Re: [Qemu-devel] vhost acceleration broken?

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Jul 25, 2013 at 08:28:00AM -0500, Anthony Liguori wrote:
> Rusty Russell <rusty@rustcorp.com.au> writes:
> 
> > Anthony Liguori <anthony@codemonkey.ws> writes:
> >> On Wed, Jul 24, 2013 at 8:55 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> >>> Hi all,
> >>>
> >>>         Using latest kernel and master qemu, the following doesn't use
> >>> vhost acceleration:
> >>>
> >>> sudo qemu-system-x86_64 -machine pc,accel=kvm $ARGS -m 1024 -net tap,script=/home/rusty/bin/kvm-ifup,downscript=no,vhost=on -net nic,model=virtio -drive file=$QEMUIMAGE,index=0,media=disk,if=virtio -kernel arch/x86/boot/bzImage -append "root=/dev/vda1 $KARGS $*"
> >>
> >> sudo qemu-system-x86_64 -enable-kvm $ARGS -m 1G -netdev
> >> tap,script=/home/rusty/bin/kvm-ifup,vhost=on,id=net0 -device
> >> virtio-net-pci,netdev=net0 -drive file=$QEMUIMAGE,if=virtio -kernel
> >> arch/x86/boot/bzImage -append "root=/dev/vda1 $KARGS $*"
> >>
> >> We really ought to strongly deprecate -net because it's misleading.  I
> >> suspect we can reasonably add a warning for model=virtio saying
> >> "please don't use this" and eventually remove it entirely.
> >
> > Thankyou, that works.
> >
> > I'm sure you've thought more deeply about the qemu cmdline than I have,
> > so I won't comment.
> 
> Any comment you would make is certainly fair.
> 
> We have a pretty awful legacy command line set that comes from years of
> half-baked concepts and the years when too many people just committed
> random shit to the tree.
> 
> I think we probably need to start planning for a clean break.  Maybe
> that's a good target for a 2.0 version...
> 
> Regards,
> 
> Anthony Liguori
> 
> >
> > Cheers,
> > Rusty.

Assuming -netdev supports all required configurations, we should
remove -net from the -help output.