[PATCH v6 5/7] drm/xe/vf: Add bounds checking for queried GGTT base and size

Add explicit bounds checks for GGTT base and size which can detect
and reject invalid configuration data from a misconfigured or
malfunctioning PF, preventing protocol violations and protecting VF
initialization.

Signed-off-by: Satyanarayana K V P <[email protected]>
Cc: Michal Wajdeczko <[email protected]>
---
V5 -> V6:
- Updated error codes for unaligned GGTT base and size (Michal W).
- Fixed review comments (Michal W).

V4 -> V5:
- New commit.
---
 drivers/gpu/drm/xe/xe_gt_sriov_vf.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
index 81d68fe5ad7c..d805c064377c 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
@@ -488,6 +488,7 @@ u32 xe_gt_sriov_vf_gmdid(struct xe_gt *gt)
 
 static int vf_get_ggtt_info(struct xe_gt *gt)
 {
+	u64 alignment = xe_vram_alignment(gt_to_xe(gt));
 	struct xe_tile *tile = gt_to_tile(gt);
 	struct xe_guc *guc = &gt->uc.guc;
 	u64 start, size, ggtt_size;
@@ -526,6 +527,18 @@ static int vf_get_ggtt_info(struct xe_gt *gt)
 		return -EREMCHG;
 	}
 
+	if (!IS_ALIGNED(start, alignment)) {
+		xe_gt_sriov_err(gt, "Unaligned GGTT base: %llu, expected %llu\n",
+				start, ALIGN(start, alignment));
+		return -EINVAL;
+	}
+
+	if (!IS_ALIGNED(size, alignment)) {
+		xe_gt_sriov_err(gt, "Unaligned GGTT size %llu, expected %llu\n",
+				size, ALIGN(size, alignment));
+		return -EINVAL;
+	}
+
 	xe_gt_sriov_dbg_verbose(gt, "GGTT %#llx-%#llx = %lluK\n",
 				start, start + size - 1, size / SZ_1K);
 
-- 
2.53.0