Changeset 87652 in vbox for trunk/src/VBox/VMM/VMMAll

Timestamp:

Feb 9, 2021 12:40:06 PM (4 years ago)

Author:

vboxsync

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

142694

Message:

AMD IOMMU: bugref:9654 Returns all 1s on PCI physical memory read failures that go through the IOMMU (but don't fake VINF_SUCCESS).

File:

• trunk/src/VBox/VMM/VMMAll/PDMAllIommu.cpp (modified) (4 diffs)

trunk/src/VBox/VMM/VMMAll/PDMAllIommu.cpp

@@ -25 +25 @@
 
 #include <VBox/vmm/vmcc.h>
+#include <iprt/string.h>
 #ifdef IN_RING3
 # include <iprt/mem.h>
@@ -122 +123 @@
                 if (RT_SUCCESS(rc))
                 {
+                    Assert(cbContig <= cbRead);
                     cbRead -= cbContig;
                     pvBuf   = (void *)((uintptr_t)pvBuf + cbContig);
@@ -132 +134 @@
             {
                 LogFunc(("IOMMU memory read failed. uDeviceId=%#x GCPhys=%#RGp cb=%zu rc=%Rrc\n", uDeviceId, GCPhys, cbRead, rc));
+
+                /*
+                 * We should initialize the read buffer on failure for devices that don't check
+                 * return codes (but would verify the data). But we still want to propagate the
+                 * error code from the IOMMU to the device, see @bugref{9936#c3}.
+                 */
+                memset(pvBuf, 0xff, cbRead);
                 break;
             }
@@ -178 +187 @@
                 if (RT_SUCCESS(rc))
                 {
+                    Assert(cbContig <= cbWrite);
                     cbWrite -= cbContig;
                     pvBuf    = (const void *)((uintptr_t)pvBuf + cbContig);