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).
86 @item Palm Tungsten|E PDA (OMAP310 processor)
89 For user emulation, x86, PowerPC, ARM, MIPS, Sparc32/64 and ColdFire(m68k) CPUs are supported.
94 If you want to compile QEMU yourself, see @ref{compilation}.
97 * install_linux:: Linux
98 * install_windows:: Windows
99 * install_mac:: Macintosh
105 If a precompiled package is available for your distribution - you just
106 have to install it. Otherwise, see @ref{compilation}.
108 @node install_windows
111 Download the experimental binary installer at
112 @url{http://www.free.oszoo.org/@/download.html}.
117 Download the experimental binary installer at
118 @url{http://www.free.oszoo.org/@/download.html}.
120 @node QEMU PC System emulator
121 @chapter QEMU PC System emulator
124 * pcsys_introduction:: Introduction
125 * pcsys_quickstart:: Quick Start
126 * sec_invocation:: Invocation
128 * pcsys_monitor:: QEMU Monitor
129 * disk_images:: Disk Images
130 * pcsys_network:: Network emulation
131 * direct_linux_boot:: Direct Linux Boot
132 * pcsys_usb:: USB emulation
133 * vnc_security:: VNC security
134 * gdb_usage:: GDB usage
135 * pcsys_os_specific:: Target OS specific information
138 @node pcsys_introduction
139 @section Introduction
141 @c man begin DESCRIPTION
143 The QEMU PC System emulator simulates the
144 following peripherals:
148 i440FX host PCI bridge and PIIX3 PCI to ISA bridge
150 Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA
151 extensions (hardware level, including all non standard modes).
153 PS/2 mouse and keyboard
155 2 PCI IDE interfaces with hard disk and CD-ROM support
159 PCI/ISA PCI network adapters
163 Creative SoundBlaster 16 sound card
165 ENSONIQ AudioPCI ES1370 sound card
167 Adlib(OPL2) - Yamaha YM3812 compatible chip
169 PCI UHCI USB controller and a virtual USB hub.
172 SMP is supported with up to 255 CPUs.
174 Note that adlib is only available when QEMU was configured with
177 QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL
180 QEMU uses YM3812 emulation by Tatsuyuki Satoh.
184 @node pcsys_quickstart
187 Download and uncompress the linux image (@file{linux.img}) and type:
193 Linux should boot and give you a prompt.
199 @c man begin SYNOPSIS
200 usage: qemu [options] [disk_image]
205 @var{disk_image} is a raw hard disk image for IDE hard disk 0.
210 Select the emulated machine (@code{-M ?} for list)
214 Use @var{file} as floppy disk 0/1 image (@pxref{disk_images}). You can
215 use the host floppy by using @file{/dev/fd0} as filename (@pxref{host_drives}).
221 Use @var{file} as hard disk 0, 1, 2 or 3 image (@pxref{disk_images}).
224 Use @var{file} as CD-ROM image (you cannot use @option{-hdc} and and
225 @option{-cdrom} at the same time). You can use the host CD-ROM by
226 using @file{/dev/cdrom} as filename (@pxref{host_drives}).
228 @item -boot [a|c|d|n]
229 Boot on floppy (a), hard disk (c), CD-ROM (d), or Etherboot (n). Hard disk boot
233 Write to temporary files instead of disk image files. In this case,
234 the raw disk image you use is not written back. You can however force
235 the write back by pressing @key{C-a s} (@pxref{disk_images}).
238 Disable boot signature checking for floppy disks in Bochs BIOS. It may
239 be needed to boot from old floppy disks.
242 Set virtual RAM size to @var{megs} megabytes. Default is 128 MB.
245 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
246 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
251 Will show the audio subsystem help: list of drivers, tunable
254 @item -soundhw card1,card2,... or -soundhw all
256 Enable audio and selected sound hardware. Use ? to print all
257 available sound hardware.
260 qemu -soundhw sb16,adlib hda
261 qemu -soundhw es1370 hda
262 qemu -soundhw all hda
267 Set the real time clock to local time (the default is to UTC
268 time). This option is needed to have correct date in MS-DOS or
272 Store the QEMU process PID in @var{file}. It is useful if you launch QEMU
276 Daemonize the QEMU process after initialization. QEMU will not detach from
277 standard IO until it is ready to receive connections on any of its devices.
278 This option is a useful way for external programs to launch QEMU without having
279 to cope with initialization race conditions.
282 Use it when installing Windows 2000 to avoid a disk full bug. After
283 Windows 2000 is installed, you no longer need this option (this option
284 slows down the IDE transfers).
286 @item -option-rom file
287 Load the contents of file as an option ROM. This option is useful to load
288 things like EtherBoot.
291 Sets the name of the guest. This name will be display in the SDL window
292 caption. The name will also be used for the VNC server.
301 Normally, QEMU uses SDL to display the VGA output. With this option,
302 you can totally disable graphical output so that QEMU is a simple
303 command line application. The emulated serial port is redirected on
304 the console. Therefore, you can still use QEMU to debug a Linux kernel
305 with a serial console.
309 Do not use decorations for SDL windows and start them using the whole
310 available screen space. This makes the using QEMU in a dedicated desktop
311 workspace more convenient.
314 Start in full screen.
316 @item -vnc display[,option[,option[,...]]]
318 Normally, QEMU uses SDL to display the VGA output. With this option,
319 you can have QEMU listen on VNC display @var{display} and redirect the VGA
320 display over the VNC session. It is very useful to enable the usb
321 tablet device when using this option (option @option{-usbdevice
322 tablet}). When using the VNC display, you must use the @option{-k}
323 parameter to set the keyboard layout if you are not using en-us. Valid
324 syntax for the @var{display} is
328 @item @var{interface:d}
330 TCP connections will only be allowed from @var{interface} on display @var{d}.
331 By convention the TCP port is 5900+@var{d}. Optionally, @var{interface} can
332 be omitted in which case the server will bind to all interfaces.
334 @item @var{unix:path}
336 Connections will be allowed over UNIX domain sockets where @var{path} is the
337 location of a unix socket to listen for connections on.
341 VNC is initialized by not started. The monitor @code{change} command can be used
342 to later start the VNC server.
346 Following the @var{display} value there may be one or more @var{option} flags
347 separated by commas. Valid options are
353 Require that password based authentication is used for client connections.
354 The password must be set separately using the @code{change} command in the
359 Require that client use TLS when communicating with the VNC server. This
360 uses anonymous TLS credentials so is susceptible to a man-in-the-middle
361 attack. It is recommended that this option be combined with either the
362 @var{x509} or @var{x509verify} options.
364 @item @var{x509=/path/to/certificate/dir}
366 Valid if @var{tls} is specified. Require that x509 credentials are used
367 for negotiating the TLS session. The server will send its x509 certificate
368 to the client. It is recommended that a password be set on the VNC server
369 to provide authentication of the client when this is used. The path following
370 this option specifies where the x509 certificates are to be loaded from.
371 See the @ref{vnc_security} section for details on generating certificates.
373 @item @var{x509verify=/path/to/certificate/dir}
375 Valid if @var{tls} is specified. Require that x509 credentials are used
376 for negotiating the TLS session. The server will send its x509 certificate
377 to the client, and request that the client send its own x509 certificate.
378 The server will validate the client's certificate against the CA certificate,
379 and reject clients when validation fails. If the certificate authority is
380 trusted, this is a sufficient authentication mechanism. You may still wish
381 to set a password on the VNC server as a second authentication layer. The
382 path following this option specifies where the x509 certificates are to
383 be loaded from. See the @ref{vnc_security} section for details on generating
390 Use keyboard layout @var{language} (for example @code{fr} for
391 French). This option is only needed where it is not easy to get raw PC
392 keycodes (e.g. on Macs, with some X11 servers or with a VNC
393 display). You don't normally need to use it on PC/Linux or PC/Windows
396 The available layouts are:
398 ar de-ch es fo fr-ca hu ja mk no pt-br sv
399 da en-gb et fr fr-ch is lt nl pl ru th
400 de en-us fi fr-be hr it lv nl-be pt sl tr
403 The default is @code{en-us}.
411 Enable the USB driver (will be the default soon)
413 @item -usbdevice devname
414 Add the USB device @var{devname}. @xref{usb_devices}.
421 @item -net nic[,vlan=n][,macaddr=addr][,model=type]
422 Create a new Network Interface Card and connect it to VLAN @var{n} (@var{n}
423 = 0 is the default). The NIC is an ne2k_pci by default on the PC
424 target. Optionally, the MAC address can be changed. If no
425 @option{-net} option is specified, a single NIC is created.
