1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
7 @documentencoding UTF-8
9 @settitle QEMU version @value{VERSION} User Documentation
16 * QEMU: (qemu-doc). The QEMU Emulator User Documentation.
23 @center @titlefont{QEMU version @value{VERSION}}
25 @center @titlefont{User Documentation}
36 * QEMU PC System emulator::
37 * QEMU System emulator for non PC targets::
39 * QEMU User space emulator::
40 * Implementation notes::
41 * Deprecated features::
53 * intro_features:: Features
59 QEMU is a FAST! processor emulator using dynamic translation to
60 achieve good emulation speed.
62 @cindex operating modes
63 QEMU has two operating modes:
66 @cindex system emulation
67 @item Full system emulation. In this mode, QEMU emulates a full system (for
68 example a PC), including one or several processors and various
69 peripherals. It can be used to launch different Operating Systems
70 without rebooting the PC or to debug system code.
72 @cindex user mode emulation
73 @item User mode emulation. In this mode, QEMU can launch
74 processes compiled for one CPU on another CPU. It can be used to
75 launch the Wine Windows API emulator (@url{https://www.winehq.org}) or
76 to ease cross-compilation and cross-debugging.
80 QEMU has the following features:
83 @item QEMU can run without a host kernel driver and yet gives acceptable
84 performance. It uses dynamic translation to native code for reasonable speed,
85 with support for self-modifying code and precise exceptions.
87 @item It is portable to several operating systems (GNU/Linux, *BSD, Mac OS X,
88 Windows) and architectures.
90 @item It performs accurate software emulation of the FPU.
93 QEMU user mode emulation has the following features:
95 @item Generic Linux system call converter, including most ioctls.
97 @item clone() emulation using native CPU clone() to use Linux scheduler for threads.
99 @item Accurate signal handling by remapping host signals to target signals.
102 QEMU full system emulation has the following features:
105 QEMU uses a full software MMU for maximum portability.
108 QEMU can optionally use an in-kernel accelerator, like kvm. The accelerators
109 execute most of the guest code natively, while
110 continuing to emulate the rest of the machine.
113 Various hardware devices can be emulated and in some cases, host
114 devices (e.g. serial and parallel ports, USB, drives) can be used
115 transparently by the guest Operating System. Host device passthrough
116 can be used for talking to external physical peripherals (e.g. a
117 webcam, modem or tape drive).
120 Symmetric multiprocessing (SMP) support. Currently, an in-kernel
121 accelerator is required to use more than one host CPU for emulation.
126 @node QEMU PC System emulator
127 @chapter QEMU PC System emulator
128 @cindex system emulation (PC)
131 * pcsys_introduction:: Introduction
132 * pcsys_quickstart:: Quick Start
133 * sec_invocation:: Invocation
134 * pcsys_keys:: Keys in the graphical frontends
135 * mux_keys:: Keys in the character backend multiplexer
136 * pcsys_monitor:: QEMU Monitor
137 * disk_images:: Disk Images
138 * pcsys_network:: Network emulation
139 * pcsys_other_devs:: Other Devices
140 * direct_linux_boot:: Direct Linux Boot
141 * pcsys_usb:: USB emulation
142 * vnc_security:: VNC security
143 * gdb_usage:: GDB usage
144 * pcsys_os_specific:: Target OS specific information
147 @node pcsys_introduction
148 @section Introduction
150 @c man begin DESCRIPTION
152 The QEMU PC System emulator simulates the
153 following peripherals:
157 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
159 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
160 extensions (hardware level, including all non standard modes).
162 PS/2 mouse and keyboard
164 2 PCI IDE interfaces with hard disk and CD-ROM support
168 PCI and ISA network adapters
172 IPMI BMC, either and internal or external one
174 Creative SoundBlaster 16 sound card
176 ENSONIQ AudioPCI ES1370 sound card
178 Intel 82801AA AC97 Audio compatible sound card
180 Intel HD Audio Controller and HDA codec
182 Adlib (OPL2) - Yamaha YM3812 compatible chip
184 Gravis Ultrasound GF1 sound card
186 CS4231A compatible sound card
188 PCI UHCI, OHCI, EHCI or XHCI USB controller and a virtual USB-1.1 hub.
191 SMP is supported with up to 255 CPUs.
193 QEMU uses the PC BIOS from the Seabios project and the Plex86/Bochs LGPL
196 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
198 QEMU uses GUS emulation (GUSEMU32 @url{http://www.deinmeister.de/gusemu/})
199 by Tibor "TS" Schütz.
201 Note that, by default, GUS shares IRQ(7) with parallel ports and so
202 QEMU must be told to not have parallel ports to have working GUS.
205 qemu-system-i386 dos.img -soundhw gus -parallel none
210 qemu-system-i386 dos.img -device gus,irq=5
213 Or some other unclaimed IRQ.
215 CS4231A is the chip used in Windows Sound System and GUSMAX products
219 @node pcsys_quickstart
223 Download and uncompress the linux image (@file{linux.img}) and type:
226 qemu-system-i386 linux.img
229 Linux should boot and give you a prompt.
235 @c man begin SYNOPSIS
236 @command{qemu-system-i386} [@var{options}] [@var{disk_image}]
241 @var{disk_image} is a raw hard disk image for IDE hard disk 0. Some
242 targets do not need a disk image.
244 @include qemu-options.texi
248 @subsection Device URL Syntax
249 @c TODO merge this with section Disk Images
253 In addition to using normal file images for the emulated storage devices,
254 QEMU can also use networked resources such as iSCSI devices. These are
255 specified using a special URL syntax.
259 iSCSI support allows QEMU to access iSCSI resources directly and use as
260 images for the guest storage. Both disk and cdrom images are supported.
262 Syntax for specifying iSCSI LUNs is
263 ``iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>''
265 By default qemu will use the iSCSI initiator-name
266 'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from the command
267 line or a configuration file.
269 Since version Qemu 2.4 it is possible to specify a iSCSI request timeout to detect
270 stalled requests and force a reestablishment of the session. The timeout
271 is specified in seconds. The default is 0 which means no timeout. Libiscsi
272 1.15.0 or greater is required for this feature.
274 Example (without authentication):
276 qemu-system-i386 -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
277 -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
278 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
281 Example (CHAP username/password via URL):
283 qemu-system-i386 -drive file=iscsi://user%password@@192.0.2.1/iqn.2001-04.com.example/1
286 Example (CHAP username/password via environment variables):
288 LIBISCSI_CHAP_USERNAME="user" \
289 LIBISCSI_CHAP_PASSWORD="password" \
290 qemu-system-i386 -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
294 QEMU supports NBD (Network Block Devices) both using TCP protocol as well
295 as Unix Domain Sockets.
297 Syntax for specifying a NBD device using TCP
298 ``nbd:<server-ip>:<port>[:exportname=<export>]''
300 Syntax for specifying a NBD device using Unix Domain Sockets
301 ``nbd:unix:<domain-socket>[:exportname=<export>]''
305 qemu-system-i386 --drive file=nbd:192.0.2.1:30000
308 Example for Unix Domain Sockets
310 qemu-system-i386 --drive file=nbd:unix:/tmp/nbd-socket
314 QEMU supports SSH (Secure Shell) access to remote disks.
318 qemu-system-i386 -drive file=ssh://user@@host/path/to/disk.img
319 qemu-system-i386 -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
322 Currently authentication must be done using ssh-agent. Other
323 authentication methods may be supported in future.
326 Sheepdog is a distributed storage system for QEMU.
327 QEMU supports using either local sheepdog devices or remote networked
330 Syntax for specifying a sheepdog device
332 sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]
337 qemu-system-i386 --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
340 See also @url{https://sheepdog.github.io/sheepdog/}.
343 GlusterFS is a user space distributed file system.
344 QEMU supports the use of GlusterFS volumes for hosting VM disk images using
345 TCP, Unix Domain Sockets and RDMA transport protocols.
347 Syntax for specifying a VM disk image on GlusterFS volume is
351 gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
354 'json:@{"driver":"qcow2","file":@{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
355 @ "server":[@{"type":"tcp","host":"...","port":"..."@},
356 @ @{"type":"unix","socket":"..."@}]@}@}'
363 qemu-system-x86_64 --drive file=gluster://192.0.2.1/testvol/a.img,
364 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log
367 qemu-system-x86_64 'json:@{"driver":"qcow2",
368 @ "file":@{"driver":"gluster",
369 @ "volume":"testvol","path":"a.img",
370 @ "debug":9,"logfile":"/var/log/qemu-gluster.log",
371 @ "server":[@{"type":"tcp","host":"1.2.3.4","port":24007@},
372 @ @{"type":"unix","socket":"/var/run/glusterd.socket"@}]@}@}'
373 qemu-system-x86_64 -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
374 @ file.debug=9,file.logfile=/var/log/qemu-gluster.log,
375 @ file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
376 @ file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
379 See also @url{http://www.gluster.org}.
381 @item HTTP/HTTPS/FTP/FTPS
382 QEMU supports read-only access to files accessed over http(s) and ftp(s).
384 Syntax using a single filename:
386 <protocol>://[<username>[:<password>]@@]<host>/<path>
392 'http', 'https', 'ftp', or 'ftps'.
