Samuel Čavoj <samuel@xxxxxxxxx> writes: Hello Samuel, > On 2023-03-20 13:12, Javier Martinez Canillas wrote: >> Samuel Čavoj <samuel@xxxxxxxxx> writes: >> >> [...] >> >>>>>> This call to sysfb_disable() has been causing trouble with regard >>>>>> to >>>>>> VFIO. VFIO has been calling aperture_remove_conflicting_pci_devices >>>>>> to >>>>>> get rid of any console drivers (d173780620792c) using the device in >>>>>> question, but now even unrelated drivers are getting killed. >>>>>> Example >>>>>> situation: >>>>> >>>>> Which drivers do you use? >>> >>> This happens with either no drivers loaded or the proprietary nvidia >>> driver. Nouveau is fine as it doesn't rely on efifb but brings its >>> own. >>> >> >> Which is what all DRM drivers should do. If they want to make sure that >> a >> fbdev will be present after the DRM driver probes, then should register >> an >> emulated fbdev. > > I don't see how this is specific to Nvidia or DRM drivers. > Not specific to Nvidia per se but as mentioned it only affected Nvidia due that driver relying on a different graphics driver to get a VT console. > The efifb is killed if vfio-pci (or another driver which uses the > aperture system to remove conflicting drivers) is bound to ANY pci > device, regardless of whether it's nvidia's fault for not implementing > a framebuffer. Fair enough, I agree that they should, but > I for one expect my efifb to not die at a random time > when a random unrelated driver does a random thing with another > unrelated GPU. > There was a patch series to address that: https://patchwork.kernel.org/project/dri-devel/list/?series=711019&archive=both In particular, this patch: https://patchwork.kernel.org/project/dri-devel/patch/20230111154112.90575-11-daniel.vetter@xxxxxxxx/ > Or is the efifb considered a stop-gap solution the only purpose of > which is early boot--before another GPU driver is loaded? > All the firmware-provided graphics drivers are really a best effort IMO, that is something only to be used to get early video output and any in the case of "nomodeset" (i.e: some distros have a "Safe graphics mode" boot entry that prevents DRM drivers to be loaded but used for troubleshooting. But as soon as a real DRM driver is probed (either in the host or a guest when the device is passed-through), I believe that is very likely that it won't work anymore. In other words, is not a robust way to get output and is just a best effort. -- Best regards, Javier Martinez Canillas Core Platforms Red Hat
