Changeset 86084 in vbox for trunk/src/VBox/Devices/Bus

Timestamp:

Sep 10, 2020 1:12:30 PM (5 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

140313

Message:

AMD IOMMU: bugref:9654 Don't forget to multiply the size of each DTE entry when indexing into the DTE!
Also when device segmentation is used we need to shift by 15, 14 or 13 bits,
shifting always by 13 would include erroneous bits from the device ID.

File:

• trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp (modified) (2 diffs)

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

@@ -403 +403 @@
 
 /**
+ * An array of the shift values to select the device table segment index from a
+ * device ID.
+ */
+static uint8_t const g_auDevTabSegShifts[] = { 0, 15, 14, 13 };
+
+/**
  * The maximum size (inclusive) of each device table segment (0 to 7).
  * Indexed by the device table segment index.
@@ -1974 +1980 @@
 
     uint8_t const idxSegsEn = Ctrl.n.u3DevTabSegEn;
+    Assert(idxSegsEn < RT_ELEMENTS(g_auDevTabSegShifts));
     Assert(idxSegsEn < RT_ELEMENTS(g_auDevTabSegMasks));
 
-    uint8_t const idxSeg = uDevId & g_auDevTabSegMasks[idxSegsEn] >> 13;
+    uint8_t const idxSeg = (uDevId & g_auDevTabSegMasks[idxSegsEn]) >> g_auDevTabSegShifts[idxSegsEn];
     Assert(idxSeg < RT_ELEMENTS(pThis->aDevTabBaseAddrs));
 
     RTGCPHYS const GCPhysDevTab = pThis->aDevTabBaseAddrs[idxSeg].n.u40Base << X86_PAGE_4K_SHIFT;
-    uint16_t const offDte       = uDevId & ~g_auDevTabSegMasks[idxSegsEn];
+    uint16_t const offDte       = (uDevId & ~g_auDevTabSegMasks[idxSegsEn]) * sizeof(DTE_T);
     RTGCPHYS const GCPhysDte    = GCPhysDevTab + offDte;