x86/mce: Use "safe" MSR functions when enabling additional error logging

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

  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.

Fixes: 68299a42f842 ("x86/mce: Enable additional error logging on certain Intel CPUs")
Reported-by: Qian Cai <cai@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201111003954.GA11878@agluck-desk2.amr.corp.intel.com

diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c
index b47883e..c2476fe 100644 (file)
--- 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;
        }
 }