On Wed, Jul 10, 2024 at 05:15:18AM +0200, David Hildenbrand wrote: > On 04.07.24 23:30, Michael S. Tsirkin wrote: > > Currently, if VIRTIO_BALLOON_F_FREE_PAGE_HINT is off but > > VIRTIO_BALLOON_F_REPORTING is on, then the reporting vq > > gets number 3 while spec says it's number 4. > > It happens to work because the linux virtio pci driver > > is *also* out of spec. > > > > To fix: > > 1. add vq4 as per spec > > 2. to help out the buggy Linux driver, in the above configuration, > > also create vq3, and handle it exactly as we do vq4. > > > > I think that some clever hack is doable to address the issue > > for existing machine types (which would get it in user's hands > > sooner), but I'm not 100% sure what, exactly. > > > > This is a simpler, straight-forward approach. > > > > Reported-by: Xuan Zhuo <xuanz...@linux.alibaba.com> > > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > > --- > > > > I don't think I'll stop here, I want to fix exiting machine types, > > but sending this here for comparison. > > I'll send a Linux patch later. > > The downside is that new machine types will stop working with mainline Linux > / major distros in that feature combination, right?
The should keep working, that's why I put in part 2. above. > What's the approach that you are thinking of? > > -- > Cheers, > > David / dhildenb
