1 \input texinfo @c -*- texinfo -*-
3 @setfilename qemu-doc.info
4 @settitle QEMU Emulator User Documentation
12 @center @titlefont{QEMU Emulator}
14 @center @titlefont{User Documentation}
26 * QEMU PC System emulator::
27 * QEMU System emulator for non PC targets::
28 * QEMU User space emulator::
29 * compilation:: Compilation from the sources
40 * intro_features:: Features
46 QEMU is a FAST! processor emulator using dynamic translation to
47 achieve good emulation speed.
49 QEMU has two operating modes:
54 Full system emulation. In this mode, QEMU emulates a full system (for
55 example a PC), including one or several processors and various
56 peripherals. It can be used to launch different Operating Systems
57 without rebooting the PC or to debug system code.
60 User mode emulation. In this mode, QEMU can launch
61 processes compiled for one CPU on another CPU. It can be used to
62 launch the Wine Windows API emulator (@url{http://www.winehq.org}) or
63 to ease cross-compilation and cross-debugging.
67 QEMU can run without an host kernel driver and yet gives acceptable
70 For system emulation, the following hardware targets are supported:
72 @item PC (x86 or x86_64 processor)
73 @item ISA PC (old style PC without PCI bus)
74 @item PREP (PowerPC processor)
75 @item G3 BW PowerMac (PowerPC processor)
76 @item Mac99 PowerMac (PowerPC processor, in progress)
77 @item Sun4m (32-bit Sparc processor)
78 @item Sun4u (64-bit Sparc processor, in progress)
79 @item Malta board (32-bit MIPS processor)
80 @item ARM Integrator/CP (ARM926E, 1026E or 946E processor)
81 @item ARM Versatile baseboard (ARM926E)
82 @item ARM RealView Emulation baseboard (ARM926EJ-S)
83 @item Spitz, Akita, Borzoi and Terrier PDAs (PXA270 processor)
84 @item Freescale MCF5208EVB (ColdFire V2).
85 @item Arnewsh MCF5206 evaluation board (ColdFire V2).
88 For user emulation, x86, PowerPC, ARM, MIPS, Sparc32/64 and ColdFire(m68k) CPUs are supported.
93 If you want to compile QEMU yourself, see @ref{compilation}.
96 * install_linux:: Linux
97 * install_windows:: Windows
98 * install_mac:: Macintosh
104 If a precompiled package is available for your distribution - you just
105 have to install it. Otherwise, see @ref{compilation}.
107 @node install_windows
110 Download the experimental binary installer at
111 @url{http://www.free.oszoo.org/@/download.html}.
116 Download the experimental binary installer at
117 @url{http://www.free.oszoo.org/@/download.html}.
119 @node QEMU PC System emulator
120 @chapter QEMU PC System emulator
123 * pcsys_introduction:: Introduction
124 * pcsys_quickstart:: Quick Start
125 * sec_invocation:: Invocation
127 * pcsys_monitor:: QEMU Monitor
128 * disk_images:: Disk Images
129 * pcsys_network:: Network emulation
130 * direct_linux_boot:: Direct Linux Boot
131 * pcsys_usb:: USB emulation
132 * vnc_security:: VNC security
133 * gdb_usage:: GDB usage
134 * pcsys_os_specific:: Target OS specific information
137 @node pcsys_introduction
138 @section Introduction
140 @c man begin DESCRIPTION
142 The QEMU PC System emulator simulates the
143 following peripherals:
147 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
149 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
150 extensions (hardware level, including all non standard modes).
152 PS/2 mouse and keyboard
154 2 PCI IDE interfaces with hard disk and CD-ROM support
158 PCI/ISA PCI network adapters
162 Creative SoundBlaster 16 sound card
164 ENSONIQ AudioPCI ES1370 sound card
166 Adlib(OPL2) - Yamaha YM3812 compatible chip
168 PCI UHCI USB controller and a virtual USB hub.
171 SMP is supported with up to 255 CPUs.
173 Note that adlib is only available when QEMU was configured with
176 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
179 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
183 @node pcsys_quickstart
186 Download and uncompress the linux image (@file{linux.img}) and type:
192 Linux should boot and give you a prompt.
198 @c man begin SYNOPSIS
199 usage: qemu [options] [disk_image]
204 @var{disk_image} is a raw hard disk image for IDE hard disk 0.
209 Select the emulated machine (@code{-M ?} for list)
213 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). You can
214 use the host floppy by using @file{/dev/fd0} as filename (@pxref{host_drives}).
220 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
223 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
224 @option{-cdrom} at the same time). You can use the host CD-ROM by
225 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
227 @item -boot [a|c|d|n]
228 Boot on floppy (a), hard disk (c), CD-ROM (d), or Etherboot (n). Hard disk boot
232 Write to temporary files instead of disk image files. In this case,
233 the raw disk image you use is not written back. You can however force
234 the write back by pressing @key{C-a s} (@pxref{disk_images}).
237 Disable boot signature checking for floppy disks in Bochs BIOS. It may
238 be needed to boot from old floppy disks.
241 Set virtual RAM size to @var{megs} megabytes. Default is 128 MB.
244 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
245 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
250 Will show the audio subsystem help: list of drivers, tunable
253 @item -soundhw card1,card2,... or -soundhw all
255 Enable audio and selected sound hardware. Use ? to print all
256 available sound hardware.
259 qemu -soundhw sb16,adlib hda
260 qemu -soundhw es1370 hda
261 qemu -soundhw all hda
266 Set the real time clock to local time (the default is to UTC
267 time). This option is needed to have correct date in MS-DOS or
271 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
275 Daemonize the QEMU process after initialization. QEMU will not detach from
276 standard IO until it is ready to receive connections on any of its devices.
277 This option is a useful way for external programs to launch QEMU without having
278 to cope with initialization race conditions.
281 Use it when installing Windows 2000 to avoid a disk full bug. After
282 Windows 2000 is installed, you no longer need this option (this option
283 slows down the IDE transfers).
285 @item -option-rom file
286 Load the contents of file as an option ROM. This option is useful to load
287 things like EtherBoot.
290 Sets the name of the guest. This name will be display in the SDL window
291 caption. The name will also be used for the VNC server.
300 Normally, QEMU uses SDL to display the VGA output. With this option,
301 you can totally disable graphical output so that QEMU is a simple
302 command line application. The emulated serial port is redirected on
303 the console. Therefore, you can still use QEMU to debug a Linux kernel
304 with a serial console.
308 Do not use decorations for SDL windows and start them using the whole
309 available screen space. This makes the using QEMU in a dedicated desktop
310 workspace more convenient.
313 Start in full screen.
315 @item -vnc display[,option[,option[,...]]]
317 Normally, QEMU uses SDL to display the VGA output. With this option,
318 you can have QEMU listen on VNC display @var{display} and redirect the VGA
319 display over the VNC session. It is very useful to enable the usb
320 tablet device when using this option (option @option{-usbdevice
321 tablet}). When using the VNC display, you must use the @option{-k}
322 parameter to set the keyboard layout if you are not using en-us. Valid
323 syntax for the @var{display} is
327 @item @var{interface:d}
329 TCP connections will only be allowed from @var{interface} on display @var{d}.
330 By convention the TCP port is 5900+@var{d}. Optionally, @var{interface} can
331 be omitted in which case the server will bind to all interfaces.
333 @item @var{unix:path}
335 Connections will be allowed over UNIX domain sockets where @var{path} is the
336 location of a unix socket to listen for connections on.
340 VNC is initialized by not started. The monitor @code{change} command can be used
341 to later start the VNC server.
345 Following the @var{display} value there may be one or more @var{option} flags
346 separated by commas. Valid options are
352 Require that password based authentication is used for client connections.
353 The password must be set separately using the @code{change} command in the
358 Require that client use TLS when communicating with the VNC server. This
359 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
360 attack. It is recommended that this option be combined with either the
361 @var{x509} or @var{x509verify} options.