426 Qemu can emulate several different models of network card.
427 Valid values for @var{type} are
428 @code{i82551}, @code{i82557b}, @code{i82559er},
429 @code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
430 @code{smc91c111}, @code{lance} and @code{mcf_fec}.
431 Not all devices are supported on all targets. Use -net nic,model=?
432 for a list of available devices for your target.
434 @item -net user[,vlan=n][,hostname=name]
435 Use the user mode network stack which requires no administrator
436 privilege to run. @option{hostname=name} can be used to specify the client
437 hostname reported by the builtin DHCP server.
439 @item -net tap[,vlan=n][,fd=h][,ifname=name][,script=file]
440 Connect the host TAP network interface @var{name} to VLAN @var{n} and
441 use the network script @var{file} to configure it. The default
442 network script is @file{/etc/qemu-ifup}. Use @option{script=no} to
443 disable script execution. If @var{name} is not
444 provided, the OS automatically provides one. @option{fd=h} can be
445 used to specify the handle of an already opened host TAP interface. Example:
448 qemu linux.img -net nic -net tap
451 More complicated example (two NICs, each one connected to a TAP device)
453 qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
454 -net nic,vlan=1 -net tap,vlan=1,ifname=tap1
458 @item -net socket[,vlan=n][,fd=h][,listen=[host]:port][,connect=host:port]
460 Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
461 machine using a TCP socket connection. If @option{listen} is
462 specified, QEMU waits for incoming connections on @var{port}
463 (@var{host} is optional). @option{connect} is used to connect to
464 another QEMU instance using the @option{listen} option. @option{fd=h}
465 specifies an already opened TCP socket.
469 # launch a first QEMU instance
470 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
471 -net socket,listen=:1234
472 # connect the VLAN 0 of this instance to the VLAN 0
473 # of the first instance
474 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
475 -net socket,connect=127.0.0.1:1234
478 @item -net socket[,vlan=n][,fd=h][,mcast=maddr:port]
480 Create a VLAN @var{n} shared with another QEMU virtual
481 machines using a UDP multicast socket, effectively making a bus for
482 every QEMU with same multicast address @var{maddr} and @var{port}.
486 Several QEMU can be running on different hosts and share same bus (assuming
487 correct multicast setup for these hosts).
489 mcast support is compatible with User Mode Linux (argument @option{eth@var{N}=mcast}), see
490 @url{http://user-mode-linux.sf.net}.
492 Use @option{fd=h} to specify an already opened UDP multicast socket.
497 # launch one QEMU instance
498 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
499 -net socket,mcast=230.0.0.1:1234
500 # launch another QEMU instance on same "bus"
501 qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
502 -net socket,mcast=230.0.0.1:1234
503 # launch yet another QEMU instance on same "bus"
504 qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
505 -net socket,mcast=230.0.0.1:1234
508 Example (User Mode Linux compat.):
510 # launch QEMU instance (note mcast address selected
512 qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
513 -net socket,mcast=239.192.168.1:1102
515 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
519 Indicate that no network devices should be configured. It is used to
520 override the default configuration (@option{-net nic -net user}) which
521 is activated if no @option{-net} options are provided.
524 When using the user mode network stack, activate a built-in TFTP
525 server. The files in @var{dir} will be exposed as the root of a TFTP server.
526 The TFTP client on the guest must be configured in binary mode (use the command
527 @code{bin} of the Unix TFTP client). The host IP address on the guest is as
531 When using the user mode network stack, broadcast @var{file} as the BOOTP
532 filename. In conjunction with @option{-tftp}, this can be used to network boot
533 a guest from a local directory.
535 Example (using pxelinux):
537 qemu -hda linux.img -boot n -tftp /path/to/tftp/files -bootp /pxelinux.0
541 When using the user mode network stack, activate a built-in SMB
542 server so that Windows OSes can access to the host files in @file{dir}
545 In the guest Windows OS, the line:
549 must be added in the file @file{C:\WINDOWS\LMHOSTS} (for windows 9x/Me)
550 or @file{C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS} (Windows NT/2000).
552 Then @file{dir} can be accessed in @file{\\smbserver\qemu}.
554 Note that a SAMBA server must be installed on the host OS in
555 @file{/usr/sbin/smbd}. QEMU was tested successfully with smbd version
556 2.2.7a from the Red Hat 9 and version 3.0.10-1.fc3 from Fedora Core 3.
558 @item -redir [tcp|udp]:host-port:[guest-host]:guest-port
560 When using the user mode network stack, redirect incoming TCP or UDP
561 connections to the host port @var{host-port} to the guest
562 @var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
563 is not specified, its value is 10.0.2.15 (default address given by the
564 built-in DHCP server).
566 For example, to redirect host X11 connection from screen 1 to guest
567 screen 0, use the following:
571 qemu -redir tcp:6001::6000 [...]
572 # this host xterm should open in the guest X11 server
576 To redirect telnet connections from host port 5555 to telnet port on
577 the guest, use the following:
581 qemu -redir tcp:5555::23 [...]
582 telnet localhost 5555
585 Then when you use on the host @code{telnet localhost 5555}, you
586 connect to the guest telnet server.
590 Linux boot specific: When using these options, you can use a given
591 Linux kernel without installing it in the disk image. It can be useful
592 for easier testing of various kernels.
596 @item -kernel bzImage
597 Use @var{bzImage} as kernel image.
599 @item -append cmdline
600 Use @var{cmdline} as kernel command line
603 Use @var{file} as initial ram disk.
607 Debug/Expert options:
611 Redirect the virtual serial port to host character device
612 @var{dev}. The default device is @code{vc} in graphical mode and
613 @code{stdio} in non graphical mode.
615 This option can be used several times to simulate up to 4 serials
618 Use @code{-serial none} to disable all serial ports.
620 Available character devices are:
623 Virtual console. Optionally, a width and height can be given in pixel with
627 It is also possible to specify width or height in characters:
632 [Linux only] Pseudo TTY (a new PTY is automatically allocated)
634 No device is allocated.
638 [Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
639 parameters are set according to the emulated ones.
641 [Linux only, parallel port only] Use host parallel port
642 @var{N}. Currently SPP and EPP parallel port features can be used.
644 Write output to filename. No character can be read.
646 [Unix only] standard input/output
648 name pipe @var{filename}
650 [Windows only] Use host serial port @var{n}
651 @item udp:[remote_host]:remote_port[@@[src_ip]:src_port]
652 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.
654 If you just want a simple readonly console you can use @code{netcat} or
655 @code{nc}, by starting qemu with: @code{-serial udp::4555} and nc as:
656 @code{nc -u -l -p 4555}. Any time qemu writes something to that port it
657 will appear in the netconsole session.
659 If you plan to send characters back via netconsole or you want to stop
660 and start qemu a lot of times, you should have qemu use the same
661 source port each time by using something like @code{-serial
662 udp::4555@@:4556} to qemu. Another approach is to use a patched
663 version of netcat which can listen to a TCP port and send and receive
664 characters via udp. If you have a patched version of netcat which
665 activates telnet remote echo and single char transfer, then you can
666 use the following options to step up a netcat redirector to allow
667 telnet on port 5555 to access the qemu port.
670 -serial udp::4555@@:4556
671 @item netcat options:
672 -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T
673 @item telnet options:
678 @item tcp:[host]:port[,server][,nowait][,nodelay]
679 The TCP Net Console has two modes of operation. It can send the serial
680 I/O to a location or wait for a connection from a location. By default
681 the TCP Net Console is sent to @var{host} at the @var{port}. If you use
682 the @var{server} option QEMU will wait for a client socket application
683 to connect to the port before continuing, unless the @code{nowait}
684 option was specified. The @code{nodelay} option disables the Nagle buffering
685 algorithm. If @var{host} is omitted, 0.0.0.0 is assumed. Only
686 one TCP connection at a time is accepted. You can use @code{telnet} to
687 connect to the corresponding character device.
689 @item Example to send tcp console to 192.168.0.2 port 4444
690 -serial tcp:192.168.0.2:4444
691 @item Example to listen and wait on port 4444 for connection
692 -serial tcp::4444,server
693 @item Example to not wait and listen on ip 192.168.0.100 port 4444
694 -serial tcp:192.168.0.100:4444,server,nowait
697 @item telnet:host:port[,server][,nowait][,nodelay]
698 The telnet protocol is used instead of raw tcp sockets. The options
699 work the same as if you had specified @code{-serial tcp}. The
700 difference is that the port acts like a telnet server or client using
701 telnet option negotiation. This will also allow you to send the
702 MAGIC_SYSRQ sequence if you use a telnet that supports sending the break
703 sequence. Typically in unix telnet you do it with Control-] and then
704 type "send break" followed by pressing the enter key.
