Hi, > -----Original Message----- > From: Chia-I Wu <olvaffe@xxxxxxxxx> > Sent: 20 February 2020 19:41 > To: Guillaume Gardet <Guillaume.Gardet@xxxxxxx> > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; Gerd Hoffmann <kraxel@xxxxxxxxxx>; > Daniel Vetter <daniel.vetter@xxxxxxxx>; Catalin Marinas > <Catalin.Marinas@xxxxxxx>; nd <nd@xxxxxxx> > Subject: Re: [Bug] virtio-gpu broken with qemu/kvm on arm64 on kernel 5.5+ > > On Thu, Feb 20, 2020 at 4:44 AM Guillaume Gardet <Guillaume.Gardet@xxxxxxx> > wrote: > > > > Hi, > > > > With (guest) kernel 5.5+ with qemu/kvm on arm64, I get lots of display > corruptions leading to this kind of screen: > > https://openqa.opensuse.org/tests/1174521#step/yast2_i/24 > Looking at the screenshot, it seems cacheline-related? It could be. > > There was a change of memory type > > https://lists.freedesktop.org/archives/dri-devel/2019-August/233456.html > > While the guest memory type is ignored on Intel, it is honored on ARM. > This attempt to fix it > > https://lists.freedesktop.org/archives/dri-devel/2019-December/248271.html > > does not seem to land. I applied this patch on top of 5.5.4, but it does not fix the problem. Maybe more similar changes are required? Regards, Guillaume > > > > > > I git bisected it to commit c66df701e783bc666593e6e665f13670760883ee > > ********** > > drm/virtio: switch from ttm to gem shmem helpers > > > > virtio-gpu basically needs a sg_table for the bo, to tell the host where > > the backing pages for the object are. So the gem shmem helpers are a > > perfect fit. Some drm_gem_object_funcs need thin wrappers to update the > > host state, but otherwise the helpers handle everything just fine. > > > > Once the fencing was sorted the switch was surprisingly easy and for the > > most part just removing the ttm code. > > > > v4: fix drm_gem_object_funcs name. > > > > Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> > > Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Reviewed-by: Chia-I Wu <olvaffe@xxxxxxxxx> > > Link: > > http://patchwork.freedesktop.org/patch/msgid/20190829103301.3539-15-kr > > axel@xxxxxxxxxx > > ********** > > > > I also tested kernel 5.6-rc2 which has the same bug. > > Without kvm, the display is fine. > > > > Regards, > > Guillaume > > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