363 @item @var{x509=/path/to/certificate/dir}
365 Valid if @var{tls} is specified. Require that x509 credentials are used
366 for negotiating the TLS session. The server will send its x509 certificate
367 to the client. It is recommended that a password be set on the VNC server
368 to provide authentication of the client when this is used. The path following
369 this option specifies where the x509 certificates are to be loaded from.
370 See the @ref{vnc_security} section for details on generating certificates.
372 @item @var{x509verify=/path/to/certificate/dir}
374 Valid if @var{tls} is specified. Require that x509 credentials are used
375 for negotiating the TLS session. The server will send its x509 certificate
376 to the client, and request that the client send its own x509 certificate.
377 The server will validate the client's certificate against the CA certificate,
378 and reject clients when validation fails. If the certificate authority is
379 trusted, this is a sufficient authentication mechanism. You may still wish
380 to set a password on the VNC server as a second authentication layer. The
381 path following this option specifies where the x509 certificates are to
382 be loaded from. See the @ref{vnc_security} section for details on generating
389 Use keyboard layout @var{language} (for example @code{fr} for
390 French). This option is only needed where it is not easy to get raw PC
391 keycodes (e.g. on Macs, with some X11 servers or with a VNC
392 display). You don't normally need to use it on PC/Linux or PC/Windows
395 The available layouts are:
397 ar de-ch es fo fr-ca hu ja mk no pt-br sv
398 da en-gb et fr fr-ch is lt nl pl ru th
399 de en-us fi fr-be hr it lv nl-be pt sl tr
402 The default is @code{en-us}.
410 Enable the USB driver (will be the default soon)
412 @item -usbdevice devname
413 Add the USB device @var{devname}. @xref{usb_devices}.
420 @item -net nic[,vlan=n][,macaddr=addr][,model=type]
421 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
422 = 0 is the default). The NIC is an ne2k_pci by default on the PC
423 target. Optionally, the MAC address can be changed. If no
424 @option{-net} option is specified, a single NIC is created.
425 Qemu can emulate several different models of network card.
426 Valid values for @var{type} are
427 @code{i82551}, @code{i82557b}, @code{i82559er},
428 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
429 @code{smc91c111}, @code{lance} and @code{mcf_fec}.
430 Not all devices are supported on all targets. Use -net nic,model=?
431 for a list of available devices for your target.
433 @item -net user[,vlan=n][,hostname=name]
434 Use the user mode network stack which requires no administrator
435 privilege to run. @option{hostname=name} can be used to specify the client
436 hostname reported by the builtin DHCP server.
438 @item -net tap[,vlan=n][,fd=h][,ifname=name][,script=file]
439 Connect the host TAP network interface @var{name} to VLAN @var{n} and
440 use the network script @var{file} to configure it. The default
441 network script is @file{/etc/qemu-ifup}. Use @option{script=no} to
442 disable script execution. If @var{name} is not
443 provided, the OS automatically provides one. @option{fd=h} can be
444 used to specify the handle of an already opened host TAP interface. Example:
447 qemu linux.img -net nic -net tap
450 More complicated example (two NICs, each one connected to a TAP device)
452 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
453 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
457 @item -net socket[,vlan=n][,fd=h][,listen=[host]:port][,connect=host:port]
459 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
460 machine using a TCP socket connection. If @option{listen} is
461 specified, QEMU waits for incoming connections on @var{port}
462 (@var{host} is optional). @option{connect} is used to connect to
463 another QEMU instance using the @option{listen} option. @option{fd=h}
464 specifies an already opened TCP socket.
468 # launch a first QEMU instance
469 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
470 -net socket,listen=:1234
471 # connect the VLAN 0 of this instance to the VLAN 0
472 # of the first instance
473 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
474 -net socket,connect=127.0.0.1:1234
477 @item -net socket[,vlan=n][,fd=h][,mcast=maddr:port]
479 Create a VLAN @var{n} shared with another QEMU virtual
480 machines using a UDP multicast socket, effectively making a bus for
481 every QEMU with same multicast address @var{maddr} and @var{port}.
485 Several QEMU can be running on different hosts and share same bus (assuming
486 correct multicast setup for these hosts).
488 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
489 @url{http://user-mode-linux.sf.net}.
491 Use @option{fd=h} to specify an already opened UDP multicast socket.
496 # launch one QEMU instance
497 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
498 -net socket,mcast=230.0.0.1:1234
499 # launch another QEMU instance on same "bus"
500 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
501 -net socket,mcast=230.0.0.1:1234
502 # launch yet another QEMU instance on same "bus"
503 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
504 -net socket,mcast=230.0.0.1:1234
507 Example (User Mode Linux compat.):
509 # launch QEMU instance (note mcast address selected
511 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
512 -net socket,mcast=239.192.168.1:1102
514 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
518 Indicate that no network devices should be configured. It is used to
519 override the default configuration (@option{-net nic -net user}) which
520 is activated if no @option{-net} options are provided.
523 When using the user mode network stack, activate a built-in TFTP
524 server. The files in @var{dir} will be exposed as the root of a TFTP server.
525 The TFTP client on the guest must be configured in binary mode (use the command
526 @code{bin} of the Unix TFTP client). The host IP address on the guest is as
530 When using the user mode network stack, broadcast @var{file} as the BOOTP
531 filename. In conjunction with @option{-tftp}, this can be used to network boot
532 a guest from a local directory.
534 Example (using pxelinux):
536 qemu -hda linux.img -boot n -tftp /path/to/tftp/files -bootp /pxelinux.0
540 When using the user mode network stack, activate a built-in SMB
541 server so that Windows OSes can access to the host files in @file{dir}
544 In the guest Windows OS, the line:
548 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
549 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
551 Then @file{dir} can be accessed in @file{\\smbserver\qemu}.
553 Note that a SAMBA server must be installed on the host OS in
554 @file{/usr/sbin/smbd}. QEMU was tested successfully with smbd version
555 2.2.7a from the Red Hat 9 and version 3.0.10-1.fc3 from Fedora Core 3.
557 @item -redir [tcp|udp]:host-port:[guest-host]:guest-port
559 When using the user mode network stack, redirect incoming TCP or UDP
560 connections to the host port @var{host-port} to the guest
561 @var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
562 is not specified, its value is 10.0.2.15 (default address given by the
563 built-in DHCP server).
565 For example, to redirect host X11 connection from screen 1 to guest
566 screen 0, use the following:
570 qemu -redir tcp:6001::6000 [...]
571 # this host xterm should open in the guest X11 server
575 To redirect telnet connections from host port 5555 to telnet port on
576 the guest, use the following:
580 qemu -redir tcp:5555::23 [...]
581 telnet localhost 5555
584 Then when you use on the host @code{telnet localhost 5555}, you
585 connect to the guest telnet server.
589 Linux boot specific: When using these options, you can use a given
590 Linux kernel without installing it in the disk image. It can be useful
591 for easier testing of various kernels.
595 @item -kernel bzImage
596 Use @var{bzImage} as kernel image.
598 @item -append cmdline
599 Use @var{cmdline} as kernel command line
602 Use @var{file} as initial ram disk.
606 Debug/Expert options:
610 Redirect the virtual serial port to host character device
611 @var{dev}. The default device is @code{vc} in graphical mode and
612 @code{stdio} in non graphical mode.
614 This option can be used several times to simulate up to 4 serials
617 Use @code{-serial none} to disable all serial ports.
619 Available character devices are:
622 Virtual console. Optionally, a width and height can be given in pixel with
626 It is also possible to specify width or height in characters:
631 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
633 No device is allocated.
637 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
638 parameters are set according to the emulated ones.
640 [Linux only, parallel port only] Use host parallel port
641 @var{N}. Currently SPP and EPP parallel port features can be used.
