           it is strongly recommended that you use the "reconnect=" chardev
           option to reconnect to the simulator if the connection is lost.
           Note that if this is not used carefully, it can be a security
           issue, as the interface has the ability to send resets, NMIs, and
           power off the VM.  It's best if QEMU makes a connection to an
           external simulator running on a secure port on localhost, so
           neither the simulator nor QEMU is exposed to any outside network.

           See the "lanserv/README.vm" file in the OpenIPMI library for more
           details on the external interface.

       -device isa-ipmi-kcs,bmc=id[,ioport=val][,irq=val]
           Add a KCS IPMI interafce on the ISA bus.  This also adds a
           corresponding ACPI and SMBIOS entries, if appropriate.

           bmc=id
               The BMC to connect to, one of ipmi-bmc-sim or ipmi-bmc-extern
               above.

           ioport=val
               Define the I/O address of the interface.  The default is 0xca0
               for KCS.

           irq=val
               Define the interrupt to use.  The default is 5.  To disable
               interrupts, set this to 0.

       -device isa-ipmi-bt,bmc=id[,ioport=val][,irq=val]
           Like the KCS interface, but defines a BT interface.  The default
           port is 0xe4 and the default interrupt is 5.

       -name name
           Sets the name of the guest.  This name will be displayed in the SDL
           window caption.  The name will also be used for the VNC server.
           Also optionally set the top visible process name in Linux.  Naming
           of individual threads can also be enabled on Linux to aid
           debugging.

       -uuid uuid
           Set system UUID.

       Block device options

       -fda file
       -fdb file
           Use file as floppy disk 0/1 image.

       -hda file
       -hdb file
       -hdc file
       -hdd file
           Use file as hard disk 0, 1, 2 or 3 image.

       -cdrom file
           Use file as CD-ROM image (you cannot use -hdc and -cdrom at the
           same time). You can use the host CD-ROM by using /dev/cdrom as
           filename.

       -blockdev option[,option[,option[,...]]]
           Define a new block driver node. Some of the options apply to all
           block drivers, other options are only accepted for a specific block
           driver. See below for a list of generic options and options for the
           most common block drivers.

           Options that expect a reference to another node (e.g. "file") can
           be given in two ways. Either you specify the node name of an
           already existing node (file=node-name), or you define a new node
           inline, adding options for the referenced node after a dot
           (file.filename=path,file.aio=native).

           A block driver node created with -blockdev can be used for a guest
           device by specifying its node name for the "drive" property in a
           -device argument that defines a block device.

           Valid options for any block driver node:
               "driver"
                   Specifies the block driver to use for the given node.

               "node-name"
                   This defines the name of the block driver node by which it
                   will be referenced later. The name must be unique, i.e. it
                   must not match the name of a different block driver node,
                   or (if you use -drive as well) the ID of a drive.

                   If no node name is specified, it is automatically
                   generated. The generated node name is not intended to be
                   predictable and changes between QEMU invocations.  For the
                   top level, an explicit node name must be specified.

               "read-only"
                   Open the node read-only. Guest write attempts will fail.

               "cache.direct"
                   The host page cache can be avoided with cache.direct=on.
                   This will attempt to do disk IO directly to the guest's
                   memory. QEMU may still perform an internal copy of the
                   data.

               "cache.no-flush"
                   In case you don't care about data integrity over host
                   failures, you can use cache.no-flush=on. This option tells
                   QEMU that it never needs to write any data to the disk but
                   can instead keep things in cache. If anything goes wrong,
                   like your host losing power, the disk storage getting
                   disconnected accidentally, etc. your image will most
                   probably be rendered unusable.

               "discard=discard"
                   discard is one of "ignore" (or "off") or "unmap" (or "on")
                   and controls whether "discard" (also known as "trim" or
                   "unmap") requests are ignored or passed to the filesystem.
                   Some machine types may not support discard requests.

               "detect-zeroes=detect-zeroes"
                   detect-zeroes is "off", "on" or "unmap" and enables the
                   automatic conversion of plain zero writes by the OS to
                   driver specific optimized zero write commands. You may even
                   choose "unmap" if discard is set to "unmap" to allow a zero
                   write to be converted to an "unmap" operation.

           Driver-specific options for "file"
               This is the protocol-level block driver for accessing regular
               files.

               "filename"
                   The path to the image file in the local filesystem

               "aio"
                   Specifies the AIO backend (threads/native, default:
                   threads)

               Example:

                       -blockdev driver=file,node-name=disk,filename=disk.img

           Driver-specific options for "raw"
               This is the image format block driver for raw images. It is
               usually stacked on top of a protocol level block driver such as
               "file".

               "file"
                   Reference to or definition of the data source block driver
                   node (e.g. a "file" driver node)

               Example 1:

                       -blockdev driver=file,node-name=disk_file,filename=disk.img
                       -blockdev driver=raw,node-name=disk,file=disk_file

               Example 2:

                       -blockdev driver=raw,node-name=disk,file.driver=file,file.filename=disk.img

           Driver-specific options for "qcow2"
               This is the image format block driver for qcow2 images. It is
               usually stacked on top of a protocol level block driver such as
               "file".

               "file"
                   Reference to or definition of the data source block driver
                   node (e.g. a "file" driver node)

               "backing"
                   Reference to or definition of the backing file block device
                   (default is taken from the image file). It is allowed to
                   pass an empty string here in order to disable the default
                   backing file.

               "lazy-refcounts"
                   Whether to enable the lazy refcounts feature (on/off;
                   default is taken from the image file)

               "cache-size"
                   The maximum total size of the L2 table and refcount block
                   caches in bytes (default: 1048576 bytes or 8 clusters,
                   whichever is larger)

               "l2-cache-size"
                   The maximum size of the L2 table cache in bytes (default:
                   4/5 of the total cache size)

               "refcount-cache-size"
                   The maximum size of the refcount block cache in bytes
                   (default: 1/5 of the total cache size)

               "cache-clean-interval"
                   Clean unused entries in the L2 and refcount caches. The
                   interval is in seconds.  The default value is 0 and it
                   disables this feature.

               "pass-discard-request"
                   Whether discard requests to the qcow2 device should be
                   forwarded to the data source (on/off; default: on if
                   discard=unmap is specified, off otherwise)

               "pass-discard-snapshot"
                   Whether discard requests for the data source should be
                   issued when a snapshot operation (e.g. deleting a snapshot)
                   frees clusters in the qcow2 file (on/off; default: on)

               "pass-discard-other"
                   Whether discard requests for the data source should be
                   issued on other occasions where a cluster gets freed
                   (on/off; default: off)

               "overlap-check"
                   Which overlap checks to perform for writes to the image
                   (none/constant/cached/all; default: cached). For details or
                   finer granularity control refer to the QAPI documentation
                   of "blockdev-add".

               Example 1:

                       -blockdev driver=file,node-name=my_file,filename=/tmp/disk.qcow2
                       -blockdev driver=qcow2,node-name=hda,file=my_file,overlap-check=none,cache-size=16777216

               Example 2:

                       -blockdev driver=qcow2,node-name=disk,file.driver=http,file.filename=http://example.com/image.qcow2

           Driver-specific options for other drivers
               Please refer to the QAPI documentation of the "blockdev-add"
               QMP command.

       -drive option[,option[,option[,...]]]
           Define a new drive. This includes creating a block driver node (the
           backend) as well as a guest device, and is mostly a shortcut for
           defining the corresponding -blockdev and -device options.

           -drive accepts all options that are accepted by -blockdev. In
           addition, it knows the following options:

           file=file
               This option defines which disk image to use with this drive. If
               the filename contains comma, you must double it (for instance,
               "file=my,,file" to use file "my,file").

               Special files such as iSCSI devices can be specified using
               protocol specific URLs. See the section for "Device URL Syntax"
               for more information.

           if=interface
               This option defines on which type on interface the drive is
               connected.  Available types are: ide, scsi, sd, mtd, floppy,
               pflash, virtio, none.

           bus=bus,unit=unit
               These options define where is connected the drive by defining
               the bus number and the unit id.

           index=index
               This option defines where is connected the drive by using an
               index in the list of available connectors of a given interface
               type.

           media=media
               This option defines the type of the media: disk or cdrom.

           cyls=c,heads=h,secs=s[,trans=t]
               These options have the same definition as they have in -hdachs.
               These parameters are deprecated, use the corresponding
               parameters of "-device" instead.

           snapshot=snapshot
               snapshot is "on" or "off" and controls snapshot mode for the
               given drive (see -snapshot).

           cache=cache
               cache is "none", "writeback", "unsafe", "directsync" or
               "writethrough" and controls how the host cache is used to
               access block data. This is a shortcut that sets the
               cache.direct and cache.no-flush options (as in -blockdev), and
               additionally cache.writeback, which provides a default for the
               write-cache option of block guest devices (as in -device). The
               modes correspond to the following settings:

                                    | cache.writeback   cache.direct   cache.no-flush

                       writeback    | on                off            off
                       none         | on                on             off
                       writethrough | off               off            off
                       directsync   | off               on             off
                       unsafe       | on                off            on

               The default mode is cache=writeback.

           aio=aio
               aio is "threads", or "native" and selects between pthread based
               disk I/O and native Linux AIO.

           format=format
               Specify which disk format will be used rather than detecting
               the format.  Can be used to specify format=raw to avoid
               interpreting an untrusted format header.

           serial=serial
               This option specifies the serial number to assign to the
               device. This parameter is deprecated, use the corresponding
               parameter of "-device" instead.

           addr=addr
               Specify the controller's PCI address (if=virtio only). This
               parameter is deprecated, use the corresponding parameter of
               "-device" instead.

           werror=action,rerror=action
               Specify which action to take on write and read errors. Valid
               actions are: "ignore" (ignore the error and try to continue),
               "stop" (pause QEMU), "report" (report the error to the guest),
               "enospc" (pause QEMU only if the host disk is full; report the
               error to the guest otherwise).  The default setting is
               werror=enospc and rerror=report.

           copy-on-read=copy-on-read
               copy-on-read is "on" or "off" and enables whether to copy read
               backing file sectors into the image file.

           bps=b,bps_rd=r,bps_wr=w
               Specify bandwidth throttling limits in bytes per second, either
               for all request types or for reads or writes only.  Small
               values can lead to timeouts or hangs inside the guest.  A safe
               minimum for disks is 2 MB/s.

           bps_max=bm,bps_rd_max=rm,bps_wr_max=wm
               Specify bursts in bytes per second, either for all request
               types or for reads or writes only.  Bursts allow the guest I/O
               to spike above the limit temporarily.

           iops=i,iops_rd=r,iops_wr=w
               Specify request rate limits in requests per second, either for
               all request types or for reads or writes only.

           iops_max=bm,iops_rd_max=rm,iops_wr_max=wm
               Specify bursts in requests per second, either for all request
               types or for reads or writes only.  Bursts allow the guest I/O
               to spike above the limit temporarily.

           iops_size=is
               Let every is bytes of a request count as a new request for iops
               throttling purposes.  Use this option to prevent guests from
               circumventing iops limits by sending fewer but larger requests.

           group=g
               Join a throttling quota group with given name g.  All drives
               that are members of the same group are accounted for together.
               Use this option to prevent guests from circumventing throttling
               limits by using many small disks instead of a single larger
               disk.

           By default, the cache.writeback=on mode is used. It will report
           data writes as completed as soon as the data is present in the host
           page cache.  This is safe as long as your guest OS makes sure to
           correctly flush disk caches where needed. If your guest OS does not
           handle volatile disk write caches correctly and your host crashes
           or loses power, then the guest may experience data corruption.

           For such guests, you should consider using cache.writeback=off.
           This means that the host page cache will be used to read and write
           data, but write notification will be sent to the guest only after
           QEMU has made sure to flush each write to the disk. Be aware that
           this has a major impact on performance.

           When using the -snapshot option, unsafe caching is always used.

           Copy-on-read avoids accessing the same backing file sectors
           repeatedly and is useful when the backing file is over a slow
           network.  By default copy-on-read is off.

