Module Name: src
Committed By: maxv
Date: Thu Dec 12 16:49:20 UTC 2019
Modified Files:
src/sys/arch/x86/x86: spectre.c
Log Message:
Check CPUID.IBRS in addition to ARCH_CAP.IBRS_ALL. For clarity, and also
because VirtualBox clears the former but forgets to clear the latter (which
makes us hit a #GP on RDMSR).
To generate a diff of this commit:
cvs rdiff -u -r1.31 -r1.32 src/sys/arch/x86/x86/spectre.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/x86/spectre.c
diff -u src/sys/arch/x86/x86/spectre.c:1.31 src/sys/arch/x86/x86/spectre.c:1.32
--- src/sys/arch/x86/x86/spectre.c:1.31 Tue Nov 12 18:00:13 2019
+++ src/sys/arch/x86/x86/spectre.c Thu Dec 12 16:49:20 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: spectre.c,v 1.31 2019/11/12 18:00:13 maxv Exp $ */
+/* $NetBSD: spectre.c,v 1.32 2019/12/12 16:49:20 maxv Exp $ */
/*
* Copyright (c) 2018-2019 NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.31 2019/11/12 18:00:13 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spectre.c,v 1.32 2019/12/12 16:49:20 maxv Exp $");
#include "opt_spectre.h"
@@ -126,20 +126,20 @@ v2_detect_method(void)
if (cpuid_level >= 7) {
x86_cpuid(7, descs);
- if (descs[3] & CPUID_SEF_ARCH_CAP) {
- msr = rdmsr(MSR_IA32_ARCH_CAPABILITIES);
- if (msr & IA32_ARCH_IBRS_ALL) {
- v2_mitigation_method =
- V2_MITIGATION_INTEL_ENHANCED_IBRS;
- return;
+ if (descs[3] & CPUID_SEF_IBRS) {
+ if (descs[3] & CPUID_SEF_ARCH_CAP) {
+ msr = rdmsr(MSR_IA32_ARCH_CAPABILITIES);
+ if (msr & IA32_ARCH_IBRS_ALL) {
+ v2_mitigation_method =
+ V2_MITIGATION_INTEL_ENHANCED_IBRS;
+ return;
+ }
}
- }
#ifdef __x86_64__
- if (descs[3] & CPUID_SEF_IBRS) {
v2_mitigation_method = V2_MITIGATION_INTEL_IBRS;
return;
- }
#endif
+ }
}
v2_mitigation_method = V2_MITIGATION_NONE;
} else if (cpu_vendor == CPUVENDOR_AMD) {
