On Wed, Mar 14, 2018 at 10:43:01AM +0800, Wei Wang wrote: > On 03/14/2018 12:49 AM, Michael S. Tsirkin wrote: > > On Wed, Mar 07, 2018 at 08:34:24PM +0800, Wei Wang wrote: > > > > > Signed-off-by: Wei Wang <wei.w.w...@intel.com> > > > Signed-off-by: Liang Li <liang.z...@intel.com> > > > CC: Michael S. Tsirkin <m...@redhat.com> > > > CC: Dr. David Alan Gilbert <dgilb...@redhat.com> > > > CC: Juan Quintela <quint...@redhat.com> > > I find it suspicious that neither unrealize nor reset > > functions have been touched at all. > > Are you sure you have thought through scenarious like > > hot-unplug or disabling the device by guest? > > OK. I think we can call balloon_free_page_stop in unrealize and reset. > > > > +static void *virtio_balloon_poll_free_page_hints(void *opaque) > > +{ > > + VirtQueueElement *elem; > > + VirtIOBalloon *dev = opaque; > > + VirtQueue *vq = dev->free_page_vq; > > + uint32_t id; > > + size_t size; > > What makes it safe to poke at this device from multiple threads? > > I think that it would be safer to do it from e.g. BH. > > > > Actually the free_page_optimization thread is the only user of free_page_vq, > and there is only one optimization thread each time. Would this be safe > enough? > > Best, > Wei
Aren't there other fields there? Also things like reset affect all VQs. -- MST