           Instead of -cdrom you can use:

                   qemu-system-i386 -drive file=file,index=2,media=cdrom

           Instead of -hda, -hdb, -hdc, -hdd, you can use:

                   qemu-system-i386 -drive file=file,index=0,media=disk
                   qemu-system-i386 -drive file=file,index=1,media=disk
                   qemu-system-i386 -drive file=file,index=2,media=disk
                   qemu-system-i386 -drive file=file,index=3,media=disk

           You can open an image using pre-opened file descriptors from an fd
           set:

                   qemu-system-i386
                   -add-fd fd=3,set=2,opaque="rdwr:/path/to/file"
                   -add-fd fd=4,set=2,opaque="rdonly:/path/to/file"
                   -drive file=/dev/fdset/2,index=0,media=disk

           You can connect a CDROM to the slave of ide0:

                   qemu-system-i386 -drive file=file,if=ide,index=1,media=cdrom

           If you don't specify the "file=" argument, you define an empty
           drive:

                   qemu-system-i386 -drive if=ide,index=1,media=cdrom

           Instead of -fda, -fdb, you can use:

                   qemu-system-i386 -drive file=file,index=0,if=floppy
                   qemu-system-i386 -drive file=file,index=1,if=floppy

           By default, interface is "ide" and index is automatically
           incremented:

                   qemu-system-i386 -drive file=a -drive file=b"

           is interpreted like:

                   qemu-system-i386 -hda a -hdb b

       -mtdblock file
           Use file as on-board Flash memory image.

       -sd file
           Use file as SecureDigital card image.

       -pflash file
           Use file as a parallel flash image.

       -snapshot
           Write to temporary files instead of disk image files. In this case,
           the raw disk image you use is not written back. You can however
           force the write back by pressing C-a s.

       -hdachs c,h,s,[,t]
           Force hard disk 0 physical geometry (1 <= c <= 16383, 1 <= h <= 16,
           1 <= s <= 63) and optionally force the BIOS translation mode
           (t=none, lba or auto). Usually QEMU can guess all those parameters.
           This option is deprecated, please use "-device
           ide-hd,cyls=c,heads=h,secs=s,..." instead.

       -fsdev
       fsdriver,id=id,path=path,[security_model=security_model][,writeout=writeout][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]
           Define a new file system device. Valid options are:

           fsdriver
               This option specifies the fs driver backend to use.  Currently
               "local", "handle" and "proxy" file system drivers are
               supported.

           id=id
               Specifies identifier for this device

           path=path
               Specifies the export path for the file system device. Files
               under this path will be available to the 9p client on the
               guest.

           security_model=security_model
               Specifies the security model to be used for this export path.
               Supported security models are "passthrough", "mapped-xattr",
               "mapped-file" and "none".  In "passthrough" security model,
               files are stored using the same credentials as they are created
               on the guest. This requires QEMU to run as root. In "mapped-
               xattr" security model, some of the file attributes like uid,
               gid, mode bits and link target are stored as file attributes.
               For "mapped-file" these attributes are stored in the hidden
               .virtfs_metadata directory. Directories exported by this
               security model cannot interact with other unix tools. "none"
               security model is same as passthrough except the sever won't
               report failures if it fails to set file attributes like
               ownership. Security model is mandatory only for local fsdriver.
               Other fsdrivers (like handle, proxy) don't take security model
               as a parameter.

           writeout=writeout
               This is an optional argument. The only supported value is
               "immediate".  This means that host page cache will be used to
               read and write data but write notification will be sent to the
               guest only when the data has been reported as written by the
               storage subsystem.

           readonly
               Enables exporting 9p share as a readonly mount for guests. By
               default read-write access is given.

           socket=socket
               Enables proxy filesystem driver to use passed socket file for
               communicating with virtfs-proxy-helper

           sock_fd=sock_fd
               Enables proxy filesystem driver to use passed socket descriptor
               for communicating with virtfs-proxy-helper. Usually a helper
               like libvirt will create socketpair and pass one of the fds as
               sock_fd

           fmode=fmode
               Specifies the default mode for newly created files on the host.
               Works only with security models "mapped-xattr" and "mapped-
               file".

           dmode=dmode
               Specifies the default mode for newly created directories on the
               host. Works only with security models "mapped-xattr" and
               "mapped-file".

           -fsdev option is used along with -device driver "virtio-9p-pci".

       -device virtio-9p-pci,fsdev=id,mount_tag=mount_tag
           Options for virtio-9p-pci driver are:

           fsdev=id
               Specifies the id value specified along with -fsdev option

           mount_tag=mount_tag
               Specifies the tag name to be used by the guest to mount this
               export point

       -virtfs
       fsdriver[,path=path],mount_tag=mount_tag[,security_model=security_model][,writeout=writeout][,readonly][,socket=socket|sock_fd=sock_fd][,fmode=fmode][,dmode=dmode]
           The general form of a Virtual File system pass-through options are:

           fsdriver
               This option specifies the fs driver backend to use.  Currently
               "local", "handle" and "proxy" file system drivers are
               supported.

           id=id
               Specifies identifier for this device

           path=path
               Specifies the export path for the file system device. Files
               under this path will be available to the 9p client on the
               guest.

           security_model=security_model
               Specifies the security model to be used for this export path.
               Supported security models are "passthrough", "mapped-xattr",
               "mapped-file" and "none".  In "passthrough" security model,
               files are stored using the same credentials as they are created
               on the guest. This requires QEMU to run as root. In "mapped-
               xattr" security model, some of the file attributes like uid,
               gid, mode bits and link target are stored as file attributes.
               For "mapped-file" these attributes are stored in the hidden
               .virtfs_metadata directory. Directories exported by this
               security model cannot interact with other unix tools. "none"
               security model is same as passthrough except the sever won't
               report failures if it fails to set file attributes like
               ownership. Security model is mandatory only for local fsdriver.
               Other fsdrivers (like handle, proxy) don't take security model
               as a parameter.

           writeout=writeout
               This is an optional argument. The only supported value is
               "immediate".  This means that host page cache will be used to
               read and write data but write notification will be sent to the
               guest only when the data has been reported as written by the
               storage subsystem.

           readonly
               Enables exporting 9p share as a readonly mount for guests. By
               default read-write access is given.

           socket=socket
               Enables proxy filesystem driver to use passed socket file for
               communicating with virtfs-proxy-helper. Usually a helper like
               libvirt will create socketpair and pass one of the fds as
               sock_fd

           sock_fd
               Enables proxy filesystem driver to use passed 'sock_fd' as the
               socket descriptor for interfacing with virtfs-proxy-helper

           fmode=fmode
               Specifies the default mode for newly created files on the host.
               Works only with security models "mapped-xattr" and "mapped-
               file".

           dmode=dmode
               Specifies the default mode for newly created directories on the
               host. Works only with security models "mapped-xattr" and
               "mapped-file".

       -virtfs_synth
           Create synthetic file system image

       USB options

       -usb
           Enable the USB driver (if it is not used by default yet).

       -usbdevice devname
           Add the USB device devname. Note that this option is deprecated,
           please use "-device usb-..." instead.

           mouse
               Virtual Mouse. This will override the PS/2 mouse emulation when
               activated.

           tablet
               Pointer device that uses absolute coordinates (like a
               touchscreen). This means QEMU is able to report the mouse
               position without having to grab the mouse. Also overrides the
               PS/2 mouse emulation when activated.

           disk:[format=format]:file
               Mass storage device based on file. The optional format argument
               will be used rather than detecting the format. Can be used to
               specify "format=raw" to avoid interpreting an untrusted format
               header.

           host:bus.addr
               Pass through the host device identified by bus.addr (Linux
               only).

           host:vendor_id:product_id
               Pass through the host device identified by vendor_id:product_id
               (Linux only).

           serial:[vendorid=vendor_id][,productid=product_id]:dev
               Serial converter to host character device dev, see "-serial"
               for the available devices.

           braille
               Braille device.  This will use BrlAPI to display the braille
               output on a real or fake device.

           net:options
               Network adapter that supports CDC ethernet and RNDIS protocols.

       Display options

       -display type
           Select type of display to use. This option is a replacement for the
           old style -sdl/-curses/... options. Valid values for type are

           sdl Display video output via SDL (usually in a separate graphics
               window; see the SDL documentation for other possibilities).

           curses
               Display video output via curses. For graphics device models
               which support a text mode, QEMU can display this output using a
               curses/ncurses interface. Nothing is displayed when the
               graphics device is in graphical mode or if the graphics device
               does not support a text mode. Generally only the VGA device
               models support text mode.

           none
               Do not display video output. The guest will still see an
               emulated graphics card, but its output will not be displayed to
               the QEMU user. This option differs from the -nographic option
               in that it only affects what is done with video output;
               -nographic also changes the destination of the serial and
               parallel port data.

           gtk Display video output in a GTK window. This interface provides
               drop-down menus and other UI elements to configure and control
               the VM during runtime.

           vnc Start a VNC server on display <arg>

       -nographic
           Normally, if QEMU is compiled with graphical window support, it
           displays output such as guest graphics, guest console, and the QEMU
           monitor in a window. With this option, you can totally disable
           graphical output so that QEMU is a simple command line application.
           The emulated serial port is redirected on the console and muxed
           with the monitor (unless redirected elsewhere explicitly).
           Therefore, you can still use QEMU to debug a Linux kernel with a
           serial console. Use C-a h for help on switching between the console
           and monitor.

       -curses
           Normally, if QEMU is compiled with graphical window support, it
           displays output such as guest graphics, guest console, and the QEMU
           monitor in a window. With this option, QEMU can display the VGA
           output when in text mode using a curses/ncurses interface. Nothing
           is displayed in graphical mode.

       -no-frame
           Do not use decorations for SDL windows and start them using the
           whole available screen space. This makes the using QEMU in a
           dedicated desktop workspace more convenient.

       -alt-grab
           Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that
           this also affects the special keys (for fullscreen, monitor-mode
           switching, etc).

       -ctrl-grab
           Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this
           also affects the special keys (for fullscreen, monitor-mode
           switching, etc).

       -no-quit
           Disable SDL window close capability.

       -sdl
           Enable SDL.

       -spice option[,option[,...]]
           Enable the spice remote desktop protocol. Valid options are

           port=<nr>
               Set the TCP port spice is listening on for plaintext channels.

           addr=<addr>
               Set the IP address spice is listening on.  Default is any
               address.

           ipv4
           ipv6
           unix
               Force using the specified IP version.

           password=<secret>
               Set the password you need to authenticate.

           sasl
               Require that the client use SASL to authenticate with the
               spice.  The exact choice of authentication method used is
               controlled from the system / user's SASL configuration file for
               the 'qemu' service. This is typically found in
               /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
               an environment variable SASL_CONF_PATH can be used to make it
               search alternate locations for the service config.  While some
               SASL auth methods can also provide data encryption (eg GSSAPI),
               it is recommended that SASL always be combined with the 'tls'
               and 'x509' settings to enable use of SSL and server
               certificates. This ensures a data encryption preventing
               compromise of authentication credentials.

           disable-ticketing
               Allow client connects without authentication.

           disable-copy-paste
               Disable copy paste between the client and the guest.

           disable-agent-file-xfer
               Disable spice-vdagent based file-xfer between the client and
               the guest.

           tls-port=<nr>
               Set the TCP port spice is listening on for encrypted channels.

           x509-dir=<dir>
               Set the x509 file directory. Expects same filenames as -vnc
               $display,x509=$dir

           x509-key-file=<file>
           x509-key-password=<file>
           x509-cert-file=<file>
           x509-cacert-file=<file>
           x509-dh-key-file=<file>
               The x509 file names can also be configured individually.

           tls-ciphers=<list>
               Specify which ciphers to use.

           tls-channel=[main|display|cursor|inputs|record|playback]
           plaintext-channel=[main|display|cursor|inputs|record|playback]
               Force specific channel to be used with or without TLS
               encryption.  The options can be specified multiple times to
               configure multiple channels.  The special name "default" can be
               used to set the default mode.  For channels which are not
               explicitly forced into one mode the spice client is allowed to
               pick tls/plaintext as he pleases.

           image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
               Configure image compression (lossless).  Default is auto_glz.

           jpeg-wan-compression=[auto|never|always]
           zlib-glz-wan-compression=[auto|never|always]
               Configure wan image compression (lossy for slow links).
               Default is auto.

           streaming-video=[off|all|filter]
               Configure video stream detection.  Default is off.

           agent-mouse=[on|off]
               Enable/disable passing mouse events via vdagent.  Default is
               on.

           playback-compression=[on|off]
               Enable/disable audio stream compression (using celt 0.5.1).
               Default is on.

           seamless-migration=[on|off]
               Enable/disable spice seamless migration. Default is off.

           gl=[on|off]
               Enable/disable OpenGL context. Default is off.

           rendernode=<file>
               DRM render node for OpenGL rendering. If not specified, it will
               pick the first available. (Since 2.9)

       -portrait
           Rotate graphical output 90 deg left (only PXA LCD).