395 Optional username for authentication to the remote server.
398 Optional password for authentication to the remote server.
401 Address of the remote server.
404 Path on the remote server, including any query string.
407 The following options are also supported:
410 The full URL when passing options to the driver explicitly.
413 The amount of data to read ahead with each range request to the remote server.
414 This value may optionally have the suffix 'T', 'G', 'M', 'K', 'k' or 'b'. If it
415 does not have a suffix, it will be assumed to be in bytes. The value must be a
416 multiple of 512 bytes. It defaults to 256k.
419 Whether to verify the remote server's certificate when connecting over SSL. It
420 can have the value 'on' or 'off'. It defaults to 'on'.
423 Send this cookie (it can also be a list of cookies separated by ';') with
424 each outgoing request. Only supported when using protocols such as HTTP
425 which support cookies, otherwise ignored.
428 Set the timeout in seconds of the CURL connection. This timeout is the time
429 that CURL waits for a response from the remote server to get the size of the
430 image to be downloaded. If not set, the default timeout of 5 seconds is used.
433 Note that when passing options to qemu explicitly, @option{driver} is the value
436 Example: boot from a remote Fedora 20 live ISO image
438 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
440 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
443 Example: boot from a remote Fedora 20 cloud image using a local overlay for
444 writes, copy-on-read, and a readahead of 64k
446 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
448 qemu-system-x86_64 -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
451 Example: boot from an image stored on a VMware vSphere server with a self-signed
452 certificate using a local overlay for writes, a readahead of 64k and a timeout
455 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
457 qemu-system-x86_64 -drive file=/tmp/test.qcow2
465 @section Keys in the graphical frontends
469 During the graphical emulation, you can use special key combinations to change
470 modes. The default key mappings are shown below, but if you use @code{-alt-grab}
471 then the modifier is Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use
472 @code{-ctrl-grab} then the modifier is the right Ctrl key (instead of Ctrl-Alt):
489 Restore the screen's un-scaled dimensions
493 Switch to virtual console 'n'. Standard console mappings are:
496 Target system display
505 Toggle mouse and keyboard grab.
511 @kindex Ctrl-PageDown
512 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
513 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
518 @section Keys in the character backend multiplexer
522 During emulation, if you are using a character backend multiplexer
523 (which is the default if you are using @option{-nographic}) then
524 several commands are available via an escape sequence. These
525 key sequences all start with an escape character, which is @key{Ctrl-a}
526 by default, but can be changed with @option{-echr}. The list below assumes
527 you're using the default.
538 Save disk data back to file (if -snapshot)
541 Toggle console timestamps
544 Send break (magic sysrq in Linux)
547 Rotate between the frontends connected to the multiplexer (usually
548 this switches between the monitor and the console)
550 @kindex Ctrl-a Ctrl-a
551 Send the escape character to the frontend
558 The HTML documentation of QEMU for more precise information and Linux
559 user mode emulator invocation.
569 @section QEMU Monitor
572 The QEMU monitor is used to give complex commands to the QEMU
573 emulator. You can use it to:
578 Remove or insert removable media images
579 (such as CD-ROM or floppies).
582 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
585 @item Inspect the VM state without an external debugger.
591 The following commands are available:
593 @include qemu-monitor.texi
595 @include qemu-monitor-info.texi
597 @subsection Integer expressions
599 The monitor understands integers expressions for every integer
600 argument. You can use register names to get the value of specifics
601 CPU registers by prefixing them with @emph{$}.
606 QEMU supports many disk image formats, including growable disk images
607 (their size increase as non empty sectors are written), compressed and
608 encrypted disk images.
611 * disk_images_quickstart:: Quick start for disk image creation
612 * disk_images_snapshot_mode:: Snapshot mode
613 * vm_snapshots:: VM snapshots
614 * qemu_img_invocation:: qemu-img Invocation
615 * qemu_nbd_invocation:: qemu-nbd Invocation
616 * disk_images_formats:: Disk image file formats
617 * host_drives:: Using host drives
618 * disk_images_fat_images:: Virtual FAT disk images
619 * disk_images_nbd:: NBD access
620 * disk_images_sheepdog:: Sheepdog disk images
621 * disk_images_iscsi:: iSCSI LUNs
622 * disk_images_gluster:: GlusterFS disk images
623 * disk_images_ssh:: Secure Shell (ssh) disk images
624 * disk_images_nvme:: NVMe userspace driver
625 * disk_image_locking:: Disk image file locking
628 @node disk_images_quickstart
629 @subsection Quick start for disk image creation
631 You can create a disk image with the command:
633 qemu-img create myimage.img mysize
635 where @var{myimage.img} is the disk image filename and @var{mysize} is its
636 size in kilobytes. You can add an @code{M} suffix to give the size in
637 megabytes and a @code{G} suffix for gigabytes.
639 See @ref{qemu_img_invocation} for more information.
641 @node disk_images_snapshot_mode
642 @subsection Snapshot mode
644 If you use the option @option{-snapshot}, all disk images are
645 considered as read only. When sectors in written, they are written in
646 a temporary file created in @file{/tmp}. You can however force the
647 write back to the raw disk images by using the @code{commit} monitor
648 command (or @key{C-a s} in the serial console).
651 @subsection VM snapshots
653 VM snapshots are snapshots of the complete virtual machine including
654 CPU state, RAM, device state and the content of all the writable
655 disks. In order to use VM snapshots, you must have at least one non
656 removable and writable block device using the @code{qcow2} disk image
657 format. Normally this device is the first virtual hard drive.
659 Use the monitor command @code{savevm} to create a new VM snapshot or
660 replace an existing one. A human readable name can be assigned to each
661 snapshot in addition to its numerical ID.
663 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
664 a VM snapshot. @code{info snapshots} lists the available snapshots
665 with their associated information:
668 (qemu) info snapshots
669 Snapshot devices: hda
670 Snapshot list (from hda):
671 ID TAG VM SIZE DATE VM CLOCK
672 1 start 41M 2006-08-06 12:38:02 00:00:14.954
673 2 40M 2006-08-06 12:43:29 00:00:18.633
674 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
677 A VM snapshot is made of a VM state info (its size is shown in
678 @code{info snapshots}) and a snapshot of every writable disk image.
679 The VM state info is stored in the first @code{qcow2} non removable
680 and writable block device. The disk image snapshots are stored in
681 every disk image. The size of a snapshot in a disk image is difficult
682 to evaluate and is not shown by @code{info snapshots} because the
683 associated disk sectors are shared among all the snapshots to save
684 disk space (otherwise each snapshot would need a full copy of all the
687 When using the (unrelated) @code{-snapshot} option
688 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
689 but they are deleted as soon as you exit QEMU.
691 VM snapshots currently have the following known limitations:
694 They cannot cope with removable devices if they are removed or
695 inserted after a snapshot is done.
697 A few device drivers still have incomplete snapshot support so their
698 state is not saved or restored properly (in particular USB).
701 @node qemu_img_invocation
702 @subsection @code{qemu-img} Invocation
704 @include qemu-img.texi
706 @node qemu_nbd_invocation
707 @subsection @code{qemu-nbd} Invocation
709 @include qemu-nbd.texi
711 @include docs/qemu-block-drivers.texi
714 @section Network emulation
716 QEMU can simulate several network cards (PCI or ISA cards on the PC
717 target) and can connect them to an arbitrary number of Virtual Local
718 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
719 VLAN. VLAN can be connected between separate instances of QEMU to
720 simulate large networks. For simpler usage, a non privileged user mode
721 network stack can replace the TAP device to have a basic network
726 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
727 connection between several network devices. These devices can be for
728 example QEMU virtual Ethernet cards or virtual Host ethernet devices
731 @subsection Using TAP network interfaces
733 This is the standard way to connect QEMU to a real network. QEMU adds
734 a virtual network device on your host (called @code{tapN}), and you
735 can then configure it as if it was a real ethernet card.
737 @subsubsection Linux host
739 As an example, you can download the @file{linux-test-xxx.tar.gz}
740 archive and copy the script @file{qemu-ifup} in @file{/etc} and
741 configure properly @code{sudo} so that the command @code{ifconfig}
742 contained in @file{qemu-ifup} can be executed as root. You must verify
743 that your host kernel supports the TAP network interfaces: the
744 device @file{/dev/net/tun} must be present.
746 See @ref{sec_invocation} to have examples of command lines using the
747 TAP network interfaces.
749 @subsubsection Windows host
751 There is a virtual ethernet driver for Windows 2000/XP systems, called
752 TAP-Win32. But it is not included in standard QEMU for Windows,
753 so you will need to get it separately. It is part of OpenVPN package,
754 so download OpenVPN from : @url{https://openvpn.net/}.
756 @subsection Using the user mode network stack
758 By using the option @option{-net user} (default configuration if no
759 @option{-net} option is specified), QEMU uses a completely user mode
760 network stack (you don't need root privilege to use the virtual
761 network). The virtual network configuration is the following:
765 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
768 ----> DNS server (10.0.2.3)
770 ----> SMB server (10.0.2.4)
773 The QEMU VM behaves as if it was behind a firewall which blocks all
774 incoming connections. You can use a DHCP client to automatically
775 configure the network in the QEMU VM. The DHCP server assign addresses
776 to the hosts starting from 10.0.2.15.
778 In order to check that the user mode network is working, you can ping
779 the address 10.0.2.2 and verify that you got an address in the range
780 10.0.2.x from the QEMU virtual DHCP server.