643 Write output to filename. No character can be read.
645 [Unix only] standard input/output
647 name pipe @var{filename}
649 [Windows only] Use host serial port @var{n}
650 @item udp:[remote_host]:remote_port[@@[src_ip]:src_port]
651 This implements UDP Net Console. When @var{remote_host} or @var{src_ip} are not specified they default to @code{0.0.0.0}. When not using a specified @var{src_port} a random port is automatically chosen.
653 If you just want a simple readonly console you can use @code{netcat} or
654 @code{nc}, by starting qemu with: @code{-serial udp::4555} and nc as:
655 @code{nc -u -l -p 4555}. Any time qemu writes something to that port it
656 will appear in the netconsole session.
658 If you plan to send characters back via netconsole or you want to stop
659 and start qemu a lot of times, you should have qemu use the same
660 source port each time by using something like @code{-serial
661 udp::4555@@:4556} to qemu. Another approach is to use a patched
662 version of netcat which can listen to a TCP port and send and receive
663 characters via udp. If you have a patched version of netcat which
664 activates telnet remote echo and single char transfer, then you can
665 use the following options to step up a netcat redirector to allow
666 telnet on port 5555 to access the qemu port.
669 -serial udp::4555@@:4556
670 @item netcat options:
671 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
672 @item telnet options:
677 @item tcp:[host]:port[,server][,nowait][,nodelay]
678 The TCP Net Console has two modes of operation. It can send the serial
679 I/O to a location or wait for a connection from a location. By default
680 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
681 the @var{server} option QEMU will wait for a client socket application
682 to connect to the port before continuing, unless the @code{nowait}
683 option was specified. The @code{nodelay} option disables the Nagle buffering
684 algorithm. If @var{host} is omitted, 0.0.0.0 is assumed. Only
685 one TCP connection at a time is accepted. You can use @code{telnet} to
686 connect to the corresponding character device.
688 @item Example to send tcp console to 192.168.0.2 port 4444
689 -serial tcp:192.168.0.2:4444
690 @item Example to listen and wait on port 4444 for connection
691 -serial tcp::4444,server
692 @item Example to not wait and listen on ip 192.168.0.100 port 4444
693 -serial tcp:192.168.0.100:4444,server,nowait
696 @item telnet:host:port[,server][,nowait][,nodelay]
697 The telnet protocol is used instead of raw tcp sockets. The options
698 work the same as if you had specified @code{-serial tcp}. The
699 difference is that the port acts like a telnet server or client using
700 telnet option negotiation. This will also allow you to send the
701 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
702 sequence. Typically in unix telnet you do it with Control-] and then
703 type "send break" followed by pressing the enter key.
705 @item unix:path[,server][,nowait]
706 A unix domain socket is used instead of a tcp socket. The option works the
707 same as if you had specified @code{-serial tcp} except the unix domain socket
708 @var{path} is used for connections.
711 This is a special option to allow the monitor to be multiplexed onto
712 another serial port. The monitor is accessed with key sequence of
713 @key{Control-a} and then pressing @key{c}. See monitor access
714 @ref{pcsys_keys} in the -nographic section for more keys.
715 @var{dev_string} should be any one of the serial devices specified
716 above. An example to multiplex the monitor onto a telnet server
717 listening on port 4444 would be:
719 @item -serial mon:telnet::4444,server,nowait
725 Redirect the virtual parallel port to host device @var{dev} (same
726 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
727 be used to use hardware devices connected on the corresponding host
730 This option can be used several times to simulate up to 3 parallel
733 Use @code{-parallel none} to disable all parallel ports.
736 Redirect the monitor to host device @var{dev} (same devices as the
738 The default device is @code{vc} in graphical mode and @code{stdio} in
741 @item -echr numeric_ascii_value
742 Change the escape character used for switching to the monitor when using
743 monitor and serial sharing. The default is @code{0x01} when using the
744 @code{-nographic} option. @code{0x01} is equal to pressing
745 @code{Control-a}. You can select a different character from the ascii
746 control keys where 1 through 26 map to Control-a through Control-z. For
747 instance you could use the either of the following to change the escape
748 character to Control-t.
755 Wait gdb connection to port 1234 (@pxref{gdb_usage}).
757 Change gdb connection port. @var{port} can be either a decimal number
758 to specify a TCP port, or a host device (same devices as the serial port).
760 Do not start CPU at startup (you must type 'c' in the monitor).
762 Output log in /tmp/qemu.log
763 @item -hdachs c,h,s,[,t]
764 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
765 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
766 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
767 all those parameters. This option is useful for old MS-DOS disk
771 Set the directory for the BIOS, VGA BIOS and keymaps.
774 Simulate a standard VGA card with Bochs VBE extensions (default is
775 Cirrus Logic GD5446 PCI VGA). If your guest OS supports the VESA 2.0
776 VBE extensions (e.g. Windows XP) and if you want to use high
777 resolution modes (>= 1280x1024x16) then you should use this option.
780 Disable ACPI (Advanced Configuration and Power Interface) support. Use
781 it if your guest OS complains about ACPI problems (PC target machine
785 Exit instead of rebooting.
788 Start right away with a saved state (@code{loadvm} in monitor)
791 Enable semihosting syscall emulation (ARM and M68K target machines only).
793 On ARM this implements the "Angel" interface.
794 On M68K this implements the "ColdFire GDB" interface used by libgloss.
796 Note that this allows guest direct access to the host filesystem,
797 so should only be used with trusted guest OS.
807 During the graphical emulation, you can use the following keys:
813 Switch to virtual console 'n'. Standard console mappings are:
816 Target system display
824 Toggle mouse and keyboard grab.
827 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
828 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
830 During emulation, if you are using the @option{-nographic} option, use
831 @key{Ctrl-a h} to get terminal commands:
839 Save disk data back to file (if -snapshot)
841 toggle console timestamps
843 Send break (magic sysrq in Linux)
845 Switch between console and monitor
854 The HTML documentation of QEMU for more precise information and Linux
855 user mode emulator invocation.
865 @section QEMU Monitor
867 The QEMU monitor is used to give complex commands to the QEMU
868 emulator. You can use it to:
873 Remove or insert removable media images
874 (such as CD-ROM or floppies)
877 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
880 @item Inspect the VM state without an external debugger.
886 The following commands are available:
890 @item help or ? [cmd]
891 Show the help for all commands or just for command @var{cmd}.
894 Commit changes to the disk images (if -snapshot is used)
896 @item info subcommand
897 show various information about the system state
901 show the various VLANs and the associated devices
903 show the block devices
905 show the cpu registers
907 show the command line history
909 show emulated PCI device
911 show USB devices plugged on the virtual USB hub
913 show all USB host devices
915 show information about active capturing
917 show list of VM snapshots
919 show which guest mouse is receiving events
925 @item eject [-f] device
926 Eject a removable medium (use -f to force it).
928 @item change device setting
930 Change the configuration of a device
933 @item change @var{diskdevice} @var{filename}
934 Change the medium for a removable disk device to point to @var{filename}. eg
937 (qemu) change cdrom /path/to/some.iso
940 @item change vnc @var{display,options}
941 Change the configuration of the VNC server. The valid syntax for @var{display}
942 and @var{options} are described at @ref{sec_invocation}. eg
945 (qemu) change vnc localhost:1
948 @item change vnc password
950 Change the password associated with the VNC server. The monitor will prompt for
951 the new password to be entered. VNC passwords are only significant upto 8 letters.
955 (qemu) change vnc password
961 @item screendump filename
962 Save screen into PPM image @var{filename}.
964 @item mouse_move dx dy [dz]
965 Move the active mouse to the specified coordinates @var{dx} @var{dy}
966 with optional scroll axis @var{dz}.
