| Message ID | 1491358106-26329-1-git-send-email-xiong.y.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Apr 05, 2017 at 10:08:26AM +0800, Xiong Zhang wrote: > Stolen memory is in RMRR and has identity mapping in iommu, so > gt could access stolen memory in host OS. While RMRR isn't supported > by kvm, both EPT and guest iommu domain lack of maaping for stolen memory, > so both vcpu and gt couldn't access stolen memory in guest. > > commit "04a68a3 drm/i915/gvt: Disable access to stolen memory as a guest" > isn't enough in IGD passthrough environment where vgt code doesn't run. This > patch detects i915 running as a guest through the existence of emulated ISA > bridge. > > v2:GVT-g may run in non qemu (Zhenyu) > v3:Make commit message clear (Daniel) > v4:Fix typo > > References: c875d2c iommu/vt-d: Exclude devices using RMRRs from IOMMU API domains > Link: https://access.redhat.com/sites/default/files/attachments/rmrr-wp1.pdf > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99028 > > Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com> > Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com> > Cc: stable@vger.kernel.org Yeah, commit message is now much improved. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/i915/i915_drv.c | 1 + > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_stolen.c | 4 ++-- > 3 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > index 03d9e45..8b807a9 100644 > --- a/drivers/gpu/drm/i915/i915_drv.c > +++ b/drivers/gpu/drm/i915/i915_drv.c > @@ -223,6 +223,7 @@ static void intel_detect_pch(struct drm_i915_private *dev_priv) > PCI_SUBVENDOR_ID_REDHAT_QUMRANET && > pch->subsystem_device == > PCI_SUBDEVICE_ID_QEMU)) { > + dev_priv->run_on_qemu = true; > dev_priv->pch_type = > intel_virt_detect_pch(dev_priv); > } else > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index a5947a4..ad95c87 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2145,6 +2145,7 @@ struct drm_i915_private { > struct intel_uncore uncore; > > struct i915_virtual_gpu vgpu; > + bool run_on_qemu; > > struct intel_gvt *gvt; > > diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c > index f3abdc2..6a011b0 100644 > --- a/drivers/gpu/drm/i915/i915_gem_stolen.c > +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c > @@ -409,8 +409,8 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) > > mutex_init(&dev_priv->mm.stolen_lock); > > - if (intel_vgpu_active(dev_priv)) { > - DRM_INFO("iGVT-g active, disabling use of stolen memory\n"); > + if (dev_priv->run_on_qemu || intel_vgpu_active(dev_priv)) { > + DRM_INFO("Running in guest, disabling use of stolen memory\n"); > return 0; > } > > -- > 1.9.1 >
On Wed, 05 Apr 2017, Daniel Vetter <daniel@ffwll.ch> wrote: > On Wed, Apr 05, 2017 at 10:08:26AM +0800, Xiong Zhang wrote: >> Stolen memory is in RMRR and has identity mapping in iommu, so >> gt could access stolen memory in host OS. While RMRR isn't supported >> by kvm, both EPT and guest iommu domain lack of maaping for stolen memory, >> so both vcpu and gt couldn't access stolen memory in guest. >> >> commit "04a68a3 drm/i915/gvt: Disable access to stolen memory as a guest" >> isn't enough in IGD passthrough environment where vgt code doesn't run. This >> patch detects i915 running as a guest through the existence of emulated ISA >> bridge. >> >> v2:GVT-g may run in non qemu (Zhenyu) >> v3:Make commit message clear (Daniel) >> v4:Fix typo >> >> References: c875d2c iommu/vt-d: Exclude devices using RMRRs from IOMMU API domains What does it mean to References: a commit? The message text doesn't say anything about this commit. Does this patch fix commit 04a68a3 or c875d2c? If so, there should be a Fixes: tag. The canonical format for commit references is 04a68a35ce6d ("drm/i915/gvt: Disable access to stolen memory as a guest") c875d2c1b808 ("iommu/vt-d: Exclude devices using RMRRs from IOMMU API domains") In particular, note that 12 digits is preferred for sha1 references to avoid ambiguity in the kernel git repo. >> Link: https://access.redhat.com/sites/default/files/attachments/rmrr-wp1.pdf Please use References: for stuff like this. Link: is reserved for the backlink to the patch and discussion. >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99028 >> >> Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com> >> Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com> >> Cc: stable@vger.kernel.org With a Fixes: tag it would be possible to decide which stable kernels to backport to. > Yeah, commit message is now much improved. I'm sorry, but from the fixes backports POV it still lacks clarity. I wouldn't know if and where this should be backported. BR, Jani. > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > >> --- >> drivers/gpu/drm/i915/i915_drv.c | 1 + >> drivers/gpu/drm/i915/i915_drv.h | 1 + >> drivers/gpu/drm/i915/i915_gem_stolen.c | 4 ++-- >> 3 files changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c >> index 03d9e45..8b807a9 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.c >> +++ b/drivers/gpu/drm/i915/i915_drv.c >> @@ -223,6 +223,7 @@ static void intel_detect_pch(struct drm_i915_private *dev_priv) >> PCI_SUBVENDOR_ID_REDHAT_QUMRANET && >> pch->subsystem_device == >> PCI_SUBDEVICE_ID_QEMU)) { >> + dev_priv->run_on_qemu = true; >> dev_priv->pch_type = >> intel_virt_detect_pch(dev_priv); >> } else >> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h >> index a5947a4..ad95c87 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.h >> +++ b/drivers/gpu/drm/i915/i915_drv.h >> @@ -2145,6 +2145,7 @@ struct drm_i915_private { >> struct intel_uncore uncore; >> >> struct i915_virtual_gpu vgpu; >> + bool run_on_qemu; >> >> struct intel_gvt *gvt; >> >> diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c >> index f3abdc2..6a011b0 100644 >> --- a/drivers/gpu/drm/i915/i915_gem_stolen.c >> +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c >> @@ -409,8 +409,8 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) >> >> mutex_init(&dev_priv->mm.stolen_lock); >> >> - if (intel_vgpu_active(dev_priv)) { >> - DRM_INFO("iGVT-g active, disabling use of stolen memory\n"); >> + if (dev_priv->run_on_qemu || intel_vgpu_active(dev_priv)) { >> + DRM_INFO("Running in guest, disabling use of stolen memory\n"); >> return 0; >> } >> >> -- >> 1.9.1 >>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 03d9e45..8b807a9 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -223,6 +223,7 @@ static void intel_detect_pch(struct drm_i915_private *dev_priv) PCI_SUBVENDOR_ID_REDHAT_QUMRANET && pch->subsystem_device == PCI_SUBDEVICE_ID_QEMU)) { + dev_priv->run_on_qemu = true; dev_priv->pch_type = intel_virt_detect_pch(dev_priv); } else diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index a5947a4..ad95c87 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2145,6 +2145,7 @@ struct drm_i915_private { struct intel_uncore uncore; struct i915_virtual_gpu vgpu; + bool run_on_qemu; struct intel_gvt *gvt; diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index f3abdc2..6a011b0 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -409,8 +409,8 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) mutex_init(&dev_priv->mm.stolen_lock); - if (intel_vgpu_active(dev_priv)) { - DRM_INFO("iGVT-g active, disabling use of stolen memory\n"); + if (dev_priv->run_on_qemu || intel_vgpu_active(dev_priv)) { + DRM_INFO("Running in guest, disabling use of stolen memory\n"); return 0; }