On 03/31/2010 02:38 PM, Blue Swirl wrote: > On 3/31/10, Michael S. Tsirkin wrote: > >> On Wed, Mar 31, 2010 at 03:38:05PM -0300, Luiz Capitulino wrote: >> > On Wed, 31 Mar 2010 13:26:23 -0500 >> > Anthony Liguori wrote: >> > >> > > On 03/31/2010 01:20 PM, Michael S. Tsirkin wrote: >> > > > From: David L Stevens >> > > > >> > > > 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 >> > > > Signed-off-by: Michael S. Tsirkin >> > > > --- >> > > > >> > > > 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 >> > 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. >> > As has been explained many times, knowledge about CPU specific > features has no place in devices. Actively removing CPU specifics from > devices is good but preventing new bad code to be committed is better. > > I don't have distro computing powers (unless some distro's compute > center only has two low power machines) and I guess some other > developers don't have either. All developers and patch submitters are > expected to compile all targets. This patch set has decreased the > number of files compiled by about 20%. > BTW, this seems to do it. I'll commit after some testing. Regards, Anthony Liguori