782 Note that ICMP traffic in general does not work with user mode networking.
783 @code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
784 however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
785 ping sockets to allow @code{ping} to the Internet. The host admin has to set
786 the ping_group_range in order to grant access to those sockets. To allow ping
787 for GID 100 (usually users group):
790 echo 100 100 > /proc/sys/net/ipv4/ping_group_range
793 When using the built-in TFTP server, the router is also the TFTP
796 When using the @option{'-netdev user,hostfwd=...'} option, TCP or UDP
797 connections can be redirected from the host to the guest. It allows for
798 example to redirect X11, telnet or SSH connections.
800 @subsection Connecting VLANs between QEMU instances
802 Using the @option{-net socket} option, it is possible to make VLANs
803 that span several QEMU instances. See @ref{sec_invocation} to have a
806 @node pcsys_other_devs
807 @section Other Devices
809 @subsection Inter-VM Shared Memory device
811 On Linux hosts, a shared memory device is available. The basic syntax
815 qemu-system-x86_64 -device ivshmem-plain,memdev=@var{hostmem}
818 where @var{hostmem} names a host memory backend. For a POSIX shared
819 memory backend, use something like
822 -object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=@var{hostmem}
825 If desired, interrupts can be sent between guest VMs accessing the same shared
826 memory region. Interrupt support requires using a shared memory server and
827 using a chardev socket to connect to it. The code for the shared memory server
828 is qemu.git/contrib/ivshmem-server. An example syntax when using the shared
832 # First start the ivshmem server once and for all
833 ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
835 # Then start your qemu instances with matching arguments
836 qemu-system-x86_64 -device ivshmem-doorbell,vectors=@var{vectors},chardev=@var{id}
837 -chardev socket,path=@var{path},id=@var{id}
840 When using the server, the guest will be assigned a VM ID (>=0) that allows guests
841 using the same server to communicate via interrupts. Guests can read their
842 VM ID from a device register (see ivshmem-spec.txt).
844 @subsubsection Migration with ivshmem
846 With device property @option{master=on}, the guest will copy the shared
847 memory on migration to the destination host. With @option{master=off},
848 the guest will not be able to migrate with the device attached. In the
849 latter case, the device should be detached and then reattached after
850 migration using the PCI hotplug support.
852 At most one of the devices sharing the same memory can be master. The
853 master must complete migration before you plug back the other devices.
855 @subsubsection ivshmem and hugepages
857 Instead of specifying the <shm size> using POSIX shm, you may specify
858 a memory backend that has hugepage support:
861 qemu-system-x86_64 -object memory-backend-file,size=1G,mem-path=/dev/hugepages/my-shmem-file,share,id=mb1
862 -device ivshmem-plain,memdev=mb1
865 ivshmem-server also supports hugepages mount points with the
866 @option{-m} memory path argument.
868 @node direct_linux_boot
869 @section Direct Linux Boot
871 This section explains how to launch a Linux kernel inside QEMU without
872 having to make a full bootable image. It is very useful for fast Linux
877 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
880 Use @option{-kernel} to provide the Linux kernel image and
881 @option{-append} to give the kernel command line arguments. The
882 @option{-initrd} option can be used to provide an INITRD image.
884 When using the direct Linux boot, a disk image for the first hard disk
885 @file{hda} is required because its boot sector is used to launch the
888 If you do not need graphical output, you can disable it and redirect
889 the virtual serial port and the QEMU monitor to the console with the
890 @option{-nographic} option. The typical command line is:
892 qemu-system-i386 -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
893 -append "root=/dev/hda console=ttyS0" -nographic
896 Use @key{Ctrl-a c} to switch between the serial console and the
897 monitor (@pxref{pcsys_keys}).
900 @section USB emulation
902 QEMU can emulate a PCI UHCI, OHCI, EHCI or XHCI USB controller. You can
903 plug virtual USB devices or real host USB devices (only works with certain
904 host operating systems). QEMU will automatically create and connect virtual
905 USB hubs as necessary to connect multiple USB devices.
912 @subsection Connecting USB devices
914 USB devices can be connected with the @option{-device usb-...} command line
915 option or the @code{device_add} monitor command. Available devices are:
919 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
921 Pointer device that uses absolute coordinates (like a touchscreen).
922 This means QEMU is able to report the mouse position without having
923 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
924 @item usb-storage,drive=@var{drive_id}
925 Mass storage device backed by @var{drive_id} (@pxref{disk_images})
927 USB attached SCSI device, see
928 @url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt}
931 Bulk-only transport storage device, see
932 @url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/usb-storage.txt,usb-storage.txt}
933 for details here, too
934 @item usb-mtp,x-root=@var{dir}
935 Media transfer protocol device, using @var{dir} as root of the file tree
936 that is presented to the guest.
937 @item usb-host,hostbus=@var{bus},hostaddr=@var{addr}
938 Pass through the host device identified by @var{bus} and @var{addr}
939 @item usb-host,vendorid=@var{vendor},productid=@var{product}
940 Pass through the host device identified by @var{vendor} and @var{product} ID
941 @item usb-wacom-tablet
942 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
943 above but it can be used with the tslib library because in addition to touch
944 coordinates it reports touch pressure.
946 Standard USB keyboard. Will override the PS/2 keyboard (if present).
947 @item usb-serial,chardev=@var{id}
948 Serial converter. This emulates an FTDI FT232BM chip connected to host character
950 @item usb-braille,chardev=@var{id}
951 Braille device. This will use BrlAPI to display the braille output on a real
952 or fake device referenced by @var{id}.
953 @item usb-net[,netdev=@var{id}]
954 Network adapter that supports CDC ethernet and RNDIS protocols. @var{id}
955 specifies a netdev defined with @code{-netdev @dots{},id=@var{id}}.
956 For instance, user-mode networking can be used with
958 qemu-system-i386 [...] -netdev user,id=net0 -device usb-net,netdev=net0
961 Smartcard reader device
965 Bluetooth dongle for the transport layer of HCI. It is connected to HCI
966 scatternet 0 by default (corresponds to @code{-bt hci,vlan=0}).
967 Note that the syntax for the @code{-device usb-bt-dongle} option is not as
968 useful yet as it was with the legacy @code{-usbdevice} option. So to
969 configure an USB bluetooth device, you might need to use
970 "@code{-usbdevice bt}[:@var{hci-type}]" instead. This configures a
971 bluetooth dongle whose type is specified in the same format as with
972 the @option{-bt hci} option, @pxref{bt-hcis,,allowed HCI types}. If
973 no type is given, the HCI logic corresponds to @code{-bt hci,vlan=0}.
974 This USB device implements the USB Transport Layer of HCI. Example
977 @command{qemu-system-i386} [...@var{OPTIONS}...] @option{-usbdevice} bt:hci,vlan=3 @option{-bt} device:keyboard,vlan=3
981 @node host_usb_devices
982 @subsection Using host USB devices on a Linux host
984 WARNING: this is an experimental feature. QEMU will slow down when
985 using it. USB devices requiring real time streaming (i.e. USB Video
986 Cameras) are not supported yet.
989 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
990 is actually using the USB device. A simple way to do that is simply to
991 disable the corresponding kernel module by renaming it from @file{mydriver.o}
992 to @file{mydriver.o.disabled}.
994 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1000 @item Since only root can access to the USB devices directly, you can either launch QEMU as root or change the permissions of the USB devices you want to use. For testing, the following suffices:
1002 chown -R myuid /proc/bus/usb
1005 @item Launch QEMU and do in the monitor:
1008 Device 1.2, speed 480 Mb/s
1009 Class 00: USB device 1234:5678, USB DISK
1011 You should see the list of the devices you can use (Never try to use
1012 hubs, it won't work).
1014 @item Add the device in QEMU by using:
1016 device_add usb-host,vendorid=0x1234,productid=0x5678
1019 Normally the guest OS should report that a new USB device is plugged.
1020 You can use the option @option{-device usb-host,...} to do the same.
1022 @item Now you can try to use the host USB device in QEMU.
1026 When relaunching QEMU, you may have to unplug and plug again the USB
1027 device to make it work again (this is a bug).
1030 @section VNC security
1032 The VNC server capability provides access to the graphical console
1033 of the guest VM across the network. This has a number of security
1034 considerations depending on the deployment scenarios.
1038 * vnc_sec_password::
1039 * vnc_sec_certificate::
1040 * vnc_sec_certificate_verify::
1041 * vnc_sec_certificate_pw::
1043 * vnc_sec_certificate_sasl::
1044 * vnc_generate_cert::
1048 @subsection Without passwords
1050 The simplest VNC server setup does not include any form of authentication.
1051 For this setup it is recommended to restrict it to listen on a UNIX domain
1052 socket only. For example
1055 qemu-system-i386 [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1058 This ensures that only users on local box with read/write access to that
1059 path can access the VNC server. To securely access the VNC server from a
1060 remote machine, a combination of netcat+ssh can be used to provide a secure
1063 @node vnc_sec_password
1064 @subsection With passwords
1066 The VNC protocol has limited support for password based authentication. Since
1067 the protocol limits passwords to 8 characters it should not be considered
1068 to provide high security. The password can be fairly easily brute-forced by
1069 a client making repeat connections. For this reason, a VNC server using password
1070 authentication should be restricted to only listen on the loopback interface
1071 or UNIX domain sockets. Password authentication is not supported when operating
1072 in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password
1073 authentication is requested with the @code{password} option, and then once QEMU
1074 is running the password is set with the monitor. Until the monitor is used to
1075 set the password all clients will be rejected.