       -rotate deg
           Rotate graphical output some deg left (only PXA LCD).

       -vga type
           Select type of VGA card to emulate. Valid values for type are

           cirrus
               Cirrus Logic GD5446 Video card. All Windows versions starting
               from Windows 95 should recognize and use this graphic card. For
               optimal performances, use 16 bit color depth in the guest and
               the host OS.  (This card was the default before QEMU 2.2)

           std Standard VGA card with Bochs VBE extensions.  If your guest OS
               supports the VESA 2.0 VBE extensions (e.g. Windows XP) and if
               you want to use high resolution modes (>= 1280x1024x16) then
               you should use this option. (This card is the default since
               QEMU 2.2)

           vmware
               VMWare SVGA-II compatible adapter. Use it if you have
               sufficiently recent XFree86/XOrg server or Windows guest with a
               driver for this card.

           qxl QXL paravirtual graphic card.  It is VGA compatible (including
               VESA 2.0 VBE support).  Works best with qxl guest drivers
               installed though.  Recommended choice when using the spice
               protocol.

           tcx (sun4m only) Sun TCX framebuffer. This is the default
               framebuffer for sun4m machines and offers both 8-bit and 24-bit
               colour depths at a fixed resolution of 1024x768.

           cg3 (sun4m only) Sun cgthree framebuffer. This is a simple 8-bit
               framebuffer for sun4m machines available in both 1024x768
               (OpenBIOS) and 1152x900 (OBP) resolutions aimed at people
               wishing to run older Solaris versions.

           virtio
               Virtio VGA card.

           none
               Disable VGA card.

       -full-screen
           Start in full screen.

       -g widthxheight[xdepth]
           Set the initial graphical resolution and depth (PPC, SPARC only).

       -vnc display[,option[,option[,...]]]
           Normally, if QEMU is compiled with graphical window support, it
           displays output such as guest graphics, guest console, and the QEMU
           monitor in a window. With this option, you can have QEMU listen on
           VNC display display and redirect the VGA display over the VNC
           session. It is very useful to enable the usb tablet device when
           using this option (option -device usb-tablet). When using the VNC
           display, you must use the -k parameter to set the keyboard layout
           if you are not using en-us. Valid syntax for the display is

           to=L
               With this option, QEMU will try next available VNC displays,
               until the number L, if the origianlly defined "-vnc display" is
               not available, e.g. port 5900+display is already used by
               another application. By default, to=0.

           host:d
               TCP connections will only be allowed from host on display d.
               By convention the TCP port is 5900+d. Optionally, host can be
               omitted in which case the server will accept connections from
               any host.

           unix:path
               Connections will be allowed over UNIX domain sockets where path
               is the location of a unix socket to listen for connections on.

           none
               VNC is initialized but not started. The monitor "change"
               command can be used to later start the VNC server.

           Following the display value there may be one or more option flags
           separated by commas. Valid options are

           reverse
               Connect to a listening VNC client via a "reverse" connection.
               The client is specified by the display. For reverse network
               connections (host:d,"reverse"), the d argument is a TCP port
               number, not a display number.

           websocket
               Opens an additional TCP listening port dedicated to VNC
               Websocket connections.  If a bare websocket option is given,
               the Websocket port is 5700+display. An alternative port can be
               specified with the syntax "websocket"=port.

               If host is specified connections will only be allowed from this
               host.  It is possible to control the websocket listen address
               independently, using the syntax "websocket"=host:port.

               If no TLS credentials are provided, the websocket connection
               runs in unencrypted mode. If TLS credentials are provided, the
               websocket connection requires encrypted client connections.

           password
               Require that password based authentication is used for client
               connections.

               The password must be set separately using the "set_password"
               command in the pcsys_monitor. The syntax to change your
               password is: "set_password <protocol> <password>" where
               <protocol> could be either "vnc" or "spice".

               If you would like to change <protocol> password expiration, you
               should use "expire_password <protocol> <expiration-time>" where
               expiration time could be one of the following options: now,
               never, +seconds or UNIX time of expiration, e.g. +60 to make
               password expire in 60 seconds, or 1335196800 to make password
               expire on "Mon Apr 23 12:00:00 EDT 2012" (UNIX time for this
               date and time).

               You can also use keywords "now" or "never" for the expiration
               time to allow <protocol> password to expire immediately or
               never expire.

           tls-creds=ID
               Provides the ID of a set of TLS credentials to use to secure
               the VNC server. They will apply to both the normal VNC server
               socket and the websocket socket (if enabled). Setting TLS
               credentials will cause the VNC server socket to enable the
               VeNCrypt auth mechanism.  The credentials should have been
               previously created using the -object tls-creds argument.

               The tls-creds parameter obsoletes the tls, x509, and x509verify
               options, and as such it is not permitted to set both new and
               old type options at the same time.

           tls Require that client use TLS when communicating with the VNC
               server. This uses anonymous TLS credentials so is susceptible
               to a man-in-the-middle attack. It is recommended that this
               option be combined with either the x509 or x509verify options.

               This option is now deprecated in favor of using the tls-creds
               argument.

           x509=/path/to/certificate/dir
               Valid if tls is specified. Require that x509 credentials are
               used for negotiating the TLS session. The server will send its
               x509 certificate to the client. It is recommended that a
               password be set on the VNC server to provide authentication of
               the client when this is used. The path following this option
               specifies where the x509 certificates are to be loaded from.
               See the vnc_security section for details on generating
               certificates.

               This option is now deprecated in favour of using the tls-creds
               argument.

           x509verify=/path/to/certificate/dir
               Valid if tls is specified. Require that x509 credentials are
               used for negotiating the TLS session. The server will send its
               x509 certificate to the client, and request that the client
               send its own x509 certificate.  The server will validate the
               client's certificate against the CA certificate, and reject
               clients when validation fails. If the certificate authority is
               trusted, this is a sufficient authentication mechanism. You may
               still wish to set a password on the VNC server as a second
               authentication layer. The path following this option specifies
               where the x509 certificates are to be loaded from. See the
               vnc_security section for details on generating certificates.

               This option is now deprecated in favour of using the tls-creds
               argument.

           sasl
               Require that the client use SASL to authenticate with the VNC
               server.  The exact choice of authentication method used is
               controlled from the system / user's SASL configuration file for
               the 'qemu' service. This is typically found in
               /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user,
               an environment variable SASL_CONF_PATH can be used to make it
               search alternate locations for the service config.  While some
               SASL auth methods can also provide data encryption (eg GSSAPI),
               it is recommended that SASL always be combined with the 'tls'
               and 'x509' settings to enable use of SSL and server
               certificates. This ensures a data encryption preventing
               compromise of authentication credentials. See the vnc_security
               section for details on using SASL authentication.

           acl Turn on access control lists for checking of the x509 client
               certificate and SASL party. For x509 certs, the ACL check is
               made against the certificate's distinguished name. This is
               something that looks like "C=GB,O=ACME,L=Boston,CN=bob". For
               SASL party, the ACL check is made against the username, which
               depending on the SASL plugin, may include a realm component, eg
               "bob" or "bob@EXAMPLE.COM".  When the acl flag is set, the
               initial access list will be empty, with a "deny" policy. Thus
               no one will be allowed to use the VNC server until the ACLs
               have been loaded. This can be achieved using the "acl" monitor
               command.

           lossy
               Enable lossy compression methods (gradient, JPEG, ...). If this
               option is set, VNC client may receive lossy framebuffer updates
               depending on its encoding settings. Enabling this option can
               save a lot of bandwidth at the expense of quality.

           non-adaptive
               Disable adaptive encodings. Adaptive encodings are enabled by
               default.  An adaptive encoding will try to detect frequently
               updated screen regions, and send updates in these regions using
               a lossy encoding (like JPEG).  This can be really helpful to
               save bandwidth when playing videos. Disabling adaptive
               encodings restores the original static behavior of encodings
               like Tight.

           share=[allow-exclusive|force-shared|ignore]
               Set display sharing policy.  'allow-exclusive' allows clients
               to ask for exclusive access.  As suggested by the rfb spec this
               is implemented by dropping other connections.  Connecting
               multiple clients in parallel requires all clients asking for a
               shared session (vncviewer: -shared switch).  This is the
               default.  'force-shared' disables exclusive client access.
               Useful for shared desktop sessions, where you don't want
               someone forgetting specify -shared disconnect everybody else.
               'ignore' completely ignores the shared flag and allows
               everybody connect unconditionally.  Doesn't conform to the rfb
               spec but is traditional QEMU behavior.

           key-delay-ms
               Set keyboard delay, for key down and key up events, in
               milliseconds.  Default is 10.  Keyboards are low-bandwidth
               devices, so this slowdown can help the device and guest to keep
               up and not lose events in case events are arriving in bulk.
               Possible causes for the latter are flaky network connections,
               or scripts for automated testing.

       i386 target only

       -win2k-hack
           Use it when installing Windows 2000 to avoid a disk full bug. After
           Windows 2000 is installed, you no longer need this option (this
           option slows down the IDE transfers).

       -no-fd-bootchk
           Disable boot signature checking for floppy disks in BIOS. May be
           needed to boot from old floppy disks.

       -no-acpi
           Disable ACPI (Advanced Configuration and Power Interface) support.
           Use it if your guest OS complains about ACPI problems (PC target
           machine only).

       -no-hpet
           Disable HPET support.

       -acpitable
       [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n]
       [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]
           Add ACPI table with specified header fields and context from
           specified files.  For file=, take whole ACPI table from the
           specified files, including all ACPI headers (possible overridden by
           other options).  For data=, only data portion of the table is used,
           all header information is specified in the command line.  If a SLIC
           table is supplied to QEMU, then the SLIC's oem_id and oem_table_id
           fields will override the same in the RSDT and the FADT (a.k.a.
           FACP), in order to ensure the field matches required by the
           Microsoft SLIC spec and the ACPI spec.

       -smbios file=binary
           Load SMBIOS entry from binary file.

       -smbios
       type=0[,vendor=str][,version=str][,date=str][,release=%d.%d][,uefi=on|off]
           Specify SMBIOS type 0 fields

       -smbios
       type=1[,manufacturer=str][,product=str][,version=str][,serial=str][,uuid=uuid][,sku=str][,family=str]
           Specify SMBIOS type 1 fields

       -smbios
       type=2[,manufacturer=str][,product=str][,version=str][,serial=str][,asset=str][,location=str][,family=str]
           Specify SMBIOS type 2 fields

       -smbios
       type=3[,manufacturer=str][,version=str][,serial=str][,asset=str][,sku=str]
           Specify SMBIOS type 3 fields

       -smbios
       type=4[,sock_pfx=str][,manufacturer=str][,version=str][,serial=str][,asset=str][,part=str]
           Specify SMBIOS type 4 fields

       -smbios
       type=17[,loc_pfx=str][,bank=str][,manufacturer=str][,serial=str][,asset=str][,part=str][,speed=%d]
           Specify SMBIOS type 17 fields

       Network options

       -net nic[,vlan=n][,macaddr=mac][,model=type]
       [,name=name][,addr=addr][,vectors=v]
           Create a new Network Interface Card and connect it to VLAN n (n = 0
           is the default). The NIC is an e1000 by default on the PC target.
           Optionally, the MAC address can be changed to mac, the device
           address set to addr (PCI cards only), and a name can be assigned
           for use in monitor commands.  Optionally, for PCI cards, you can
           specify the number v of MSI-X vectors that the card should have;
           this option currently only affects virtio cards; set v = 0 to
           disable MSI-X. If no -net option is specified, a single NIC is
           created.  QEMU can emulate several different models of network
           card.  Valid values for type are "virtio", "i82551", "i82557b",
           "i82559er", "ne2k_pci", "ne2k_isa", "pcnet", "rtl8139", "e1000",
           "smc91c111", "lance" and "mcf_fec".  Not all devices are supported
           on all targets.  Use "-net nic,model=help" for a list of available
           devices for your target.

