diff options
Diffstat (limited to 'arch/x86/xen/time.c')
| -rw-r--r-- | arch/x86/xen/time.c | 87 |
1 files changed, 59 insertions, 28 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index befbdd8b17f0..9ef0a5cca96e 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -39,6 +39,7 @@ static unsigned long xen_tsc_khz(void) struct pvclock_vcpu_time_info *info = &HYPERVISOR_shared_info->vcpu_info[0].time; + setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ); return pvclock_tsc_khz(info); } @@ -145,12 +146,19 @@ static struct notifier_block xen_pvclock_gtod_notifier = { .notifier_call = xen_pvclock_gtod_notify, }; +static int xen_cs_enable(struct clocksource *cs) +{ + vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK); + return 0; +} + static struct clocksource xen_clocksource __read_mostly = { - .name = "xen", - .rating = 400, - .read = xen_clocksource_get_cycles, - .mask = ~0, - .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .name = "xen", + .rating = 400, + .read = xen_clocksource_get_cycles, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .enable = xen_cs_enable, }; /* @@ -371,11 +379,6 @@ void xen_timer_resume(void) } } -static const struct pv_time_ops xen_time_ops __initconst = { - .sched_clock = xen_sched_clock, - .steal_clock = xen_steal_clock, -}; - static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; static u64 xen_clock_value_saved; @@ -412,12 +415,13 @@ void xen_restore_time_memory_area(void) ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t); /* - * We don't disable VCLOCK_PVCLOCK entirely if it fails to register the - * secondary time info with Xen or if we migrated to a host without the - * necessary flags. On both of these cases what happens is either - * process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT - * bit set. Userspace checks the latter and if 0, it discards the data - * in pvti and fallbacks to a system call for a reliable timestamp. + * We don't disable VDSO_CLOCKMODE_PVCLOCK entirely if it fails to + * register the secondary time info with Xen or if we migrated to a + * host without the necessary flags. On both of these cases what + * happens is either process seeing a zeroed out pvti or seeing no + * PVCLOCK_TSC_STABLE_BIT bit set. Userspace checks the latter and + * if 0, it discards the data in pvti and fallbacks to a system + * call for a reliable timestamp. */ if (ret != 0) pr_notice("Cannot restore secondary vcpu_time_info (err %d)", @@ -443,7 +447,7 @@ static void xen_setup_vsyscall_time_info(void) ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t); if (ret) { - pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret); + pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (err %d)\n", ret); free_page((unsigned long)ti); return; } @@ -460,14 +464,14 @@ static void xen_setup_vsyscall_time_info(void) if (!ret) free_page((unsigned long)ti); - pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n"); + pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (tsc unstable)\n"); return; } xen_clock = ti; pvclock_set_pvti_cpu0_va(xen_clock); - xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK; + xen_clocksource.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK; } static void __init xen_time_init(void) @@ -516,17 +520,24 @@ static void __init xen_time_init(void) pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); } -void __init xen_init_time_ops(void) +static void __init xen_init_time_common(void) { xen_sched_clock_offset = xen_clocksource_read(); - pv_ops.time = xen_time_ops; + static_call_update(pv_steal_clock, xen_steal_clock); + paravirt_set_sched_clock(xen_sched_clock); + + x86_platform.calibrate_tsc = xen_tsc_khz; + x86_platform.get_wallclock = xen_get_wallclock; +} + +void __init xen_init_time_ops(void) +{ + xen_init_time_common(); x86_init.timers.timer_init = xen_time_init; x86_init.timers.setup_percpu_clockev = x86_init_noop; x86_cpuinit.setup_percpu_clockev = x86_init_noop; - x86_platform.calibrate_tsc = xen_tsc_khz; - x86_platform.get_wallclock = xen_get_wallclock; /* Dom0 uses the native method to set the hardware RTC. */ if (!xen_initial_domain()) x86_platform.set_wallclock = xen_set_wallclock; @@ -547,6 +558,11 @@ static void xen_hvm_setup_cpu_clockevents(void) void __init xen_hvm_init_time_ops(void) { + static bool hvm_time_initialized; + + if (hvm_time_initialized) + return; + /* * vector callback is needed otherwise we cannot receive interrupts * on cpu > 0 and at this point we don't know how many cpus are @@ -556,18 +572,33 @@ void __init xen_hvm_init_time_ops(void) return; if (!xen_feature(XENFEAT_hvm_safe_pvclock)) { - pr_info("Xen doesn't support pvclock on HVM, disable pv timer"); + pr_info_once("Xen doesn't support pvclock on HVM, disable pv timer"); return; } - xen_sched_clock_offset = xen_clocksource_read(); - pv_ops.time = xen_time_ops; + /* + * Only MAX_VIRT_CPUS 'vcpu_info' are embedded inside 'shared_info'. + * The __this_cpu_read(xen_vcpu) is still NULL when Xen HVM guest + * boots on vcpu >= MAX_VIRT_CPUS (e.g., kexec), To access + * __this_cpu_read(xen_vcpu) via xen_clocksource_read() will panic. + * + * The xen_hvm_init_time_ops() should be called again later after + * __this_cpu_read(xen_vcpu) is available. + */ + if (!__this_cpu_read(xen_vcpu)) { + pr_info("Delay xen_init_time_common() as kernel is running on vcpu=%d\n", + xen_vcpu_nr(0)); + return; + } + + xen_init_time_common(); + x86_init.timers.setup_percpu_clockev = xen_time_init; x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents; - x86_platform.calibrate_tsc = xen_tsc_khz; - x86_platform.get_wallclock = xen_get_wallclock; x86_platform.set_wallclock = xen_set_wallclock; + + hvm_time_initialized = true; } #endif |