1078 qemu-system-i386 [...OPTIONS...] -vnc :1,password -monitor stdio
1079 (qemu) change vnc password
1084 @node vnc_sec_certificate
1085 @subsection With x509 certificates
1087 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1088 TLS for encryption of the session, and x509 certificates for authentication.
1089 The use of x509 certificates is strongly recommended, because TLS on its
1090 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1091 support provides a secure session, but no authentication. This allows any
1092 client to connect, and provides an encrypted session.
1095 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1098 In the above example @code{/etc/pki/qemu} should contain at least three files,
1099 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1100 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1101 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1102 only be readable by the user owning it.
1104 @node vnc_sec_certificate_verify
1105 @subsection With x509 certificates and client verification
1107 Certificates can also provide a means to authenticate the client connecting.
1108 The server will request that the client provide a certificate, which it will
1109 then validate against the CA certificate. This is a good choice if deploying
1110 in an environment with a private internal certificate authority.
1113 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1117 @node vnc_sec_certificate_pw
1118 @subsection With x509 certificates, client verification and passwords
1120 Finally, the previous method can be combined with VNC password authentication
1121 to provide two layers of authentication for clients.
1124 qemu-system-i386 [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1125 (qemu) change vnc password
1132 @subsection With SASL authentication
1134 The SASL authentication method is a VNC extension, that provides an
1135 easily extendable, pluggable authentication method. This allows for
1136 integration with a wide range of authentication mechanisms, such as
1137 PAM, GSSAPI/Kerberos, LDAP, SQL databases, one-time keys and more.
1138 The strength of the authentication depends on the exact mechanism
1139 configured. If the chosen mechanism also provides a SSF layer, then
1140 it will encrypt the datastream as well.
1142 Refer to the later docs on how to choose the exact SASL mechanism
1143 used for authentication, but assuming use of one supporting SSF,
1144 then QEMU can be launched with:
1147 qemu-system-i386 [...OPTIONS...] -vnc :1,sasl -monitor stdio
1150 @node vnc_sec_certificate_sasl
1151 @subsection With x509 certificates and SASL authentication
1153 If the desired SASL authentication mechanism does not supported
1154 SSF layers, then it is strongly advised to run it in combination
1155 with TLS and x509 certificates. This provides securely encrypted
1156 data stream, avoiding risk of compromising of the security
1157 credentials. This can be enabled, by combining the 'sasl' option
1158 with the aforementioned TLS + x509 options:
1161 qemu-system-i386 [...OPTIONS...] -vnc :1,tls,x509,sasl -monitor stdio
1165 @node vnc_generate_cert
1166 @subsection Generating certificates for VNC
1168 The GNU TLS packages provides a command called @code{certtool} which can
1169 be used to generate certificates and keys in PEM format. At a minimum it
1170 is necessary to setup a certificate authority, and issue certificates to
1171 each server. If using certificates for authentication, then each client
1172 will also need to be issued a certificate. The recommendation is for the
1173 server to keep its certificates in either @code{/etc/pki/qemu} or for
1174 unprivileged users in @code{$HOME/.pki/qemu}.
1178 * vnc_generate_server::
1179 * vnc_generate_client::
1181 @node vnc_generate_ca
1182 @subsubsection Setup the Certificate Authority
1184 This step only needs to be performed once per organization / organizational
1185 unit. First the CA needs a private key. This key must be kept VERY secret
1186 and secure. If this key is compromised the entire trust chain of the certificates
1187 issued with it is lost.
1190 # certtool --generate-privkey > ca-key.pem
1193 A CA needs to have a public certificate. For simplicity it can be a self-signed
1194 certificate, or one issue by a commercial certificate issuing authority. To
1195 generate a self-signed certificate requires one core piece of information, the
1196 name of the organization.
1199 # cat > ca.info <<EOF
1200 cn = Name of your organization
1204 # certtool --generate-self-signed \
1205 --load-privkey ca-key.pem
1206 --template ca.info \
1207 --outfile ca-cert.pem
1210 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1211 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1213 @node vnc_generate_server
1214 @subsubsection Issuing server certificates
1216 Each server (or host) needs to be issued with a key and certificate. When connecting
1217 the certificate is sent to the client which validates it against the CA certificate.
1218 The core piece of information for a server certificate is the hostname. This should
1219 be the fully qualified hostname that the client will connect with, since the client
1220 will typically also verify the hostname in the certificate. On the host holding the
1221 secure CA private key:
1224 # cat > server.info <<EOF
1225 organization = Name of your organization
1226 cn = server.foo.example.com
1231 # certtool --generate-privkey > server-key.pem
1232 # certtool --generate-certificate \
1233 --load-ca-certificate ca-cert.pem \
1234 --load-ca-privkey ca-key.pem \
1235 --load-privkey server-key.pem \
1236 --template server.info \
1237 --outfile server-cert.pem
1240 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1241 to the server for which they were generated. The @code{server-key.pem} is security
1242 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1244 @node vnc_generate_client
1245 @subsubsection Issuing client certificates
1247 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1248 certificates as its authentication mechanism, each client also needs to be issued
1249 a certificate. The client certificate contains enough metadata to uniquely identify
1250 the client, typically organization, state, city, building, etc. On the host holding
1251 the secure CA private key:
1254 # cat > client.info <<EOF
1258 organization = Name of your organization
1259 cn = client.foo.example.com
1264 # certtool --generate-privkey > client-key.pem
1265 # certtool --generate-certificate \
1266 --load-ca-certificate ca-cert.pem \
1267 --load-ca-privkey ca-key.pem \
1268 --load-privkey client-key.pem \
1269 --template client.info \
1270 --outfile client-cert.pem
1273 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1274 copied to the client for which they were generated.
1277 @node vnc_setup_sasl
1279 @subsection Configuring SASL mechanisms
1281 The following documentation assumes use of the Cyrus SASL implementation on a
1282 Linux host, but the principals should apply to any other SASL impl. When SASL
1283 is enabled, the mechanism configuration will be loaded from system default
1284 SASL service config /etc/sasl2/qemu.conf. If running QEMU as an
1285 unprivileged user, an environment variable SASL_CONF_PATH can be used
1286 to make it search alternate locations for the service config.
1288 If the TLS option is enabled for VNC, then it will provide session encryption,
1289 otherwise the SASL mechanism will have to provide encryption. In the latter
1290 case the list of possible plugins that can be used is drastically reduced. In
1291 fact only the GSSAPI SASL mechanism provides an acceptable level of security
1292 by modern standards. Previous versions of QEMU referred to the DIGEST-MD5
1293 mechanism, however, it has multiple serious flaws described in detail in
1294 RFC 6331 and thus should never be used any more. The SCRAM-SHA-1 mechanism
1295 provides a simple username/password auth facility similar to DIGEST-MD5, but
1296 does not support session encryption, so can only be used in combination with
1299 When not using TLS the recommended configuration is
1303 keytab: /etc/qemu/krb5.tab
1306 This says to use the 'GSSAPI' mechanism with the Kerberos v5 protocol, with
1307 the server principal stored in /etc/qemu/krb5.tab. For this to work the
1308 administrator of your KDC must generate a Kerberos principal for the server,
1309 with a name of 'qemu/somehost.example.com@@EXAMPLE.COM' replacing
1310 'somehost.example.com' with the fully qualified host name of the machine
1311 running QEMU, and 'EXAMPLE.COM' with the Kerberos Realm.
1313 When using TLS, if username+password authentication is desired, then a
1314 reasonable configuration is
1317 mech_list: scram-sha-1
1318 sasldb_path: /etc/qemu/passwd.db
1321 The saslpasswd2 program can be used to populate the passwd.db file with
1324 Other SASL configurations will be left as an exercise for the reader. Note that
1325 all mechanisms except GSSAPI, should be combined with use of TLS to ensure a
1326 secure data channel.
1331 QEMU has a primitive support to work with gdb, so that you can do
1332 'Ctrl-C' while the virtual machine is running and inspect its state.
1334 In order to use gdb, launch QEMU with the '-s' option. It will wait for a
1337 qemu-system-i386 -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1338 -append "root=/dev/hda"
1339 Connected to host network interface: tun0
1340 Waiting gdb connection on port 1234
1343 Then launch gdb on the 'vmlinux' executable:
1348 In gdb, connect to QEMU:
1350 (gdb) target remote localhost:1234
1353 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1358 Here are some useful tips in order to use gdb on system code:
1362 Use @code{info reg} to display all the CPU registers.
1364 Use @code{x/10i $eip} to display the code at the PC position.
1366 Use @code{set architecture i8086} to dump 16 bit code. Then use
1367 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1370 Advanced debugging options:
1372 The default single stepping behavior is step with the IRQs and timer service routines off. It is set this way because when gdb executes a single step it expects to advance beyond the current instruction. With the IRQs and timer service routines on, a single step might jump into the one of the interrupt or exception vectors instead of executing the current instruction. This means you may hit the same breakpoint a number of times before executing the instruction gdb wants to have executed. Because there are rare circumstances where you want to single step into an interrupt vector the behavior can be controlled from GDB. There are three commands you can query and set the single step behavior:
1374 @item maintenance packet qqemu.sstepbits
1376 This will display the MASK bits used to control the single stepping IE:
1378 (gdb) maintenance packet qqemu.sstepbits
1379 sending: "qqemu.sstepbits"
1380 received: "ENABLE=1,NOIRQ=2,NOTIMER=4"
1382 @item maintenance packet qqemu.sstep
1384 This will display the current value of the mask used when single stepping IE:
1386 (gdb) maintenance packet qqemu.sstep
1387 sending: "qqemu.sstep"
1390 @item maintenance packet Qqemu.sstep=HEX_VALUE
1392 This will change the single step mask, so if wanted to enable IRQs on the single step, but not timers, you would use:
1394 (gdb) maintenance packet Qqemu.sstep=0x5
1395 sending: "qemu.sstep=0x5"
1400 @node pcsys_os_specific
1401 @section Target OS specific information
1405 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1406 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1407 color depth in the guest and the host OS.
