KVM - User contributions [en]

Documents

2012-08-01T06:45:03Z

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= Documents =

== User/Admin documentation ==
* [[HOWTO]]
* [http://wiki.qemu.org/Qemu-doc.html QEMU user manual]
* [[Tuning_KVM]]
* [[Tuning_Kernel]]
== Presentations ==
* Presentations on many aspects of KVM were made at [[KVM Forum 2007]] (Aug 2007).
* Presentations from the [[KVM Forum 2008]] (June 2008)
* Avi Kivity's presentation from the [http://ols.108.redhat.com/2007/Reprints/kivity-Reprint.pdf Ottawa Linux Symposium 2007] (Jun 2007).
* TPR patching [attachment:kvm-tpr-patching.odp overview] (Avi Kivity, Oct 2008)
* [http://markmc.fedorapeople.org/virtio-code-review/VirtioCodeReview.pdf Virtio code walkthrough], [http://markmc.fedorapeople.org/virtio-code-review/virtio-talk.txt notes], [http://blogs.gnome.org/markmc/2008/05/28/checksums-scatter-gather-io-and-segmentation-offload/ GSO background] (Mark McLoughlin, Oct 2008), and [http://portal.acm.org/citation.cfm?id=1400097.1400108 ACM pdf about virtio by Rusty Russell]
== White papers: ==
* Qumranet's [http://www.qumranet.com/files/white_papers/KVM_Whitepaper.pdf KVM Whitepaper]
== Books ==
* [http://www.dpunkt.de/buecher/3519.html Book "KVM Best Practices", ISBN 978-3-89864-737-3]
* [http://qemu-buch.de/english/order.php Book "QEMU & KVM", ISBN 978-3-8370-0876-0]
* [http://www.seshop.com/product/detail/12214/ Book "KVM tettei nyuumon", ISBN 4798121401]
== Magazine Articles ==
* [http://www.linux-magazine.com/Issues/2008/86/DEEP-VIRTUE Linux Magazine]
* [http://www.linuxplanet.com/linuxplanet/reports/6490/4/ KVM for Embedded] at Linux Planet
* [http://www.linuxplanet.com/linuxplanet/reports/6503/1/ Linux as a hypervisor] at Linux Planet
== Benchmarks ==
* [http://www.phoronix.com/scan.php?page=article&item=ubuntu_virt_benchmarks&num=1 Phoronix - Ubuntu 8.04 KVM Benchmarks]
* [http://www.phoronix.com/scan.php?page=article&item=intel_corei7_virt&num=1 Phoronix - Intel Core i7 Virtualization Performance]
== Documentation ==
* [[small_look_inside|small look inside(kvm-54)]]
* [[buildup|qemu kvm buildup]]
* [[vl_runthrough|qemu-system-x86_64 startup (kvm-57)]]
* [[initialization|initialization (kvm-57)]]
* [[file_layout_in_kernel|file layout in kernel (~kvm-58)]]
* [http://qemu-buch.de/ Wikibook "QEMU & KVM"]
* [[Memory|How KVM deals with memory]] - a look inside how KVM interacts with the Linux VM.
* [[perf_events|Counting and tracing KVM events]]
* [http://blog.stgolabs.net/2012/03/kvm-virtual-x86-mmu-setup.html KVM x86 vMMU setup] - describes how KVM sets up a virtual memory management unit for x86.
* [http://blog.stgolabs.net/2012/03/kvm-hardware-assisted-paging.html KVM x86 hardware support paging] - a look inside how KVM deals with x86 2D hardware paging.
* [http://blog.stgolabs.net/2012/05/kvm-intel-associative-tlbs.html KVM Intel VPID implementation] - how KVM supports Intel's tagged TLBs

== KVM Doxygen Documentation ==
* [http://doxygen.org/ kvm doxygen documentation tool]
== Tools ==
* [[tools|Tools]]
== Supported cpus ==
* [[processor_support|cpus]]

VirtFS

2012-08-01T06:41:03Z

Steil:

= VirtFS =

VirtFS is a new paravirtualized filesystem interface designed for improving passthrough technologies in the KVM environment. It is based on the VirtIO framework and uses the 9P protocol.

