On Thu, Aug 27, 2015 at 10:28:49AM +0800, Zhiyuan Lv wrote: > Hi Danie, > > On Wed, Aug 26, 2015 at 10:47:37AM +0200, Daniel Vetter wrote: > > On Thu, Aug 20, 2015 at 01:57:13PM +0300, Joonas Lahtinen wrote: > > > On to, 2015-08-20 at 15:45 +0800, Zhiyuan Lv wrote: > > > > The full ppgtt is supported in Intel GVT-g device model. So the > > > > restriction can be removed. > > > > > > > > Signed-off-by: Zhiyuan Lv <zhiyuan.lv@xxxxxxxxx> > > > > Signed-off-by: Zhi Wang <zhi.a.wang@xxxxxxxxx> > > > > > > Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > > > > > > > --- > > > > drivers/gpu/drm/i915/i915_gem_gtt.c | 3 --- > > > > 1 file changed, 3 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c > > > > b/drivers/gpu/drm/i915/i915_gem_gtt.c > > > > index ed10e77..823005c 100644 > > > > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c > > > > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c > > > > @@ -108,9 +108,6 @@ static int sanitize_enable_ppgtt(struct > > > > drm_device *dev, int enable_ppgtt) > > > > has_aliasing_ppgtt = INTEL_INFO(dev)->gen >= 6; > > > > has_full_ppgtt = INTEL_INFO(dev)->gen >= 7; > > > > > > > > - if (intel_vgpu_active(dev)) > > > > - has_full_ppgtt = false; /* emulation is too hard */ > > > > Don't we need a feature check for the virtual gpu here? Or at least a > > platform check? Seems like the backwards/forwards compat story isn't too > > thought out yet here. Note that the kernel of the host and the guest might > > not be the same at all, much less the kvm part. > > Yeah, backwards/forwards compatibility is not considered, since we are > just to start the upstream of iGVT-g host changes. Right now if people > uses new enough iGVT-g code (off-tree now), both HSW and BDW should > work with PPGTT. > > So new host with both old guest or new guest are working. The only > thing impacted is old host with new guest kernel. In order to keep it > work, I can change the code like: > > + if (intel_vgpu_active(dev)) > + has_full_ppgtt = !IS_HASWELL(dev); > > Any comments? Thanks for the review! In the end that's your call (well until we have users screaming that a kernel upgrade breaks their xengt setup, then you have to keep backwards compat). But since it's a requirement from Linus Torvalds for upstream I highly suggest you start thinking/testing for backwards compat (both on host and guest side when the other part is older) right away. Otherwise trying to shoehorn a good backwards compat scheme later on could be really painful. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
