On Thu, 26 Apr 2018 08:14:27 +0200 Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > On Thu, Apr 26, 2018 at 03:44:15AM +0000, Tian, Kevin wrote: > > > From: Alex Williamson > > > Sent: Thursday, April 19, 2018 2:32 AM > > > > > > That almost begins to look reasonable, but then we can only expose this > > > for mdev devices, what if we were to hack a back door into a directly > > > assigned GPU that tracks the location of active display in the > > > framebuffer and implement the GFX_PLANE interface for that? We have no > > > sysfs representation for either the template or the actual device for > > > anything other than mdev. This inconsistency with physically assigned > > > devices has been one of my arguments against enhancing mdev sysfs. > > > > One possible option is to wrap directly assigned GPU into a mdev. The > > parent driver could be a dummy PCI driver which does basic PCI > > initialization, and then provide hooks for vendor-specific hack. > > Thowing amdgpu into the mix. Looks they have vgpu support too, but > using sriov instead of mdev. Having VFIO_GFX support surely looks > useful there. Adding a mdev dependency to the VFIO_GFX api would makes > things more complicated there for (IMHO) no good reason ... Yes, it may be that a device wanting to implement display or migration might take the mdev approach, but that should be a choice of the implementation, not a requirement imposed by the API. Thanks, Alex