1409 When using a 2.6 guest Linux kernel, you should add the option
1410 @code{clock=pit} on the kernel command line because the 2.6 Linux
1411 kernels make very strict real time clock checks by default that QEMU
1412 cannot simulate exactly.
1414 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1415 not activated because QEMU is slower with this patch. The QEMU
1416 Accelerator Module is also much slower in this case. Earlier Fedora
1417 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1418 patch by default. Newer kernels don't have it.
1422 If you have a slow host, using Windows 95 is better as it gives the
1423 best speed. Windows 2000 is also a good choice.
1425 @subsubsection SVGA graphic modes support
1427 QEMU emulates a Cirrus Logic GD5446 Video
1428 card. All Windows versions starting from Windows 95 should recognize
1429 and use this graphic card. For optimal performances, use 16 bit color
1430 depth in the guest and the host OS.
1432 If you are using Windows XP as guest OS and if you want to use high
1433 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1434 1280x1024x16), then you should use the VESA VBE virtual graphic card
1435 (option @option{-std-vga}).
1437 @subsubsection CPU usage reduction
1439 Windows 9x does not correctly use the CPU HLT
1440 instruction. The result is that it takes host CPU cycles even when
1441 idle. You can install the utility from
1442 @url{https://web.archive.org/web/20060212132151/http://www.user.cityline.ru/~maxamn/amnhltm.zip}
1443 to solve this problem. Note that no such tool is needed for NT, 2000 or XP.
1445 @subsubsection Windows 2000 disk full problem
1447 Windows 2000 has a bug which gives a disk full problem during its
1448 installation. When installing it, use the @option{-win2k-hack} QEMU
1449 option to enable a specific workaround. After Windows 2000 is
1450 installed, you no longer need this option (this option slows down the
1453 @subsubsection Windows 2000 shutdown
1455 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1456 can. It comes from the fact that Windows 2000 does not automatically
1457 use the APM driver provided by the BIOS.
1459 In order to correct that, do the following (thanks to Struan
1460 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1461 Add/Troubleshoot a device => Add a new device & Next => No, select the
1462 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1463 (again) a few times. Now the driver is installed and Windows 2000 now
1464 correctly instructs QEMU to shutdown at the appropriate moment.
1466 @subsubsection Share a directory between Unix and Windows
1468 See @ref{sec_invocation} about the help of the option
1469 @option{'-netdev user,smb=...'}.
1471 @subsubsection Windows XP security problem
1473 Some releases of Windows XP install correctly but give a security
1476 A problem is preventing Windows from accurately checking the
1477 license for this computer. Error code: 0x800703e6.
1480 The workaround is to install a service pack for XP after a boot in safe
1481 mode. Then reboot, and the problem should go away. Since there is no
1482 network while in safe mode, its recommended to download the full
1483 installation of SP1 or SP2 and transfer that via an ISO or using the
1484 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1486 @subsection MS-DOS and FreeDOS
1488 @subsubsection CPU usage reduction
1490 DOS does not correctly use the CPU HLT instruction. The result is that
1491 it takes host CPU cycles even when idle. You can install the utility from
1492 @url{https://web.archive.org/web/20051222085335/http://www.vmware.com/software/dosidle210.zip}
1493 to solve this problem.
1495 @node QEMU System emulator for non PC targets
1496 @chapter QEMU System emulator for non PC targets
1498 QEMU is a generic emulator and it emulates many non PC
1499 machines. Most of the options are similar to the PC emulator. The
1500 differences are mentioned in the following sections.
1503 * PowerPC System emulator::
1504 * Sparc32 System emulator::
1505 * Sparc64 System emulator::
1506 * MIPS System emulator::
1507 * ARM System emulator::
1508 * ColdFire System emulator::
1509 * Cris System emulator::
1510 * Microblaze System emulator::
1511 * SH4 System emulator::
1512 * Xtensa System emulator::
1515 @node PowerPC System emulator
1516 @section PowerPC System emulator
1517 @cindex system emulation (PowerPC)
1519 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1520 or PowerMac PowerPC system.
1522 QEMU emulates the following PowerMac peripherals:
1526 UniNorth or Grackle PCI Bridge
1528 PCI VGA compatible card with VESA Bochs Extensions
1530 2 PMAC IDE interfaces with hard disk and CD-ROM support
1536 VIA-CUDA with ADB keyboard and mouse.
1539 QEMU emulates the following PREP peripherals:
1545 PCI VGA compatible card with VESA Bochs Extensions
1547 2 IDE interfaces with hard disk and CD-ROM support
1551 NE2000 network adapters
1555 PREP Non Volatile RAM
1557 PC compatible keyboard and mouse.
1560 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1561 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1563 Since version 0.9.1, QEMU uses OpenBIOS @url{https://www.openbios.org/}
1564 for the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL
1565 v2) portable firmware implementation. The goal is to implement a 100%
1566 IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
1568 @c man begin OPTIONS
1570 The following options are specific to the PowerPC emulation:
1574 @item -g @var{W}x@var{H}[x@var{DEPTH}]
1576 Set the initial VGA graphic mode. The default is 800x600x32.
1578 @item -prom-env @var{string}
1580 Set OpenBIOS variables in NVRAM, for example:
1583 qemu-system-ppc -prom-env 'auto-boot?=false' \
1584 -prom-env 'boot-device=hd:2,\yaboot' \
1585 -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
1588 These variables are not used by Open Hack'Ware.
1595 More information is available at
1596 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
1598 @node Sparc32 System emulator
1599 @section Sparc32 System emulator
1600 @cindex system emulation (Sparc32)
1602 Use the executable @file{qemu-system-sparc} to simulate the following
1603 Sun4m architecture machines:
1618 SPARCstation Voyager
1625 The emulation is somewhat complete. SMP up to 16 CPUs is supported,
1626 but Linux limits the number of usable CPUs to 4.
1628 QEMU emulates the following sun4m peripherals:
1634 TCX or cgthree Frame buffer
1636 Lance (Am7990) Ethernet
1638 Non Volatile RAM M48T02/M48T08
1640 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
1641 and power/reset logic
1643 ESP SCSI controller with hard disk and CD-ROM support
1645 Floppy drive (not on SS-600MP)
1647 CS4231 sound device (only on SS-5, not working yet)
1650 The number of peripherals is fixed in the architecture. Maximum
1651 memory size depends on the machine type, for SS-5 it is 256MB and for
1654 Since version 0.8.2, QEMU uses OpenBIOS
1655 @url{https://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
1656 firmware implementation. The goal is to implement a 100% IEEE
1657 1275-1994 (referred to as Open Firmware) compliant firmware.
1659 A sample Linux 2.6 series kernel and ram disk image are available on
1660 the QEMU web site. There are still issues with NetBSD and OpenBSD, but
1661 most kernel versions work. Please note that currently older Solaris kernels
1662 don't work probably due to interface issues between OpenBIOS and
1665 @c man begin OPTIONS
1667 The following options are specific to the Sparc32 emulation:
1671 @item -g @var{W}x@var{H}x[x@var{DEPTH}]
1673 Set the initial graphics mode. For TCX, the default is 1024x768x8 with the
1674 option of 1024x768x24. For cgthree, the default is 1024x768x8 with the option
1675 of 1152x900x8 for people who wish to use OBP.
1677 @item -prom-env @var{string}
1679 Set OpenBIOS variables in NVRAM, for example:
1682 qemu-system-sparc -prom-env 'auto-boot?=false' \
1683 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
1686 @item -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic] [|SPARCbook]
1688 Set the emulated machine type. Default is SS-5.
1694 @node Sparc64 System emulator
1695 @section Sparc64 System emulator
1696 @cindex system emulation (Sparc64)
1698 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u
1699 (UltraSPARC PC-like machine), Sun4v (T1 PC-like machine), or generic
1700 Niagara (T1) machine. The Sun4u emulator is mostly complete, being
1701 able to run Linux, NetBSD and OpenBSD in headless (-nographic) mode. The
1702 Sun4v emulator is still a work in progress.
1704 The Niagara T1 emulator makes use of firmware and OS binaries supplied in the S10image/ directory
1705 of the OpenSPARC T1 project @url{http://download.oracle.com/technetwork/systems/opensparc/OpenSPARCT1_Arch.1.5.tar.bz2}
1706 and is able to boot the disk.s10hw2 Solaris image.
