x86, paravirt: don't compute pvclock adjustments if we trust the tsc

If the HV told us we can fully trust the TSC, skip any
correction

Signed-off-by: Glauber Costa <glommer@redhat.com>
Acked-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 59c740fcb9b3..eb9b76c716c2 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -215,4 +215,7 @@ void __init kvmclock_init(void)
         clocksource_register(&kvm_clock);
         pv_info.paravirt_enabled = 1;
         pv_info.name = "KVM";
+
+        if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))
+                pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);
 }