968 @item mouse_button val
969 Change the active mouse button state @var{val} (1=L, 2=M, 4=R).
971 @item mouse_set index
972 Set which mouse device receives events at given @var{index}, index
978 @item wavcapture filename [frequency [bits [channels]]]
979 Capture audio into @var{filename}. Using sample rate @var{frequency}
980 bits per sample @var{bits} and number of channels @var{channels}.
984 @item Sample rate = 44100 Hz - CD quality
986 @item Number of channels = 2 - Stereo
989 @item stopcapture index
990 Stop capture with a given @var{index}, index can be obtained with
995 @item log item1[,...]
996 Activate logging of the specified items to @file{/tmp/qemu.log}.
998 @item savevm [tag|id]
999 Create a snapshot of the whole virtual machine. If @var{tag} is
1000 provided, it is used as human readable identifier. If there is already
1001 a snapshot with the same tag or ID, it is replaced. More info at
1005 Set the whole virtual machine to the snapshot identified by the tag
1006 @var{tag} or the unique snapshot ID @var{id}.
1009 Delete the snapshot identified by @var{tag} or @var{id}.
1017 @item gdbserver [port]
1018 Start gdbserver session (default port=1234)
1021 Virtual memory dump starting at @var{addr}.
1024 Physical memory dump starting at @var{addr}.
1026 @var{fmt} is a format which tells the command how to format the
1027 data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
1031 is the number of items to be dumped.
1034 can be x (hex), d (signed decimal), u (unsigned decimal), o (octal),
1035 c (char) or i (asm instruction).
1038 can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
1039 @code{h} or @code{w} can be specified with the @code{i} format to
1040 respectively select 16 or 32 bit code instruction size.
1047 Dump 10 instructions at the current instruction pointer:
1052 0x90107065: lea 0x0(%esi,1),%esi
1053 0x90107069: lea 0x0(%edi,1),%edi
1055 0x90107071: jmp 0x90107080
1063 Dump 80 16 bit values at the start of the video memory.
1065 (qemu) xp/80hx 0xb8000
1066 0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
1067 0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
1068 0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
1069 0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
1070 0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
1071 0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
1072 0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1073 0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1074 0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1075 0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1079 @item p or print/fmt expr
1081 Print expression value. Only the @var{format} part of @var{fmt} is
1086 Send @var{keys} to the emulator. Use @code{-} to press several keys
1087 simultaneously. Example:
1092 This command is useful to send keys that your graphical user interface
1093 intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
1099 @item usb_add devname
1101 Add the USB device @var{devname}. For details of available devices see
1104 @item usb_del devname
1106 Remove the USB device @var{devname} from the QEMU virtual USB
1107 hub. @var{devname} has the syntax @code{bus.addr}. Use the monitor
1108 command @code{info usb} to see the devices you can remove.
1112 @subsection Integer expressions
1114 The monitor understands integers expressions for every integer
1115 argument. You can use register names to get the value of specifics
1116 CPU registers by prefixing them with @emph{$}.
1119 @section Disk Images
1121 Since version 0.6.1, QEMU supports many disk image formats, including
1122 growable disk images (their size increase as non empty sectors are
1123 written), compressed and encrypted disk images. Version 0.8.3 added
1124 the new qcow2 disk image format which is essential to support VM
1128 * disk_images_quickstart:: Quick start for disk image creation
1129 * disk_images_snapshot_mode:: Snapshot mode
1130 * vm_snapshots:: VM snapshots
1131 * qemu_img_invocation:: qemu-img Invocation
1132 * host_drives:: Using host drives
1133 * disk_images_fat_images:: Virtual FAT disk images
1136 @node disk_images_quickstart
1137 @subsection Quick start for disk image creation
1139 You can create a disk image with the command:
1141 qemu-img create myimage.img mysize
1143 where @var{myimage.img} is the disk image filename and @var{mysize} is its
1144 size in kilobytes. You can add an @code{M} suffix to give the size in
1145 megabytes and a @code{G} suffix for gigabytes.
1147 See @ref{qemu_img_invocation} for more information.
1149 @node disk_images_snapshot_mode
1150 @subsection Snapshot mode
1152 If you use the option @option{-snapshot}, all disk images are
1153 considered as read only. When sectors in written, they are written in
1154 a temporary file created in @file{/tmp}. You can however force the
1155 write back to the raw disk images by using the @code{commit} monitor
1156 command (or @key{C-a s} in the serial console).
1159 @subsection VM snapshots
1161 VM snapshots are snapshots of the complete virtual machine including
1162 CPU state, RAM, device state and the content of all the writable
1163 disks. In order to use VM snapshots, you must have at least one non
1164 removable and writable block device using the @code{qcow2} disk image
1165 format. Normally this device is the first virtual hard drive.
1167 Use the monitor command @code{savevm} to create a new VM snapshot or
1168 replace an existing one. A human readable name can be assigned to each
1169 snapshot in addition to its numerical ID.
1171 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
1172 a VM snapshot. @code{info snapshots} lists the available snapshots
1173 with their associated information:
1176 (qemu) info snapshots
1177 Snapshot devices: hda
1178 Snapshot list (from hda):
1179 ID TAG VM SIZE DATE VM CLOCK
1180 1 start 41M 2006-08-06 12:38:02 00:00:14.954
1181 2 40M 2006-08-06 12:43:29 00:00:18.633
1182 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
1185 A VM snapshot is made of a VM state info (its size is shown in
1186 @code{info snapshots}) and a snapshot of every writable disk image.
1187 The VM state info is stored in the first @code{qcow2} non removable
1188 and writable block device. The disk image snapshots are stored in
1189 every disk image. The size of a snapshot in a disk image is difficult
1190 to evaluate and is not shown by @code{info snapshots} because the
1191 associated disk sectors are shared among all the snapshots to save
1192 disk space (otherwise each snapshot would need a full copy of all the
1195 When using the (unrelated) @code{-snapshot} option
1196 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
1197 but they are deleted as soon as you exit QEMU.
1199 VM snapshots currently have the following known limitations:
1202 They cannot cope with removable devices if they are removed or
1203 inserted after a snapshot is done.
1205 A few device drivers still have incomplete snapshot support so their
1206 state is not saved or restored properly (in particular USB).
1209 @node qemu_img_invocation
1210 @subsection @code{qemu-img} Invocation
1212 @include qemu-img.texi
1215 @subsection Using host drives
1217 In addition to disk image files, QEMU can directly access host
1218 devices. We describe here the usage for QEMU version >= 0.8.3.
1220 @subsubsection Linux
1222 On Linux, you can directly use the host device filename instead of a
1223 disk image filename provided you have enough privileges to access
1224 it. For example, use @file{/dev/cdrom} to access to the CDROM or
1225 @file{/dev/fd0} for the floppy.
1229 You can specify a CDROM device even if no CDROM is loaded. QEMU has
1230 specific code to detect CDROM insertion or removal. CDROM ejection by
1231 the guest OS is supported. Currently only data CDs are supported.
1233 You can specify a floppy device even if no floppy is loaded. Floppy
1234 removal is currently not detected accurately (if you change floppy
1235 without doing floppy access while the floppy is not loaded, the guest
1236 OS will think that the same floppy is loaded).
1238 Hard disks can be used. Normally you must specify the whole disk
1239 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
1240 see it as a partitioned disk. WARNING: unless you know what you do, it
1241 is better to only make READ-ONLY accesses to the hard disk otherwise
1242 you may corrupt your host data (use the @option{-snapshot} command
1243 line option or modify the device permissions accordingly).
1246 @subsubsection Windows
1250 The preferred syntax is the drive letter (e.g. @file{d:}). The
1251 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
1252 supported as an alias to the first CDROM drive.
1254 Currently there is no specific code to handle removable media, so it
1255 is better to use the @code{change} or @code{eject} monitor commands to
1256 change or eject media.
1258 Hard disks can be used with the syntax: @file{\\.\PhysicalDriveN}
1259 where @var{N} is the drive number (0 is the first hard disk).
