Commit f0148711 authored by Andreas Herrmann's avatar Andreas Herrmann Committed by H. Peter Anvin
Browse files

x86, amd: Check X86_FEATURE_OSVW bit before accessing OSVW MSRs

If host CPU is exposed to a guest the OSVW MSRs are not guaranteed
to be present and a GP fault occurs. Thus checking the feature flag is

Cc: <> # .32.x .33.x
Signed-off-by: default avatarAndreas Herrmann <>
LKML-Reference: <>
Signed-off-by: default avatarH. Peter Anvin <>
parent b0c4d952
......@@ -546,12 +546,14 @@ static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c)
* check OSVW bit for CPUs that are not affected
* by erratum #400
if (cpu_has(c, X86_FEATURE_OSVW)) {
rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, val);
if (val >= 2) {
rdmsrl(MSR_AMD64_OSVW_STATUS, val);
if (!(val & BIT(1)))
goto no_c1e_idle;
return 1;
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