From 409771d258e9dd71c30f3c9520fd2b796ffc40f0 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 14 May 2010 12:48:19 +0100 Subject: [PATCH] x86: Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock. Use xen_vcpuop_clockevent instead of hpet and APIC timers as main clockevent device on all vcpus, use the xen wallclock time as wallclock instead of rtc and use xen_clocksource as clocksource. The pv clock algorithm needs to work correctly for the xen_clocksource and xen wallclock to be usable, only modern Xen versions offer a reliable pv clock in HVM guests (XENFEAT_hvm_safe_pvclock). Using the hpet as clocksource means a VMEXIT every time we read/write to the hpet mmio addresses, pvclock give us a better rating without VMEXITs. Same goes for the xen wallclock and xen_vcpuop_clockevent Signed-off-by: Stefano Stabellini Signed-off-by: Don Dutile Signed-off-by: Jeremy Fitzhardinge --- arch/x86/xen/enlighten.c | 14 ++------ arch/x86/xen/suspend.c | 6 ++++ arch/x86/xen/time.c | 58 +++++++++++++++++++++++++++++--- arch/x86/xen/xen-ops.h | 7 ++-- include/xen/interface/features.h | 3 ++ 5 files changed, 66 insertions(+), 22 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 127c95c8d15e..a90172963884 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -935,10 +935,6 @@ static const struct pv_init_ops xen_init_ops __initdata = { .patch = xen_patch, }; -static const struct pv_time_ops xen_time_ops __initdata = { - .sched_clock = xen_sched_clock, -}; - static const struct pv_cpu_ops xen_cpu_ops __initdata = { .cpuid = xen_cpuid, @@ -1076,7 +1072,6 @@ asmlinkage void __init xen_start_kernel(void) /* Install Xen paravirt ops */ pv_info = xen_info; pv_init_ops = xen_init_ops; - pv_time_ops = xen_time_ops; pv_cpu_ops = xen_cpu_ops; pv_apic_ops = xen_apic_ops; @@ -1084,13 +1079,7 @@ asmlinkage void __init xen_start_kernel(void) x86_init.oem.arch_setup = xen_arch_setup; x86_init.oem.banner = xen_banner; - 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; - x86_platform.set_wallclock = xen_set_wallclock; + xen_init_time_ops(); /* * Set up some pagetable state before starting to set any ptes. @@ -1327,6 +1316,7 @@ static void __init xen_hvm_guest_init(void) register_cpu_notifier(&xen_hvm_cpu_notifier); have_vcpu_info_placement = 0; x86_init.irqs.intr_init = xen_init_IRQ; + xen_hvm_init_time_ops(); } static bool __init xen_hvm_platform(void) diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index d07479c340f5..1d789d56877c 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -28,8 +28,14 @@ void xen_pre_suspend(void) void xen_hvm_post_suspend(int suspend_cancelled) { + int cpu; xen_hvm_init_shared_info(); xen_callback_vector(); + if (xen_feature(XENFEAT_hvm_safe_pvclock)) { + for_each_online_cpu(cpu) { + xen_setup_runstate_info(cpu); + } + } } void xen_post_suspend(int suspend_cancelled) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index b3c6c59ed302..4780e55886a5 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -20,6 +20,7 @@ #include #include +#include #include #include @@ -160,7 +161,7 @@ static void do_stolen_accounting(void) * nanoseconds, which is nanoseconds the VCPU spent in RUNNING+BLOCKED * states. */ -unsigned long long xen_sched_clock(void) +static unsigned long long xen_sched_clock(void) { struct vcpu_runstate_info state; cycle_t now; @@ -195,7 +196,7 @@ unsigned long long xen_sched_clock(void) /* Get the TSC speed from Xen */ -unsigned long xen_tsc_khz(void) +static unsigned long xen_tsc_khz(void) { struct pvclock_vcpu_time_info *info = &HYPERVISOR_shared_info->vcpu_info[0].time; @@ -230,7 +231,7 @@ static void xen_read_wallclock(struct timespec *ts) put_cpu_var(xen_vcpu); } -unsigned long xen_get_wallclock(void) +static unsigned long xen_get_wallclock(void) { struct timespec ts; @@ -238,7 +239,7 @@ unsigned long xen_get_wallclock(void) return ts.tv_sec; } -int xen_set_wallclock(unsigned long now) +static int xen_set_wallclock(unsigned long now) { /* do nothing for domU */ return -1; @@ -473,7 +474,11 @@ void xen_timer_resume(void) } } -__init void xen_time_init(void) +static const struct pv_time_ops xen_time_ops __initdata = { + .sched_clock = xen_sched_clock, +}; + +static __init void xen_time_init(void) { int cpu = smp_processor_id(); struct timespec tp; @@ -497,3 +502,46 @@ __init void xen_time_init(void) xen_setup_timer(cpu); xen_setup_cpu_clockevents(); } + +__init void xen_init_time_ops(void) +{ + pv_time_ops = xen_time_ops; + + 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; + x86_platform.set_wallclock = xen_set_wallclock; +} + +static void xen_hvm_setup_cpu_clockevents(void) +{ + int cpu = smp_processor_id(); + xen_setup_runstate_info(cpu); + xen_setup_timer(cpu); + xen_setup_cpu_clockevents(); +} + +__init void xen_hvm_init_time_ops(void) +{ + /* vector callback is needed otherwise we cannot receive interrupts + * on cpu > 0 */ + if (!xen_have_vector_callback && num_present_cpus() > 1) + return; + if (!xen_feature(XENFEAT_hvm_safe_pvclock)) { + printk(KERN_INFO "Xen doesn't support pvclock on HVM," + "disable pv timer\n"); + return; + } + + pv_time_ops = xen_time_ops; + 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; +} + diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 01c9dd386522..089d18923d2b 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -49,11 +49,8 @@ void xen_setup_runstate_info(int cpu); void xen_teardown_timer(int cpu); cycle_t xen_clocksource_read(void); void xen_setup_cpu_clockevents(void); -unsigned long xen_tsc_khz(void); -void __init xen_time_init(void); -unsigned long xen_get_wallclock(void); -int xen_set_wallclock(unsigned long time); -unsigned long long xen_sched_clock(void); +void __init xen_init_time_ops(void); +void __init xen_hvm_init_time_ops(void); irqreturn_t xen_debug_interrupt(int irq, void *dev_id); diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h index 8ab08b91bf6f..70d2563ab166 100644 --- a/include/xen/interface/features.h +++ b/include/xen/interface/features.h @@ -44,6 +44,9 @@ /* x86: Does this Xen host support the HVM callback vector type? */ #define XENFEAT_hvm_callback_vector 8 +/* x86: pvclock algorithm is safe to use on HVM */ +#define XENFEAT_hvm_safe_pvclock 9 + #define XENFEAT_NR_SUBMAPS 1 #endif /* __XEN_PUBLIC_FEATURES_H__ */ -- 2.39.2