Hi Lucas: Vhost-net backend is only valid when we use tap, so it should work with "nic_mode=tap". Maybe we could add a comment above the "vhost=on" to warn the user to use tap when he need vhost. ----- "Lucas Meneghel Rodrigues" <lmr@xxxxxxxxxx> wrote: > On Fri, 2010-10-08 at 12:19 -0300, Lucas Meneghel Rodrigues wrote: > > On Sun, 2010-09-26 at 10:28 +0800, Jason Wang wrote: > > > Vhost is a kernel-level backend for virtio. This patch add a > nic_params named > > > "vhost" to enable/disable vhost backend. > > > > Jason, I had rebased your patches. The patches themselves look good, > but > > apparently the syntax proposed here is invalid, and I've tried with > > different qemu variants: > > > > - qemu from rhel6 > > - qemu-kvm.git HEAD > > - qemu.git HEAD > > > > All of them don't support vhost with netdev: > > 10:40:01 ERROR| VM could not be created; qemu command failed: > /root/autotest/client/tests/kvm/qemu -name 'vm1' -monitor > unix:'/tmp/monitor-humanmonitor1-20101008-103957-4nMr',server,nowait > -serial unix:'/tmp/serial-20101008-103957-4nMr',server,nowait -drive > file='/tmp/kvm_autotest_root/images/f13-64.qcow2',index=0,if=virtio,boot=on > -device virtio-net-pci,mac=9a:0b:5d:7a:c1:7b,netdev=idlTBuUt -netdev > user,id=idlTBuUt,vhost=on,hostfwd=tcp::5000-:22 -m 512 -smp 2 -drive > file='/tmp/kvm_autotest_root/isos/linux/Fedora-13-x86_64-DVD.iso',media=cdrom,index=1 > -vnc :0 > 10:40:01 ERROR| Status: 1 > 10:40:01 ERROR| Output: > qemu: -drive > file=/tmp/kvm_autotest_root/images/f13-64.qcow2,index=0,if=virtio,boot=on: > Invalid parameter 'boot' > qemu: -netdev user,id=idlTBuUt,vhost=on,hostfwd=tcp::5000-:22: Invalid > parameter 'vhost' > > Ok, the 'drive' problem I am going to fix, let's consider only > 'vhost'. > When I read all the different qemu helps, it seems that vhost is tied > to > -net: > > -net > tap[,vlan=n][,name=str][,fd=h][,ifname=name][,script=file][,downscript=dfile][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h] > connect the host TAP network interface to VLAN 'n' and > use the > network scripts 'file' (default=/etc/qemu-ifup) > and 'dfile' (default=/etc/qemu-ifdown); > use '[down]script=no' to disable script execution; > use 'fd=h' to connect to an already opened TAP > interface > use 'sndbuf=nbytes' to limit the size of the send > buffer; the > default of 'sndbuf=1048576' can be disabled using > 'sndbuf=0' > use vnet_hdr=off to avoid enabling the IFF_VNET_HDR > tap flag; use > vnet_hdr=on to make the lack of IFF_VNET_HDR support > an error condition > use vhost=on to enable experimental in kernel > accelerator > use 'vhostfd=h' to connect to an already opened vhost > net device > > I don't think what I am missing here. I'd like to apply this, but > since > I couldn't verify it working with none of the qemu versions I tried, > I > am going to hold on for your comments. > > Cheers, > > Lucas -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
