Hi Chris, I checked GVT shadow PPGTT handling codes and think GVT does propagate guest PTE flags to shadow PPGTT entry. Then I run i915 self-test case "igt_ctx_readonly" in KVMGT's guest. The case doesn't report any errors. Can I know if there are any other reasons that you think GVT breaks read-only support? Thanks, Henry > ----- Forwarded message from Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> ----- > > Date: Thu, 12 Jul 2018 19:53:12 +0100 > From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>, Zhenyu Wang > <zhenyuw@xxxxxxxxxxxxxxx>, Jon Bloomfield <jon.bloomfield@xxxxxxxxx>, > Joonas Lahtinen > <joonas.lahtinen@xxxxxxxxxxxxxxx>, Matthew Auld > <matthew.william.auld@xxxxxxxxx> > Subject: [PATCH 3/6] drm/i915/gtt: Disable read-only support under GVT > X-Mailer: git-send-email 2.18.0 > > GVT is not propagating the PTE bits, and is always setting the read-write bit, > thus breaking read-only support. > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> > Cc: Jon Bloomfield <jon.bloomfield@xxxxxxxxx> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> > Cc: Matthew Auld <matthew.william.auld@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_gem_gtt.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c > b/drivers/gpu/drm/i915/i915_gem_gtt.c > index 6c0b438afe46..8e70a45b8a90 100644 > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c > @@ -1662,8 +1662,12 @@ static struct i915_hw_ppgtt > *gen8_ppgtt_create(struct drm_i915_private *i915) > 1ULL << 48 : > 1ULL << 32; > > - /* From bdw, there is support for read-only pages in the PPGTT */ > - ppgtt->vm.has_read_only = true; > + /* > + * From bdw, there is support for read-only pages in the PPGTT. > + * > + * XXX GVT is not setting honouring the PTE bits. > + */ > + ppgtt->vm.has_read_only = !intel_vgpu_active(i915); > > i915_address_space_init(&ppgtt->vm, i915); > > -- > 2.18.0 > > > ----- End forwarded message ----- > > -- > Open Source Technology Center, Intel ltd. > > $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