706 @item unix:path[,server][,nowait]
707 A unix domain socket is used instead of a tcp socket. The option works the
708 same as if you had specified @code{-serial tcp} except the unix domain socket
709 @var{path} is used for connections.
712 This is a special option to allow the monitor to be multiplexed onto
713 another serial port. The monitor is accessed with key sequence of
714 @key{Control-a} and then pressing @key{c}. See monitor access
715 @ref{pcsys_keys} in the -nographic section for more keys.
716 @var{dev_string} should be any one of the serial devices specified
717 above. An example to multiplex the monitor onto a telnet server
718 listening on port 4444 would be:
720 @item -serial mon:telnet::4444,server,nowait
726 Redirect the virtual parallel port to host device @var{dev} (same
727 devices as the serial port). On Linux hosts, @file{/dev/parportN} can
728 be used to use hardware devices connected on the corresponding host
731 This option can be used several times to simulate up to 3 parallel
734 Use @code{-parallel none} to disable all parallel ports.
737 Redirect the monitor to host device @var{dev} (same devices as the
739 The default device is @code{vc} in graphical mode and @code{stdio} in
742 @item -echr numeric_ascii_value
743 Change the escape character used for switching to the monitor when using
744 monitor and serial sharing. The default is @code{0x01} when using the
745 @code{-nographic} option. @code{0x01} is equal to pressing
746 @code{Control-a}. You can select a different character from the ascii
747 control keys where 1 through 26 map to Control-a through Control-z. For
748 instance you could use the either of the following to change the escape
749 character to Control-t.
756 Wait gdb connection to port 1234 (@pxref{gdb_usage}).
758 Change gdb connection port. @var{port} can be either a decimal number
759 to specify a TCP port, or a host device (same devices as the serial port).
761 Do not start CPU at startup (you must type 'c' in the monitor).
763 Output log in /tmp/qemu.log
764 @item -hdachs c,h,s,[,t]
765 Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
766 @var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
767 translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
768 all those parameters. This option is useful for old MS-DOS disk
772 Set the directory for the BIOS, VGA BIOS and keymaps.
775 Simulate a standard VGA card with Bochs VBE extensions (default is
776 Cirrus Logic GD5446 PCI VGA). If your guest OS supports the VESA 2.0
777 VBE extensions (e.g. Windows XP) and if you want to use high
778 resolution modes (>= 1280x1024x16) then you should use this option.
781 Disable ACPI (Advanced Configuration and Power Interface) support. Use
782 it if your guest OS complains about ACPI problems (PC target machine
786 Exit instead of rebooting.
789 Start right away with a saved state (@code{loadvm} in monitor)
792 Enable semihosting syscall emulation (ARM and M68K target machines only).
794 On ARM this implements the "Angel" interface.
795 On M68K this implements the "ColdFire GDB" interface used by libgloss.
797 Note that this allows guest direct access to the host filesystem,
798 so should only be used with trusted guest OS.
808 During the graphical emulation, you can use the following keys:
814 Switch to virtual console 'n'. Standard console mappings are:
817 Target system display
825 Toggle mouse and keyboard grab.
828 In the virtual consoles, you can use @key{Ctrl-Up}, @key{Ctrl-Down},
829 @key{Ctrl-PageUp} and @key{Ctrl-PageDown} to move in the back log.
831 During emulation, if you are using the @option{-nographic} option, use
832 @key{Ctrl-a h} to get terminal commands:
840 Save disk data back to file (if -snapshot)
842 toggle console timestamps
844 Send break (magic sysrq in Linux)
846 Switch between console and monitor
855 The HTML documentation of QEMU for more precise information and Linux
856 user mode emulator invocation.
866 @section QEMU Monitor
868 The QEMU monitor is used to give complex commands to the QEMU
869 emulator. You can use it to:
874 Remove or insert removable media images
875 (such as CD-ROM or floppies)
878 Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
881 @item Inspect the VM state without an external debugger.
887 The following commands are available:
891 @item help or ? [cmd]
892 Show the help for all commands or just for command @var{cmd}.
895 Commit changes to the disk images (if -snapshot is used)
897 @item info subcommand
898 show various information about the system state
902 show the various VLANs and the associated devices
904 show the block devices
906 show the cpu registers
908 show the command line history
910 show emulated PCI device
912 show USB devices plugged on the virtual USB hub
914 show all USB host devices
916 show information about active capturing
918 show list of VM snapshots
920 show which guest mouse is receiving events
926 @item eject [-f] device
927 Eject a removable medium (use -f to force it).
929 @item change device setting
931 Change the configuration of a device
934 @item change @var{diskdevice} @var{filename}
935 Change the medium for a removable disk device to point to @var{filename}. eg
938 (qemu) change cdrom /path/to/some.iso
941 @item change vnc @var{display,options}
942 Change the configuration of the VNC server. The valid syntax for @var{display}
943 and @var{options} are described at @ref{sec_invocation}. eg
946 (qemu) change vnc localhost:1
949 @item change vnc password
951 Change the password associated with the VNC server. The monitor will prompt for
952 the new password to be entered. VNC passwords are only significant upto 8 letters.
956 (qemu) change vnc password
962 @item screendump filename
963 Save screen into PPM image @var{filename}.
965 @item mouse_move dx dy [dz]
966 Move the active mouse to the specified coordinates @var{dx} @var{dy}
967 with optional scroll axis @var{dz}.
969 @item mouse_button val
970 Change the active mouse button state @var{val} (1=L, 2=M, 4=R).
972 @item mouse_set index
973 Set which mouse device receives events at given @var{index}, index
979 @item wavcapture filename [frequency [bits [channels]]]
980 Capture audio into @var{filename}. Using sample rate @var{frequency}
981 bits per sample @var{bits} and number of channels @var{channels}.
985 @item Sample rate = 44100 Hz - CD quality
987 @item Number of channels = 2 - Stereo
990 @item stopcapture index
991 Stop capture with a given @var{index}, index can be obtained with
996 @item log item1[,...]
997 Activate logging of the specified items to @file{/tmp/qemu.log}.
999 @item savevm [tag|id]
1000 Create a snapshot of the whole virtual machine. If @var{tag} is
1001 provided, it is used as human readable identifier. If there is already
1002 a snapshot with the same tag or ID, it is replaced. More info at
1006 Set the whole virtual machine to the snapshot identified by the tag
1007 @var{tag} or the unique snapshot ID @var{id}.
1010 Delete the snapshot identified by @var{tag} or @var{id}.
1018 @item gdbserver [port]
1019 Start gdbserver session (default port=1234)
1022 Virtual memory dump starting at @var{addr}.
1025 Physical memory dump starting at @var{addr}.
1027 @var{fmt} is a format which tells the command how to format the
1028 data. Its syntax is: @option{/@{count@}@{format@}@{size@}}
1032 is the number of items to be dumped.
1035 can be x (hex), d (signed decimal), u (unsigned decimal), o (octal),
1036 c (char) or i (asm instruction).
1039 can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
1040 @code{h} or @code{w} can be specified with the @code{i} format to
1041 respectively select 16 or 32 bit code instruction size.
1048 Dump 10 instructions at the current instruction pointer:
1053 0x90107065: lea 0x0(%esi,1),%esi
1054 0x90107069: lea 0x0(%edi,1),%edi
1056 0x90107071: jmp 0x90107080
1064 Dump 80 16 bit values at the start of the video memory.
1066 (qemu) xp/80hx 0xb8000
1067 0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
1068 0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
1069 0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
1070 0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
1071 0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
1072 0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
1073 0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1074 0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1075 0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1076 0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
1080 @item p or print/fmt expr
1082 Print expression value. Only the @var{format} part of @var{fmt} is
1087 Send @var{keys} to the emulator. Use @code{-} to press several keys
1088 simultaneously. Example:
1093 This command is useful to send keys that your graphical user interface
1094 intercepts at low level, such as @code{ctrl-alt-f1} in X Window.
1100 @item usb_add devname
1102 Add the USB device @var{devname}. For details of available devices see
1105 @item usb_del devname
1107 Remove the USB device @var{devname} from the QEMU virtual USB
1108 hub. @var{devname} has the syntax @code{bus.addr}. Use the monitor
1109 command @code{info usb} to see the devices you can remove.