       -netdev user,id=id[,option][,option][,...]
       -net user[,option][,option][,...]
           Use the user mode network stack which requires no administrator
           privilege to run. Valid options are:

           vlan=n
               Connect user mode stack to VLAN n (n = 0 is the default).

           id=id
           name=name
               Assign symbolic name for use in monitor commands.

               ipv4 and ipv6 specify that either IPv4 or IPv6 must be enabled.
               If neither is specified both protocols are enabled.

           net=addr[/mask]
               Set IP network address the guest will see. Optionally specify
               the netmask, either in the form a.b.c.d or as number of valid
               top-most bits. Default is 10.0.2.0/24.

           host=addr
               Specify the guest-visible address of the host. Default is the
               2nd IP in the guest network, i.e. x.x.x.2.

           ipv6-net=addr[/int]
               Set IPv6 network address the guest will see (default is
               fec0::/64). The network prefix is given in the usual
               hexadecimal IPv6 address notation. The prefix size is optional,
               and is given as the number of valid top-most bits (default is
               64).

           ipv6-host=addr
               Specify the guest-visible IPv6 address of the host. Default is
               the 2nd IPv6 in the guest network, i.e. xxxx::2.

           restrict=on|off
               If this option is enabled, the guest will be isolated, i.e. it
               will not be able to contact the host and no guest IP packets
               will be routed over the host to the outside. This option does
               not affect any explicitly set forwarding rules.

           hostname=name
               Specifies the client hostname reported by the built-in DHCP
               server.

           dhcpstart=addr
               Specify the first of the 16 IPs the built-in DHCP server can
               assign. Default is the 15th to 31st IP in the guest network,
               i.e. x.x.x.15 to x.x.x.31.

           dns=addr
               Specify the guest-visible address of the virtual nameserver.
               The address must be different from the host address. Default is
               the 3rd IP in the guest network, i.e. x.x.x.3.

           ipv6-dns=addr
               Specify the guest-visible address of the IPv6 virtual
               nameserver. The address must be different from the host
               address. Default is the 3rd IP in the guest network, i.e.
               xxxx::3.

           dnssearch=domain
               Provides an entry for the domain-search list sent by the built-
               in DHCP server. More than one domain suffix can be transmitted
               by specifying this option multiple times. If supported, this
               will cause the guest to automatically try to append the given
               domain suffix(es) in case a domain name can not be resolved.

               Example:

                       qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]

           tftp=dir
               When using the user mode network stack, activate a built-in
               TFTP server. The files in dir will be exposed as the root of a
               TFTP server.  The TFTP client on the guest must be configured
               in binary mode (use the command "bin" of the Unix TFTP client).

           bootfile=file
               When using the user mode network stack, broadcast file as the
               BOOTP filename. In conjunction with tftp, this can be used to
               network boot a guest from a local directory.

               Example (using pxelinux):

                       qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0

           smb=dir[,smbserver=addr]
               When using the user mode network stack, activate a built-in SMB
               server so that Windows OSes can access to the host files in dir
               transparently. The IP address of the SMB server can be set to
               addr. By default the 4th IP in the guest network is used, i.e.
               x.x.x.4.

               In the guest Windows OS, the line:

                       10.0.2.4 smbserver

               must be added in the file C:\WINDOWS\LMHOSTS (for windows
               9x/Me) or C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS (Windows
               NT/2000).

               Then dir can be accessed in \\smbserver\qemu.

               Note that a SAMBA server must be installed on the host OS.
               QEMU was tested successfully with smbd versions from Red Hat 9,
               Fedora Core 3 and OpenSUSE 11.x.

           hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport
               Redirect incoming TCP or UDP connections to the host port
               hostport to the guest IP address guestaddr on guest port
               guestport. If guestaddr is not specified, its value is x.x.x.15
               (default first address given by the built-in DHCP server). By
               specifying hostaddr, the rule can be bound to a specific host
               interface. If no connection type is set, TCP is used. This
               option can be given multiple times.

               For example, to redirect host X11 connection from screen 1 to
               guest screen 0, use the following:

                       # on the host
                       qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
                       # this host xterm should open in the guest X11 server
                       xterm -display :1

               To redirect telnet connections from host port 5555 to telnet
               port on the guest, use the following:

                       # on the host
                       qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
                       telnet localhost 5555

               Then when you use on the host "telnet localhost 5555", you
               connect to the guest telnet server.

           guestfwd=[tcp]:server:port-dev
           guestfwd=[tcp]:server:port-cmd:command
               Forward guest TCP connections to the IP address server on port
               port to the character device dev or to a program executed by
               cmd:command which gets spawned for each connection. This option
               can be given multiple times.

               You can either use a chardev directly and have that one used
               throughout QEMU's lifetime, like in the following example:

                       # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
                       # the guest accesses it
                       qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]

               Or you can execute a command on every TCP connection
               established by the guest, so that QEMU behaves similar to an
               inetd process for that virtual server:

                       # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
                       # and connect the TCP stream to its stdin/stdout
                       qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'

           Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are
           still processed and applied to -net user. Mixing them with the new
           configuration syntax gives undefined results. Their use for new
           applications is discouraged as they will be removed from future
           versions.

       -netdev
       tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]
       -net
       tap[,vlan=n][,name=name][,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]
           Connect the host TAP network interface name to VLAN n.

           Use the network script file to configure it and the network script
           dfile to deconfigure it. If name is not provided, the OS
           automatically provides one. The default network configure script is
           /etc/qemu-ifup and the default network deconfigure script is
           /etc/qemu-ifdown. Use script=no or downscript=no to disable script
           execution.

           If running QEMU as an unprivileged user, use the network helper
           helper to configure the TAP interface and attach it to the bridge.
           The default network helper executable is
           /path/to/qemu-bridge-helper and the default bridge device is br0.

           fd=h can be used to specify the handle of an already opened host
           TAP interface.

           Examples:

                   #launch a QEMU instance with the default network script
                   qemu-system-i386 linux.img -net nic -net tap

                   #launch a QEMU instance with two NICs, each one connected
                   #to a TAP device
                   qemu-system-i386 linux.img \
                   -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
                   -net nic,vlan=1 -net tap,vlan=1,ifname=tap1

                   #launch a QEMU instance with the default network helper to
                   #connect a TAP device to bridge br0
                   qemu-system-i386 linux.img \
                   -net nic -net tap,"helper=/path/to/qemu-bridge-helper"

       -netdev bridge,id=id[,br=bridge][,helper=helper]
       -net bridge[,vlan=n][,name=name][,br=bridge][,helper=helper]
           Connect a host TAP network interface to a host bridge device.

           Use the network helper helper to configure the TAP interface and
           attach it to the bridge. The default network helper executable is
           /path/to/qemu-bridge-helper and the default bridge device is br0.

           Examples:

                   #launch a QEMU instance with the default network helper to
                   #connect a TAP device to bridge br0
                   qemu-system-i386 linux.img -net bridge -net nic,model=virtio

                   #launch a QEMU instance with the default network helper to
                   #connect a TAP device to bridge qemubr0
                   qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio

       -netdev socket,id=id[,fd=h][,listen=[host]:port][,connect=host:port]
       -net socket[,vlan=n][,name=name][,fd=h]
       [,listen=[host]:port][,connect=host:port]
           Connect the VLAN n to a remote VLAN in another QEMU virtual machine
           using a TCP socket connection. If listen is specified, QEMU waits
           for incoming connections on port (host is optional). connect is
           used to connect to another QEMU instance using the listen option.
           fd=h specifies an already opened TCP socket.

           Example:

                   # launch a first QEMU instance
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,listen=:1234
                   # connect the VLAN 0 of this instance to the VLAN 0
                   # of the first instance
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:57 \
                   -net socket,connect=127.0.0.1:1234

       -netdev socket,id=id[,fd=h][,mcast=maddr:port[,localaddr=addr]]
       -net
       socket[,vlan=n][,name=name][,fd=h][,mcast=maddr:port[,localaddr=addr]]
           Create a VLAN n shared with another QEMU virtual machines using a
           UDP multicast socket, effectively making a bus for every QEMU with
           same multicast address maddr and port.  NOTES:

           1.  Several QEMU can be running on different hosts and share same
               bus (assuming correct multicast setup for these hosts).

           2.  mcast support is compatible with User Mode Linux (argument
               ethN=mcast), see <http://user-mode-linux.sf.net>.

           3.  Use fd=h to specify an already opened UDP multicast socket.

           Example:

                   # launch one QEMU instance
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=230.0.0.1:1234
                   # launch another QEMU instance on same "bus"
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:57 \
                   -net socket,mcast=230.0.0.1:1234
                   # launch yet another QEMU instance on same "bus"
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:58 \
                   -net socket,mcast=230.0.0.1:1234

           Example (User Mode Linux compat.):

                   # launch QEMU instance (note mcast address selected
                   # is UML's default)
                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=239.192.168.1:1102
                   # launch UML
                   /path/to/linux ubd0=/path/to/root_fs eth0=mcast

           Example (send packets from host's 1.2.3.4):

                   qemu-system-i386 linux.img \
                   -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4

       -netdev
       l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]
       -net
       l2tpv3[,vlan=n][,name=name],src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]
           Connect VLAN n to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
           protocol to transport Ethernet (and other Layer 2) data frames
           between two systems. It is present in routers, firewalls and the
           Linux kernel (from version 3.3 onwards).

           This transport allows a VM to communicate to another VM, router or
           firewall directly.

       src=srcaddr
           source address (mandatory)

       dst=dstaddr
           destination address (mandatory)

       udp select udp encapsulation (default is ip).

       srcport=srcport
           source udp port.

       dstport=dstport
           destination udp port.

       ipv6
           force v6, otherwise defaults to v4.

       rxcookie=rxcookie
       txcookie=txcookie
           Cookies are a weak form of security in the l2tpv3 specification.
           Their function is mostly to prevent misconfiguration. By default
           they are 32 bit.

       cookie64
           Set cookie size to 64 bit instead of the default 32

       counter=off
           Force a 'cut-down' L2TPv3 with no counter as in
           draft-mkonstan-l2tpext-keyed-ipv6-tunnel-00

       pincounter=on
           Work around broken counter handling in peer. This may also help on
           networks which have packet reorder.

       offset=offset
           Add an extra offset between header and data

           For example, to attach a VM running on host 4.3.2.1 via L2TPv3 to
           the bridge br-lan on the remote Linux host 1.2.3.4:

                   # Setup tunnel on linux host using raw ip as encapsulation
                   # on 1.2.3.4
                   ip l2tp add tunnel remote 4.3.2.1 local 1.2.3.4 tunnel_id 1 peer_tunnel_id 1 \
                   encap udp udp_sport 16384 udp_dport 16384
                   ip l2tp add session tunnel_id 1 name vmtunnel0 session_id \
                   0xFFFFFFFF peer_session_id 0xFFFFFFFF
                   ifconfig vmtunnel0 mtu 1500
                   ifconfig vmtunnel0 up
                   brctl addif br-lan vmtunnel0

                   # on 4.3.2.1
                   # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter

                   qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter

       -netdev
       vde,id=id[,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]
       -net vde[,vlan=n][,name=name][,sock=socketpath]
       [,port=n][,group=groupname][,mode=octalmode]
           Connect VLAN n to PORT n of a vde switch running on host and
           listening for incoming connections on socketpath. Use GROUP
           groupname and MODE octalmode to change default ownership and
           permissions for communication port. This option is only available
           if QEMU has been compiled with vde support enabled.

           Example:

                   # launch vde switch
                   vde_switch -F -sock /tmp/myswitch
                   # launch QEMU instance
                   qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch

       -netdev hubport,id=id,hubid=hubid
           Create a hub port on QEMU "vlan" hubid.

           The hubport netdev lets you connect a NIC to a QEMU "vlan" instead
           of a single netdev.  "-net" and "-device" with parameter vlan
           create the required hub automatically.

       -netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]
           Establish a vhost-user netdev, backed by a chardev id. The chardev
           should be a unix domain socket backed one. The vhost-user uses a
           specifically defined protocol to pass vhost ioctl replacement
           messages to an application on the other end of the socket. On non-
           MSIX guests, the feature can be forced with vhostforce. Use
           'queues=n' to specify the number of queues to be created for
           multiqueue vhost-user.

           Example:

                   qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,share=on \
                   -numa node,memdev=mem \
                   -chardev socket,id=chr0,path=/path/to/socket \
                   -netdev type=vhost-user,id=net0,chardev=chr0 \
                   -device virtio-net-pci,netdev=net0

       -net dump[,vlan=n][,file=file][,len=len]
           Dump network traffic on VLAN n to file file (qemu-vlan0.pcap by
           default).  At most len bytes (64k by default) per packet are
           stored. The file format is libpcap, so it can be analyzed with
           tools such as tcpdump or Wireshark.  Note: For devices created with
           '-netdev', use '-object filter-dump,...' instead.

       -net none
           Indicate that no network devices should be configured. It is used
           to override the default configuration (-net nic -net user) which is
           activated if no -net options are provided.

