Changeset 38243 in vbox

Timestamp:

Jul 31, 2011 8:36:00 PM (14 years ago)

Author:

vboxsync

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

73226

Message:

HWACCM/SVM: Fix running 64bit guests on AMD E-350 CPUs. The DPL field of the hidden segment selector can be wrong and the CPU uses the CPL field in the VMCB to get privilege level

File:

• trunk/src/VBox/VMM/VMMR0/HWSVMR0.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMR0/HWSVMR0.cpp

@@ -1493 +1493 @@
     SVM_ASSERT_SEL_GRANULARITY(gs);
 #undef  SVM_ASSERT_SEL_GRANULARITY
+
+    /*
+     * Correct the hidden SS DPL field. It can be wrong on certain CPUs
+     * sometimes (seen it on AMD Fusion APUs with 64bit guests). The CPU
+     * always uses the CPL field in the VMCB instead of the DPL in the hidden
+     * SS (chapter 15.5.1 Basic operation).
+     */
+    Assert(!(pVMCB->guest.u8CPL & ~0x3));
+    pCtx->ssHid.Attr.n.u2Dpl = pVMCB->guest.u8CPL & 0x3;
 
     /* Remaining guest CPU context: TR, IDTR, GDTR, LDTR; must sync everything otherwise we can get out of sync when jumping to ring 3. */