== Feature functional description ==

== Detailed ==

=== Why use it? ===

* virtualization aware filesystem
* offers paravirtualized system services
* simple passthrough for directories from host to guest

== Backward/forward compatibility issues ==

Virtual Machine Manager integration since version 0.9.1

== Links & Sources ==

[[9p_virtio]] (Example Sharing A Host Directory With The Guest)

VirtFS

2012-08-01T06:33:08Z

Steil:

9p virtio

2012-08-01T06:27:18Z

Steil:

== Example Sharing Host files with the Guest ==

This example is based on qemu-kvm (0.15.0) as installed in Fedora 15.
Will first show how to do this manually, and second how to do it using the virt-manager tool. This HOWTO is documenting 9p virtio as the transport for sharing files.

In both cases we'll share files in /tmp/share on the host. In the guest, they'll show up in /tmp/host_files.

== Manually, using qemu-kvm command line ==

There are a nice set of details on the [http://wiki.qemu.org/Documentation/9psetup QEMU wiki] describing this, so this section will be quite short. To share host files w/ the guest, we use 9p over virtio in conjunction w/ a filesystem device exporting the portion of the host filesystem that we'd like to share with the guest.

# /usr/bin/qemu-kvm -m 1024 -name f15 -drive file=/images/f15.img,if=virtio
-fsdev local,security_model=passthrough,id=fsdev0,path=/tmp/share -device virtio-9p-pci,id=fs0,fsdev=fsdev0,mount_tag=hostshare

This tells qemu to create a 9pvirtio device exposing the mount_tag <code>hostshare</code> (just a name to identify the mount point). That device is coupled to an fsdev named <code>fsdev0</code>, which specifies which portion of the host filesystem we are sharing, and in which mode (see [http://wiki.qemu.org/Documentation/9psetup QEMU wiki] for details on the security models).

Now, in the guest we need to mount the 9p filesystem from the host using the virtio transport. The mount_tag is used to identify the host's share.

# mkdir /tmp/host_files
# mount -t 9p -o trans=virtio,version=9p2000.L hostshare /tmp/host_files

That's it...now we can read/write files in that directory from either the host or the guest.

== Managed, using virt-manager ==

This assumes you've already installed a guest with virt-manager or virt-install and it's shut off.

Start virt-manager, and open your VM by double clicking on it. Click the virtual hardware details (lightbulb). Click Add Hardware, and choose a Filesystem. Chose the mode, we chose squash which translates to none (see [http://wiki.qemu.org/Documentation/9psetup QEMU wiki] for details on the security models), the source (we are sharing /tmp/share), and the target (we called this /hostshare).

[[Image:Screenshot-add-filesystem-share.png]]

Now, start the VM. In the guest we need to mount the 9p filesystem from the host using the virtio transport. The mount_tag is used to identify the host's share.

# mkdir /tmp/host_files
# mount -t 9p -o trans=virtio,version=9p2000.L /hostshare /tmp/host_files

That's it...now we can read/write files in that directory from either the host or the guest. (Note: likely to hit some issues w/ privileges since Fedora libvirt runs guests unprivileged and with SELinux confinement...careful use of chown, chmod and chcon should get it working).

VirtFS

2012-08-01T06:06:49Z

Steil:

= VirtFS =

VirtFS is a new paravirtualized file system interface designed for improving passthrough technologies in the KVM environment. It's based on the VirtIO framework and uses the 9P protocol.

VirtFS

2012-08-01T06:06:19Z

Steil:

= VirtFS

VirtFS is a new paravirtualized file system interface designed for improving passthrough technologies in the KVM environment. It's based on the VirtIO framework and uses the 9P protocol.