1708 qemu-system-sparc64 -M niagara -L /path-to/S10image/ \
1710 -drive if=pflash,readonly=on,file=/S10image/disk.s10hw2
1714 QEMU emulates the following peripherals:
1718 UltraSparc IIi APB PCI Bridge
1720 PCI VGA compatible card with VESA Bochs Extensions
1722 PS/2 mouse and keyboard
1724 Non Volatile RAM M48T59
1726 PC-compatible serial ports
1728 2 PCI IDE interfaces with hard disk and CD-ROM support
1733 @c man begin OPTIONS
1735 The following options are specific to the Sparc64 emulation:
1739 @item -prom-env @var{string}
1741 Set OpenBIOS variables in NVRAM, for example:
1744 qemu-system-sparc64 -prom-env 'auto-boot?=false'
1747 @item -M [sun4u|sun4v|niagara]
1749 Set the emulated machine type. The default is sun4u.
1755 @node MIPS System emulator
1756 @section MIPS System emulator
1757 @cindex system emulation (MIPS)
1759 Four executables cover simulation of 32 and 64-bit MIPS systems in
1760 both endian options, @file{qemu-system-mips}, @file{qemu-system-mipsel}
1761 @file{qemu-system-mips64} and @file{qemu-system-mips64el}.
1762 Five different machine types are emulated:
1766 A generic ISA PC-like machine "mips"
1768 The MIPS Malta prototype board "malta"
1770 An ACER Pica "pica61". This machine needs the 64-bit emulator.
1772 MIPS emulator pseudo board "mipssim"
1774 A MIPS Magnum R4000 machine "magnum". This machine needs the 64-bit emulator.
1777 The generic emulation is supported by Debian 'Etch' and is able to
1778 install Debian into a virtual disk image. The following devices are
1783 A range of MIPS CPUs, default is the 24Kf
1785 PC style serial port
1792 The Malta emulation supports the following devices:
1796 Core board with MIPS 24Kf CPU and Galileo system controller
1798 PIIX4 PCI/USB/SMbus controller
1800 The Multi-I/O chip's serial device
1802 PCI network cards (PCnet32 and others)
1804 Malta FPGA serial device
1806 Cirrus (default) or any other PCI VGA graphics card
1809 The ACER Pica emulation supports:
1815 PC-style IRQ and DMA controllers
1822 The mipssim pseudo board emulation provides an environment similar
1823 to what the proprietary MIPS emulator uses for running Linux.
1828 A range of MIPS CPUs, default is the 24Kf
1830 PC style serial port
1832 MIPSnet network emulation
1835 The MIPS Magnum R4000 emulation supports:
1841 PC-style IRQ controller
1851 @node ARM System emulator
1852 @section ARM System emulator
1853 @cindex system emulation (ARM)
1855 Use the executable @file{qemu-system-arm} to simulate a ARM
1856 machine. The ARM Integrator/CP board is emulated with the following
1861 ARM926E, ARM1026E, ARM946E, ARM1136 or Cortex-A8 CPU
1865 SMC 91c111 Ethernet adapter
1867 PL110 LCD controller
1869 PL050 KMI with PS/2 keyboard and mouse.
1871 PL181 MultiMedia Card Interface with SD card.
1874 The ARM Versatile baseboard is emulated with the following devices:
1878 ARM926E, ARM1136 or Cortex-A8 CPU
1880 PL190 Vectored Interrupt Controller
1884 SMC 91c111 Ethernet adapter
1886 PL110 LCD controller
1888 PL050 KMI with PS/2 keyboard and mouse.
1890 PCI host bridge. Note the emulated PCI bridge only provides access to
1891 PCI memory space. It does not provide access to PCI IO space.
1892 This means some devices (eg. ne2k_pci NIC) are not usable, and others
1893 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
1894 mapped control registers.
1896 PCI OHCI USB controller.
1898 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
1900 PL181 MultiMedia Card Interface with SD card.
1903 Several variants of the ARM RealView baseboard are emulated,
1904 including the EB, PB-A8 and PBX-A9. Due to interactions with the
1905 bootloader, only certain Linux kernel configurations work out
1906 of the box on these boards.
1908 Kernels for the PB-A8 board should have CONFIG_REALVIEW_HIGH_PHYS_OFFSET
1909 enabled in the kernel, and expect 512M RAM. Kernels for The PBX-A9 board
1910 should have CONFIG_SPARSEMEM enabled, CONFIG_REALVIEW_HIGH_PHYS_OFFSET
1911 disabled and expect 1024M RAM.
1913 The following devices are emulated:
1917 ARM926E, ARM1136, ARM11MPCore, Cortex-A8 or Cortex-A9 MPCore CPU
1919 ARM AMBA Generic/Distributed Interrupt Controller
1923 SMC 91c111 or SMSC LAN9118 Ethernet adapter
1925 PL110 LCD controller
1927 PL050 KMI with PS/2 keyboard and mouse
1931 PCI OHCI USB controller
1933 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
1935 PL181 MultiMedia Card Interface with SD card.
1938 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
1939 and "Terrier") emulation includes the following peripherals:
1943 Intel PXA270 System-on-chip (ARM V5TE core)
1947 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
1949 On-chip OHCI USB controller
1951 On-chip LCD controller
1953 On-chip Real Time Clock
1955 TI ADS7846 touchscreen controller on SSP bus
1957 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
1959 GPIO-connected keyboard controller and LEDs
1961 Secure Digital card connected to PXA MMC/SD host
1965 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
1968 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
1973 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
1975 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
1977 On-chip LCD controller
1979 On-chip Real Time Clock
1981 TI TSC2102i touchscreen controller / analog-digital converter / Audio
1982 CODEC, connected through MicroWire and I@math{^2}S busses
1984 GPIO-connected matrix keypad
1986 Secure Digital card connected to OMAP MMC/SD host
1991 Nokia N800 and N810 internet tablets (known also as RX-34 and RX-44 / 48)
1992 emulation supports the following elements:
1996 Texas Instruments OMAP2420 System-on-chip (ARM 1136 core)
1998 RAM and non-volatile OneNAND Flash memories
2000 Display connected to EPSON remote framebuffer chip and OMAP on-chip
2001 display controller and a LS041y3 MIPI DBI-C controller
2003 TI TSC2301 (in N800) and TI TSC2005 (in N810) touchscreen controllers
2004 driven through SPI bus
2006 National Semiconductor LM8323-controlled qwerty keyboard driven
2007 through I@math{^2}C bus
2009 Secure Digital card connected to OMAP MMC/SD host
2011 Three OMAP on-chip UARTs and on-chip STI debugging console
2013 A Bluetooth(R) transceiver and HCI connected to an UART
2015 Mentor Graphics "Inventra" dual-role USB controller embedded in a TI
2016 TUSB6010 chip - only USB host mode is supported
2018 TI TMP105 temperature sensor driven through I@math{^2}C bus
2020 TI TWL92230C power management companion with an RTC on I@math{^2}C bus
2022 Nokia RETU and TAHVO multi-purpose chips with an RTC, connected
2026 The Luminary Micro Stellaris LM3S811EVB emulation includes the following
2033 64k Flash and 8k SRAM.
2035 Timers, UARTs, ADC and I@math{^2}C interface.
2037 OSRAM Pictiva 96x16 OLED with SSD0303 controller on I@math{^2}C bus.
2040 The Luminary Micro Stellaris LM3S6965EVB emulation includes the following
2047 256k Flash and 64k SRAM.
2049 Timers, UARTs, ADC, I@math{^2}C and SSI interfaces.
2051 OSRAM Pictiva 128x64 OLED with SSD0323 controller connected via SSI.
2054 The Freecom MusicPal internet radio emulation includes the following
2059 Marvell MV88W8618 ARM core.
2061 32 MB RAM, 256 KB SRAM, 8 MB flash.
2065 MV88W8xx8 Ethernet controller
2067 MV88W8618 audio controller, WM8750 CODEC and mixer
2069 128×64 display with brightness control
2071 2 buttons, 2 navigation wheels with button function
2074 The Siemens SX1 models v1 and v2 (default) basic emulation.
2075 The emulation includes the following elements:
2079 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2081 ROM and RAM memories (ROM firmware image can be loaded with -pflash)
2083 1 Flash of 16MB and 1 Flash of 8MB
2087 On-chip LCD controller
2089 On-chip Real Time Clock
2091 Secure Digital card connected to OMAP MMC/SD host
2096 A Linux 2.6 test image is available on the QEMU web site. More
2097 information is available in the QEMU mailing-list archive.
2099 @c man begin OPTIONS
2101 The following options are specific to the ARM emulation:
2106 Enable semihosting syscall emulation.
2108 On ARM this implements the "Angel" interface.
2110 Note that this allows guest direct access to the host filesystem,
2111 so should only be used with trusted guest OS.
2117 @node ColdFire System emulator
2118 @section ColdFire System emulator
2119 @cindex system emulation (ColdFire)
2120 @cindex system emulation (M68K)
2122 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2123 The emulator is able to boot a uClinux kernel.
2125 The M5208EVB emulation includes the following devices:
2129 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2131 Three Two on-chip UARTs.
2133 Fast Ethernet Controller (FEC)
2136 The AN5206 emulation includes the following devices:
2140 MCF5206 ColdFire V2 Microprocessor.
2145 @c man begin OPTIONS
2147 The following options are specific to the ColdFire emulation:
2152 Enable semihosting syscall emulation.
2154 On M68K this implements the "ColdFire GDB" interface used by libgloss.
2156 Note that this allows guest direct access to the host filesystem,
2157 so should only be used with trusted guest OS.
