Changeset 50540 in vbox

Timestamp:

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

Author:

vboxsync

Message:

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

Location:

trunk

Files:

• include/VBox/err.h (modified) (1 diff)
• src/VBox/HostDrivers/Support/SUPDrv.c (modified) (7 diffs)
• src/VBox/VMM/VMMR0/HMR0.cpp (modified) (3 diffs)
• src/VBox/VMM/VMMR3/HM.cpp (modified) (2 diffs)

trunk/include/VBox/err.h

@@ -1947 +1947 @@
 /** Internal VMX processing error no 1. */
 #define VERR_HMVMX_IPE_5                            (-4027)
-/** VT-x features for SMX operation disabled by the BIOS. */
-#define VERR_VMX_MSR_SMX_VMXON_DISABLED             (-4028)
+/** VT-x features for all modes (SMX and non-SMX) disabled by the BIOS. */
+#define VERR_VMX_MSR_ALL_VMXON_DISABLED             (-4028)
 /** VT-x features disabled by the BIOS. */
 #define VERR_VMX_MSR_VMXON_DISABLED                 (-4029)

trunk/src/VBox/HostDrivers/Support/SUPDrv.c

@@ -3394 +3394 @@
  * @returns VBox status code.
  * @retval  VERR_VMX_NO_VMX
- * @retval  VERR_VMX_MSR_SMX_VMXON_DISABLED
+ * @retval  VERR_VMX_MSR_ALL_VMXON_DISABLED
  * @retval  VERR_VMX_MSR_VMXON_DISABLED
  * @retval  VERR_VMX_MSR_LOCKING_FAILED
@@ -3407 +3407 @@
 SUPR0DECL(int) SUPR0QueryVTCaps(PSUPDRVSESSION pSession, uint32_t *pfCaps)
 {
-    int rc = VERR_UNSUPPORTED_CPU;
+    int  rc = VERR_UNSUPPORTED_CPU;
+    bool fIsSmxModeAmbiguous = false;
     RTTHREADPREEMPTSTATE PreemptState = RTTHREADPREEMPTSTATE_INITIALIZER;
 
@@ -3439 +3440 @@
                 /** @todo Unify code with hmR0InitIntelCpu(). */
                 uint64_t   u64FeatMsr     = ASMRdMsr(MSR_IA32_FEATURE_CONTROL);
-                bool const fInSmxMode     = RT_BOOL(ASMGetCR4() & X86_CR4_SMXE);
+                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);
@@ -3447 +3448 @@
                 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);
+                        fIsSmxModeAmbiguous = true;
                         rc = VINF_SUCCESS;
+                    }
                 }
                 else
@@ -3459 +3476 @@
                      * 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}.
                      */
-                    bool fAllowed;
-                    u64FeatMsr |= MSR_IA32_FEATURE_CONTROL_LOCK;
-                    if (fInSmxMode)
-                        u64FeatMsr |= MSR_IA32_FEATURE_CONTROL_SMX_VMXON;
-                    else
-                        u64FeatMsr |= MSR_IA32_FEATURE_CONTROL_VMXON;
-
+                    u64FeatMsr |=   MSR_IA32_FEATURE_CONTROL_LOCK
+                                  | MSR_IA32_FEATURE_CONTROL_SMX_VMXON
+                                  | MSR_IA32_FEATURE_CONTROL_VMXON;
                     ASMWrMsr(MSR_IA32_FEATURE_CONTROL, u64FeatMsr);
 
@@ -3474 +3490 @@
                     fSmxVmxAllowed = fMsrLocked && RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_SMX_VMXON);
                     fVmxAllowed    = fMsrLocked && RT_BOOL(u64FeatMsr & MSR_IA32_FEATURE_CONTROL_VMXON);
-                    fAllowed       = fInSmxMode ? fSmxVmxAllowed : fVmxAllowed;
-                    if (fAllowed)
+                    if (fSmxVmxAllowed && fVmxAllowed)
                         rc = VINF_SUCCESS;
                     else
@@ -3535 +3550 @@
 
     RTThreadPreemptRestore(&PreemptState);
+    if (fIsSmxModeAmbiguous)
+        SUPR0Printf(("Warning!!! CR4 hints SMX mode but your CPU is too secretive. Proceeding anyway... Wish us luck!\n"));
     return rc;
 }

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

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

@@ -508 +508 @@
                     break;
 
-                case VERR_VMX_MSR_SMX_VMXON_DISABLED:
-                    pszMsg = "VT-x is disabled in the BIOS for Safer-Mode/Trusted Extensions.";
+                case VERR_VMX_MSR_ALL_VMXON_DISABLED:
+                    pszMsg = "VT-x is disabled in the BIOS for all CPU modes.";
                     break;
 
@@ -917 +917 @@
             case VERR_VMX_MSR_VMXON_DISABLED:
                 return VM_SET_ERROR(pVM, VERR_VMX_NO_VMX, "VT-x is disabled in the BIOS.");
-            case VERR_VMX_MSR_SMX_VMXON_DISABLED:
-                return VM_SET_ERROR(pVM, VERR_VMX_NO_VMX, "VT-x is disabled in the BIOS for Safer-Mode/Trusted Extensions.");
+            case VERR_VMX_MSR_ALL_VMXON_DISABLED:
+                return VM_SET_ERROR(pVM, VERR_VMX_NO_VMX, "VT-x is disabled in the BIOS for all CPU modes.");
             case VERR_VMX_MSR_LOCKING_FAILED:
                 return VM_SET_ERROR(pVM, VERR_VMX_NO_VMX, "Failed to enable and lock VT-x features.");