diff options
Diffstat (limited to 'qemu-doc.texi')
| -rw-r--r-- | qemu-doc.texi | 56 |
1 files changed, 54 insertions, 2 deletions
diff --git a/qemu-doc.texi b/qemu-doc.texi index ac3c41718..612e5feb3 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -183,8 +183,8 @@ PCI UHCI USB controller and a virtual USB hub. SMP is supported with up to 255 CPUs. Note that adlib, ac97, gus and cs4231a are only available when QEMU -was configured with --enable-adlib, --enable-ac97, --enable-gus or ---enable-cs4231a respectively. +was configured with --audio-card-list option containing the name(s) of +required card(s). QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL VGA BIOS. @@ -973,6 +973,17 @@ On M68K this implements the "ColdFire GDB" interface used by libgloss. Note that this allows guest direct access to the host filesystem, so should only be used with trusted guest OS. + +@item -icount [N|auto] +Enable virtual instruction counter. The virtual cpu will execute one +instruction every 2^N ns of virtual time. If @code{auto} is specified +then the virtual cpu speed will be automatically adjusted to keep virtual +time within a few seconds of real time. + +Note that while this option can give deterministic behavior, it does not +provide cycle accurate emulation. Modern CPUs contain superscalar out of +order cores with complex cache hierarchies. The number of instructions +executed often has little or no correlation with actual performance. @end table @c man end @@ -1315,8 +1326,10 @@ snapshots. * disk_images_snapshot_mode:: Snapshot mode * vm_snapshots:: VM snapshots * qemu_img_invocation:: qemu-img Invocation +* qemu_nbd_invocation:: qemu-nbd Invocation * host_drives:: Using host drives * disk_images_fat_images:: Virtual FAT disk images +* disk_images_nbd:: NBD access @end menu @node disk_images_quickstart @@ -1397,6 +1410,11 @@ state is not saved or restored properly (in particular USB). @include qemu-img.texi +@node qemu_nbd_invocation +@subsection @code{qemu-nbd} Invocation + +@include qemu-nbd.texi + @node host_drives @subsection Using host drives @@ -1494,6 +1512,40 @@ What you should @emph{never} do: @item write to the FAT directory on the host system while accessing it with the guest system. @end itemize +@node disk_images_nbd +@subsection NBD access + +QEMU can access directly to block device exported using the Network Block Device +protocol. + +@example +qemu linux.img -hdb nbd:my_nbd_server.mydomain.org:1024 +@end example + +If the NBD server is located on the same host, you can use an unix socket instead +of an inet socket: + +@example +qemu linux.img -hdb nbd:unix:/tmp/my_socket +@end example + +In this case, the block device must be exported using qemu-nbd: + +@example +qemu-nbd --socket=/tmp/my_socket my_disk.qcow2 +@end example + +The use of qemu-nbd allows to share a disk between several guests: +@example +qemu-nbd --socket=/tmp/my_socket --share=2 my_disk.qcow2 +@end example + +and then you can use it with two guests: +@example +qemu linux1.img -hdb nbd:unix:/tmp/my_socket +qemu linux2.img -hdb nbd:unix:/tmp/my_socket +@end example + @node pcsys_network @section Network emulation |