1261 WARNING: unless you know what you do, it is better to only make
1262 READ-ONLY accesses to the hard disk otherwise you may corrupt your
1263 host data (use the @option{-snapshot} command line so that the
1264 modifications are written in a temporary file).
1268 @subsubsection Mac OS X
1270 @file{/dev/cdrom} is an alias to the first CDROM.
1272 Currently there is no specific code to handle removable media, so it
1273 is better to use the @code{change} or @code{eject} monitor commands to
1274 change or eject media.
1276 @node disk_images_fat_images
1277 @subsection Virtual FAT disk images
1279 QEMU can automatically create a virtual FAT disk image from a
1280 directory tree. In order to use it, just type:
1283 qemu linux.img -hdb fat:/my_directory
1286 Then you access access to all the files in the @file{/my_directory}
1287 directory without having to copy them in a disk image or to export
1288 them via SAMBA or NFS. The default access is @emph{read-only}.
1290 Floppies can be emulated with the @code{:floppy:} option:
1293 qemu linux.img -fda fat:floppy:/my_directory
1296 A read/write support is available for testing (beta stage) with the
1300 qemu linux.img -fda fat:floppy:rw:/my_directory
1303 What you should @emph{never} do:
1305 @item use non-ASCII filenames ;
1306 @item use "-snapshot" together with ":rw:" ;
1307 @item expect it to work when loadvm'ing ;
1308 @item write to the FAT directory on the host system while accessing it with the guest system.
1312 @section Network emulation
1314 QEMU can simulate several network cards (PCI or ISA cards on the PC
1315 target) and can connect them to an arbitrary number of Virtual Local
1316 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1317 VLAN. VLAN can be connected between separate instances of QEMU to
1318 simulate large networks. For simpler usage, a non privileged user mode
1319 network stack can replace the TAP device to have a basic network
1324 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1325 connection between several network devices. These devices can be for
1326 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1329 @subsection Using TAP network interfaces
1331 This is the standard way to connect QEMU to a real network. QEMU adds
1332 a virtual network device on your host (called @code{tapN}), and you
1333 can then configure it as if it was a real ethernet card.
1335 @subsubsection Linux host
1337 As an example, you can download the @file{linux-test-xxx.tar.gz}
1338 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1339 configure properly @code{sudo} so that the command @code{ifconfig}
1340 contained in @file{qemu-ifup} can be executed as root. You must verify
1341 that your host kernel supports the TAP network interfaces: the
1342 device @file{/dev/net/tun} must be present.
1344 See @ref{sec_invocation} to have examples of command lines using the
1345 TAP network interfaces.
1347 @subsubsection Windows host
1349 There is a virtual ethernet driver for Windows 2000/XP systems, called
1350 TAP-Win32. But it is not included in standard QEMU for Windows,
1351 so you will need to get it separately. It is part of OpenVPN package,
1352 so download OpenVPN from : @url{http://openvpn.net/}.
1354 @subsection Using the user mode network stack
1356 By using the option @option{-net user} (default configuration if no
1357 @option{-net} option is specified), QEMU uses a completely user mode
1358 network stack (you don't need root privilege to use the virtual
1359 network). The virtual network configuration is the following:
1363 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1366 ----> DNS server (10.0.2.3)
1368 ----> SMB server (10.0.2.4)
1371 The QEMU VM behaves as if it was behind a firewall which blocks all
1372 incoming connections. You can use a DHCP client to automatically
1373 configure the network in the QEMU VM. The DHCP server assign addresses
1374 to the hosts starting from 10.0.2.15.
1376 In order to check that the user mode network is working, you can ping
1377 the address 10.0.2.2 and verify that you got an address in the range
1378 10.0.2.x from the QEMU virtual DHCP server.
1380 Note that @code{ping} is not supported reliably to the internet as it
1381 would require root privileges. It means you can only ping the local
1384 When using the built-in TFTP server, the router is also the TFTP
1387 When using the @option{-redir} option, TCP or UDP connections can be
1388 redirected from the host to the guest. It allows for example to
1389 redirect X11, telnet or SSH connections.
1391 @subsection Connecting VLANs between QEMU instances
1393 Using the @option{-net socket} option, it is possible to make VLANs
1394 that span several QEMU instances. See @ref{sec_invocation} to have a
1397 @node direct_linux_boot
1398 @section Direct Linux Boot
1400 This section explains how to launch a Linux kernel inside QEMU without
1401 having to make a full bootable image. It is very useful for fast Linux
1406 qemu -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1409 Use @option{-kernel} to provide the Linux kernel image and
1410 @option{-append} to give the kernel command line arguments. The
1411 @option{-initrd} option can be used to provide an INITRD image.
1413 When using the direct Linux boot, a disk image for the first hard disk
1414 @file{hda} is required because its boot sector is used to launch the
1417 If you do not need graphical output, you can disable it and redirect
1418 the virtual serial port and the QEMU monitor to the console with the
1419 @option{-nographic} option. The typical command line is:
1421 qemu -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1422 -append "root=/dev/hda console=ttyS0" -nographic
1425 Use @key{Ctrl-a c} to switch between the serial console and the
1426 monitor (@pxref{pcsys_keys}).
1429 @section USB emulation
1431 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1432 virtual USB devices or real host USB devices (experimental, works only
1433 on Linux hosts). Qemu will automatically create and connect virtual USB hubs
1434 as necessary to connect multiple USB devices.
1438 * host_usb_devices::
1441 @subsection Connecting USB devices
1443 USB devices can be connected with the @option{-usbdevice} commandline option
1444 or the @code{usb_add} monitor command. Available devices are:
1448 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1450 Pointer device that uses absolute coordinates (like a touchscreen).
1451 This means qemu is able to report the mouse position without having
1452 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1453 @item @code{disk:file}
1454 Mass storage device based on @var{file} (@pxref{disk_images})
1455 @item @code{host:bus.addr}
1456 Pass through the host device identified by @var{bus.addr}
1458 @item @code{host:vendor_id:product_id}
1459 Pass through the host device identified by @var{vendor_id:product_id}
1461 @item @code{wacom-tablet}
1462 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1463 above but it can be used with the tslib library because in addition to touch
1464 coordinates it reports touch pressure.
1465 @item @code{keyboard}
1466 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1469 @node host_usb_devices
1470 @subsection Using host USB devices on a Linux host
1472 WARNING: this is an experimental feature. QEMU will slow down when
1473 using it. USB devices requiring real time streaming (i.e. USB Video
1474 Cameras) are not supported yet.
1477 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1478 is actually using the USB device. A simple way to do that is simply to
1479 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1480 to @file{mydriver.o.disabled}.
1482 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1488 @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:
1490 chown -R myuid /proc/bus/usb
1493 @item Launch QEMU and do in the monitor:
1496 Device 1.2, speed 480 Mb/s
1497 Class 00: USB device 1234:5678, USB DISK
1499 You should see the list of the devices you can use (Never try to use
1500 hubs, it won't work).
1502 @item Add the device in QEMU by using:
1504 usb_add host:1234:5678
1507 Normally the guest OS should report that a new USB device is
1508 plugged. You can use the option @option{-usbdevice} to do the same.
1510 @item Now you can try to use the host USB device in QEMU.
1514 When relaunching QEMU, you may have to unplug and plug again the USB
1515 device to make it work again (this is a bug).
1518 @section VNC security
1520 The VNC server capability provides access to the graphical console
1521 of the guest VM across the network. This has a number of security
1522 considerations depending on the deployment scenarios.