       Character device options

       The general form of a character device option is:

       -chardev backend ,id=id [,mux=on|off] [,options]
           Backend is one of: null, socket, udp, msmouse, vc, ringbuf, file,
           pipe, console, serial, pty, stdio, braille, tty, parallel, parport,
           spicevmc.  spiceport.  The specific backend will determine the
           applicable options.

           Use "-chardev help" to print all available chardev backend types.

           All devices must have an id, which can be any string up to 127
           characters long.  It is used to uniquely identify this device in
           other command line directives.

           A character device may be used in multiplexing mode by multiple
           front-ends.  Specify mux=on to enable this mode.  A multiplexer is
           a "1:N" device, and here the "1" end is your specified chardev
           backend, and the "N" end is the various parts of QEMU that can talk
           to a chardev.  If you create a chardev with id=myid and mux=on,
           QEMU will create a multiplexer with your specified ID, and you can
           then configure multiple front ends to use that chardev ID for their
           input/output. Up to four different front ends can be connected to a
           single multiplexed chardev. (Without multiplexing enabled, a
           chardev can only be used by a single front end.)  For instance you
           could use this to allow a single stdio chardev to be used by two
           serial ports and the QEMU monitor:

                   -chardev stdio,mux=on,id=char0 \
                   -mon chardev=char0,mode=readline \
                   -serial chardev:char0 \
                   -serial chardev:char0

           You can have more than one multiplexer in a system configuration;
           for instance you could have a TCP port multiplexed between UART 0
           and UART 1, and stdio multiplexed between the QEMU monitor and a
           parallel port:

                   -chardev stdio,mux=on,id=char0 \
                   -mon chardev=char0,mode=readline \
                   -parallel chardev:char0 \
                   -chardev tcp,...,mux=on,id=char1 \
                   -serial chardev:char1 \
                   -serial chardev:char1

           When you're using a multiplexed character device, some escape
           sequences are interpreted in the input.

           Note that some other command line options may implicitly create
           multiplexed character backends; for instance -serial mon:stdio
           creates a multiplexed stdio backend connected to the serial port
           and the QEMU monitor, and -nographic also multiplexes the console
           and the monitor to stdio.

           There is currently no support for multiplexing in the other
           direction (where a single QEMU front end takes input and output
           from multiple chardevs).

           Every backend supports the logfile option, which supplies the path
           to a file to record all data transmitted via the backend. The
           logappend option controls whether the log file will be truncated or
           appended to when opened.

           Further options to each backend are described below.

       -chardev null ,id=id
           A void device. This device will not emit any data, and will drop
           any data it receives. The null backend does not take any options.

       -chardev socket ,id=id [TCP options or unix options] [,server]
       [,nowait] [,telnet] [,reconnect=seconds] [,tls-creds=id]
           Create a two-way stream socket, which can be either a TCP or a unix
           socket. A unix socket will be created if path is specified.
           Behaviour is undefined if TCP options are specified for a unix
           socket.

           server specifies that the socket shall be a listening socket.

           nowait specifies that QEMU should not block waiting for a client to
           connect to a listening socket.

           telnet specifies that traffic on the socket should interpret telnet
           escape sequences.

           reconnect sets the timeout for reconnecting on non-server sockets
           when the remote end goes away.  qemu will delay this many seconds
           and then attempt to reconnect.  Zero disables reconnecting, and is
           the default.

           tls-creds requests enablement of the TLS protocol for encryption,
           and specifies the id of the TLS credentials to use for the
           handshake. The credentials must be previously created with the
           -object tls-creds argument.

           TCP and unix socket options are given below:

           TCP options: port=port [,host=host] [,to=to] [,ipv4] [,ipv6]
           [,nodelay]
               host for a listening socket specifies the local address to be
               bound.  For a connecting socket species the remote host to
               connect to. host is optional for listening sockets. If not
               specified it defaults to 0.0.0.0.

               port for a listening socket specifies the local port to be
               bound. For a connecting socket specifies the port on the remote
               host to connect to.  port can be given as either a port number
               or a service name.  port is required.

               to is only relevant to listening sockets. If it is specified,
               and port cannot be bound, QEMU will attempt to bind to
               subsequent ports up to and including to until it succeeds. to
               must be specified as a port number.

               ipv4 and ipv6 specify that either IPv4 or IPv6 must be used.
               If neither is specified the socket may use either protocol.

               nodelay disables the Nagle algorithm.

           unix options: path=path
               path specifies the local path of the unix socket. path is
               required.

       -chardev udp ,id=id [,host=host] ,port=port [,localaddr=localaddr]
       [,localport=localport] [,ipv4] [,ipv6]
           Sends all traffic from the guest to a remote host over UDP.

           host specifies the remote host to connect to. If not specified it
           defaults to "localhost".

           port specifies the port on the remote host to connect to. port is
           required.

           localaddr specifies the local address to bind to. If not specified
           it defaults to 0.0.0.0.

           localport specifies the local port to bind to. If not specified any
           available local port will be used.

           ipv4 and ipv6 specify that either IPv4 or IPv6 must be used.  If
           neither is specified the device may use either protocol.

       -chardev msmouse ,id=id
           Forward QEMU's emulated msmouse events to the guest. msmouse does
           not take any options.

       -chardev vc ,id=id [[,width=width] [,height=height]] [[,cols=cols]
       [,rows=rows]]
           Connect to a QEMU text console. vc may optionally be given a
           specific size.

           width and height specify the width and height respectively of the
           console, in pixels.

           cols and rows specify that the console be sized to fit a text
           console with the given dimensions.

       -chardev ringbuf ,id=id [,size=size]
           Create a ring buffer with fixed size size.  size must be a power of
           two and defaults to "64K".

       -chardev file ,id=id ,path=path
           Log all traffic received from the guest to a file.

           path specifies the path of the file to be opened. This file will be
           created if it does not already exist, and overwritten if it does.
           path is required.

       -chardev pipe ,id=id ,path=path
           Create a two-way connection to the guest. The behaviour differs
           slightly between Windows hosts and other hosts:

           On Windows, a single duplex pipe will be created at \\.pipe\path.

           On other hosts, 2 pipes will be created called path.in and
           path.out. Data written to path.in will be received by the guest.
           Data written by the guest can be read from path.out. QEMU will not
           create these fifos, and requires them to be present.

           path forms part of the pipe path as described above. path is
           required.

       -chardev console ,id=id
           Send traffic from the guest to QEMU's standard output. console does
           not take any options.

           console is only available on Windows hosts.

       -chardev serial ,id=id ,path=path
           Send traffic from the guest to a serial device on the host.

           On Unix hosts serial will actually accept any tty device, not only
           serial lines.

           path specifies the name of the serial device to open.

       -chardev pty ,id=id
           Create a new pseudo-terminal on the host and connect to it. pty
           does not take any options.

           pty is not available on Windows hosts.

       -chardev stdio ,id=id [,signal=on|off]
           Connect to standard input and standard output of the QEMU process.

           signal controls if signals are enabled on the terminal, that
           includes exiting QEMU with the key sequence Control-c. This option
           is enabled by default, use signal=off to disable it.

       -chardev braille ,id=id
           Connect to a local BrlAPI server. braille does not take any
           options.

       -chardev tty ,id=id ,path=path
           tty is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and
           DragonFlyBSD hosts.  It is an alias for serial.

           path specifies the path to the tty. path is required.

       -chardev parallel ,id=id ,path=path
       -chardev parport ,id=id ,path=path
           parallel is only available on Linux, FreeBSD and DragonFlyBSD
           hosts.

           Connect to a local parallel port.

           path specifies the path to the parallel port device. path is
           required.

       -chardev spicevmc ,id=id ,debug=debug, name=name
           spicevmc is only available when spice support is built in.

           debug debug level for spicevmc

           name name of spice channel to connect to

           Connect to a spice virtual machine channel, such as vdiport.

       -chardev spiceport ,id=id ,debug=debug, name=name
           spiceport is only available when spice support is built in.

           debug debug level for spicevmc

           name name of spice port to connect to

           Connect to a spice port, allowing a Spice client to handle the
           traffic identified by a name (preferably a fqdn).

       Device URL Syntax

       In addition to using normal file images for the emulated storage
       devices, QEMU can also use networked resources such as iSCSI devices.
       These are specified using a special URL syntax.

       iSCSI
           iSCSI support allows QEMU to access iSCSI resources directly and
           use as images for the guest storage. Both disk and cdrom images are
           supported.

           Syntax for specifying iSCSI LUNs is
           "iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>"

           By default qemu will use the iSCSI initiator-name
           'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from
           the command line or a configuration file.

           Since version Qemu 2.4 it is possible to specify a iSCSI request
           timeout to detect stalled requests and force a reestablishment of
           the session. The timeout is specified in seconds. The default is 0
           which means no timeout. Libiscsi 1.15.0 or greater is required for
           this feature.

           Example (without authentication):

                   qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
                   -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
                   -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

           Example (CHAP username/password via URL):

                   qemu-system-i386 -drive file=iscsi://user%password@192.0.2.1/iqn.2001-04.com.example/1

           Example (CHAP username/password via environment variables):

                   LIBISCSI_CHAP_USERNAME="user" \
                   LIBISCSI_CHAP_PASSWORD="password" \
                   qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

           iSCSI support is an optional feature of QEMU and only available
           when compiled and linked against libiscsi.

           iSCSI parameters such as username and password can also be
           specified via a configuration file. See qemu-doc for more
           information and examples.

       NBD QEMU supports NBD (Network Block Devices) both using TCP protocol
           as well as Unix Domain Sockets.

           Syntax for specifying a NBD device using TCP
           "nbd:<server-ip>:<port>[:exportname=<export>]"

           Syntax for specifying a NBD device using Unix Domain Sockets
           "nbd:unix:<domain-socket>[:exportname=<export>]"

           Example for TCP

                   qemu-system-i386 --drive file=nbd:192.0.2.1:30000

           Example for Unix Domain Sockets

                   qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket

       SSH QEMU supports SSH (Secure Shell) access to remote disks.

           Examples:

                   qemu-system-i386 -drive file=ssh://user@host/path/to/disk.img
                   qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img

           Currently authentication must be done using ssh-agent.  Other
           authentication methods may be supported in future.

       Sheepdog
           Sheepdog is a distributed storage system for QEMU.  QEMU supports
           using either local sheepdog devices or remote networked devices.

           Syntax for specifying a sheepdog device

                   sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]

           Example

                   qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine

           See also <https://sheepdog.github.io/sheepdog/>.

       GlusterFS
           GlusterFS is a user space distributed file system.  QEMU supports
           the use of GlusterFS volumes for hosting VM disk images using TCP,
           Unix Domain Sockets and RDMA transport protocols.

           Syntax for specifying a VM disk image on GlusterFS volume is

                   URI:
                   gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]

                   JSON:
                   'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
                                                    "server":[{"type":"tcp","host":"...","port":"..."},
                                                              {"type":"unix","socket":"..."}]}}'

           Example

                   URI:
                   qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
                                                  file.debug=9,file.logfile=/var/log/qemu-gluster.log

                   JSON:
                   qemu-system-x86_64 'json:{"driver":"qcow2",
                                             "file":{"driver":"gluster",
                                                      "volume":"testvol","path":"a.img",
                                                      "debug":9,"logfile":"/var/log/qemu-gluster.log",
                                                      "server":[{"type":"tcp","host":"1.2.3.4","port":24007},
                                                                {"type":"unix","socket":"/var/run/glusterd.socket"}]}}'
                   qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
                                                         file.debug=9,file.logfile=/var/log/qemu-gluster.log,
                                                         file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
                                                         file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket

           See also <http://www.gluster.org>.

       HTTP/HTTPS/FTP/FTPS
           QEMU supports read-only access to files accessed over http(s) and
           ftp(s).

           Syntax using a single filename:

                   <protocol>://[<username>[:<password>]@]<host>/<path>

           where:

           protocol
               'http', 'https', 'ftp', or 'ftps'.

           username
               Optional username for authentication to the remote server.

           password
               Optional password for authentication to the remote server.

           host
               Address of the remote server.

           path
               Path on the remote server, including any query string.

