[Intel-gfx] [PATCH v3 05/28] drm/i915/gvt: Explicitly check that vGPU is attached before shadowing

Sean Christopherson
2023-05-13T00:36:21Z

Move the check that a vGPU is attacked from is_2MB_gtt_possible() to its
sole caller, ppgtt_populate_shadow_entry(). All of the paths in
ppgtt_populate_shadow_entry() eventually check for attachment by way of
intel_gvt_dma_map_guest_page(), but explicitly checking can avoid
unnecessary work and will make it more obvious that a future cleanup of
is_2MB_gtt_possible() isn't introducing a bug.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
drivers/gpu/drm/i915/gvt/gtt.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 5426a27c1b71..2aed31b497c9 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1163,8 +1163,6 @@ static int is_2MB_gtt_possible(struct intel_vgpu *vgpu,
if (!HAS_PAGE_SIZES(vgpu->gvt->gt->i915, I915_GTT_PAGE_SIZE_2M))
return 0;

- if (!test_bit(INTEL_VGPU_STATUS_ATTACHED, vgpu->status))
- return -EINVAL;
pfn = gfn_to_pfn(vgpu->vfio_device.kvm, ops->get_pfn(entry));
if (is_error_noslot_pfn(pfn))
return -EINVAL;
@@ -1277,6 +1275,9 @@ static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
if (!pte_ops->test_present(ge))
return 0;

+ if (!test_bit(INTEL_VGPU_STATUS_ATTACHED, vgpu->status))
+ return -EINVAL;
+
gfn = pte_ops->get_pfn(ge);

switch (ge->type) {
--
2.40.1.606.ga4b1b128d6-goog