1526 * vnc_sec_password::
1527 * vnc_sec_certificate::
1528 * vnc_sec_certificate_verify::
1529 * vnc_sec_certificate_pw::
1530 * vnc_generate_cert::
1533 @subsection Without passwords
1535 The simplest VNC server setup does not include any form of authentication.
1536 For this setup it is recommended to restrict it to listen on a UNIX domain
1537 socket only. For example
1540 qemu [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1543 This ensures that only users on local box with read/write access to that
1544 path can access the VNC server. To securely access the VNC server from a
1545 remote machine, a combination of netcat+ssh can be used to provide a secure
1548 @node vnc_sec_password
1549 @subsection With passwords
1551 The VNC protocol has limited support for password based authentication. Since
1552 the protocol limits passwords to 8 characters it should not be considered
1553 to provide high security. The password can be fairly easily brute-forced by
1554 a client making repeat connections. For this reason, a VNC server using password
1555 authentication should be restricted to only listen on the loopback interface
1556 or UNIX domain sockets. Password ayuthentication is requested with the @code{password}
1557 option, and then once QEMU is running the password is set with the monitor. Until
1558 the monitor is used to set the password all clients will be rejected.
1561 qemu [...OPTIONS...] -vnc :1,password -monitor stdio
1562 (qemu) change vnc password
1567 @node vnc_sec_certificate
1568 @subsection With x509 certificates
1570 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1571 TLS for encryption of the session, and x509 certificates for authentication.
1572 The use of x509 certificates is strongly recommended, because TLS on its
1573 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1574 support provides a secure session, but no authentication. This allows any
1575 client to connect, and provides an encrypted session.
1578 qemu [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1581 In the above example @code{/etc/pki/qemu} should contain at least three files,
1582 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1583 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1584 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1585 only be readable by the user owning it.
1587 @node vnc_sec_certificate_verify
1588 @subsection With x509 certificates and client verification
1590 Certificates can also provide a means to authenticate the client connecting.
1591 The server will request that the client provide a certificate, which it will
1592 then validate against the CA certificate. This is a good choice if deploying
1593 in an environment with a private internal certificate authority.
1596 qemu [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1600 @node vnc_sec_certificate_pw
1601 @subsection With x509 certificates, client verification and passwords
1603 Finally, the previous method can be combined with VNC password authentication
1604 to provide two layers of authentication for clients.
1607 qemu [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1608 (qemu) change vnc password
1613 @node vnc_generate_cert
1614 @subsection Generating certificates for VNC
1616 The GNU TLS packages provides a command called @code{certtool} which can
1617 be used to generate certificates and keys in PEM format. At a minimum it
1618 is neccessary to setup a certificate authority, and issue certificates to
1619 each server. If using certificates for authentication, then each client
1620 will also need to be issued a certificate. The recommendation is for the
1621 server to keep its certificates in either @code{/etc/pki/qemu} or for
1622 unprivileged users in @code{$HOME/.pki/qemu}.
1626 * vnc_generate_server::
1627 * vnc_generate_client::
1629 @node vnc_generate_ca
1630 @subsubsection Setup the Certificate Authority
1632 This step only needs to be performed once per organization / organizational
1633 unit. First the CA needs a private key. This key must be kept VERY secret
1634 and secure. If this key is compromised the entire trust chain of the certificates
1635 issued with it is lost.
1638 # certtool --generate-privkey > ca-key.pem
1641 A CA needs to have a public certificate. For simplicity it can be a self-signed
1642 certificate, or one issue by a commercial certificate issuing authority. To
1643 generate a self-signed certificate requires one core piece of information, the
1644 name of the organization.
1647 # cat > ca.info <<EOF
1648 cn = Name of your organization
1652 # certtool --generate-self-signed \
1653 --load-privkey ca-key.pem
1654 --template ca.info \
1655 --outfile ca-cert.pem
1658 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1659 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1661 @node vnc_generate_server
1662 @subsubsection Issuing server certificates
1664 Each server (or host) needs to be issued with a key and certificate. When connecting
1665 the certificate is sent to the client which validates it against the CA certificate.
1666 The core piece of information for a server certificate is the hostname. This should
1667 be the fully qualified hostname that the client will connect with, since the client
1668 will typically also verify the hostname in the certificate. On the host holding the
1669 secure CA private key:
1672 # cat > server.info <<EOF
1673 organization = Name of your organization
1674 cn = server.foo.example.com
1679 # certtool --generate-privkey > server-key.pem
1680 # certtool --generate-certificate \
1681 --load-ca-certificate ca-cert.pem \
1682 --load-ca-privkey ca-key.pem \
1683 --load-privkey server server-key.pem \
1684 --template server.info \
1685 --outfile server-cert.pem
1688 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1689 to the server for which they were generated. The @code{server-key.pem} is security
1690 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1692 @node vnc_generate_client
1693 @subsubsection Issuing client certificates
1695 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1696 certificates as its authentication mechanism, each client also needs to be issued
1697 a certificate. The client certificate contains enough metadata to uniquely identify
1698 the client, typically organization, state, city, building, etc. On the host holding
1699 the secure CA private key:
1702 # cat > client.info <<EOF
1706 organiazation = Name of your organization
1707 cn = client.foo.example.com
1712 # certtool --generate-privkey > client-key.pem
1713 # certtool --generate-certificate \
1714 --load-ca-certificate ca-cert.pem \
1715 --load-ca-privkey ca-key.pem \
1716 --load-privkey client-key.pem \
1717 --template client.info \
1718 --outfile client-cert.pem
1721 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1722 copied to the client for which they were generated.
1727 QEMU has a primitive support to work with gdb, so that you can do
1728 'Ctrl-C' while the virtual machine is running and inspect its state.
1730 In order to use gdb, launch qemu with the '-s' option. It will wait for a
1733 > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1734 -append "root=/dev/hda"
1735 Connected to host network interface: tun0
1736 Waiting gdb connection on port 1234
1739 Then launch gdb on the 'vmlinux' executable:
1744 In gdb, connect to QEMU:
1746 (gdb) target remote localhost:1234
1749 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1754 Here are some useful tips in order to use gdb on system code:
1758 Use @code{info reg} to display all the CPU registers.
1760 Use @code{x/10i $eip} to display the code at the PC position.
1762 Use @code{set architecture i8086} to dump 16 bit code. Then use
1763 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1766 @node pcsys_os_specific
1767 @section Target OS specific information
1771 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1772 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1773 color depth in the guest and the host OS.
1775 When using a 2.6 guest Linux kernel, you should add the option
1776 @code{clock=pit} on the kernel command line because the 2.6 Linux
1777 kernels make very strict real time clock checks by default that QEMU
1778 cannot simulate exactly.
1780 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1781 not activated because QEMU is slower with this patch. The QEMU
1782 Accelerator Module is also much slower in this case. Earlier Fedora
1783 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1784 patch by default. Newer kernels don't have it.
1788 If you have a slow host, using Windows 95 is better as it gives the
1789 best speed. Windows 2000 is also a good choice.
1791 @subsubsection SVGA graphic modes support
1793 QEMU emulates a Cirrus Logic GD5446 Video
1794 card. All Windows versions starting from Windows 95 should recognize
1795 and use this graphic card. For optimal performances, use 16 bit color
1796 depth in the guest and the host OS.
1798 If you are using Windows XP as guest OS and if you want to use high
1799 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1800 1280x1024x16), then you should use the VESA VBE virtual graphic card
1801 (option @option{-std-vga}).
1803 @subsubsection CPU usage reduction
1805 Windows 9x does not correctly use the CPU HLT
1806 instruction. The result is that it takes host CPU cycles even when
1807 idle. You can install the utility from
1808 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1809 problem. Note that no such tool is needed for NT, 2000 or XP.
1811 @subsubsection Windows 2000 disk full problem
1813 Windows 2000 has a bug which gives a disk full problem during its
1814 installation. When installing it, use the @option{-win2k-hack} QEMU
1815 option to enable a specific workaround. After Windows 2000 is
1816 installed, you no longer need this option (this option slows down the
1819 @subsubsection Windows 2000 shutdown
1821 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1822 can. It comes from the fact that Windows 2000 does not automatically
1823 use the APM driver provided by the BIOS.
