[libvirt] How to enable vhost for virtIO NIC?
Hi gurus on the list,
I'm trying to bring up a Linux with virtio vhost backend. My system is running on
kernel 2.6.34-rc7, libvirt 0.8.0.
Two questions regarding to vhost:
1) XML format for vhost
I didn't find any documents on libvirt.org description the XML or QMU argument format
for vhost.
According to http://www.linux-kvm.org/page/VhostNet#vhost-net_driver_projects, I tried
*domxml-from-native* to convert following qemu argument to XML
qemu-system-x86_64 -m 1G disk-c.qcow2 \
-net nic,model=virtio,netdev=foo \
-netdev tap,id=foo,ifname=msttap0,script=/home/mst/ifup,downscript=no,vhost=on
But the output clearly ignore the network.
<domain type='qemu'>
<name>unnamed</name>
<uuid>9cc877c1-7ac2-463d-3d3f-fa8f8918fe23</uuid>
<memory>1048576</memory>
<currentMemory>1048576</currentMemory>
<vcpu>1</vcpu>
<os>
<type arch='x86_64'>hvm</type>
</os>
<features>
<acpi/>
</features>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<emulator>qemu-system-x86_64</emulator>
<input type='mouse' bus='ps2'/>
<graphics type='sdl'/>
<video>
<model type='cirrus' vram='9216' heads='1'/>
</video>
</devices>
</domain>
What's the problem here?
2) Virtio driver.
It's said that vhost require guest kernel version > 2.6.31 because vhost requires
MSI-X. How about frontend of virtio driver? Say I'm running a Windows 2008 (with
MSI-X support) + virtio NIC, is it necessary to upgrade frontend driver too?
Regards,
HUANG, Zhiteng