@@ -49,6 +49,8 @@
/* AccessReenlightenmentControls privilege */
#define HV_X64_ACCESS_REENLIGHTENMENT BIT(13)
+/* AccessTscInvariantControls privilege */
+#define HV_X64_ACCESS_TSC_INVARIANT BIT(15)
/*
* Basic SynIC MSRs (HV_X64_MSR_SCONTROL through HV_X64_MSR_EOM
@@ -315,6 +317,9 @@ struct hv_reenlightenment_control {
#define HV_X64_MSR_TSC_EMULATION_CONTROL 0x40000107
#define HV_X64_MSR_TSC_EMULATION_STATUS 0x40000108
+/* TSC invariant control */
+#define HV_X64_MSR_TSC_INVARIANT_CONTROL 0x40000118
+
struct hv_tsc_emulation_control {
u64 enabled:1;
u64 reserved:63;
@@ -236,7 +236,12 @@ static void __init ms_hyperv_init_platform(void)
machine_ops.shutdown = hv_machine_shutdown;
machine_ops.crash_shutdown = hv_machine_crash_shutdown;
#endif
- mark_tsc_unstable("running on Hyper-V");
+ if (ms_hyperv.features & HV_X64_ACCESS_TSC_INVARIANT) {
+ wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
+ setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+ } else {
+ mark_tsc_unstable("running on Hyper-V");
+ }
/*
* Generation 2 instances don't support reading the NMI status from