Changeset 70654 in vbox for trunk/src/VBox

Timestamp:

Jan 20, 2018 7:02:32 AM (7 years ago)

Author:

vboxsync

Message:

VMM/CPUM: Mask out INVPCID in addition to PCID when FSGSBASE is not present.

File:

• trunk/src/VBox/VMM/VMMR3/CPUMR3CpuId.cpp (modified) (4 diffs)

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

@@ -2696 +2696 @@
                            ;
 
-    /* Mask out the PCID unless FSGSBASE is exposed due to a bug in Windows 10 SMP guests, see @bugref{9089#c15}. */
+    /* Mask out PCID unless FSGSBASE is exposed due to a bug in Windows 10 SMP guests, see @bugref{9089#c15}. */
     if (   !pVM->cpum.s.GuestFeatures.fFsGsBase
         && (pStdFeatureLeaf->uEcx & X86_CPUID_FEATURE_ECX_PCID))
@@ -3148 +3148 @@
                 pCurLeaf->uEdx &= 0; /** @todo X86_CPUID_STEXT_FEATURE_EDX_IBRS_IBPB, X86_CPUID_STEXT_FEATURE_EDX_STIBP and X86_CPUID_STEXT_FEATURE_EDX_ARCHCAP */
 
+                /* Mask out INVPCID unless FSGSBASE is exposed due to a bug in Windows 10 SMP guests, see @bugref{9089#c15}. */
+                if (  !pVM->cpum.s.GuestFeatures.fFsGsBase
+                   && (pCurLeaf->uEbx & X86_CPUID_STEXT_FEATURE_EBX_INVPCID))
+                {
+                    pCurLeaf->uEbx &= ~X86_CPUID_STEXT_FEATURE_EBX_INVPCID;
+                    LogRel(("CPUM: Disabled INVPCID without FSGSBASE to workaround buggy guests\n"));
+                }
+
                 if (pCpum->u8PortableCpuIdLevel > 0)
                 {
@@ -4093 +4101 @@
      * Whether to expose the PCID feature to the guest.
      */
-    rc = cpumR3CpuIdReadIsaExtCfg(pVM, pIsaExts, "PCID", &pConfig->enmPcid, true);
+    rc = cpumR3CpuIdReadIsaExtCfg(pVM, pIsaExts, "PCID", &pConfig->enmPcid, pConfig->enmFsGsBase);
     AssertLogRelRCReturn(rc, rc);
 
@@ -4099 +4107 @@
      * Whether to expose the INVPCID instruction to the guest.
      */
-    rc = cpumR3CpuIdReadIsaExtCfg(pVM, pIsaExts, "INVPCID", &pConfig->enmInvpcid, true);
+    rc = cpumR3CpuIdReadIsaExtCfg(pVM, pIsaExts, "INVPCID", &pConfig->enmInvpcid, pConfig->enmFsGsBase);
     AssertLogRelRCReturn(rc, rc);