qemu-doc.texi

qemu虚拟机代码

@file{/usr/sbin/smbd}. QEMU was tested succesfully with smbd version
2.2.7a from the Red Hat 9 and version 3.0.10-1.fc3 from Fedora Core 3.

@item -redir [tcp|udp]:host-port:[guest-host]:guest-port

When using the user mode network stack, redirect incoming TCP or UDP
connections to the host port @var{host-port} to the guest
@var{guest-host} on guest port @var{guest-port}. If @var{guest-host}
is not specified, its value is 10.0.2.15 (default address given by the
built-in DHCP server).

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

@example
# on the host
qemu -redir tcp:6001::6000 [...]
# this host xterm should open in the guest X11 server
xterm -display :1
@end example

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

@example
# on the host
qemu -redir tcp:5555::23 [...]
telnet localhost 5555
@end example

Then when you use on the host @code{telnet localhost 5555}, you
connect to the guest telnet server.

@end table

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

@table @option

@item -kernel bzImage 
Use @var{bzImage} as kernel image.

@item -append cmdline 
Use @var{cmdline} as kernel command line

@item -initrd file
Use @var{file} as initial ram disk.

@end table

Debug/Expert options:
@table @option

@item -serial dev
Redirect the virtual serial port to host device @var{dev}. Available
devices are:
@table @code
@item vc
Virtual console
@item pty
[Linux only] Pseudo TTY (a new PTY is automatically allocated)
@item null
void device
@item /dev/XXX
[Linux only] Use host tty, e.g. @file{/dev/ttyS0}. The host serial port
parameters are set according to the emulated ones.
@item /dev/parportN
[Linux only, parallel port only] Use host parallel port
@var{N}. Currently only SPP parallel port features can be used.
@item file:filename
Write output to filename. No character can be read.
@item stdio
[Unix only] standard input/output
@item pipe:filename
[Unix only] name pipe @var{filename}
@end table
The default device is @code{vc} in graphical mode and @code{stdio} in
non graphical mode.

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

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

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

@item -monitor dev
Redirect the monitor to host device @var{dev} (same devices as the
serial port).
The default device is @code{vc} in graphical mode and @code{stdio} in
non graphical mode.

@item -s
Wait gdb connection to port 1234 (@pxref{gdb_usage}). 
@item -p port
Change gdb connection port.
@item -S
Do not start CPU at startup (you must type 'c' in the monitor).
@item -d             
Output log in /tmp/qemu.log
@item -hdachs c,h,s,[,t]
Force hard disk 0 physical geometry (1 <= @var{c} <= 16383, 1 <=
@var{h} <= 16, 1 <= @var{s} <= 63) and optionally force the BIOS
translation mode (@var{t}=none, lba or auto). Usually QEMU can guess
all thoses parameters. This option is useful for old MS-DOS disk
images.

@item -std-vga
Simulate a standard VGA card with Bochs VBE extensions (default is
Cirrus Logic GD5446 PCI VGA)
@item -loadvm file
Start right away with a saved state (@code{loadvm} in monitor)
@end table

@c man end

@node pcsys_keys
@section Keys

@c man begin OPTIONS

During the graphical emulation, you can use the following keys:
@table @key
@item Ctrl-Alt-f
Toggle full screen

@item Ctrl-Alt-n
Switch to virtual console 'n'. Standard console mappings are:
@table @emph
@item 1
Target system display
@item 2
Monitor
@item 3
Serial port
@end table

@item Ctrl-Alt
Toggle mouse and keyboard grab.
@end table

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

During emulation, if you are using the @option{-nographic} option, use
@key{Ctrl-a h} to get terminal commands:

@table @key
@item Ctrl-a h
Print this help
@item Ctrl-a x    
Exit emulatior
@item Ctrl-a s    
Save disk data back to file (if -snapshot)
@item Ctrl-a b
Send break (magic sysrq in Linux)
@item Ctrl-a c
Switch between console and monitor
@item Ctrl-a Ctrl-a
Send Ctrl-a
@end table
@c man end

@ignore

@c man begin SEEALSO
The HTML documentation of QEMU for more precise information and Linux
user mode emulator invocation.
@c man end

@c man begin AUTHOR
Fabrice Bellard
@c man end

@end ignore

@node pcsys_monitor
@section QEMU Monitor

The QEMU monitor is used to give complex commands to the QEMU
emulator. You can use it to:

@itemize @minus

@item
Remove or insert removable medias images
(such as CD-ROM or floppies)

@item 
Freeze/unfreeze the Virtual Machine (VM) and save or restore its state
from a disk file.

@item Inspect the VM state without an external debugger.

@end itemize

@subsection Commands

The following commands are available:

@table @option

@item help or ? [cmd]
Show the help for all commands or just for command @var{cmd}.

@item commit  
Commit changes to the disk images (if -snapshot is used)

@item info subcommand 
show various information about the system state

@table @option
@item info network
show the various VLANs and the associated devices
@item info block
show the block devices
@item info registers
show the cpu registers
@item info history
show the command line history
@item info pci
show emulated PCI device
@item info usb
show USB devices plugged on the virtual USB hub
@item info usbhost
show all USB host devices
@end table

@item q or quit
Quit the emulator.

@item eject [-f] device
Eject a removable media (use -f to force it).

@item change device filename
Change a removable media.

@item screendump filename
Save screen into PPM image @var{filename}.

@item log item1[,...]
Activate logging of the specified items to @file{/tmp/qemu.log}.

@item savevm filename
Save the whole virtual machine state to @var{filename}.

@item loadvm filename
Restore the whole virtual machine state from @var{filename}.

