svn commit: r330793 - head/sys/x86/x86

[Andriy Gapon]

Author: avg
Date: Mon Mar 12 11:28:09 2018
New Revision: 330793
URL: https://svnweb.freebsd.org/changeset/base/330793

Log:
  fix r297857, do not modify CPU extension bits under virtual machines
  
  r297857 was meant for real hardware only.
  
  PR:		213155
  Submitted by:	mainland at apeiron.net
  MFC after:	1 week

Modified:
  head/sys/x86/x86/identcpu.c

Modified: head/sys/x86/x86/identcpu.c
==============================================================================
--- head/sys/x86/x86/identcpu.c	Mon Mar 12 09:40:46 2018	(r330792)
+++ head/sys/x86/x86/identcpu.c	Mon Mar 12 11:28:09 2018	(r330793)
@@ -1395,7 +1395,8 @@ fix_cpuid(void)
 	 * See BIOS and Kernel Developer’s Guide (BKDG) for AMD Family 15h
 	 * Models 60h-6Fh Processors, Publication # 50742.
 	 */
-	if (cpu_vendor_id == CPU_VENDOR_AMD && CPUID_TO_FAMILY(cpu_id) == 0x15) {
+	if (vm_guest == VM_GUEST_NO && cpu_vendor_id == CPU_VENDOR_AMD &&
+	    CPUID_TO_FAMILY(cpu_id) == 0x15) {
 		msr = rdmsr(MSR_EXTFEATURES);
 		if ((msr & ((uint64_t)1 << 54)) == 0) {
 			msr |= (uint64_t)1 << 54;