On Wed, Mar 31, 2010 at 03:38:05PM -0300, Luiz Capitulino wrote:
> On Wed, 31 Mar 2010 13:26:23 -0500
> Anthony Liguori<address@hidden> wrote:
>
> > On 03/31/2010 01:20 PM, Michael S. Tsirkin wrote:
> > > From: David L Stevens<address@hidden>
> > >
> > > vhost driver in qemu didn't ack features, and this happens
> > > to work because we don't really require any features. However,
> > > it's better not to rely on this. This patch passes features to
> > > vhost as guest acks them.
> > >
> > > Signed-off-by: David L Stevens<address@hidden>
> > > Signed-off-by: Michael S. Tsirkin<address@hidden>
> > > ---
> > >
> > > Anthony, here's a fixup patch to address an issue in vhost
> > > patches. Incidentially, what's the status of the vhost patchset?
> > >
> >
> > http://repo.or.cz/w/qemu/aliguori-queue.git vhost
> >
> > Is what I'm currently testing. With vhost disabled, the following seg
> > faults:
> >
> > qemu-system-x86_64 -hda ~/images/linux.img -net tap -net
> > nic,model=virtio -enable-kvm
> >
> > But not when using TCG. I'm not sure that it's your patches at fault
> > and I'm attempting to bisect now to figure that out.
>
> Probably this is the same segfault I'm getting right now in master,
> bisect says it's:
>
> """
> commit ad96090a01d848df67d70c5259ed8aa321fa8716
> Author: Blue Swirl<address@hidden>
> Date: Mon Mar 29 19:23:52 2010 +0000
>
> Refactor target specific handling, compile vl.c only once
> """
Why are the compile once patches helpful? They seem to introduce
churn and bugs, they actively make it harder to extend qemu as you can't use
target-specific code in code that is compiled once, they might have
performance penalty - and what do we gain? Any given user is unlikely to
need to build on more than one target, distros have enough computing
power to build in parallel.