On Mon, May 27, 2019 at 05:07:41PM +0800, Zhenyu Wang wrote: > On 2019.05.27 16:43:11 +0800, Tina Zhang wrote: > > Add VFIO_DEVICE_SET_GFX_FLIP_EVENTFD ioctl command to set eventfd > > based signaling mechanism to deliver vGPU framebuffer page flip > > event to userspace. > > Should we add probe to see if driver can support gfx flip event? Userspace can simply call VFIO_DEVICE_SET_GFX_FLIP_EVENTFD and see if it worked. If so -> use the eventfd. Otherwise take the fallback path (timer based polling). I can't see any advantage a separate feature probe steps adds. cheers, Gerd