@item stop
Stop emulation.

@item c or cont
Resume emulation.

@item gdbserver [port]
Start gdbserver session (default port=1234)

@item x/fmt addr
Virtual memory dump starting at @var{addr}.

@item xp /fmt addr
Physical memory dump starting at @var{addr}.

@var{fmt} is a format which tells the command how to format the
data. Its syntax is: @option{/@{count@}@{format@}@{size@}}

@table @var
@item count 
is the number of items to be dumped.

@item format
can be x (hexa), d (signed decimal), u (unsigned decimal), o (octal),
c (char) or i (asm instruction).

@item size
can be b (8 bits), h (16 bits), w (32 bits) or g (64 bits). On x86,
@code{h} or @code{w} can be specified with the @code{i} format to
respectively select 16 or 32 bit code instruction size.

@end table

Examples: 
@itemize
@item
Dump 10 instructions at the current instruction pointer:
@example 
(qemu) x/10i $eip
0x90107063:  ret
0x90107064:  sti
0x90107065:  lea    0x0(%esi,1),%esi
0x90107069:  lea    0x0(%edi,1),%edi
0x90107070:  ret
0x90107071:  jmp    0x90107080
0x90107073:  nop
0x90107074:  nop
0x90107075:  nop
0x90107076:  nop
@end example

@item
Dump 80 16 bit values at the start of the video memory.
@smallexample 
(qemu) xp/80hx 0xb8000
0x000b8000: 0x0b50 0x0b6c 0x0b65 0x0b78 0x0b38 0x0b36 0x0b2f 0x0b42
0x000b8010: 0x0b6f 0x0b63 0x0b68 0x0b73 0x0b20 0x0b56 0x0b47 0x0b41
0x000b8020: 0x0b42 0x0b69 0x0b6f 0x0b73 0x0b20 0x0b63 0x0b75 0x0b72
0x000b8030: 0x0b72 0x0b65 0x0b6e 0x0b74 0x0b2d 0x0b63 0x0b76 0x0b73
0x000b8040: 0x0b20 0x0b30 0x0b35 0x0b20 0x0b4e 0x0b6f 0x0b76 0x0b20
0x000b8050: 0x0b32 0x0b30 0x0b30 0x0b33 0x0720 0x0720 0x0720 0x0720
0x000b8060: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
0x000b8070: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
0x000b8080: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
0x000b8090: 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720 0x0720
@end smallexample
@end itemize

@item p or print/fmt expr

Print expression value. Only the @var{format} part of @var{fmt} is
used.

@item sendkey keys

Send @var{keys} to the emulator. Use @code{-} to press several keys
simultaneously. Example:
@example
sendkey ctrl-alt-f1
@end example

This command is useful to send keys that your graphical user interface
intercepts at low level, such as @code{ctrl-alt-f1} in X Window.

@item system_reset

Reset the system.

@item usb_add devname

Plug the USB device devname to the QEMU virtual USB hub. @var{devname}
is either a virtual device name (for example @code{mouse}) or a host
USB device identifier. Host USB device identifiers have the following
syntax: @code{host:bus.addr} or @code{host:vendor_id:product_id}.

@item usb_del devname

Remove the USB device @var{devname} from the QEMU virtual USB
hub. @var{devname} has the syntax @code{bus.addr}. Use the monitor
command @code{info usb} to see the devices you can remove.

@end table

@subsection Integer expressions

The monitor understands integers expressions for every integer
argument. You can use register names to get the value of specifics
CPU registers by prefixing them with @emph{$}.

@node disk_images
@section Disk Images

Since version 0.6.1, QEMU supports many disk image formats, including
growable disk images (their size increase as non empty sectors are
written), compressed and encrypted disk images.

@menu
* disk_images_quickstart::    Quick start for disk image creation
* disk_images_snapshot_mode:: Snapshot mode
* qemu_img_invocation::       qemu-img Invocation
* disk_images_fat_images::    Virtual FAT disk images
@end menu

@node disk_images_quickstart
@subsection Quick start for disk image creation

You can create a disk image with the command:
@example
qemu-img create myimage.img mysize
@end example
where @var{myimage.img} is the disk image filename and @var{mysize} is its
size in kilobytes. You can add an @code{M} suffix to give the size in
megabytes and a @code{G} suffix for gigabytes.

See @ref{qemu_img_invocation} for more information.

@node disk_images_snapshot_mode
@subsection Snapshot mode

If you use the option @option{-snapshot}, all disk images are
considered as read only. When sectors in written, they are written in
a temporary file created in @file{/tmp}. You can however force the
write back to the raw disk images by using the @code{commit} monitor
command (or @key{C-a s} in the serial console).

@node qemu_img_invocation
@subsection @code{qemu-img} Invocation

@include qemu-img.texi

@node disk_images_fat_images
@subsection Virtual FAT disk images

QEMU can automatically create a virtual FAT disk image from a
directory tree. In order to use it, just type:

@example 
qemu linux.img -hdb fat:/my_directory
@end example

Then you access access to all the files in the @file{/my_directory}
directory without having to copy them in a disk image or to export
them via SAMBA or NFS. The default access is @emph{read-only}.

Floppies can be emulated with the @code{:floppy:} option:

@example 
qemu linux.img -fda fat:floppy:/my_directory
@end example

A read/write support is available for testing (beta stage) with the
@code{:rw:} option:

@example 
qemu linux.img -fda fat:floppy:rw:/my_directory
@end example

What you should @emph{never} do:
@itemize
@item use non-ASCII filenames ;
@item use "-snapshot" together with ":rw:" ;
@item expect it to work when loadvm'ing ;