UsingVhost: Difference between revisions

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=== example command line ===
=== example command line ===
To start a guest with vhost:
To start a guest with vhost:
* /usr/bin/kvm -netdev type=tap,id=guest0,script=kvm-ifup,'''vhost=on''' -device virtio-net-pci,netdev=guest0,mac=00:16:3e:00:00:01 ..other options..
* kvm -netdev type=tap,id=guest0,script=kvm-ifup,'''vhost=on''' -device virtio-net-pci,netdev=guest0,mac=''ma:c:a:dd:re:ss'' ..''other options''..


=== Caveats ===
=== Caveats ===
Some DHCP clients have problems with this implementation, more [http://www.spinics.net/lists/kvm/msg37660.html details here].
Some DHCP clients have problems with this implementation, more [http://www.spinics.net/lists/kvm/msg37660.html details here].

Revision as of 05:16, 24 February 2011

As of September 2010, vhost is not included in any released tarballs, so you need the git version.

VhostNet provides better latency (10% less than e1000 on my system) and greater throughput (8x the normal virtio, around 7~8 Gigabits/sec here) for network.

Obtaining the code

you need the at least qemu-kvm-0.13.0 (http://sourceforge.net/projects/kvm/files/qemu-kvm/)

kernel requirements

On the host you need a kernel with CONFIG_VHOST_NET=y and in the guest you need a kernel with CONFIG_PCI_MSI=y

example command line

To start a guest with vhost:

  • kvm -netdev type=tap,id=guest0,script=kvm-ifup,vhost=on -device virtio-net-pci,netdev=guest0,mac=ma:c:a:dd:re:ss ..other options..

Caveats

Some DHCP clients have problems with this implementation, more details here.