           The following options are also supported:

           url The full URL when passing options to the driver explicitly.

           readahead
               The amount of data to read ahead with each range request to the
               remote server.  This value may optionally have the suffix 'T',
               'G', 'M', 'K', 'k' or 'b'. If it does not have a suffix, it
               will be assumed to be in bytes. The value must be a multiple of
               512 bytes. It defaults to 256k.

           sslverify
               Whether to verify the remote server's certificate when
               connecting over SSL. It can have the value 'on' or 'off'. It
               defaults to 'on'.

           cookie
               Send this cookie (it can also be a list of cookies separated by
               ';') with each outgoing request.  Only supported when using
               protocols such as HTTP which support cookies, otherwise
               ignored.

           timeout
               Set the timeout in seconds of the CURL connection. This timeout
               is the time that CURL waits for a response from the remote
               server to get the size of the image to be downloaded. If not
               set, the default timeout of 5 seconds is used.

           Note that when passing options to qemu explicitly, driver is the
           value of <protocol>.

           Example: boot from a remote Fedora 20 live ISO image

                   qemu-system-x86_64 --drive media=cdrom,file=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly

                   qemu-system-x86_64 --drive media=cdrom,file.driver=http,file.url=http://dl.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly

           Example: boot from a remote Fedora 20 cloud image using a local
           overlay for writes, copy-on-read, and a readahead of 64k

                   qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"http",, "file.url":"https://dl.fedoraproject.org/pub/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2

                   qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on

           Example: boot from an image stored on a VMware vSphere server with
           a self-signed certificate using a local overlay for writes, a
           readahead of 64k and a timeout of 10 seconds.

                   qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"https",, "file.url":"https://user:password@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10}' /tmp/test.qcow2

                   qemu-system-x86_64 -drive file=/tmp/test.qcow2

       Bluetooth(R) options

       -bt hci[...]
           Defines the function of the corresponding Bluetooth HCI.  -bt
           options are matched with the HCIs present in the chosen machine
           type.  For example when emulating a machine with only one HCI built
           into it, only the first "-bt hci[...]" option is valid and defines
           the HCI's logic.  The Transport Layer is decided by the machine
           type.  Currently the machines "n800" and "n810" have one HCI and
           all other machines have none.

           The following three types are recognized:

           -bt hci,null
               (default) The corresponding Bluetooth HCI assumes no internal
               logic and will not respond to any HCI commands or emit events.

           -bt hci,host[:id]
               ("bluez" only) The corresponding HCI passes commands / events
               to / from the physical HCI identified by the name id (default:
               "hci0") on the computer running QEMU.  Only available on
               "bluez" capable systems like Linux.

           -bt hci[,vlan=n]
               Add a virtual, standard HCI that will participate in the
               Bluetooth scatternet n (default 0).  Similarly to -net VLANs,
               devices inside a bluetooth network n can only communicate with
               other devices in the same network (scatternet).

       -bt vhci[,vlan=n]
           (Linux-host only) Create a HCI in scatternet n (default 0) attached
           to the host bluetooth stack instead of to the emulated target.
           This allows the host and target machines to participate in a common
           scatternet and communicate.  Requires the Linux "vhci" driver
           installed.  Can be used as following:

                   qemu-system-i386 [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5

       -bt device:dev[,vlan=n]
           Emulate a bluetooth device dev and place it in network n (default
           0).  QEMU can only emulate one type of bluetooth devices currently:

           keyboard
               Virtual wireless keyboard implementing the HIDP bluetooth
               profile.

       TPM device options

       The general form of a TPM device option is:

       -tpmdev backend ,id=id [,options]
           Backend type must be: passthrough.

           The specific backend type will determine the applicable options.
           The "-tpmdev" option creates the TPM backend and requires a
           "-device" option that specifies the TPM frontend interface model.

           Options to each backend are described below.

           Use 'help' to print all available TPM backend types.

                   qemu -tpmdev help

       -tpmdev passthrough, id=id, path=path, cancel-path=cancel-path
           (Linux-host only) Enable access to the host's TPM using the
           passthrough driver.

           path specifies the path to the host's TPM device, i.e., on a Linux
           host this would be "/dev/tpm0".  path is optional and by default
           "/dev/tpm0" is used.

           cancel-path specifies the path to the host TPM device's sysfs entry
           allowing for cancellation of an ongoing TPM command.  cancel-path
           is optional and by default QEMU will search for the sysfs entry to
           use.

           Some notes about using the host's TPM with the passthrough driver:

           The TPM device accessed by the passthrough driver must not be used
           by any other application on the host.

           Since the host's firmware (BIOS/UEFI) has already initialized the
           TPM, the VM's firmware (BIOS/UEFI) will not be able to initialize
           the TPM again and may therefore not show a TPM-specific menu that
           would otherwise allow the user to configure the TPM, e.g., allow
           the user to enable/disable or activate/deactivate the TPM.
           Further, if TPM ownership is released from within a VM then the
           host's TPM will get disabled and deactivated. To enable and
           activate the TPM again afterwards, the host has to be rebooted and
           the user is required to enter the firmware's menu to enable and
           activate the TPM.  If the TPM is left disabled and/or deactivated
           most TPM commands will fail.

           To create a passthrough TPM use the following two options:

                   -tpmdev passthrough,id=tpm0 -device tpm-tis,tpmdev=tpm0

           Note that the "-tpmdev" id is "tpm0" and is referenced by
           "tpmdev=tpm0" in the device option.

       Linux/Multiboot boot specific

       When using these options, you can use a given Linux or Multiboot kernel
       without installing it in the disk image. It can be useful for easier
       testing of various kernels.

       -kernel bzImage
           Use bzImage as kernel image. The kernel can be either a Linux
           kernel or in multiboot format.

       -append cmdline
           Use cmdline as kernel command line

       -initrd file
           Use file as initial ram disk.

       -initrd "file1 arg=foo,file2"
           This syntax is only available with multiboot.

           Use file1 and file2 as modules and pass arg=foo as parameter to the
           first module.

       -dtb file
           Use file as a device tree binary (dtb) image and pass it to the
           kernel on boot.

       Debug/Expert options

       -fw_cfg [name=]name,file=file
           Add named fw_cfg entry with contents from file file.

       -fw_cfg [name=]name,string=str
           Add named fw_cfg entry with contents from string str.

           The terminating NUL character of the contents of str will not be
           included as part of the fw_cfg item data. To insert contents with
           embedded NUL characters, you have to use the file parameter.

           The fw_cfg entries are passed by QEMU through to the guest.

           Example:

                   -fw_cfg name=opt/com.mycompany/blob,file=./my_blob.bin

           creates an fw_cfg entry named opt/com.mycompany/blob with contents
           from ./my_blob.bin.

       -serial dev
           Redirect the virtual serial port to host character device dev. The
           default device is "vc" in graphical mode and "stdio" in non
           graphical mode.

           This option can be used several times to simulate up to 4 serial
           ports.

           Use "-serial none" to disable all serial ports.

           Available character devices are:

           vc[:WxH]
               Virtual console. Optionally, a width and height can be given in
               pixel with

                       vc:800x600

               It is also possible to specify width or height in characters:

                       vc:80Cx24C

           pty [Linux only] Pseudo TTY (a new PTY is automatically allocated)

           none
               No device is allocated.

           null
               void device

           chardev:id
               Use a named character device defined with the "-chardev"
               option.

           /dev/XXX
               [Linux only] Use host tty, e.g. /dev/ttyS0. The host serial
               port parameters are set according to the emulated ones.

           /dev/parportN
               [Linux only, parallel port only] Use host parallel port N.
               Currently SPP and EPP parallel port features can be used.

           file:filename
               Write output to filename. No character can be read.

           stdio
               [Unix only] standard input/output

           pipe:filename
               name pipe filename

           COMn
               [Windows only] Use host serial port n

           udp:[remote_host]:remote_port[@[src_ip]:src_port]
               This implements UDP Net Console.  When remote_host or src_ip
               are not specified they default to 0.0.0.0.  When not using a
               specified src_port a random port is automatically chosen.

               If you just want a simple readonly console you can use "netcat"
               or "nc", by starting QEMU with: "-serial udp::4555" and nc as:
               "nc -u -l -p 4555". Any time QEMU writes something to that port
               it will appear in the netconsole session.

               If you plan to send characters back via netconsole or you want
               to stop and start QEMU a lot of times, you should have QEMU use
               the same source port each time by using something like "-serial
               udp::4555@4556" to QEMU. Another approach is to use a patched
               version of netcat which can listen to a TCP port and send and
               receive characters via udp.  If you have a patched version of
               netcat which activates telnet remote echo and single char
               transfer, then you can use the following options to set up a
               netcat redirector to allow telnet on port 5555 to access the
               QEMU port.

               "QEMU Options:"
                   -serial udp::4555@4556

               "netcat options:"
                   -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T

               "telnet options:"
                   localhost 5555

           tcp:[host]:port[,server][,nowait][,nodelay][,reconnect=seconds]
               The TCP Net Console has two modes of operation.  It can send
               the serial I/O to a location or wait for a connection from a
               location.  By default the TCP Net Console is sent to host at
               the port.  If you use the server option QEMU will wait for a
               client socket application to connect to the port before
               continuing, unless the "nowait" option was specified.  The
               "nodelay" option disables the Nagle buffering algorithm.  The
               "reconnect" option only applies if noserver is set, if the
               connection goes down it will attempt to reconnect at the given
               interval.  If host is omitted, 0.0.0.0 is assumed. Only one TCP
               connection at a time is accepted. You can use "telnet" to
               connect to the corresponding character device.

               "Example to send tcp console to 192.168.0.2 port 4444"
                   -serial tcp:192.168.0.2:4444

               "Example to listen and wait on port 4444 for connection"
                   -serial tcp::4444,server

               "Example to not wait and listen on ip 192.168.0.100 port 4444"
                   -serial tcp:192.168.0.100:4444,server,nowait

           telnet:host:port[,server][,nowait][,nodelay]
               The telnet protocol is used instead of raw tcp sockets.  The
               options work the same as if you had specified "-serial tcp".
               The difference is that the port acts like a telnet server or
               client using telnet option negotiation.  This will also allow
               you to send the MAGIC_SYSRQ sequence if you use a telnet that
               supports sending the break sequence.  Typically in unix telnet
               you do it with Control-] and then type "send break" followed by
               pressing the enter key.

           unix:path[,server][,nowait][,reconnect=seconds]
               A unix domain socket is used instead of a tcp socket.  The
               option works the same as if you had specified "-serial tcp"
               except the unix domain socket path is used for connections.

           mon:dev_string
               This is a special option to allow the monitor to be multiplexed
               onto another serial port.  The monitor is accessed with key
               sequence of Control-a and then pressing c.  dev_string should
               be any one of the serial devices specified above.  An example
               to multiplex the monitor onto a telnet server listening on port
               4444 would be:

               "-serial mon:telnet::4444,server,nowait"

               When the monitor is multiplexed to stdio in this way, Ctrl+C
               will not terminate QEMU any more but will be passed to the
               guest instead.

           braille
               Braille device.  This will use BrlAPI to display the braille
               output on a real or fake device.

           msmouse
               Three button serial mouse. Configure the guest to use Microsoft
               protocol.

       -parallel dev
           Redirect the virtual parallel port to host device dev (same devices
           as the serial port). On Linux hosts, /dev/parportN can be used to
           use hardware devices connected on the corresponding host parallel
           port.

           This option can be used several times to simulate up to 3 parallel
           ports.

           Use "-parallel none" to disable all parallel ports.

       -monitor dev
           Redirect the monitor to host device dev (same devices as the serial
           port).  The default device is "vc" in graphical mode and "stdio" in
           non graphical mode.  Use "-monitor none" to disable the default
           monitor.

       -qmp dev
           Like -monitor but opens in 'control' mode.

       -qmp-pretty dev
           Like -qmp but uses pretty JSON formatting.

       -mon [chardev=]name[,mode=readline|control]
           Setup monitor on chardev name.

       -debugcon dev
           Redirect the debug console to host device dev (same devices as the
           serial port).  The debug console is an I/O port which is typically
           port 0xe9; writing to that I/O port sends output to this device.
           The default device is "vc" in graphical mode and "stdio" in non
           graphical mode.

       -pidfile file
           Store the QEMU process PID in file. It is useful if you launch QEMU
           from a script.

       -singlestep
           Run the emulation in single step mode.

       -S  Do not start CPU at startup (you must type 'c' in the monitor).

       -realtime mlock=on|off
           Run qemu with realtime features.  mlocking qemu and guest memory
           can be enabled via mlock=on (enabled by default).

       -gdb dev
           Wait for gdb connection on device dev. Typical connections will
           likely be TCP-based, but also UDP, pseudo TTY, or even stdio are
           reasonable use case. The latter is allowing to start QEMU from
           within gdb and establish the connection via a pipe:

                   (gdb) target remote | exec qemu-system-i386 -gdb stdio ...

