Changeset 10655 in vbox

Timestamp:

Jul 15, 2008 1:05:08 PM (17 years ago)

Author:

vboxsync

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

33365

Message:

Guest MSR_K6_EFER_FFXSR value is not relevant. Always manually save/restore.

File:

• trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp

@@ -168 +168 @@
      *
      * MSR_K6_EFER_FFXSR changes the behaviour of fxsave and fxrstore: the XMM state isn't saved/restored
-     *
-     * If the guest uses the MSR_K6_EFER_FFXSR as well, then it has to manually restore the XMM state. 
-     * In that case we don't care.
-     *
-     * We would end up saving/restoring too much if the guest has it enabled, but the host hasn't.
-     */
-    if (    (pVM->cpum.s.aGuestCpuIdExt[1].edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR) /* 0x80000001 */
-        &&  !(pCtx->msrEFER & MSR_K6_EFER_FFXSR))
+     */
+    if (pVM->cpum.s.aGuestCpuIdExt[1].edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR /* cpuid 0x80000001 */)
     {
         /* @todo Do we really need to read this every time?? The host could change this on the fly though. */