2163 @node Cris System emulator
2164 @section Cris System emulator
2165 @cindex system emulation (Cris)
2169 @node Microblaze System emulator
2170 @section Microblaze System emulator
2171 @cindex system emulation (Microblaze)
2175 @node SH4 System emulator
2176 @section SH4 System emulator
2177 @cindex system emulation (SH4)
2181 @node Xtensa System emulator
2182 @section Xtensa System emulator
2183 @cindex system emulation (Xtensa)
2185 Two executables cover simulation of both Xtensa endian options,
2186 @file{qemu-system-xtensa} and @file{qemu-system-xtensaeb}.
2187 Two different machine types are emulated:
2191 Xtensa emulator pseudo board "sim"
2193 Avnet LX60/LX110/LX200 board
2196 The sim pseudo board emulation provides an environment similar
2197 to one provided by the proprietary Tensilica ISS.
2202 A range of Xtensa CPUs, default is the DC232B
2204 Console and filesystem access via semihosting calls
2207 The Avnet LX60/LX110/LX200 emulation supports:
2211 A range of Xtensa CPUs, default is the DC232B
2215 OpenCores 10/100 Mbps Ethernet MAC
2218 @c man begin OPTIONS
2220 The following options are specific to the Xtensa emulation:
2225 Enable semihosting syscall emulation.
2227 Xtensa semihosting provides basic file IO calls, such as open/read/write/seek/select.
2228 Tensilica baremetal libc for ISS and linux platform "sim" use this interface.
2230 Note that this allows guest direct access to the host filesystem,
2231 so should only be used with trusted guest OS.
2237 @node QEMU Guest Agent
2238 @chapter QEMU Guest Agent invocation
2240 @include qemu-ga.texi
2242 @node QEMU User space emulator
2243 @chapter QEMU User space emulator
2246 * Supported Operating Systems ::
2248 * Linux User space emulator::
2249 * BSD User space emulator ::
2252 @node Supported Operating Systems
2253 @section Supported Operating Systems
2255 The following OS are supported in user space emulation:
2259 Linux (referred as qemu-linux-user)
2261 BSD (referred as qemu-bsd-user)
2267 QEMU user space emulation has the following notable features:
2270 @item System call translation:
2271 QEMU includes a generic system call translator. This means that
2272 the parameters of the system calls can be converted to fix
2273 endianness and 32/64-bit mismatches between hosts and targets.
2274 IOCTLs can be converted too.
2276 @item POSIX signal handling:
2277 QEMU can redirect to the running program all signals coming from
2278 the host (such as @code{SIGALRM}), as well as synthesize signals from
2279 virtual CPU exceptions (for example @code{SIGFPE} when the program
2280 executes a division by zero).
2282 QEMU relies on the host kernel to emulate most signal system
2283 calls, for example to emulate the signal mask. On Linux, QEMU
2284 supports both normal and real-time signals.
2287 On Linux, QEMU can emulate the @code{clone} syscall and create a real
2288 host thread (with a separate virtual CPU) for each emulated thread.
2289 Note that not all targets currently emulate atomic operations correctly.
2290 x86 and ARM use a global lock in order to preserve their semantics.
2293 QEMU was conceived so that ultimately it can emulate itself. Although
2294 it is not very useful, it is an important test to show the power of the
2297 @node Linux User space emulator
2298 @section Linux User space emulator
2303 * Command line options::
2308 @subsection Quick Start
2310 In order to launch a Linux process, QEMU needs the process executable
2311 itself and all the target (x86) dynamic libraries used by it.
2315 @item On x86, you can just try to launch any process by using the native
2319 qemu-i386 -L / /bin/ls
2322 @code{-L /} tells that the x86 dynamic linker must be searched with a
2325 @item Since QEMU is also a linux process, you can launch QEMU with
2326 QEMU (NOTE: you can only do that if you compiled QEMU from the sources):
2329 qemu-i386 -L / qemu-i386 -L / /bin/ls
2332 @item On non x86 CPUs, you need first to download at least an x86 glibc
2333 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2334 @code{LD_LIBRARY_PATH} is not set:
2337 unset LD_LIBRARY_PATH
2340 Then you can launch the precompiled @file{ls} x86 executable:
2343 qemu-i386 tests/i386/ls
2345 You can look at @file{scripts/qemu-binfmt-conf.sh} so that
2346 QEMU is automatically launched by the Linux kernel when you try to
2347 launch x86 executables. It requires the @code{binfmt_misc} module in the
2350 @item The x86 version of QEMU is also included. You can try weird things such as:
2352 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2353 /usr/local/qemu-i386/bin/ls-i386
2359 @subsection Wine launch
2363 @item Ensure that you have a working QEMU with the x86 glibc
2364 distribution (see previous section). In order to verify it, you must be
2368 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2371 @item Download the binary x86 Wine install
2372 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2374 @item Configure Wine on your account. Look at the provided script
2375 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2376 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2378 @item Then you can try the example @file{putty.exe}:
2381 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2382 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2387 @node Command line options
2388 @subsection Command line options
2391 @command{qemu-i386} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-cpu} @var{model}] [@option{-g} @var{port}] [@option{-B} @var{offset}] [@option{-R} @var{size}] @var{program} [@var{arguments}...]
2398 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2400 Set the x86 stack size in bytes (default=524288)
2402 Select CPU model (-cpu help for list and additional feature selection)
2403 @item -E @var{var}=@var{value}
2404 Set environment @var{var} to @var{value}.
2406 Remove @var{var} from the environment.
2408 Offset guest address by the specified number of bytes. This is useful when
2409 the address region required by guest applications is reserved on the host.
2410 This option is currently only supported on some hosts.
2412 Pre-allocate a guest virtual address space of the given size (in bytes).
2413 "G", "M", and "k" suffixes may be used when specifying the size.
2420 Activate logging of the specified items (use '-d help' for a list of log items)
2422 Act as if the host page size was 'pagesize' bytes
2424 Wait gdb connection to port
2426 Run the emulation in single step mode.
2429 Environment variables:
2433 Print system calls and arguments similar to the 'strace' program
2434 (NOTE: the actual 'strace' program will not work because the user
2435 space emulator hasn't implemented ptrace). At the moment this is
2436 incomplete. All system calls that don't have a specific argument
2437 format are printed with information for six arguments. Many
2438 flag-style arguments don't have decoders and will show up as numbers.
2441 @node Other binaries
2442 @subsection Other binaries
2444 @cindex user mode (Alpha)
2445 @command{qemu-alpha} TODO.
2447 @cindex user mode (ARM)
2448 @command{qemu-armeb} TODO.
2450 @cindex user mode (ARM)
2451 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2452 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2453 configurations), and arm-uclinux bFLT format binaries.
2455 @cindex user mode (ColdFire)
2456 @cindex user mode (M68K)
2457 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2458 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2459 coldfire uClinux bFLT format binaries.
2461 The binary format is detected automatically.
2463 @cindex user mode (Cris)
2464 @command{qemu-cris} TODO.
2466 @cindex user mode (i386)
2467 @command{qemu-i386} TODO.
2468 @command{qemu-x86_64} TODO.
2470 @cindex user mode (Microblaze)
2471 @command{qemu-microblaze} TODO.
2473 @cindex user mode (MIPS)
2474 @command{qemu-mips} TODO.
2475 @command{qemu-mipsel} TODO.
2477 @cindex user mode (NiosII)
2478 @command{qemu-nios2} TODO.
2480 @cindex user mode (PowerPC)
2481 @command{qemu-ppc64abi32} TODO.
2482 @command{qemu-ppc64} TODO.
2483 @command{qemu-ppc} TODO.
2485 @cindex user mode (SH4)
2486 @command{qemu-sh4eb} TODO.
2487 @command{qemu-sh4} TODO.
2489 @cindex user mode (SPARC)
2490 @command{qemu-sparc} can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
2492 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2493 (Sparc64 CPU, 32 bit ABI).
2495 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2496 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2498 @node BSD User space emulator
2499 @section BSD User space emulator
2504 * BSD Command line options::
2508 @subsection BSD Status
2512 target Sparc64 on Sparc64: Some trivial programs work.
2515 @node BSD Quick Start
2516 @subsection Quick Start
2518 In order to launch a BSD process, QEMU needs the process executable
2519 itself and all the target dynamic libraries used by it.
2523 @item On Sparc64, you can just try to launch any process by using the native
2527 qemu-sparc64 /bin/ls
2532 @node BSD Command line options
2533 @subsection Command line options
2536 @command{qemu-sparc64} [@option{-h]} [@option{-d]} [@option{-L} @var{path}] [@option{-s} @var{size}] [@option{-bsd} @var{type}] @var{program} [@var{arguments}...]
2543 Set the library root path (default=/)
2545 Set the stack size in bytes (default=524288)
2546 @item -ignore-environment
2547 Start with an empty environment. Without this option,
2548 the initial environment is a copy of the caller's environment.
2549 @item -E @var{var}=@var{value}
2550 Set environment @var{var} to @var{value}.
2552 Remove @var{var} from the environment.
2554 Set the type of the emulated BSD Operating system. Valid values are
2555 FreeBSD, NetBSD and OpenBSD (default).
2562 Activate logging of the specified items (use '-d help' for a list of log items)
2564 Act as if the host page size was 'pagesize' bytes
2566 Run the emulation in single step mode.
2570 @include qemu-tech.texi
2572 @node Deprecated features
2573 @appendix Deprecated features
2575 In general features are intended to be supported indefinitely once
2576 introduced into QEMU. In the event that a feature needs to be removed,
2577 it will be listed in this appendix. The feature will remain functional
2578 for 2 releases prior to actual removal. Deprecated features may also
2579 generate warnings on the console when QEMU starts up, or if activated
2580 via a monitor command, however, this is not a mandatory requirement.