1825 In order to correct that, do the following (thanks to Struan
1826 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1827 Add/Troubleshoot a device => Add a new device & Next => No, select the
1828 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1829 (again) a few times. Now the driver is installed and Windows 2000 now
1830 correctly instructs QEMU to shutdown at the appropriate moment.
1832 @subsubsection Share a directory between Unix and Windows
1834 See @ref{sec_invocation} about the help of the option @option{-smb}.
1836 @subsubsection Windows XP security problem
1838 Some releases of Windows XP install correctly but give a security
1841 A problem is preventing Windows from accurately checking the
1842 license for this computer. Error code: 0x800703e6.
1845 The workaround is to install a service pack for XP after a boot in safe
1846 mode. Then reboot, and the problem should go away. Since there is no
1847 network while in safe mode, its recommended to download the full
1848 installation of SP1 or SP2 and transfer that via an ISO or using the
1849 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1851 @subsection MS-DOS and FreeDOS
1853 @subsubsection CPU usage reduction
1855 DOS does not correctly use the CPU HLT instruction. The result is that
1856 it takes host CPU cycles even when idle. You can install the utility
1857 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1860 @node QEMU System emulator for non PC targets
1861 @chapter QEMU System emulator for non PC targets
1863 QEMU is a generic emulator and it emulates many non PC
1864 machines. Most of the options are similar to the PC emulator. The
1865 differences are mentioned in the following sections.
1868 * QEMU PowerPC System emulator::
1869 * Sparc32 System emulator::
1870 * Sparc64 System emulator::
1871 * MIPS System emulator::
1872 * ARM System emulator::
1873 * ColdFire System emulator::
1876 @node QEMU PowerPC System emulator
1877 @section QEMU PowerPC System emulator
1879 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1880 or PowerMac PowerPC system.
1882 QEMU emulates the following PowerMac peripherals:
1888 PCI VGA compatible card with VESA Bochs Extensions
1890 2 PMAC IDE interfaces with hard disk and CD-ROM support
1896 VIA-CUDA with ADB keyboard and mouse.
1899 QEMU emulates the following PREP peripherals:
1905 PCI VGA compatible card with VESA Bochs Extensions
1907 2 IDE interfaces with hard disk and CD-ROM support
1911 NE2000 network adapters
1915 PREP Non Volatile RAM
1917 PC compatible keyboard and mouse.
1920 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1921 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1923 @c man begin OPTIONS
1925 The following options are specific to the PowerPC emulation:
1929 @item -g WxH[xDEPTH]
1931 Set the initial VGA graphic mode. The default is 800x600x15.
1938 More information is available at
1939 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
1941 @node Sparc32 System emulator
1942 @section Sparc32 System emulator
1944 Use the executable @file{qemu-system-sparc} to simulate a SparcStation 5
1945 or SparcStation 10 (sun4m architecture). The emulation is somewhat complete.
1946 SMP up to 16 CPUs is supported, but Linux limits the number of usable CPUs
1949 QEMU emulates the following sun4m peripherals:
1957 Lance (Am7990) Ethernet
1959 Non Volatile RAM M48T08
1961 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
1962 and power/reset logic
1964 ESP SCSI controller with hard disk and CD-ROM support
1968 CS4231 sound device (only on SS-5, not working yet)
1971 The number of peripherals is fixed in the architecture. Maximum memory size
1972 depends on the machine type, for SS-5 it is 256MB and for SS-10 2047MB.
1974 Since version 0.8.2, QEMU uses OpenBIOS
1975 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
1976 firmware implementation. The goal is to implement a 100% IEEE
1977 1275-1994 (referred to as Open Firmware) compliant firmware.
1979 A sample Linux 2.6 series kernel and ram disk image are available on
1980 the QEMU web site. Please note that currently NetBSD, OpenBSD or
1981 Solaris kernels don't work.
1983 @c man begin OPTIONS
1985 The following options are specific to the Sparc32 emulation:
1989 @item -g WxHx[xDEPTH]
1991 Set the initial TCX graphic mode. The default is 1024x768x8, currently
1992 the only other possible mode is 1024x768x24.
1994 @item -prom-env string
1996 Set OpenBIOS variables in NVRAM, for example:
1999 qemu-system-sparc -prom-env 'auto-boot?=false' \
2000 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2003 @item -M [SS-5|SS-10]
2005 Set the emulated machine type. Default is SS-5.
2011 @node Sparc64 System emulator
2012 @section Sparc64 System emulator
2014 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u machine.
2015 The emulator is not usable for anything yet.
2017 QEMU emulates the following sun4u peripherals:
2021 UltraSparc IIi APB PCI Bridge
2023 PCI VGA compatible card with VESA Bochs Extensions
2025 Non Volatile RAM M48T59
2027 PC-compatible serial ports
2030 @node MIPS System emulator
2031 @section MIPS System emulator
2033 Use the executable @file{qemu-system-mips} to simulate a MIPS machine.
2034 Three different machine types are emulated:
2038 A generic ISA PC-like machine "mips"
2040 The MIPS Malta prototype board "malta"
2042 An ACER Pica "pica61"
2044 MIPS emulator pseudo board "mipssim"
2047 The generic emulation is supported by Debian 'Etch' and is able to
2048 install Debian into a virtual disk image. The following devices are
2053 A range of MIPS CPUs, default is the 24Kf
2055 PC style serial port
2062 The Malta emulation supports the following devices:
2066 Core board with MIPS 24Kf CPU and Galileo system controller
2068 PIIX4 PCI/USB/SMbus controller
2070 The Multi-I/O chip's serial device
2072 PCnet32 PCI network card
2074 Malta FPGA serial device
2076 Cirrus VGA graphics card
2079 The ACER Pica emulation supports:
2085 PC-style IRQ and DMA controllers
2092 The mipssim pseudo board emulation provides an environment similiar
2093 to what the proprietary MIPS emulator uses for running Linux.
2098 A range of MIPS CPUs, default is the 24Kf
2100 PC style serial port
2102 MIPSnet network emulation
2105 @node ARM System emulator
2106 @section ARM System emulator
2108 Use the executable @file{qemu-system-arm} to simulate a ARM
2109 machine. The ARM Integrator/CP board is emulated with the following
2114 ARM926E, ARM1026E or ARM946E CPU
2118 SMC 91c111 Ethernet adapter
2120 PL110 LCD controller
2122 PL050 KMI with PS/2 keyboard and mouse.
2124 PL181 MultiMedia Card Interface with SD card.
2127 The ARM Versatile baseboard is emulated with the following devices:
2133 PL190 Vectored Interrupt Controller
2137 SMC 91c111 Ethernet adapter
2139 PL110 LCD controller
2141 PL050 KMI with PS/2 keyboard and mouse.
2143 PCI host bridge. Note the emulated PCI bridge only provides access to
2144 PCI memory space. It does not provide access to PCI IO space.
2145 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2146 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2147 mapped control registers.
2149 PCI OHCI USB controller.
2151 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2153 PL181 MultiMedia Card Interface with SD card.
2156 The ARM RealView Emulation baseboard is emulated with the following devices:
2162 ARM AMBA Generic/Distributed Interrupt Controller
2166 SMC 91c111 Ethernet adapter
2168 PL110 LCD controller
2170 PL050 KMI with PS/2 keyboard and mouse
2174 PCI OHCI USB controller
2176 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2178 PL181 MultiMedia Card Interface with SD card.
2181 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2182 and "Terrier") emulation includes the following peripherals:
2186 Intel PXA270 System-on-chip (ARM V5TE core)
2190 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2192 On-chip OHCI USB controller
2194 On-chip LCD controller
2196 On-chip Real Time Clock
2198 TI ADS7846 touchscreen controller on SSP bus
2200 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2202 GPIO-connected keyboard controller and LEDs
2204 Secure Digital card connected to PXA MMC/SD host
2208 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2211 A Linux 2.6 test image is available on the QEMU web site. More
2212 information is available in the QEMU mailing-list archive.