1113 @subsection Integer expressions
1115 The monitor understands integers expressions for every integer
1116 argument. You can use register names to get the value of specifics
1117 CPU registers by prefixing them with @emph{$}.
1120 @section Disk Images
1122 Since version 0.6.1, QEMU supports many disk image formats, including
1123 growable disk images (their size increase as non empty sectors are
1124 written), compressed and encrypted disk images. Version 0.8.3 added
1125 the new qcow2 disk image format which is essential to support VM
1129 * disk_images_quickstart:: Quick start for disk image creation
1130 * disk_images_snapshot_mode:: Snapshot mode
1131 * vm_snapshots:: VM snapshots
1132 * qemu_img_invocation:: qemu-img Invocation
1133 * host_drives:: Using host drives
1134 * disk_images_fat_images:: Virtual FAT disk images
1137 @node disk_images_quickstart
1138 @subsection Quick start for disk image creation
1140 You can create a disk image with the command:
1142 qemu-img create myimage.img mysize
1144 where @var{myimage.img} is the disk image filename and @var{mysize} is its
1145 size in kilobytes. You can add an @code{M} suffix to give the size in
1146 megabytes and a @code{G} suffix for gigabytes.
1148 See @ref{qemu_img_invocation} for more information.
1150 @node disk_images_snapshot_mode
1151 @subsection Snapshot mode
1153 If you use the option @option{-snapshot}, all disk images are
1154 considered as read only. When sectors in written, they are written in
1155 a temporary file created in @file{/tmp}. You can however force the
1156 write back to the raw disk images by using the @code{commit} monitor
1157 command (or @key{C-a s} in the serial console).
1160 @subsection VM snapshots
1162 VM snapshots are snapshots of the complete virtual machine including
1163 CPU state, RAM, device state and the content of all the writable
1164 disks. In order to use VM snapshots, you must have at least one non
1165 removable and writable block device using the @code{qcow2} disk image
1166 format. Normally this device is the first virtual hard drive.
1168 Use the monitor command @code{savevm} to create a new VM snapshot or
1169 replace an existing one. A human readable name can be assigned to each
1170 snapshot in addition to its numerical ID.
1172 Use @code{loadvm} to restore a VM snapshot and @code{delvm} to remove
1173 a VM snapshot. @code{info snapshots} lists the available snapshots
1174 with their associated information:
1177 (qemu) info snapshots
1178 Snapshot devices: hda
1179 Snapshot list (from hda):
1180 ID TAG VM SIZE DATE VM CLOCK
1181 1 start 41M 2006-08-06 12:38:02 00:00:14.954
1182 2 40M 2006-08-06 12:43:29 00:00:18.633
1183 3 msys 40M 2006-08-06 12:44:04 00:00:23.514
1186 A VM snapshot is made of a VM state info (its size is shown in
1187 @code{info snapshots}) and a snapshot of every writable disk image.
1188 The VM state info is stored in the first @code{qcow2} non removable
1189 and writable block device. The disk image snapshots are stored in
1190 every disk image. The size of a snapshot in a disk image is difficult
1191 to evaluate and is not shown by @code{info snapshots} because the
1192 associated disk sectors are shared among all the snapshots to save
1193 disk space (otherwise each snapshot would need a full copy of all the
1196 When using the (unrelated) @code{-snapshot} option
1197 (@ref{disk_images_snapshot_mode}), you can always make VM snapshots,
1198 but they are deleted as soon as you exit QEMU.
1200 VM snapshots currently have the following known limitations:
1203 They cannot cope with removable devices if they are removed or
1204 inserted after a snapshot is done.
1206 A few device drivers still have incomplete snapshot support so their
1207 state is not saved or restored properly (in particular USB).
1210 @node qemu_img_invocation
1211 @subsection @code{qemu-img} Invocation
1213 @include qemu-img.texi
1216 @subsection Using host drives
1218 In addition to disk image files, QEMU can directly access host
1219 devices. We describe here the usage for QEMU version >= 0.8.3.
1221 @subsubsection Linux
1223 On Linux, you can directly use the host device filename instead of a
1224 disk image filename provided you have enough privileges to access
1225 it. For example, use @file{/dev/cdrom} to access to the CDROM or
1226 @file{/dev/fd0} for the floppy.
1230 You can specify a CDROM device even if no CDROM is loaded. QEMU has
1231 specific code to detect CDROM insertion or removal. CDROM ejection by
1232 the guest OS is supported. Currently only data CDs are supported.
1234 You can specify a floppy device even if no floppy is loaded. Floppy
1235 removal is currently not detected accurately (if you change floppy
1236 without doing floppy access while the floppy is not loaded, the guest
1237 OS will think that the same floppy is loaded).
1239 Hard disks can be used. Normally you must specify the whole disk
1240 (@file{/dev/hdb} instead of @file{/dev/hdb1}) so that the guest OS can
1241 see it as a partitioned disk. WARNING: unless you know what you do, it
1242 is better to only make READ-ONLY accesses to the hard disk otherwise
1243 you may corrupt your host data (use the @option{-snapshot} command
1244 line option or modify the device permissions accordingly).
1247 @subsubsection Windows
1251 The preferred syntax is the drive letter (e.g. @file{d:}). The
1252 alternate syntax @file{\\.\d:} is supported. @file{/dev/cdrom} is
1253 supported as an alias to the first CDROM drive.
1255 Currently there is no specific code to handle removable media, so it
1256 is better to use the @code{change} or @code{eject} monitor commands to
1257 change or eject media.
1259 Hard disks can be used with the syntax: @file{\\.\PhysicalDriveN}
1260 where @var{N} is the drive number (0 is the first hard disk).
1262 WARNING: unless you know what you do, it is better to only make
1263 READ-ONLY accesses to the hard disk otherwise you may corrupt your
1264 host data (use the @option{-snapshot} command line so that the
1265 modifications are written in a temporary file).
1269 @subsubsection Mac OS X
1271 @file{/dev/cdrom} is an alias to the first CDROM.
1273 Currently there is no specific code to handle removable media, so it
1274 is better to use the @code{change} or @code{eject} monitor commands to
1275 change or eject media.
1277 @node disk_images_fat_images
1278 @subsection Virtual FAT disk images
1280 QEMU can automatically create a virtual FAT disk image from a
1281 directory tree. In order to use it, just type:
1284 qemu linux.img -hdb fat:/my_directory
1287 Then you access access to all the files in the @file{/my_directory}
1288 directory without having to copy them in a disk image or to export
1289 them via SAMBA or NFS. The default access is @emph{read-only}.
1291 Floppies can be emulated with the @code{:floppy:} option:
1294 qemu linux.img -fda fat:floppy:/my_directory
1297 A read/write support is available for testing (beta stage) with the
1301 qemu linux.img -fda fat:floppy:rw:/my_directory
1304 What you should @emph{never} do:
1306 @item use non-ASCII filenames ;
1307 @item use "-snapshot" together with ":rw:" ;
1308 @item expect it to work when loadvm'ing ;
1309 @item write to the FAT directory on the host system while accessing it with the guest system.
1313 @section Network emulation
1315 QEMU can simulate several network cards (PCI or ISA cards on the PC
1316 target) and can connect them to an arbitrary number of Virtual Local
1317 Area Networks (VLANs). Host TAP devices can be connected to any QEMU
1318 VLAN. VLAN can be connected between separate instances of QEMU to
1319 simulate large networks. For simpler usage, a non privileged user mode
1320 network stack can replace the TAP device to have a basic network
1325 QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
1326 connection between several network devices. These devices can be for
1327 example QEMU virtual Ethernet cards or virtual Host ethernet devices
1330 @subsection Using TAP network interfaces
1332 This is the standard way to connect QEMU to a real network. QEMU adds
1333 a virtual network device on your host (called @code{tapN}), and you
1334 can then configure it as if it was a real ethernet card.
1336 @subsubsection Linux host
1338 As an example, you can download the @file{linux-test-xxx.tar.gz}
1339 archive and copy the script @file{qemu-ifup} in @file{/etc} and
1340 configure properly @code{sudo} so that the command @code{ifconfig}
1341 contained in @file{qemu-ifup} can be executed as root. You must verify
1342 that your host kernel supports the TAP network interfaces: the
1343 device @file{/dev/net/tun} must be present.
1345 See @ref{sec_invocation} to have examples of command lines using the
1346 TAP network interfaces.
1348 @subsubsection Windows host
1350 There is a virtual ethernet driver for Windows 2000/XP systems, called
1351 TAP-Win32. But it is not included in standard QEMU for Windows,
1352 so you will need to get it separately. It is part of OpenVPN package,
1353 so download OpenVPN from : @url{http://openvpn.net/}.