       -s  Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port
           1234.

       -d item1[,...]
           Enable logging of specified items. Use '-d help' for a list of log
           items.

       -D logfile
           Output log in logfile instead of to stderr

       -dfilter range1[,...]
           Filter debug output to that relevant to a range of target
           addresses. The filter spec can be either start+size, start-size or
           start..end where start end and size are the addresses and sizes
           required. For example:

                   -dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,0xffffffc000060000-0x1000

           Will dump output for any code in the 0x1000 sized block starting at
           0x8000 and the 0x200 sized block starting at 0xffffffc000080000 and
           another 0x1000 sized block starting at 0xffffffc00005f000.

       -L  path
           Set the directory for the BIOS, VGA BIOS and keymaps.

           To list all the data directories, use "-L help".

       -bios file
           Set the filename for the BIOS.

       -enable-kvm
           Enable KVM full virtualization support. This option is only
           available if KVM support is enabled when compiling.

       -enable-hax
           Enable HAX (Hardware-based Acceleration eXecution) support. This
           option is only available if HAX support is enabled when compiling.
           HAX is only applicable to MAC and Windows platform, and thus does
           not conflict with KVM.

       -xen-domid id
           Specify xen guest domain id (XEN only).

       -xen-create
           Create domain using xen hypercalls, bypassing xend.  Warning:
           should not be used when xend is in use (XEN only).

       -xen-attach
           Attach to existing xen domain.  xend will use this when starting
           QEMU (XEN only).  Restrict set of available xen operations to
           specified domain id (XEN only).

       -no-reboot
           Exit instead of rebooting.

       -no-shutdown
           Don't exit QEMU on guest shutdown, but instead only stop the
           emulation.  This allows for instance switching to monitor to commit
           changes to the disk image.

       -loadvm file
           Start right away with a saved state ("loadvm" in monitor)

       -daemonize
           Daemonize the QEMU process after initialization.  QEMU will not
           detach from standard IO until it is ready to receive connections on
           any of its devices.  This option is a useful way for external
           programs to launch QEMU without having to cope with initialization
           race conditions.

       -option-rom file
           Load the contents of file as an option ROM.  This option is useful
           to load things like EtherBoot.

       -rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]
           Specify base as "utc" or "localtime" to let the RTC start at the
           current UTC or local time, respectively. "localtime" is required
           for correct date in MS-DOS or Windows. To start at a specific point
           in time, provide date in the format "2006-06-17T16:01:21" or
           "2006-06-17". The default base is UTC.

           By default the RTC is driven by the host system time. This allows
           using of the RTC as accurate reference clock inside the guest,
           specifically if the host time is smoothly following an accurate
           external reference clock, e.g. via NTP.  If you want to isolate the
           guest time from the host, you can set clock to "rt" instead.  To
           even prevent it from progressing during suspension, you can set it
           to "vm".

           Enable driftfix (i386 targets only) if you experience time drift
           problems, specifically with Windows' ACPI HAL. This option will try
           to figure out how many timer interrupts were not processed by the
           Windows guest and will re-inject them.

       -icount
       [shift=N|auto][,rr=record|replay,rrfile=filename,rrsnapshot=snapshot]
           Enable virtual instruction counter.  The virtual cpu will execute
           one instruction every 2^N ns of virtual time.  If "auto" is
           specified then the virtual cpu speed will be automatically adjusted
           to keep virtual time within a few seconds of real time.

           When the virtual cpu is sleeping, the virtual time will advance at
           default speed unless sleep=on|off is specified.  With sleep=on|off,
           the virtual time will jump to the next timer deadline instantly
           whenever the virtual cpu goes to sleep mode and will not advance if
           no timer is enabled. This behavior give deterministic execution
           times from the guest point of view.

           Note that while this option can give deterministic behavior, it
           does not provide cycle accurate emulation.  Modern CPUs contain
           superscalar out of order cores with complex cache hierarchies.  The
           number of instructions executed often has little or no correlation
           with actual performance.

           align=on will activate the delay algorithm which will try to
           synchronise the host clock and the virtual clock. The goal is to
           have a guest running at the real frequency imposed by the shift
           option.  Whenever the guest clock is behind the host clock and if
           align=on is specified then we print a message to the user to inform
           about the delay.  Currently this option does not work when shift is
           "auto".  Note: The sync algorithm will work for those shift values
           for which the guest clock runs ahead of the host clock. Typically
           this happens when the shift value is high (how high depends on the
           host machine).

           When rr option is specified deterministic record/replay is enabled.
           Replay log is written into filename file in record mode and read
           from this file in replay mode.

           Option rrsnapshot is used to create new vm snapshot named snapshot
           at the start of execution recording. In replay mode this option is
           used to load the initial VM state.

       -watchdog model
           Create a virtual hardware watchdog device.  Once enabled (by a
           guest action), the watchdog must be periodically polled by an agent
           inside the guest or else the guest will be restarted. Choose a
           model for which your guest has drivers.

           The model is the model of hardware watchdog to emulate. Use
           "-watchdog help" to list available hardware models. Only one
           watchdog can be enabled for a guest.

           The following models may be available:

           ib700
               iBASE 700 is a very simple ISA watchdog with a single timer.

           i6300esb
               Intel 6300ESB I/O controller hub is a much more featureful PCI-
               based dual-timer watchdog.

           diag288
               A virtual watchdog for s390x backed by the diagnose 288
               hypercall (currently KVM only).

       -watchdog-action action
           The action controls what QEMU will do when the watchdog timer
           expires.  The default is "reset" (forcefully reset the guest).
           Other possible actions are: "shutdown" (attempt to gracefully
           shutdown the guest), "poweroff" (forcefully poweroff the guest),
           "pause" (pause the guest), "debug" (print a debug message and
           continue), or "none" (do nothing).

           Note that the "shutdown" action requires that the guest responds to
           ACPI signals, which it may not be able to do in the sort of
           situations where the watchdog would have expired, and thus
           "-watchdog-action shutdown" is not recommended for production use.

           Examples:

           "-watchdog i6300esb -watchdog-action pause"
           "-watchdog ib700"
       -echr numeric_ascii_value
           Change the escape character used for switching to the monitor when
           using monitor and serial sharing.  The default is 0x01 when using
           the "-nographic" option.  0x01 is equal to pressing "Control-a".
           You can select a different character from the ascii control keys
           where 1 through 26 map to Control-a through Control-z.  For
           instance you could use the either of the following to change the
           escape character to Control-t.

           "-echr 0x14"
           "-echr 20"
       -virtioconsole c
           Set virtio console.

           This option is maintained for backward compatibility.

           Please use "-device virtconsole" for the new way of invocation.

       -show-cursor
           Show cursor.

       -tb-size n
           Set TB size.

       -incoming tcp:[host]:port[,to=maxport][,ipv4][,ipv6]
       -incoming rdma:host:port[,ipv4][,ipv6]
           Prepare for incoming migration, listen on a given tcp port.

       -incoming unix:socketpath
           Prepare for incoming migration, listen on a given unix socket.

       -incoming fd:fd
           Accept incoming migration from a given filedescriptor.

       -incoming exec:cmdline
           Accept incoming migration as an output from specified external
           command.

       -incoming defer
           Wait for the URI to be specified via migrate_incoming.  The monitor
           can be used to change settings (such as migration parameters) prior
           to issuing the migrate_incoming to allow the migration to begin.

       -only-migratable
           Only allow migratable devices. Devices will not be allowed to enter
           an unmigratable state.

       -nodefaults
           Don't create default devices. Normally, QEMU sets the default
           devices like serial port, parallel port, virtual console, monitor
           device, VGA adapter, floppy and CD-ROM drive and others. The
           "-nodefaults" option will disable all those default devices.

       -chroot dir
           Immediately before starting guest execution, chroot to the
           specified directory.  Especially useful in combination with -runas.

       -runas user
           Immediately before starting guest execution, drop root privileges,
           switching to the specified user.

       -prom-env variable=value
           Set OpenBIOS nvram variable to given value (PPC, SPARC only).

       -semihosting
           Enable semihosting mode (ARM, M68K, Xtensa, MIPS only).

       -semihosting-config
       [enable=on|off][,target=native|gdb|auto][,arg=str[,...]]
           Enable and configure semihosting (ARM, M68K, Xtensa, MIPS only).

           target="native|gdb|auto"
               Defines where the semihosting calls will be addressed, to QEMU
               ("native") or to GDB ("gdb"). The default is "auto", which
               means "gdb" during debug sessions and "native" otherwise.

           arg=str1,arg=str2,...
               Allows the user to pass input arguments, and can be used
               multiple times to build up a list. The old-style
               "-kernel"/"-append" method of passing a command line is still
               supported for backward compatibility. If both the
               "--semihosting-config arg" and the "-kernel"/"-append" are
               specified, the former is passed to semihosting as it always
               takes precedence.

       -old-param
           Old param mode (ARM only).

       -sandbox arg
           Enable Seccomp mode 2 system call filter. 'on' will enable syscall
           filtering and 'off' will disable it.  The default is 'off'.

       -readconfig file
           Read device configuration from file. This approach is useful when
           you want to spawn QEMU process with many command line options but
           you don't want to exceed the command line character limit.

       -writeconfig file
           Write device configuration to file. The file can be either filename
           to save command line and device configuration into file or dash
           "-") character to print the output to stdout. This can be later
           used as input file for "-readconfig" option.

       -nodefconfig
           Normally QEMU loads configuration files from sysconfdir and datadir
           at startup.  The "-nodefconfig" option will prevent QEMU from
           loading any of those config files.

       -no-user-config
           The "-no-user-config" option makes QEMU not load any of the user-
           provided config files on sysconfdir, but won't make it skip the
           QEMU-provided config files from datadir.

       -trace [[enable=]pattern][,events=file][,file=file]
           Specify tracing options.

           [enable=]pattern
               Immediately enable events matching pattern.  The file must
               contain one event name (as listed in the trace-events-all file)
               per line; globbing patterns are accepted too.  This option is
               only available if QEMU has been compiled with the simple, log
               or ftrace tracing backend.  To specify multiple events or
               patterns, specify the -trace option multiple times.

               Use "-trace help" to print a list of names of trace points.

           events=file
               Immediately enable events listed in file.  The file must
               contain one event name (as listed in the trace-events-all file)
               per line; globbing patterns are accepted too.  This option is
               only available if QEMU has been compiled with the simple, log
               or ftrace tracing backend.

           file=file
               Log output traces to file.  This option is only available if
               QEMU has been compiled with the simple tracing backend.

       -enable-fips
           Enable FIPS 140-2 compliance mode.

       -msg timestamp[=on|off]
           prepend a timestamp to each log message.(default:on)

       -dump-vmstate file
           Dump json-encoded vmstate information for current machine type to
           file in file

       Generic object creation

       -object typename[,prop1=value1,...]
           Create a new object of type typename setting properties in the
           order they are specified.  Note that the 'id' property must be set.
           These objects are placed in the '/objects' path.

           -object
           memory-backend-file,id=id,size=size,mem-path=dir,share=on|off
               Creates a memory file backend object, which can be used to back
               the guest RAM with huge pages. The id parameter is a unique ID
               that will be used to reference this memory region when
               configuring the -numa argument. The size option provides the
               size of the memory region, and accepts common suffixes, eg
               500M. The mem-path provides the path to either a shared memory
               or huge page filesystem mount.  The share boolean option
               determines whether the memory region is marked as private to
               QEMU, or shared. The latter allows a co-operating external
               process to access the QEMU memory region.

           -object rng-random,id=id,filename=/dev/random
               Creates a random number generator backend which obtains entropy
               from a device on the host. The id parameter is a unique ID that
               will be used to reference this entropy backend from the virtio-
               rng device. The filename parameter specifies which file to
               obtain entropy from and if omitted defaults to /dev/random.

           -object rng-egd,id=id,chardev=chardevid
               Creates a random number generator backend which obtains entropy
               from an external daemon running on the host. The id parameter
               is a unique ID that will be used to reference this entropy
               backend from the virtio-rng device. The chardev parameter is
               the unique ID of a character device backend that provides the
               connection to the RNG daemon.

           -object
           tls-creds-anon,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off
               Creates a TLS anonymous credentials object, which can be used
               to provide TLS support on network backends. The id parameter is
               a unique ID which network backends will use to access the
               credentials. The endpoint is either server or client depending
               on whether the QEMU network backend that uses the credentials
               will be acting as a client or as a server. If verify-peer is
               enabled (the default) then once the handshake is completed, the
               peer credentials will be verified, though this is a no-op for
               anonymous credentials.

