1 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 3373f84d1397..4a3374e61a93 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -208,12 +208,14 @@ static bool check_hw_exists(void)
         }
 
         /*
-         * Now write a value and read it back to see if it matches,
-         * this is needed to detect certain hardware emulators (qemu/kvm)
-         * that don't trap on the MSR access and always return 0s.
+         * Read the current value, change it and read it back to see if it
+         * matches, this is needed to detect certain hardware emulators
+         * (qemu/kvm) that don't trap on the MSR access and always return 0s.
          */
-        val = 0xabcdUL;
         reg = x86_pmu_event_addr(0);
+        if (rdmsrl_safe(reg, &val))
+                goto msr_fail;
+        val ^= 0xffffUL;
         ret = wrmsrl_safe(reg, val);
         ret |= rdmsrl_safe(reg, &val_new);
         if (ret || val != val_new)