1355 @subsection Using the user mode network stack
1357 By using the option @option{-net user} (default configuration if no
1358 @option{-net} option is specified), QEMU uses a completely user mode
1359 network stack (you don't need root privilege to use the virtual
1360 network). The virtual network configuration is the following:
1364 QEMU VLAN <------> Firewall/DHCP server <-----> Internet
1367 ----> DNS server (10.0.2.3)
1369 ----> SMB server (10.0.2.4)
1372 The QEMU VM behaves as if it was behind a firewall which blocks all
1373 incoming connections. You can use a DHCP client to automatically
1374 configure the network in the QEMU VM. The DHCP server assign addresses
1375 to the hosts starting from 10.0.2.15.
1377 In order to check that the user mode network is working, you can ping
1378 the address 10.0.2.2 and verify that you got an address in the range
1379 10.0.2.x from the QEMU virtual DHCP server.
1381 Note that @code{ping} is not supported reliably to the internet as it
1382 would require root privileges. It means you can only ping the local
1385 When using the built-in TFTP server, the router is also the TFTP
1388 When using the @option{-redir} option, TCP or UDP connections can be
1389 redirected from the host to the guest. It allows for example to
1390 redirect X11, telnet or SSH connections.
1392 @subsection Connecting VLANs between QEMU instances
1394 Using the @option{-net socket} option, it is possible to make VLANs
1395 that span several QEMU instances. See @ref{sec_invocation} to have a
1398 @node direct_linux_boot
1399 @section Direct Linux Boot
1401 This section explains how to launch a Linux kernel inside QEMU without
1402 having to make a full bootable image. It is very useful for fast Linux
1407 qemu -kernel arch/i386/boot/bzImage -hda root-2.4.20.img -append "root=/dev/hda"
1410 Use @option{-kernel} to provide the Linux kernel image and
1411 @option{-append} to give the kernel command line arguments. The
1412 @option{-initrd} option can be used to provide an INITRD image.
1414 When using the direct Linux boot, a disk image for the first hard disk
1415 @file{hda} is required because its boot sector is used to launch the
1418 If you do not need graphical output, you can disable it and redirect
1419 the virtual serial port and the QEMU monitor to the console with the
1420 @option{-nographic} option. The typical command line is:
1422 qemu -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1423 -append "root=/dev/hda console=ttyS0" -nographic
1426 Use @key{Ctrl-a c} to switch between the serial console and the
1427 monitor (@pxref{pcsys_keys}).
1430 @section USB emulation
1432 QEMU emulates a PCI UHCI USB controller. You can virtually plug
1433 virtual USB devices or real host USB devices (experimental, works only
1434 on Linux hosts). Qemu will automatically create and connect virtual USB hubs
1435 as necessary to connect multiple USB devices.
1439 * host_usb_devices::
1442 @subsection Connecting USB devices
1444 USB devices can be connected with the @option{-usbdevice} commandline option
1445 or the @code{usb_add} monitor command. Available devices are:
1449 Virtual Mouse. This will override the PS/2 mouse emulation when activated.
1451 Pointer device that uses absolute coordinates (like a touchscreen).
1452 This means qemu is able to report the mouse position without having
1453 to grab the mouse. Also overrides the PS/2 mouse emulation when activated.
1454 @item @code{disk:file}
1455 Mass storage device based on @var{file} (@pxref{disk_images})
1456 @item @code{host:bus.addr}
1457 Pass through the host device identified by @var{bus.addr}
1459 @item @code{host:vendor_id:product_id}
1460 Pass through the host device identified by @var{vendor_id:product_id}
1462 @item @code{wacom-tablet}
1463 Virtual Wacom PenPartner tablet. This device is similar to the @code{tablet}
1464 above but it can be used with the tslib library because in addition to touch
1465 coordinates it reports touch pressure.
1466 @item @code{keyboard}
1467 Standard USB keyboard. Will override the PS/2 keyboard (if present).
1470 @node host_usb_devices
1471 @subsection Using host USB devices on a Linux host
1473 WARNING: this is an experimental feature. QEMU will slow down when
1474 using it. USB devices requiring real time streaming (i.e. USB Video
1475 Cameras) are not supported yet.
1478 @item If you use an early Linux 2.4 kernel, verify that no Linux driver
1479 is actually using the USB device. A simple way to do that is simply to
1480 disable the corresponding kernel module by renaming it from @file{mydriver.o}
1481 to @file{mydriver.o.disabled}.
1483 @item Verify that @file{/proc/bus/usb} is working (most Linux distributions should enable it by default). You should see something like that:
1489 @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:
1491 chown -R myuid /proc/bus/usb
1494 @item Launch QEMU and do in the monitor:
1497 Device 1.2, speed 480 Mb/s
1498 Class 00: USB device 1234:5678, USB DISK
1500 You should see the list of the devices you can use (Never try to use
1501 hubs, it won't work).
1503 @item Add the device in QEMU by using:
1505 usb_add host:1234:5678
1508 Normally the guest OS should report that a new USB device is
1509 plugged. You can use the option @option{-usbdevice} to do the same.
1511 @item Now you can try to use the host USB device in QEMU.
1515 When relaunching QEMU, you may have to unplug and plug again the USB
1516 device to make it work again (this is a bug).
1519 @section VNC security
1521 The VNC server capability provides access to the graphical console
1522 of the guest VM across the network. This has a number of security
1523 considerations depending on the deployment scenarios.
1527 * vnc_sec_password::
1528 * vnc_sec_certificate::
1529 * vnc_sec_certificate_verify::
1530 * vnc_sec_certificate_pw::
1531 * vnc_generate_cert::
1534 @subsection Without passwords
1536 The simplest VNC server setup does not include any form of authentication.
1537 For this setup it is recommended to restrict it to listen on a UNIX domain
1538 socket only. For example
1541 qemu [...OPTIONS...] -vnc unix:/home/joebloggs/.qemu-myvm-vnc
1544 This ensures that only users on local box with read/write access to that
1545 path can access the VNC server. To securely access the VNC server from a
1546 remote machine, a combination of netcat+ssh can be used to provide a secure
1549 @node vnc_sec_password
1550 @subsection With passwords
1552 The VNC protocol has limited support for password based authentication. Since
1553 the protocol limits passwords to 8 characters it should not be considered
1554 to provide high security. The password can be fairly easily brute-forced by
1555 a client making repeat connections. For this reason, a VNC server using password
1556 authentication should be restricted to only listen on the loopback interface
1557 or UNIX domain sockets. Password ayuthentication is requested with the @code{password}
1558 option, and then once QEMU is running the password is set with the monitor. Until
1559 the monitor is used to set the password all clients will be rejected.
1562 qemu [...OPTIONS...] -vnc :1,password -monitor stdio
1563 (qemu) change vnc password
1568 @node vnc_sec_certificate
1569 @subsection With x509 certificates
1571 The QEMU VNC server also implements the VeNCrypt extension allowing use of
1572 TLS for encryption of the session, and x509 certificates for authentication.
1573 The use of x509 certificates is strongly recommended, because TLS on its
1574 own is susceptible to man-in-the-middle attacks. Basic x509 certificate
1575 support provides a secure session, but no authentication. This allows any
1576 client to connect, and provides an encrypted session.
1579 qemu [...OPTIONS...] -vnc :1,tls,x509=/etc/pki/qemu -monitor stdio
1582 In the above example @code{/etc/pki/qemu} should contain at least three files,
1583 @code{ca-cert.pem}, @code{server-cert.pem} and @code{server-key.pem}. Unprivileged
1584 users will want to use a private directory, for example @code{$HOME/.pki/qemu}.
1585 NB the @code{server-key.pem} file should be protected with file mode 0600 to
1586 only be readable by the user owning it.
1588 @node vnc_sec_certificate_verify
1589 @subsection With x509 certificates and client verification
1591 Certificates can also provide a means to authenticate the client connecting.
1592 The server will request that the client provide a certificate, which it will
1593 then validate against the CA certificate. This is a good choice if deploying
1594 in an environment with a private internal certificate authority.
1597 qemu [...OPTIONS...] -vnc :1,tls,x509verify=/etc/pki/qemu -monitor stdio
1601 @node vnc_sec_certificate_pw
1602 @subsection With x509 certificates, client verification and passwords
1604 Finally, the previous method can be combined with VNC password authentication
1605 to provide two layers of authentication for clients.