2582 Prior to the 2.10.0 release there was no official policy on how
2583 long features would be deprecated prior to their removal, nor
2584 any documented list of which features were deprecated. Thus
2585 any features deprecated prior to 2.10.0 will be treated as if
2586 they were first deprecated in the 2.10.0 release.
2588 What follows is a list of all features currently marked as
2591 @section Build options
2595 Previously QEMU has supported building against both GTK 2.x
2596 and 3.x series APIs. Support for the GTK 2.x builds will be
2597 discontinued, so maintainers should switch to using GTK 3.x,
2598 which is the default.
2602 Previously QEMU has supported building against both SDL 1.2
2603 and 2.0 series APIs. Support for the SDL 1.2 builds will be
2604 discontinued, so maintainers should switch to using SDL 2.0,
2605 which is the default.
2607 @section System emulator command line arguments
2609 @subsection -tdf (since 1.3.0)
2611 The ``-tdf'' argument is ignored. The behaviour implemented
2612 by this argument is now the default when using the KVM PIT,
2613 but can be requested explicitly using
2614 ``-global kvm-pit.lost_tick_policy=slew''.
2616 @subsection -no-kvm-pit-reinjection (since 1.3.0)
2618 The ``-no-kvm-pit-reinjection'' argument is now a
2619 synonym for setting ``-global kvm-pit.lost_tick_policy=discard''.
2621 @subsection -no-kvm-irqchip (since 1.3.0)
2623 The ``-no-kvm-irqchip'' argument is now a synonym for
2624 setting ``-machine kernel_irqchip=off''.
2626 @subsection -no-kvm (since 1.3.0)
2628 The ``-no-kvm'' argument is now a synonym for setting
2629 ``-machine accel=tcg''.
2631 @subsection -mon default=on (since 2.4.0)
2633 The ``default'' option to the ``-mon'' argument is
2634 now ignored. When multiple monitors were enabled, it
2635 indicated which monitor would receive log messages
2636 from the various subsystems. This feature is no longer
2637 required as messages are now only sent to the monitor
2638 in response to explicitly monitor commands.
2640 @subsection -vnc tls (since 2.5.0)
2642 The ``-vnc tls'' argument is now a synonym for setting
2643 ``-object tls-creds-anon,id=tls0'' combined with
2644 ``-vnc tls-creds=tls0'
2646 @subsection -vnc x509 (since 2.5.0)
2648 The ``-vnc x509=/path/to/certs'' argument is now a
2650 ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=no''
2651 combined with ``-vnc tls-creds=tls0'
2653 @subsection -vnc x509verify (since 2.5.0)
2655 The ``-vnc x509verify=/path/to/certs'' argument is now a
2657 ``-object tls-creds-x509,dir=/path/to/certs,id=tls0,verify-peer=yes''
2658 combined with ``-vnc tls-creds=tls0'
2660 @subsection -tftp (since 2.6.0)
2662 The ``-tftp /some/dir'' argument is replaced by
2663 ``-netdev user,id=x,tftp=/some/dir'', either accompanied with
2664 ``-device ...,netdev=x'' (for pluggable NICs) or ``-net nic,netdev=x''
2665 (for embedded NICs). The new syntax allows different settings to be
2668 @subsection -bootp (since 2.6.0)
2670 The ``-bootp /some/file'' argument is replaced by
2671 ``-netdev user,id=x,bootp=/some/file'', either accompanied with
2672 ``-device ...,netdev=x'' (for pluggable NICs) or ``-net nic,netdev=x''
2673 (for embedded NICs). The new syntax allows different settings to be
2676 @subsection -redir (since 2.6.0)
2678 The ``-redir [tcp|udp]:hostport:[guestaddr]:guestport'' argument is
2679 replaced by ``-netdev
2680 user,id=x,hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport'',
2681 either accompanied with ``-device ...,netdev=x'' (for pluggable NICs) or
2682 ``-net nic,netdev=x'' (for embedded NICs). The new syntax allows different
2683 settings to be provided per NIC.
2685 @subsection -smb (since 2.6.0)
2687 The ``-smb /some/dir'' argument is replaced by
2688 ``-netdev user,id=x,smb=/some/dir'', either accompanied with
2689 ``-device ...,netdev=x'' (for pluggable NICs) or ``-net nic,netdev=x''
2690 (for embedded NICs). The new syntax allows different settings to be
2693 @subsection -net vlan (since 2.9.0)
2695 The ``-net vlan=NN'' argument is partially replaced with the
2696 new ``-netdev'' argument. The remaining use cases will no
2697 longer be directly supported in QEMU.
2699 @subsection -drive if=scsi (since 2.9.0)
2701 The ``-drive if=scsi'' argument is replaced by the the
2702 ``-device BUS-TYPE'' argument combined with ``-drive if=none''.
2704 @subsection -drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
2706 The drive geometry arguments are replaced by the the geometry arguments
2707 that can be specified with the ``-device'' parameter.
2709 @subsection -drive serial=... (since 2.10.0)
2711 The drive serial argument is replaced by the the serial argument
2712 that can be specified with the ``-device'' parameter.
2714 @subsection -drive addr=... (since 2.10.0)
2716 The drive addr argument is replaced by the the addr argument
2717 that can be specified with the ``-device'' parameter.
2719 @subsection -net dump (since 2.10.0)
2721 The ``--net dump'' argument is now replaced with the
2722 ``-object filter-dump'' argument which works in combination
2723 with the modern ``-netdev`` backends instead.
2725 @subsection -usbdevice (since 2.10.0)
2727 The ``-usbdevice DEV'' argument is now a synonym for setting
2728 the ``-device usb-DEV'' argument instead. The deprecated syntax
2729 would automatically enable USB support on the machine type.
2730 If using the new syntax, USB support must be explicitly
2731 enabled via the ``-machine usb=on'' argument.
2733 @subsection -nodefconfig (since 2.11.0)
2735 The ``-nodefconfig`` argument is a synonym for ``-no-user-config``.
2737 @subsection -machine s390-squash-mcss=on|off (since 2.12.0)
2739 The ``s390-squash-mcss=on`` property has been obsoleted by allowing the
2740 cssid to be chosen freely. Instead of squashing subchannels into the
2741 default channel subsystem image for guests that do not support multiple
2742 channel subsystems, all devices can be put into the default channel
2745 @subsection -fsdev handle (since 2.12.0)
2747 The ``handle'' fsdev backend does not support symlinks and causes the 9p
2748 filesystem in the guest to fail a fair amount of tests from the PJD POSIX
2749 filesystem test suite. Also it requires the CAP_DAC_READ_SEARCH capability,
2750 which is not the recommended way to run QEMU. This backend should not be
2751 used and it will be removed with no replacement.
2753 @section qemu-img command line arguments
2755 @subsection convert -s (since 2.0.0)
2757 The ``convert -s snapshot_id_or_name'' argument is obsoleted
2758 by the ``convert -l snapshot_param'' argument instead.
2760 @section QEMU Machine Protocol (QMP) commands
2762 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)
2764 "autoload" parameter is now ignored. All bitmaps are automatically loaded
2767 @section System emulator human monitor commands
2769 @subsection host_net_add (since 2.10.0)
2771 The ``host_net_add'' command is replaced by the ``netdev_add'' command.
2773 @subsection host_net_remove (since 2.10.0)
2775 The ``host_net_remove'' command is replaced by the ``netdev_del'' command.
2777 @section System emulator devices
2779 @subsection ivshmem (since 2.6.0)
2781 The ``ivshmem'' device type is replaced by either the ``ivshmem-plain''
2782 or ``ivshmem-doorbell`` device types.
2784 @subsection Page size support < 4k for embedded PowerPC CPUs (since 2.12.0)
2786 qemu-system-ppcemb will be removed. qemu-system-ppc (or qemu-system-ppc64)
2787 should be used instead. That means that embedded 4xx PowerPC CPUs will not
2788 support page sizes < 4096 any longer.
2790 @section System emulator machines
2792 @subsection Xilinx EP108 (since 2.11.0)
2794 The ``xlnx-ep108'' machine has been replaced by the ``xlnx-zcu102'' machine.
2795 The ``xlnx-zcu102'' machine has the same features and capabilites in QEMU.
2800 QEMU is a trademark of Fabrice Bellard.
2802 QEMU is released under the
2803 @url{https://www.gnu.org/licenses/gpl-2.0.txt,GNU General Public License},
2804 version 2. Parts of QEMU have specific licenses, see file
2805 @url{https://git.qemu.org/?p=qemu.git;a=blob_plain;f=LICENSE,LICENSE}.
2819 @section Concept Index
2820 This is the main index. Should we combine all keywords in one index? TODO
2823 @node Function Index
2824 @section Function Index
2825 This index could be used for command line options and monitor functions.
2828 @node Keystroke Index
2829 @section Keystroke Index
2831 This is a list of all keystrokes which have a special function
2832 in system emulation.
2837 @section Program Index
2840 @node Data Type Index
2841 @section Data Type Index
2843 This index could be used for qdev device names and options.
2847 @node Variable Index
2848 @section Variable Index