svn commit: r328624 - head/sys/x86/x86

[Konstantin Belousov]

Author: kib
Date: Wed Jan 31 14:25:42 2018
New Revision: 328624
URL: https://svnweb.freebsd.org/changeset/base/328624

Log:
  Do not enable PTI when IA32_ARCH_CAP_RDCL_NO bit is set.
  
  Intel document 336996-001 claims that this will be the way to inform
  about Meltdown correction.
  
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

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

Modified: head/sys/x86/x86/identcpu.c
==============================================================================
--- head/sys/x86/x86/identcpu.c	Wed Jan 31 13:40:36 2018	(r328623)
+++ head/sys/x86/x86/identcpu.c	Wed Jan 31 14:25:42 2018	(r328624)
@@ -1614,7 +1614,8 @@ pti_get_default(void)
 
 	if (strcmp(cpu_vendor, AMD_VENDOR_ID) == 0)
 		return (0);
-
+	if ((cpu_ia32_arch_caps & IA32_ARCH_CAP_RDCL_NO) != 0)
+		return (0);
 	return (1);
 }