Changeset 86880 in vbox for trunk/src/VBox/Devices

Timestamp:

Nov 13, 2020 10:51:17 AM (4 years ago)

Author:

vboxsync

Message:

AMD IOMMU: bugref:9654 Fix I/O page walk when the root page table level is 0 for the DTE. Happens with OL8.

File:

• trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp

@@ -3045 +3045 @@
                 /** @todo IOMMU: Split large pages into 4K IOTLB entries and add to IOTLB cache. */
 
+                /* If translation is disabled for this device (root paging mode is 0), we're done. */
+                if (WalkResult.cShift == 0)
+                {
+                    *pGCPhysSpa = uIova;
+                    break;
+                }
+
                 /* Store the translated base address before continuing to check permissions for any more pages. */
+                Assert(WalkResult.cShift >= X86_PAGE_4K_SHIFT);
                 if (cbRemaining == cbAccess)
                 {