Changeset 50540 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

Feb 21, 2014 12:51:57 PM (11 years ago)

Author:

vboxsync

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

92390

Message:

VMM/HM: Ignore SMX mode and proceed with a warning.

File:

• trunk/src/VBox/VMM/VMMR0/HMR0.cpp (modified) (3 diffs)

trunk/src/VBox/VMM/VMMR0/HMR0.cpp

@@ -797 +797 @@
     NOREF(idCpu); NOREF(pvUser2);
 
-    uint64_t   fFC            = ASMRdMsr(MSR_IA32_FEATURE_CONTROL);
-    bool const fInSmxMode     = RT_BOOL(ASMGetCR4() & X86_CR4_SMXE);
-    bool       fMsrLocked     = RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_LOCK);
-    bool       fSmxVmxAllowed = RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_SMX_VMXON);
-    bool       fVmxAllowed    = RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_VMXON);
+    uint64_t   u64FeatMsr     = ASMRdMsr(MSR_IA32_FEATURE_CONTROL);
+    bool const fMaybeSmxMode  = RT_BOOL(ASMGetCR4() & X86_CR4_SMXE);
+    bool       fMsrLocked     = RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_LOCK);
+    bool       fSmxVmxAllowed = RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_SMX_VMXON);
+    bool       fVmxAllowed    = RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_VMXON);
 
     /* Check if the LOCK bit is set but excludes the required VMXON bit. */
@@ -807 +807 @@
     if (fMsrLocked)
     {
-        if (fInSmxMode && !fSmxVmxAllowed)
-            rc = VERR_VMX_MSR_SMX_VMXON_DISABLED;
-        else if (!fInSmxMode && !fVmxAllowed)
-            rc = VERR_VMX_MSR_VMXON_DISABLED;
+        if (fVmxAllowed && fSmxVmxAllowed)
+            rc = VINF_SUCCESS;
+        else if (!fVmxAllowed && !fSmxVmxAllowed)
+            rc = VERR_VMX_MSR_ALL_VMXON_DISABLED;
+        else if (!fMaybeSmxMode)
+        {
+            if (fVmxAllowed)
+                rc = VINF_SUCCESS;
+            else
+                rc = VERR_VMX_MSR_VMXON_DISABLED;
+        }
         else
+        {
+            /*
+             * CR4.SMXE is set but this doesn't mean the CPU is necessarily in SMX mode. We shall assume
+             * that it is -not- and that it is a stupid BIOS/OS setting CR4.SMXE for no good reason.
+             * See @bugref{6873}.
+             */
+            Assert(fMaybeSmxMode == true);
             rc = VINF_SUCCESS;
+        }
     }
     else
@@ -819 +834 @@
          * MSR is not yet locked; we can change it ourselves here.
          * Once the lock bit is set, this MSR can no longer be modified.
+         *
+         * Set both the VMXON and SMX_VMXON bits as we can't determine SMX mode
+         * accurately. See @bugref{6873}.
          */
-        fFC |= MSR_IA32_FEATURE_CONTROL_LOCK;
-        if (fInSmxMode)
-            fFC |= MSR_IA32_FEATURE_CONTROL_SMX_VMXON;
-        else
-            fFC |= MSR_IA32_FEATURE_CONTROL_VMXON;
-
-        ASMWrMsr(MSR_IA32_FEATURE_CONTROL, fFC);
+        u64FeatMsr |=   MSR_IA32_FEATURE_CONTROL_LOCK
+                      | MSR_IA32_FEATURE_CONTROL_SMX_VMXON
+                      | MSR_IA32_FEATURE_CONTROL_VMXON;
+        ASMWrMsr(MSR_IA32_FEATURE_CONTROL, u64FeatMsr);
 
         /* Verify. */
-        fFC                 = ASMRdMsr(MSR_IA32_FEATURE_CONTROL);
-        fMsrLocked          = RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_LOCK);
-        fSmxVmxAllowed      = fMsrLocked && RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_SMX_VMXON);
-        fVmxAllowed         = fMsrLocked && RT_BOOL(fFC & MSR_IA32_FEATURE_CONTROL_VMXON);
-        bool const fAllowed = fInSmxMode ? fSmxVmxAllowed : fVmxAllowed;
-        if (fAllowed)
+        u64FeatMsr     = ASMRdMsr(MSR_IA32_FEATURE_CONTROL);
+        fMsrLocked     = RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_LOCK);
+        fSmxVmxAllowed = fMsrLocked && RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_SMX_VMXON);
+        fVmxAllowed    = fMsrLocked && RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_VMXON);
+        if (fSmxVmxAllowed && fVmxAllowed)
             rc = VINF_SUCCESS;
         else