WARN if the IA32_FEATURE_CONTROL MSR is somehow left unlocked now that CPU initialization unconditionally locks the MSR. Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Cc: Wanpeng Li <wanpengli@xxxxxxxxxxx> Cc: Jim Mattson <jmattson@xxxxxxxxxx> Cc: kvm@xxxxxxxxxxxxxxx Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- arch/x86/kernel/cpu/mce/intel.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c index 88cd9598fa57..1008f14b803b 100644 --- a/arch/x86/kernel/cpu/mce/intel.c +++ b/arch/x86/kernel/cpu/mce/intel.c @@ -117,11 +117,10 @@ static bool lmce_supported(void) * generate a #GP fault. */ rdmsrl(MSR_IA32_FEATURE_CONTROL, tmp); - if ((tmp & (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE)) == - (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE)) - return true; + if (WARN_ON_ONCE(!(tmp & FEATURE_CONTROL_LOCKED))) + return false; - return false; + return tmp & FEATURE_CONTROL_LMCE; } bool mce_intel_cmci_poll(void) -- 2.22.0