               The dir parameter tells QEMU where to find the credential
               files. For server endpoints, this directory may contain a file
               dh-params.pem providing diffie-hellman parameters to use for
               the TLS server. If the file is missing, QEMU will generate a
               set of DH parameters at startup. This is a computationally
               expensive operation that consumes random pool entropy, so it is
               recommended that a persistent set of parameters be generated
               upfront and saved.

           -object
           tls-creds-x509,id=id,endpoint=endpoint,dir=/path/to/cred/dir,verify-peer=on|off,passwordid=id
               Creates a TLS anonymous credentials object, which can be used
               to provide TLS support on network backends. The id parameter is
               a unique ID which network backends will use to access the
               credentials. The endpoint is either server or client depending
               on whether the QEMU network backend that uses the credentials
               will be acting as a client or as a server. If verify-peer is
               enabled (the default) then once the handshake is completed, the
               peer credentials will be verified. With x509 certificates, this
               implies that the clients must be provided with valid client
               certificates too.

               The dir parameter tells QEMU where to find the credential
               files. For server endpoints, this directory may contain a file
               dh-params.pem providing diffie-hellman parameters to use for
               the TLS server. If the file is missing, QEMU will generate a
               set of DH parameters at startup. This is a computationally
               expensive operation that consumes random pool entropy, so it is
               recommended that a persistent set of parameters be generated
               upfront and saved.

               For x509 certificate credentials the directory will contain
               further files providing the x509 certificates. The certificates
               must be stored in PEM format, in filenames ca-cert.pem,
               ca-crl.pem (optional), server-cert.pem (only servers),
               server-key.pem (only servers), client-cert.pem (only clients),
               and client-key.pem (only clients).

               For the server-key.pem and client-key.pem files which contain
               sensitive private keys, it is possible to use an encrypted
               version by providing the passwordid parameter. This provides
               the ID of a previously created "secret" object containing the
               password for decryption.

           -object
           filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off]
               Interval t can't be 0, this filter batches the packet delivery:
               all packets arriving in a given interval on netdev netdevid are
               delayed until the end of the interval. Interval is in
               microseconds.  status is optional that indicate whether the
               netfilter is on (enabled) or off (disabled), the default status
               for netfilter will be 'on'.

               queue all|rx|tx is an option that can be applied to any
               netfilter.

               all: the filter is attached both to the receive and the
               transmit queue of the netdev (default).

               rx: the filter is attached to the receive queue of the netdev,
               where it will receive packets sent to the netdev.

               tx: the filter is attached to the transmit queue of the netdev,
               where it will receive packets sent by the netdev.

           -object
           filter-mirror,id=id,netdev=netdevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support]
               filter-mirror on netdev netdevid,mirror net packet to
               chardevchardevid, if it has the vnet_hdr_support flag, filter-
               mirror will mirror packet with vnet_hdr_len.

           -object
           filter-redirector,id=id,netdev=netdevid,indev=chardevid,outdev=chardevid,queue=all|rx|tx[,vnet_hdr_support]
               filter-redirector on netdev netdevid,redirect filter's net
               packet to chardev chardevid,and redirect indev's packet to
               filter.if it has the vnet_hdr_support flag, filter-redirector
               will redirect packet with vnet_hdr_len.  Create a filter-
               redirector we need to differ outdev id from indev id, id can
               not be the same. we can just use indev or outdev, but at least
               one of indev or outdev need to be specified.

           -object
           filter-rewriter,id=id,netdev=netdevid,queue=all|rx|tx,[vnet_hdr_support]
               Filter-rewriter is a part of COLO project.It will rewrite tcp
               packet to secondary from primary to keep secondary tcp
               connection,and rewrite tcp packet to primary from secondary
               make tcp packet can be handled by client.if it has the
               vnet_hdr_support flag, we can parse packet with vnet header.

               usage: colo secondary: -object
               filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 -object
               filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 -object
               filter-rewriter,id=rew0,netdev=hn0,queue=all

           -object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=len]
               Dump the network traffic on netdev dev to the file specified by
               filename. At most len bytes (64k by default) per packet are
               stored.  The file format is libpcap, so it can be analyzed with
               tools such as tcpdump or Wireshark.

           -object
           colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid[,vnet_hdr_support]
               Colo-compare gets packet from primary_inchardevid and
               secondary_inchardevid, than compare primary packet with
               secondary packet. If the packets are same, we will output
               primary packet to outdevchardevid, else we will notify colo-
               frame do checkpoint and send primary packet to outdevchardevid.
               if it has the vnet_hdr_support flag, colo compare will
               send/recv packet with vnet_hdr_len.

               we must use it with the help of filter-mirror and filter-
               redirector.

                       primary:
                       -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
                       -device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
                       -chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
                       -chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
                       -chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
                       -chardev socket,id=compare0-0,host=3.3.3.3,port=9001
                       -chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
                       -chardev socket,id=compare_out0,host=3.3.3.3,port=9005
                       -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
                       -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
                       -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
                       -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0

                       secondary:
                       -netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down script=/etc/qemu-ifdown
                       -device e1000,netdev=hn0,mac=52:a4:00:12:78:66
                       -chardev socket,id=red0,host=3.3.3.3,port=9003
                       -chardev socket,id=red1,host=3.3.3.3,port=9004
                       -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
                       -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1

               If you want to know the detail of above command line, you can
               read the colo-compare git log.

           -object cryptodev-backend-builtin,id=id[,queues=queues]
               Creates a cryptodev backend which executes crypto opreation
               from the QEMU cipher APIS. The id parameter is a unique ID that
               will be used to reference this cryptodev backend from the
               virtio-crypto device. The queues parameter is optional, which
               specify the queue number of cryptodev backend, the default of
               queues is 1.

                       # qemu-system-x86_64 \
                       [...] \
                       -object cryptodev-backend-builtin,id=cryptodev0 \
                       -device virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 \
                       [...]

           -object
           secret,id=id,data=string,format=raw|base64[,keyid=secretid,iv=string]
           -object
           secret,id=id,file=filename,format=raw|base64[,keyid=secretid,iv=string]
               Defines a secret to store a password, encryption key, or some
               other sensitive data. The sensitive data can either be passed
               directly via the data parameter, or indirectly via the file
               parameter. Using the data parameter is insecure unless the
               sensitive data is encrypted.

               The sensitive data can be provided in raw format (the default),
               or base64.  When encoded as JSON, the raw format only supports
               valid UTF-8 characters, so base64 is recommended for sending
               binary data. QEMU will convert from which ever format is
               provided to the format it needs internally. eg, an RBD password
               can be provided in raw format, even though it will be base64
               encoded when passed onto the RBD sever.

               For added protection, it is possible to encrypt the data
               associated with a secret using the AES-256-CBC cipher. Use of
               encryption is indicated by providing the keyid and iv
               parameters. The keyid parameter provides the ID of a previously
               defined secret that contains the AES-256 decryption key. This
               key should be 32-bytes long and be base64 encoded. The iv
               parameter provides the random initialization vector used for
               encryption of this particular secret and should be a base64
               encrypted string of the 16-byte IV.

               The simplest (insecure) usage is to provide the secret inline

                       # $QEMU -object secret,id=sec0,data=letmein,format=raw

               The simplest secure usage is to provide the secret via a file

               # printf "letmein" > mypasswd.txt # $QEMU -object
               secret,id=sec0,file=mypasswd.txt,format=raw

               For greater security, AES-256-CBC should be used. To illustrate
               usage, consider the openssl command line tool which can encrypt
               the data. Note that when encrypting, the plaintext must be
               padded to the cipher block size (32 bytes) using the standard
               PKCS#5/6 compatible padding algorithm.

               First a master key needs to be created in base64 encoding:

                       # openssl rand -base64 32 > key.b64
                       # KEY=$(base64 -d key.b64 | hexdump  -v -e '/1 "%02X"')

               Each secret to be encrypted needs to have a random
               initialization vector generated. These do not need to be kept
               secret

                       # openssl rand -base64 16 > iv.b64
                       # IV=$(base64 -d iv.b64 | hexdump  -v -e '/1 "%02X"')

               The secret to be defined can now be encrypted, in this case
               we're telling openssl to base64 encode the result, but it could
               be left as raw bytes if desired.

                       # SECRET=$(printf "letmein" |
                       openssl enc -aes-256-cbc -a -K $KEY -iv $IV)

               When launching QEMU, create a master secret pointing to
               "key.b64" and specify that to be used to decrypt the user
               password. Pass the contents of "iv.b64" to the second secret

                       # $QEMU \
                       -object secret,id=secmaster0,format=base64,file=key.b64 \
                       -object secret,id=sec0,keyid=secmaster0,format=base64,\
                       data=$SECRET,iv=$(<iv.b64)

       During the graphical emulation, you can use special key combinations to
       change modes. The default key mappings are shown below, but if you use
       "-alt-grab" then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt)
       and if you use "-ctrl-grab" then the modifier is the right Ctrl key
       (instead of Ctrl-Alt):

       Ctrl-Alt-f
           Toggle full screen

       Ctrl-Alt-+
           Enlarge the screen

       Ctrl-Alt--
           Shrink the screen

       Ctrl-Alt-u
           Restore the screen's un-scaled dimensions

       Ctrl-Alt-n
           Switch to virtual console 'n'. Standard console mappings are:

           1   Target system display

           2   Monitor

           3   Serial port

       Ctrl-Alt
           Toggle mouse and keyboard grab.

       In the virtual consoles, you can use Ctrl-Up, Ctrl-Down, Ctrl-PageUp
       and Ctrl-PageDown to move in the back log.

       During emulation, if you are using a character backend multiplexer
       (which is the default if you are using -nographic) then several
       commands are available via an escape sequence. These key sequences all
       start with an escape character, which is Ctrl-a by default, but can be
       changed with -echr. The list below assumes you're using the default.

       Ctrl-a h
           Print this help

       Ctrl-a x
           Exit emulator

       Ctrl-a s
           Save disk data back to file (if -snapshot)

       Ctrl-a t
           Toggle console timestamps

       Ctrl-a b
           Send break (magic sysrq in Linux)

       Ctrl-a c
           Rotate between the frontends connected to the multiplexer (usually
           this switches between the monitor and the console)

       Ctrl-a Ctrl-a
           Send the escape character to the frontend

       The following options are specific to the PowerPC emulation:

       -g WxH[xDEPTH]
           Set the initial VGA graphic mode. The default is 800x600x32.

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-ppc -prom-env 'auto-boot?=false' \
                    -prom-env 'boot-device=hd:2,\yaboot' \
                    -prom-env 'boot-args=conf=hd:2,\yaboot.conf'

           These variables are not used by Open Hack'Ware.

       The following options are specific to the Sparc32 emulation:

       -g WxHx[xDEPTH]
           Set the initial graphics mode. For TCX, the default is 1024x768x8
           with the option of 1024x768x24. For cgthree, the default is
           1024x768x8 with the option of 1152x900x8 for people who wish to use
           OBP.

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-sparc -prom-env 'auto-boot?=false' \
                    -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'

       -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic]
       [|SPARCbook]
           Set the emulated machine type. Default is SS-5.

       The following options are specific to the Sparc64 emulation:

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-sparc64 -prom-env 'auto-boot?=false'

       -M [sun4u|sun4v|niagara]
           Set the emulated machine type. The default is sun4u.

       The following options are specific to the ARM emulation:

       -semihosting
           Enable semihosting syscall emulation.

           On ARM this implements the "Angel" interface.

           Note that this allows guest direct access to the host filesystem,
           so should only be used with trusted guest OS.

       The following options are specific to the ColdFire emulation:

       -semihosting
           Enable semihosting syscall emulation.

           On M68K this implements the "ColdFire GDB" interface used by
           libgloss.

           Note that this allows guest direct access to the host filesystem,
           so should only be used with trusted guest OS.

       The following options are specific to the Xtensa emulation:

       -semihosting
           Enable semihosting syscall emulation.

           Xtensa semihosting provides basic file IO calls, such as
           open/read/write/seek/select.  Tensilica baremetal libc for ISS and
           linux platform "sim" use this interface.

           Note that this allows guest direct access to the host filesystem,
           so should only be used with trusted guest OS.

SEE ALSO
       The HTML documentation of QEMU for more precise information and Linux
       user mode emulator invocation.

AUTHOR
       Fabrice Bellard

                                  2017-09-23                         QEMU.1(1)

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