2214 @node ColdFire System emulator
2215 @section ColdFire System emulator
2217 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2218 The emulator is able to boot a uClinux kernel.
2220 The M5208EVB emulation includes the following devices:
2224 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2226 Three Two on-chip UARTs.
2228 Fast Ethernet Controller (FEC)
2231 The AN5206 emulation includes the following devices:
2235 MCF5206 ColdFire V2 Microprocessor.
2240 @node QEMU User space emulator
2241 @chapter QEMU User space emulator
2244 * Supported Operating Systems ::
2245 * Linux User space emulator::
2246 * Mac OS X/Darwin User space emulator ::
2249 @node Supported Operating Systems
2250 @section Supported Operating Systems
2252 The following OS are supported in user space emulation:
2256 Linux (referred as qemu-linux-user)
2258 Mac OS X/Darwin (referred as qemu-darwin-user)
2261 @node Linux User space emulator
2262 @section Linux User space emulator
2267 * Command line options::
2272 @subsection Quick Start
2274 In order to launch a Linux process, QEMU needs the process executable
2275 itself and all the target (x86) dynamic libraries used by it.
2279 @item On x86, you can just try to launch any process by using the native
2283 qemu-i386 -L / /bin/ls
2286 @code{-L /} tells that the x86 dynamic linker must be searched with a
2289 @item Since QEMU is also a linux process, you can launch qemu with
2290 qemu (NOTE: you can only do that if you compiled QEMU from the sources):
2293 qemu-i386 -L / qemu-i386 -L / /bin/ls
2296 @item On non x86 CPUs, you need first to download at least an x86 glibc
2297 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2298 @code{LD_LIBRARY_PATH} is not set:
2301 unset LD_LIBRARY_PATH
2304 Then you can launch the precompiled @file{ls} x86 executable:
2307 qemu-i386 tests/i386/ls
2309 You can look at @file{qemu-binfmt-conf.sh} so that
2310 QEMU is automatically launched by the Linux kernel when you try to
2311 launch x86 executables. It requires the @code{binfmt_misc} module in the
2314 @item The x86 version of QEMU is also included. You can try weird things such as:
2316 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2317 /usr/local/qemu-i386/bin/ls-i386
2323 @subsection Wine launch
2327 @item Ensure that you have a working QEMU with the x86 glibc
2328 distribution (see previous section). In order to verify it, you must be
2332 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2335 @item Download the binary x86 Wine install
2336 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2338 @item Configure Wine on your account. Look at the provided script
2339 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2340 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2342 @item Then you can try the example @file{putty.exe}:
2345 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2346 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2351 @node Command line options
2352 @subsection Command line options
2355 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
2362 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2364 Set the x86 stack size in bytes (default=524288)
2371 Activate log (logfile=/tmp/qemu.log)
2373 Act as if the host page size was 'pagesize' bytes
2376 @node Other binaries
2377 @subsection Other binaries
2379 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2380 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2381 configurations), and arm-uclinux bFLT format binaries.
2383 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2384 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2385 coldfire uClinux bFLT format binaries.
2387 The binary format is detected automatically.
2389 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2390 (Sparc64 CPU, 32 bit ABI).
2392 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2393 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2395 @node Mac OS X/Darwin User space emulator
2396 @section Mac OS X/Darwin User space emulator
2399 * Mac OS X/Darwin Status::
2400 * Mac OS X/Darwin Quick Start::
2401 * Mac OS X/Darwin Command line options::
2404 @node Mac OS X/Darwin Status
2405 @subsection Mac OS X/Darwin Status
2409 target x86 on x86: Most apps (Cocoa and Carbon too) works. [1]
2411 target PowerPC on x86: Not working as the ppc commpage can't be mapped (yet!)
2413 target PowerPC on PowerPC: Most apps (Cocoa and Carbon too) works. [1]
2415 target x86 on PowerPC: most utilities work. Cocoa and Carbon apps are not yet supported.
2418 [1] If you're host commpage can be executed by qemu.
2420 @node Mac OS X/Darwin Quick Start
2421 @subsection Quick Start
2423 In order to launch a Mac OS X/Darwin process, QEMU needs the process executable
2424 itself and all the target dynamic libraries used by it. If you don't have the FAT
2425 libraries (you're running Mac OS X/ppc) you'll need to obtain it from a Mac OS X
2426 CD or compile them by hand.
2430 @item On x86, you can just try to launch any process by using the native
2437 or to run the ppc version of the executable:
2443 @item On ppc, you'll have to tell qemu where your x86 libraries (and dynamic linker)
2447 qemu-i386 -L /opt/x86_root/ /bin/ls
2450 @code{-L /opt/x86_root/} tells that the dynamic linker (dyld) path is in
2451 @file{/opt/x86_root/usr/bin/dyld}.
2455 @node Mac OS X/Darwin Command line options
2456 @subsection Command line options
2459 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
2466 Set the library root path (default=/)
2468 Set the stack size in bytes (default=524288)
2475 Activate log (logfile=/tmp/qemu.log)
2477 Act as if the host page size was 'pagesize' bytes
2481 @chapter Compilation from the sources
2486 * Cross compilation for Windows with Linux::
2493 @subsection Compilation
2495 First you must decompress the sources:
2498 tar zxvf qemu-x.y.z.tar.gz
2502 Then you configure QEMU and build it (usually no options are needed):
2508 Then type as root user:
2512 to install QEMU in @file{/usr/local}.
2514 @subsection GCC version
2516 In order to compile QEMU successfully, it is very important that you
2517 have the right tools. The most important one is gcc. On most hosts and
2518 in particular on x86 ones, @emph{gcc 4.x is not supported}. If your
2519 Linux distribution includes a gcc 4.x compiler, you can usually
2520 install an older version (it is invoked by @code{gcc32} or
2521 @code{gcc34}). The QEMU configure script automatically probes for
2522 these older versions so that usually you don't have to do anything.
2528 @item Install the current versions of MSYS and MinGW from
2529 @url{http://www.mingw.org/}. You can find detailed installation
2530 instructions in the download section and the FAQ.
2533 the MinGW development library of SDL 1.2.x
2534 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2535 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
2536 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
2537 directory. Edit the @file{sdl-config} script so that it gives the
2538 correct SDL directory when invoked.
2540 @item Extract the current version of QEMU.
2542 @item Start the MSYS shell (file @file{msys.bat}).
2544 @item Change to the QEMU directory. Launch @file{./configure} and
2545 @file{make}. If you have problems using SDL, verify that
2546 @file{sdl-config} can be launched from the MSYS command line.
2548 @item You can install QEMU in @file{Program Files/Qemu} by typing
2549 @file{make install}. Don't forget to copy @file{SDL.dll} in
2550 @file{Program Files/Qemu}.
2554 @node Cross compilation for Windows with Linux
2555 @section Cross compilation for Windows with Linux
2559 Install the MinGW cross compilation tools available at
2560 @url{http://www.mingw.org/}.
2563 Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
2564 unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
2565 variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
2566 the QEMU configuration script.
2569 Configure QEMU for Windows cross compilation:
2571 ./configure --enable-mingw32
2573 If necessary, you can change the cross-prefix according to the prefix
2574 chosen for the MinGW tools with --cross-prefix. You can also use
2575 --prefix to set the Win32 install path.
2577 @item You can install QEMU in the installation directory by typing
2578 @file{make install}. Don't forget to copy @file{SDL.dll} in the
2579 installation directory.
2583 Note: Currently, Wine does not seem able to launch
2589 The Mac OS X patches are not fully merged in QEMU, so you should look
2590 at the QEMU mailing list archive to have all the necessary