[PATCH v2] x86/mce: Use "safe" MSR functions when enabling additional error logging

[Luck, Tony]

Booting as a guest under KVM results in error messages about
unchecked MSR access:

[    6.814328][    T0] unchecked MSR access error: RDMSR from 0x17f at rIP: 0xffffffff84483f16 (mce_intel_feature_init+0x156/0x270)

because KVM doesn't provide emulation for random model specific registers.

Switch to using rdmsrl_safe()/wrmsrl_safe() to avoid the message.

Reported-by: Qian Cai <cai@xxxxxxxxxx>
Fixes: 68299a42f842 ("x86/mce: Enable additional error logging on certain Intel CPUs")
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/kernel/cpu/mce/intel.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c
index b47883e364b4..42e60ef16c3a 100644
--- a/arch/x86/kernel/cpu/mce/intel.c
+++ b/arch/x86/kernel/cpu/mce/intel.c
@@ -521,9 +521,10 @@ static void intel_imc_init(struct cpuinfo_x86 *c)
 	case INTEL_FAM6_SANDYBRIDGE_X:
 	case INTEL_FAM6_IVYBRIDGE_X:
 	case INTEL_FAM6_HASWELL_X:
-		rdmsrl(MSR_ERROR_CONTROL, error_control);
+		if (rdmsrl_safe(MSR_ERROR_CONTROL, &error_control))
+			return;
 		error_control |= 2;
-		wrmsrl(MSR_ERROR_CONTROL, error_control);
+		wrmsrl_safe(MSR_ERROR_CONTROL, error_control);
 		break;
 	}
 }
-- 
2.21.1