Changeset 77032 in vbox for trunk/src/VBox/VMM/VMMR3

Timestamp:

Jan 29, 2019 2:28:03 PM (6 years ago)

Author:

vboxsync

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

128467

Message:

VMM/CPUM: bugref:9375 Check for existence of leafs before exploding SVM features.

File:

• trunk/src/VBox/VMM/VMMR3/CPUMR3CpuId.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMR3/CPUMR3CpuId.cpp

@@ -3711 +3711 @@
     cpumR3CpuIdZeroLeaf(pCpum, UINT32_C(0x80000009));
 
-    /* Cpuid 0x8000000a: SVM Information
-     * AMD: EAX - SVM revision.
-     *      EBX - Number of ASIDs.
-     *      ECX - Reserved.
-     *      EDX - SVM Feature identification.
+    /* Cpuid 0x8000000a: SVM information on AMD, invalid on Intel.
+     * AMD:   EAX - SVM revision.
+     *        EBX - Number of ASIDs.
+     *        ECX - Reserved.
+     *        EDX - SVM Feature identification.
      */
     pExtFeatureLeaf = cpumR3CpuIdGetExactLeaf(pCpum, UINT32_C(0x80000001), 0);
-    if (pExtFeatureLeaf->uEcx & X86_CPUID_AMD_FEATURE_ECX_SVM)
+    if (   pExtFeatureLeaf
+        && (pExtFeatureLeaf->uEcx & X86_CPUID_AMD_FEATURE_ECX_SVM)
+        && pCpum->GuestFeatures.enmCpuVendor == CPUMCPUVENDOR_AMD)
     {
         PCPUMCPUIDLEAF pSvmFeatureLeaf = cpumR3CpuIdGetExactLeaf(pCpum, 0x8000000a, 0);
-        pSvmFeatureLeaf->uEax  = 0x1;
-        pSvmFeatureLeaf->uEbx  = 0x8000;                                        /** @todo figure out virtual NASID. */
-        pSvmFeatureLeaf->uEcx  = 0;
-        pSvmFeatureLeaf->uEdx &= (  X86_CPUID_SVM_FEATURE_EDX_NRIP_SAVE         /** @todo Support other SVM features */
-                                  | X86_CPUID_SVM_FEATURE_EDX_FLUSH_BY_ASID
-                                  | X86_CPUID_SVM_FEATURE_EDX_DECODE_ASSISTS);
-    }
-    else
-        cpumR3CpuIdZeroLeaf(pCpum, UINT32_C(0x8000000a));
+        if (pSvmFeatureLeaf)
+        {
+            pSvmFeatureLeaf->uEax  = 0x1;
+            pSvmFeatureLeaf->uEbx  = 0x8000;                                        /** @todo figure out virtual NASID. */
+            pSvmFeatureLeaf->uEcx  = 0;
+            pSvmFeatureLeaf->uEdx &= (  X86_CPUID_SVM_FEATURE_EDX_NRIP_SAVE         /** @todo Support other SVM features */
+                                      | X86_CPUID_SVM_FEATURE_EDX_FLUSH_BY_ASID
+                                      | X86_CPUID_SVM_FEATURE_EDX_DECODE_ASSISTS);
+        }
+        else
+        {
+            LogRel(("CPUM: Warning! Expected CPUID leaf 0x8000000a not present! SVM features not exposed to the guest\n"));
+            cpumR3CpuIdZeroLeaf(pCpum, UINT32_C(0x8000000a));
+        }
+    }
 
     /* Cpuid 0x8000000b thru 0x80000018: Reserved