diff options
Diffstat (limited to 'drivers/clocksource/hyperv_timer.c')
| -rw-r--r-- | drivers/clocksource/hyperv_timer.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 2edc13ca184e..10356d4ec55c 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -549,14 +549,22 @@ static void __init hv_init_tsc_clocksource(void) union hv_reference_tsc_msr tsc_msr; /* + * When running as a guest partition: + * * If Hyper-V offers TSC_INVARIANT, then the virtualized TSC correctly * handles frequency and offset changes due to live migration, * pause/resume, and other VM management operations. So lower the * Hyper-V Reference TSC rating, causing the generic TSC to be used. * TSC_INVARIANT is not offered on ARM64, so the Hyper-V Reference * TSC will be preferred over the virtualized ARM64 arch counter. + * + * When running as the root partition: + * + * There is no HV_ACCESS_TSC_INVARIANT feature. Always lower the rating + * of the Hyper-V Reference TSC. */ - if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) { + if ((ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) || + hv_root_partition()) { hyperv_cs_tsc.rating = 250; hyperv_cs_msr.rating = 245; } |