1608 qemu [...OPTIONS...] -vnc :1,password,tls,x509verify=/etc/pki/qemu -monitor stdio
1609 (qemu) change vnc password
1614 @node vnc_generate_cert
1615 @subsection Generating certificates for VNC
1617 The GNU TLS packages provides a command called @code{certtool} which can
1618 be used to generate certificates and keys in PEM format. At a minimum it
1619 is neccessary to setup a certificate authority, and issue certificates to
1620 each server. If using certificates for authentication, then each client
1621 will also need to be issued a certificate. The recommendation is for the
1622 server to keep its certificates in either @code{/etc/pki/qemu} or for
1623 unprivileged users in @code{$HOME/.pki/qemu}.
1627 * vnc_generate_server::
1628 * vnc_generate_client::
1630 @node vnc_generate_ca
1631 @subsubsection Setup the Certificate Authority
1633 This step only needs to be performed once per organization / organizational
1634 unit. First the CA needs a private key. This key must be kept VERY secret
1635 and secure. If this key is compromised the entire trust chain of the certificates
1636 issued with it is lost.
1639 # certtool --generate-privkey > ca-key.pem
1642 A CA needs to have a public certificate. For simplicity it can be a self-signed
1643 certificate, or one issue by a commercial certificate issuing authority. To
1644 generate a self-signed certificate requires one core piece of information, the
1645 name of the organization.
1648 # cat > ca.info <<EOF
1649 cn = Name of your organization
1653 # certtool --generate-self-signed \
1654 --load-privkey ca-key.pem
1655 --template ca.info \
1656 --outfile ca-cert.pem
1659 The @code{ca-cert.pem} file should be copied to all servers and clients wishing to utilize
1660 TLS support in the VNC server. The @code{ca-key.pem} must not be disclosed/copied at all.
1662 @node vnc_generate_server
1663 @subsubsection Issuing server certificates
1665 Each server (or host) needs to be issued with a key and certificate. When connecting
1666 the certificate is sent to the client which validates it against the CA certificate.
1667 The core piece of information for a server certificate is the hostname. This should
1668 be the fully qualified hostname that the client will connect with, since the client
1669 will typically also verify the hostname in the certificate. On the host holding the
1670 secure CA private key:
1673 # cat > server.info <<EOF
1674 organization = Name of your organization
1675 cn = server.foo.example.com
1680 # certtool --generate-privkey > server-key.pem
1681 # certtool --generate-certificate \
1682 --load-ca-certificate ca-cert.pem \
1683 --load-ca-privkey ca-key.pem \
1684 --load-privkey server server-key.pem \
1685 --template server.info \
1686 --outfile server-cert.pem
1689 The @code{server-key.pem} and @code{server-cert.pem} files should now be securely copied
1690 to the server for which they were generated. The @code{server-key.pem} is security
1691 sensitive and should be kept protected with file mode 0600 to prevent disclosure.
1693 @node vnc_generate_client
1694 @subsubsection Issuing client certificates
1696 If the QEMU VNC server is to use the @code{x509verify} option to validate client
1697 certificates as its authentication mechanism, each client also needs to be issued
1698 a certificate. The client certificate contains enough metadata to uniquely identify
1699 the client, typically organization, state, city, building, etc. On the host holding
1700 the secure CA private key:
1703 # cat > client.info <<EOF
1707 organiazation = Name of your organization
1708 cn = client.foo.example.com
1713 # certtool --generate-privkey > client-key.pem
1714 # certtool --generate-certificate \
1715 --load-ca-certificate ca-cert.pem \
1716 --load-ca-privkey ca-key.pem \
1717 --load-privkey client-key.pem \
1718 --template client.info \
1719 --outfile client-cert.pem
1722 The @code{client-key.pem} and @code{client-cert.pem} files should now be securely
1723 copied to the client for which they were generated.
1728 QEMU has a primitive support to work with gdb, so that you can do
1729 'Ctrl-C' while the virtual machine is running and inspect its state.
1731 In order to use gdb, launch qemu with the '-s' option. It will wait for a
1734 > qemu -s -kernel arch/i386/boot/bzImage -hda root-2.4.20.img \
1735 -append "root=/dev/hda"
1736 Connected to host network interface: tun0
1737 Waiting gdb connection on port 1234
1740 Then launch gdb on the 'vmlinux' executable:
1745 In gdb, connect to QEMU:
1747 (gdb) target remote localhost:1234
1750 Then you can use gdb normally. For example, type 'c' to launch the kernel:
1755 Here are some useful tips in order to use gdb on system code:
1759 Use @code{info reg} to display all the CPU registers.
1761 Use @code{x/10i $eip} to display the code at the PC position.
1763 Use @code{set architecture i8086} to dump 16 bit code. Then use
1764 @code{x/10i $cs*16+$eip} to dump the code at the PC position.
1767 @node pcsys_os_specific
1768 @section Target OS specific information
1772 To have access to SVGA graphic modes under X11, use the @code{vesa} or
1773 the @code{cirrus} X11 driver. For optimal performances, use 16 bit
1774 color depth in the guest and the host OS.
1776 When using a 2.6 guest Linux kernel, you should add the option
1777 @code{clock=pit} on the kernel command line because the 2.6 Linux
1778 kernels make very strict real time clock checks by default that QEMU
1779 cannot simulate exactly.
1781 When using a 2.6 guest Linux kernel, verify that the 4G/4G patch is
1782 not activated because QEMU is slower with this patch. The QEMU
1783 Accelerator Module is also much slower in this case. Earlier Fedora
1784 Core 3 Linux kernel (< 2.6.9-1.724_FC3) were known to incorporate this
1785 patch by default. Newer kernels don't have it.
1789 If you have a slow host, using Windows 95 is better as it gives the
1790 best speed. Windows 2000 is also a good choice.
1792 @subsubsection SVGA graphic modes support
1794 QEMU emulates a Cirrus Logic GD5446 Video
1795 card. All Windows versions starting from Windows 95 should recognize
1796 and use this graphic card. For optimal performances, use 16 bit color
1797 depth in the guest and the host OS.
1799 If you are using Windows XP as guest OS and if you want to use high
1800 resolution modes which the Cirrus Logic BIOS does not support (i.e. >=
1801 1280x1024x16), then you should use the VESA VBE virtual graphic card
1802 (option @option{-std-vga}).
1804 @subsubsection CPU usage reduction
1806 Windows 9x does not correctly use the CPU HLT
1807 instruction. The result is that it takes host CPU cycles even when
1808 idle. You can install the utility from
1809 @url{http://www.user.cityline.ru/~maxamn/amnhltm.zip} to solve this
1810 problem. Note that no such tool is needed for NT, 2000 or XP.
1812 @subsubsection Windows 2000 disk full problem
1814 Windows 2000 has a bug which gives a disk full problem during its
1815 installation. When installing it, use the @option{-win2k-hack} QEMU
1816 option to enable a specific workaround. After Windows 2000 is
1817 installed, you no longer need this option (this option slows down the
1820 @subsubsection Windows 2000 shutdown
1822 Windows 2000 cannot automatically shutdown in QEMU although Windows 98
1823 can. It comes from the fact that Windows 2000 does not automatically
1824 use the APM driver provided by the BIOS.
1826 In order to correct that, do the following (thanks to Struan
1827 Bartlett): go to the Control Panel => Add/Remove Hardware & Next =>
1828 Add/Troubleshoot a device => Add a new device & Next => No, select the
1829 hardware from a list & Next => NT Apm/Legacy Support & Next => Next
1830 (again) a few times. Now the driver is installed and Windows 2000 now
1831 correctly instructs QEMU to shutdown at the appropriate moment.
1833 @subsubsection Share a directory between Unix and Windows
1835 See @ref{sec_invocation} about the help of the option @option{-smb}.
1837 @subsubsection Windows XP security problem
1839 Some releases of Windows XP install correctly but give a security
1842 A problem is preventing Windows from accurately checking the
1843 license for this computer. Error code: 0x800703e6.
1846 The workaround is to install a service pack for XP after a boot in safe
1847 mode. Then reboot, and the problem should go away. Since there is no
1848 network while in safe mode, its recommended to download the full
1849 installation of SP1 or SP2 and transfer that via an ISO or using the
1850 vvfat block device ("-hdb fat:directory_which_holds_the_SP").
1852 @subsection MS-DOS and FreeDOS
1854 @subsubsection CPU usage reduction
1856 DOS does not correctly use the CPU HLT instruction. The result is that
1857 it takes host CPU cycles even when idle. You can install the utility
1858 from @url{http://www.vmware.com/software/dosidle210.zip} to solve this
1861 @node QEMU System emulator for non PC targets
1862 @chapter QEMU System emulator for non PC targets
1864 QEMU is a generic emulator and it emulates many non PC
1865 machines. Most of the options are similar to the PC emulator. The
1866 differences are mentioned in the following sections.
