On Wed, 2017-07-19 at 00:16 +0000, Zhang, Tina wrote: > > -----Original Message----- > > From: Gerd Hoffmann [mailto:[email protected]] > > Sent: Monday, July 17, 2017 7:03 PM > > To: Kirti Wankhede <[email protected]>; Zhang, Tina > > <[email protected]>; Tian, Kevin <[email protected]>; linux- > > [email protected]; [email protected]; > > [email protected]; [email protected]; chris@chris- > > wilson.co.uk; Lv, Zhiyuan <[email protected]>; intel-gvt- > > [email protected]; Wang, Zhi A <[email protected]> > > Subject: Re: [PATCH v10] vfio: ABI for mdev display dma-buf > > operation > > > > Hi, > > > > > No need of flag here. If vGPU driver is not loaded in the guest, > > > there > > > is no surface being managed by vGPU, in that case this size will > > > be > > > zero. > > > > Ok, we certainly have the same situation with intel. When the > > guest driver is not > > loaded (yet) there is no valid surface. > > > > We should cleanly define what the ioctl should do in that case, so > > all drivers > > behave the same way. > > > > I'd suggest that all fields defining the surface (drm_format, > > width, height, stride, > > size) should be set to zero in that case. > > Yeah, it's reasonable. How about the return value? Currently, the > ioctl also returns "-ENODEV" in that situation.
I think it should not return an error. Querying the plane parameters worked fine. cheers, Gerd
