diff options
Diffstat (limited to 'drivers/clocksource/hyperv_timer.c')
| -rw-r--r-- | drivers/clocksource/hyperv_timer.c | 58 |
1 files changed, 42 insertions, 16 deletions
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 8ff7cd4e20bb..f00019b078a7 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -23,11 +23,12 @@ #include <linux/acpi.h> #include <linux/hyperv.h> #include <clocksource/hyperv_timer.h> -#include <asm/hyperv-tlfs.h> +#include <hyperv/hvhdk.h> #include <asm/mshyperv.h> static struct clock_event_device __percpu *hv_clock_event; -static u64 hv_sched_clock_offset __ro_after_init; +/* Note: offset can hold negative values after hibernation. */ +static u64 hv_sched_clock_offset __read_mostly; /* * If false, we're using the old mechanism for stimer0 interrupts @@ -81,14 +82,14 @@ static int hv_ce_set_next_event(unsigned long delta, current_tick = hv_read_reference_counter(); current_tick += delta; - hv_set_register(HV_REGISTER_STIMER0_COUNT, current_tick); + hv_set_msr(HV_MSR_STIMER0_COUNT, current_tick); return 0; } static int hv_ce_shutdown(struct clock_event_device *evt) { - hv_set_register(HV_REGISTER_STIMER0_COUNT, 0); - hv_set_register(HV_REGISTER_STIMER0_CONFIG, 0); + hv_set_msr(HV_MSR_STIMER0_COUNT, 0); + hv_set_msr(HV_MSR_STIMER0_CONFIG, 0); if (direct_mode_enabled && stimer0_irq >= 0) disable_percpu_irq(stimer0_irq); @@ -119,7 +120,7 @@ static int hv_ce_set_oneshot(struct clock_event_device *evt) timer_cfg.direct_mode = 0; timer_cfg.sintx = stimer0_message_sint; } - hv_set_register(HV_REGISTER_STIMER0_CONFIG, timer_cfg.as_uint64); + hv_set_msr(HV_MSR_STIMER0_CONFIG, timer_cfg.as_uint64); return 0; } @@ -137,7 +138,21 @@ static int hv_stimer_init(unsigned int cpu) ce->name = "Hyper-V clockevent"; ce->features = CLOCK_EVT_FEAT_ONESHOT; ce->cpumask = cpumask_of(cpu); - ce->rating = 1000; + + /* + * Lower the rating of the Hyper-V timer in a TDX VM without paravisor, + * so the local APIC timer (lapic_clockevent) is the default timer in + * such a VM. The Hyper-V timer is not preferred in such a VM because + * it depends on the slow VM Reference Counter MSR (the Hyper-V TSC + * page is not enbled in such a VM because the VM uses Invariant TSC + * as a better clocksource and it's challenging to mark the Hyper-V + * TSC page shared in very early boot). + */ + if (!ms_hyperv.paravisor_present && hv_isolation_type_tdx()) + ce->rating = 90; + else + ce->rating = 1000; + ce->set_state_shutdown = hv_ce_shutdown; ce->set_state_oneshot = hv_ce_set_oneshot; ce->set_next_event = hv_ce_set_next_event; @@ -372,11 +387,11 @@ static __always_inline u64 read_hv_clock_msr(void) * is set to 0 when the partition is created and is incremented in 100 * nanosecond units. * - * Use hv_raw_get_register() because this function is used from - * noinstr. Notable; while HV_REGISTER_TIME_REF_COUNT is a synthetic + * Use hv_raw_get_msr() because this function is used from + * noinstr. Notable; while HV_MSR_TIME_REF_COUNT is a synthetic * register it doesn't need the GHCB path. */ - return hv_raw_get_register(HV_REGISTER_TIME_REF_COUNT); + return hv_raw_get_msr(HV_MSR_TIME_REF_COUNT); } /* @@ -439,9 +454,9 @@ static void suspend_hv_clock_tsc(struct clocksource *arg) union hv_reference_tsc_msr tsc_msr; /* Disable the TSC page */ - tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); + tsc_msr.as_uint64 = hv_get_msr(HV_MSR_REFERENCE_TSC); tsc_msr.enable = 0; - hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); + hv_set_msr(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64); } @@ -450,10 +465,21 @@ static void resume_hv_clock_tsc(struct clocksource *arg) union hv_reference_tsc_msr tsc_msr; /* Re-enable the TSC page */ - tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); + tsc_msr.as_uint64 = hv_get_msr(HV_MSR_REFERENCE_TSC); tsc_msr.enable = 1; tsc_msr.pfn = tsc_pfn; - hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); + hv_set_msr(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64); +} + +/* + * Called during resume from hibernation, from overridden + * x86_platform.restore_sched_clock_state routine. This is to adjust offsets + * used to calculate time for hv tsc page based sched_clock, to account for + * time spent before hibernation. + */ +void hv_adj_sched_clock_offset(u64 offset) +{ + hv_sched_clock_offset -= offset; } #ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK @@ -555,14 +581,14 @@ static void __init hv_init_tsc_clocksource(void) * thus TSC clocksource will work even without the real TSC page * mapped. */ - tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); + tsc_msr.as_uint64 = hv_get_msr(HV_MSR_REFERENCE_TSC); if (hv_root_partition) tsc_pfn = tsc_msr.pfn; else tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page)); tsc_msr.enable = 1; tsc_msr.pfn = tsc_pfn; - hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); + hv_set_msr(HV_MSR_REFERENCE_TSC, tsc_msr.as_uint64); clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100); |