1869 * QEMU PowerPC System emulator::
1870 * Sparc32 System emulator::
1871 * Sparc64 System emulator::
1872 * MIPS System emulator::
1873 * ARM System emulator::
1874 * ColdFire System emulator::
1877 @node QEMU PowerPC System emulator
1878 @section QEMU PowerPC System emulator
1880 Use the executable @file{qemu-system-ppc} to simulate a complete PREP
1881 or PowerMac PowerPC system.
1883 QEMU emulates the following PowerMac peripherals:
1889 PCI VGA compatible card with VESA Bochs Extensions
1891 2 PMAC IDE interfaces with hard disk and CD-ROM support
1897 VIA-CUDA with ADB keyboard and mouse.
1900 QEMU emulates the following PREP peripherals:
1906 PCI VGA compatible card with VESA Bochs Extensions
1908 2 IDE interfaces with hard disk and CD-ROM support
1912 NE2000 network adapters
1916 PREP Non Volatile RAM
1918 PC compatible keyboard and mouse.
1921 QEMU uses the Open Hack'Ware Open Firmware Compatible BIOS available at
1922 @url{http://perso.magic.fr/l_indien/OpenHackWare/index.htm}.
1924 @c man begin OPTIONS
1926 The following options are specific to the PowerPC emulation:
1930 @item -g WxH[xDEPTH]
1932 Set the initial VGA graphic mode. The default is 800x600x15.
1939 More information is available at
1940 @url{http://perso.magic.fr/l_indien/qemu-ppc/}.
1942 @node Sparc32 System emulator
1943 @section Sparc32 System emulator
1945 Use the executable @file{qemu-system-sparc} to simulate a SparcStation 5
1946 or SparcStation 10 (sun4m architecture). The emulation is somewhat complete.
1947 SMP up to 16 CPUs is supported, but Linux limits the number of usable CPUs
1950 QEMU emulates the following sun4m peripherals:
1958 Lance (Am7990) Ethernet
1960 Non Volatile RAM M48T08
1962 Slave I/O: timers, interrupt controllers, Zilog serial ports, keyboard
1963 and power/reset logic
1965 ESP SCSI controller with hard disk and CD-ROM support
1969 CS4231 sound device (only on SS-5, not working yet)
1972 The number of peripherals is fixed in the architecture. Maximum memory size
1973 depends on the machine type, for SS-5 it is 256MB and for SS-10 2047MB.
1975 Since version 0.8.2, QEMU uses OpenBIOS
1976 @url{http://www.openbios.org/}. OpenBIOS is a free (GPL v2) portable
1977 firmware implementation. The goal is to implement a 100% IEEE
1978 1275-1994 (referred to as Open Firmware) compliant firmware.
1980 A sample Linux 2.6 series kernel and ram disk image are available on
1981 the QEMU web site. Please note that currently NetBSD, OpenBSD or
1982 Solaris kernels don't work.
1984 @c man begin OPTIONS
1986 The following options are specific to the Sparc32 emulation:
1990 @item -g WxHx[xDEPTH]
1992 Set the initial TCX graphic mode. The default is 1024x768x8, currently
1993 the only other possible mode is 1024x768x24.
1995 @item -prom-env string
1997 Set OpenBIOS variables in NVRAM, for example:
2000 qemu-system-sparc -prom-env 'auto-boot?=false' \
2001 -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'
2004 @item -M [SS-5|SS-10]
2006 Set the emulated machine type. Default is SS-5.
2012 @node Sparc64 System emulator
2013 @section Sparc64 System emulator
2015 Use the executable @file{qemu-system-sparc64} to simulate a Sun4u machine.
2016 The emulator is not usable for anything yet.
2018 QEMU emulates the following sun4u peripherals:
2022 UltraSparc IIi APB PCI Bridge
2024 PCI VGA compatible card with VESA Bochs Extensions
2026 Non Volatile RAM M48T59
2028 PC-compatible serial ports
2031 @node MIPS System emulator
2032 @section MIPS System emulator
2034 Use the executable @file{qemu-system-mips} to simulate a MIPS machine.
2035 Three different machine types are emulated:
2039 A generic ISA PC-like machine "mips"
2041 The MIPS Malta prototype board "malta"
2043 An ACER Pica "pica61"
2045 MIPS emulator pseudo board "mipssim"
2048 The generic emulation is supported by Debian 'Etch' and is able to
2049 install Debian into a virtual disk image. The following devices are
2054 A range of MIPS CPUs, default is the 24Kf
2056 PC style serial port
2063 The Malta emulation supports the following devices:
2067 Core board with MIPS 24Kf CPU and Galileo system controller
2069 PIIX4 PCI/USB/SMbus controller
2071 The Multi-I/O chip's serial device
2073 PCnet32 PCI network card
2075 Malta FPGA serial device
2077 Cirrus VGA graphics card
2080 The ACER Pica emulation supports:
2086 PC-style IRQ and DMA controllers
2093 The mipssim pseudo board emulation provides an environment similiar
2094 to what the proprietary MIPS emulator uses for running Linux.
2099 A range of MIPS CPUs, default is the 24Kf
2101 PC style serial port
2103 MIPSnet network emulation
2106 @node ARM System emulator
2107 @section ARM System emulator
2109 Use the executable @file{qemu-system-arm} to simulate a ARM
2110 machine. The ARM Integrator/CP board is emulated with the following
2115 ARM926E, ARM1026E or ARM946E CPU
2119 SMC 91c111 Ethernet adapter
2121 PL110 LCD controller
2123 PL050 KMI with PS/2 keyboard and mouse.
2125 PL181 MultiMedia Card Interface with SD card.
2128 The ARM Versatile baseboard is emulated with the following devices:
2134 PL190 Vectored Interrupt Controller
2138 SMC 91c111 Ethernet adapter
2140 PL110 LCD controller
2142 PL050 KMI with PS/2 keyboard and mouse.
2144 PCI host bridge. Note the emulated PCI bridge only provides access to
2145 PCI memory space. It does not provide access to PCI IO space.
2146 This means some devices (eg. ne2k_pci NIC) are not usable, and others
2147 (eg. rtl8139 NIC) are only usable when the guest drivers use the memory
2148 mapped control registers.
2150 PCI OHCI USB controller.
2152 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices.
2154 PL181 MultiMedia Card Interface with SD card.
2157 The ARM RealView Emulation baseboard is emulated with the following devices:
2163 ARM AMBA Generic/Distributed Interrupt Controller
2167 SMC 91c111 Ethernet adapter
2169 PL110 LCD controller
2171 PL050 KMI with PS/2 keyboard and mouse
2175 PCI OHCI USB controller
2177 LSI53C895A PCI SCSI Host Bus Adapter with hard disk and CD-ROM devices
2179 PL181 MultiMedia Card Interface with SD card.
2182 The XScale-based clamshell PDA models ("Spitz", "Akita", "Borzoi"
2183 and "Terrier") emulation includes the following peripherals:
2187 Intel PXA270 System-on-chip (ARM V5TE core)
2191 IBM/Hitachi DSCM microdrive in a PXA PCMCIA slot - not in "Akita"
2193 On-chip OHCI USB controller
2195 On-chip LCD controller
2197 On-chip Real Time Clock
2199 TI ADS7846 touchscreen controller on SSP bus
2201 Maxim MAX1111 analog-digital converter on I@math{^2}C bus
2203 GPIO-connected keyboard controller and LEDs
2205 Secure Digital card connected to PXA MMC/SD host
2209 WM8750 audio CODEC on I@math{^2}C and I@math{^2}S busses
2212 The Palm Tungsten|E PDA (codename "Cheetah") emulation includes the
2217 Texas Instruments OMAP310 System-on-chip (ARM 925T core)
2219 ROM and RAM memories (ROM firmware image can be loaded with -option-rom)
2221 On-chip LCD controller
2223 On-chip Real Time Clock
2225 TI TSC2102i touchscreen controller / analog-digital converter / Audio
2226 CODEC, connected through MicroWire and I@math{^2}S busses
2228 GPIO-connected matrix keypad
2230 Secure Digital card connected to OMAP MMC/SD host
2235 A Linux 2.6 test image is available on the QEMU web site. More
2236 information is available in the QEMU mailing-list archive.
