Changeset 54891 in vbox

Timestamp:

Mar 20, 2015 11:56:31 PM (10 years ago)

Author:

vboxsync

Message:

CPUM: Enabled CMPXCHG16B by defaults for VMs with nested paging and full hwvirt guest execution capabilities.

File:

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

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

@@ -3435 +3435 @@
     }
 
-    /** @cfgm{/CPUM/IsaExts/CMPXCHG16B, boolean, false}
-     * Expose CMPXCHG16B to the guest if supported by the host.
-     */
-    rc = cpumR3CpuIdReadIsaExtCfgLegacy(pVM, pIsaExts, pCpumCfg, "CMPXCHG16B", &pConfig->enmCmpXchg16b, false);
+    /** @cfgm{/CPUM/IsaExts/CMPXCHG16B, boolean, depends}
+     * Expose CMPXCHG16B to the guest if supported by the host. For the time
+     * being the default is to only do this for VMs with nested paging and AMD-V or
+     * unrestricted guest mode.
+     */
+    rc = cpumR3CpuIdReadIsaExtCfgLegacy(pVM, pIsaExts, pCpumCfg, "CMPXCHG16B", &pConfig->enmCmpXchg16b, fNestedPagingAndFullGuestExec);
     AssertLogRelRCReturn(rc, rc);