2238 @node ColdFire System emulator
2239 @section ColdFire System emulator
2241 Use the executable @file{qemu-system-m68k} to simulate a ColdFire machine.
2242 The emulator is able to boot a uClinux kernel.
2244 The M5208EVB emulation includes the following devices:
2248 MCF5208 ColdFire V2 Microprocessor (ISA A+ with EMAC).
2250 Three Two on-chip UARTs.
2252 Fast Ethernet Controller (FEC)
2255 The AN5206 emulation includes the following devices:
2259 MCF5206 ColdFire V2 Microprocessor.
2264 @node QEMU User space emulator
2265 @chapter QEMU User space emulator
2268 * Supported Operating Systems ::
2269 * Linux User space emulator::
2270 * Mac OS X/Darwin User space emulator ::
2273 @node Supported Operating Systems
2274 @section Supported Operating Systems
2276 The following OS are supported in user space emulation:
2280 Linux (referred as qemu-linux-user)
2282 Mac OS X/Darwin (referred as qemu-darwin-user)
2285 @node Linux User space emulator
2286 @section Linux User space emulator
2291 * Command line options::
2296 @subsection Quick Start
2298 In order to launch a Linux process, QEMU needs the process executable
2299 itself and all the target (x86) dynamic libraries used by it.
2303 @item On x86, you can just try to launch any process by using the native
2307 qemu-i386 -L / /bin/ls
2310 @code{-L /} tells that the x86 dynamic linker must be searched with a
2313 @item Since QEMU is also a linux process, you can launch qemu with
2314 qemu (NOTE: you can only do that if you compiled QEMU from the sources):
2317 qemu-i386 -L / qemu-i386 -L / /bin/ls
2320 @item On non x86 CPUs, you need first to download at least an x86 glibc
2321 (@file{qemu-runtime-i386-XXX-.tar.gz} on the QEMU web page). Ensure that
2322 @code{LD_LIBRARY_PATH} is not set:
2325 unset LD_LIBRARY_PATH
2328 Then you can launch the precompiled @file{ls} x86 executable:
2331 qemu-i386 tests/i386/ls
2333 You can look at @file{qemu-binfmt-conf.sh} so that
2334 QEMU is automatically launched by the Linux kernel when you try to
2335 launch x86 executables. It requires the @code{binfmt_misc} module in the
2338 @item The x86 version of QEMU is also included. You can try weird things such as:
2340 qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
2341 /usr/local/qemu-i386/bin/ls-i386
2347 @subsection Wine launch
2351 @item Ensure that you have a working QEMU with the x86 glibc
2352 distribution (see previous section). In order to verify it, you must be
2356 qemu-i386 /usr/local/qemu-i386/bin/ls-i386
2359 @item Download the binary x86 Wine install
2360 (@file{qemu-XXX-i386-wine.tar.gz} on the QEMU web page).
2362 @item Configure Wine on your account. Look at the provided script
2363 @file{/usr/local/qemu-i386/@/bin/wine-conf.sh}. Your previous
2364 @code{$@{HOME@}/.wine} directory is saved to @code{$@{HOME@}/.wine.org}.
2366 @item Then you can try the example @file{putty.exe}:
2369 qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
2370 /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
2375 @node Command line options
2376 @subsection Command line options
2379 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
2386 Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
2388 Set the x86 stack size in bytes (default=524288)
2395 Activate log (logfile=/tmp/qemu.log)
2397 Act as if the host page size was 'pagesize' bytes
2400 @node Other binaries
2401 @subsection Other binaries
2403 @command{qemu-arm} is also capable of running ARM "Angel" semihosted ELF
2404 binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
2405 configurations), and arm-uclinux bFLT format binaries.
2407 @command{qemu-m68k} is capable of running semihosted binaries using the BDM
2408 (m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
2409 coldfire uClinux bFLT format binaries.
2411 The binary format is detected automatically.
2413 @command{qemu-sparc32plus} can execute Sparc32 and SPARC32PLUS binaries
2414 (Sparc64 CPU, 32 bit ABI).
2416 @command{qemu-sparc64} can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
2417 SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
2419 @node Mac OS X/Darwin User space emulator
2420 @section Mac OS X/Darwin User space emulator
2423 * Mac OS X/Darwin Status::
2424 * Mac OS X/Darwin Quick Start::
2425 * Mac OS X/Darwin Command line options::
2428 @node Mac OS X/Darwin Status
2429 @subsection Mac OS X/Darwin Status
2433 target x86 on x86: Most apps (Cocoa and Carbon too) works. [1]
2435 target PowerPC on x86: Not working as the ppc commpage can't be mapped (yet!)
2437 target PowerPC on PowerPC: Most apps (Cocoa and Carbon too) works. [1]
2439 target x86 on PowerPC: most utilities work. Cocoa and Carbon apps are not yet supported.
2442 [1] If you're host commpage can be executed by qemu.
2444 @node Mac OS X/Darwin Quick Start
2445 @subsection Quick Start
2447 In order to launch a Mac OS X/Darwin process, QEMU needs the process executable
2448 itself and all the target dynamic libraries used by it. If you don't have the FAT
2449 libraries (you're running Mac OS X/ppc) you'll need to obtain it from a Mac OS X
2450 CD or compile them by hand.
2454 @item On x86, you can just try to launch any process by using the native
2461 or to run the ppc version of the executable:
2467 @item On ppc, you'll have to tell qemu where your x86 libraries (and dynamic linker)
2471 qemu-i386 -L /opt/x86_root/ /bin/ls
2474 @code{-L /opt/x86_root/} tells that the dynamic linker (dyld) path is in
2475 @file{/opt/x86_root/usr/bin/dyld}.
2479 @node Mac OS X/Darwin Command line options
2480 @subsection Command line options
2483 usage: qemu-i386 [-h] [-d] [-L path] [-s size] program [arguments...]
2490 Set the library root path (default=/)
2492 Set the stack size in bytes (default=524288)
2499 Activate log (logfile=/tmp/qemu.log)
2501 Act as if the host page size was 'pagesize' bytes
2505 @chapter Compilation from the sources
2510 * Cross compilation for Windows with Linux::
2517 @subsection Compilation
2519 First you must decompress the sources:
2522 tar zxvf qemu-x.y.z.tar.gz
2526 Then you configure QEMU and build it (usually no options are needed):
2532 Then type as root user:
2536 to install QEMU in @file{/usr/local}.
2538 @subsection GCC version
2540 In order to compile QEMU successfully, it is very important that you
2541 have the right tools. The most important one is gcc. On most hosts and
2542 in particular on x86 ones, @emph{gcc 4.x is not supported}. If your
2543 Linux distribution includes a gcc 4.x compiler, you can usually
2544 install an older version (it is invoked by @code{gcc32} or
2545 @code{gcc34}). The QEMU configure script automatically probes for
2546 these older versions so that usually you don't have to do anything.
2552 @item Install the current versions of MSYS and MinGW from
2553 @url{http://www.mingw.org/}. You can find detailed installation
2554 instructions in the download section and the FAQ.
2557 the MinGW development library of SDL 1.2.x
2558 (@file{SDL-devel-1.2.x-@/mingw32.tar.gz}) from
2559 @url{http://www.libsdl.org}. Unpack it in a temporary place, and
2560 unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
2561 directory. Edit the @file{sdl-config} script so that it gives the
2562 correct SDL directory when invoked.
2564 @item Extract the current version of QEMU.
2566 @item Start the MSYS shell (file @file{msys.bat}).
2568 @item Change to the QEMU directory. Launch @file{./configure} and
2569 @file{make}. If you have problems using SDL, verify that
2570 @file{sdl-config} can be launched from the MSYS command line.
2572 @item You can install QEMU in @file{Program Files/Qemu} by typing
2573 @file{make install}. Don't forget to copy @file{SDL.dll} in
2574 @file{Program Files/Qemu}.
2578 @node Cross compilation for Windows with Linux
2579 @section Cross compilation for Windows with Linux
2583 Install the MinGW cross compilation tools available at
2584 @url{http://www.mingw.org/}.
2587 Install the Win32 version of SDL (@url{http://www.libsdl.org}) by
2588 unpacking @file{i386-mingw32msvc.tar.gz}. Set up the PATH environment
2589 variable so that @file{i386-mingw32msvc-sdl-config} can be launched by
2590 the QEMU configuration script.
2593 Configure QEMU for Windows cross compilation:
2595 ./configure --enable-mingw32
2597 If necessary, you can change the cross-prefix according to the prefix
2598 chosen for the MinGW tools with --cross-prefix. You can also use
2599 --prefix to set the Win32 install path.
2601 @item You can install QEMU in the installation directory by typing
2602 @file{make install}. Don't forget to copy @file{SDL.dll} in the
2603 installation directory.
2607 Note: Currently, Wine does not seem able to launch
2613 The Mac OS X patches are not fully merged in QEMU, so you should look
2614 at the QEMU mailing list archive to have all the necessary