[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] Re: [PATCH 11/13] Use xen_vcpuop_clockevent, xen_clocksource and xen wallclock.
stefano@xxxxxxxxxxxxxx wrote: > From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> > > 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 <stefano.stabellini@xxxxxxxxxxxxx> > --- > arch/x86/xen/enlighten.c | 14 +-------- > arch/x86/xen/suspend.c | 4 ++ > arch/x86/xen/time.c | 59 ++++++++++++++++++++++++++++++++++--- > arch/x86/xen/xen-ops.h | 7 +--- > include/xen/interface/features.h | 3 ++ > 5 files changed, 65 insertions(+), 22 deletions(-) > > diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c > index 90bac21..bcd98a9 100644 > --- a/arch/x86/xen/enlighten.c > +++ b/arch/x86/xen/enlighten.c > @@ -933,10 +933,6 @@ 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, > > @@ -1074,7 +1070,6 @@ 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; > > @@ -1082,13 +1077,7 @@ 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. > @@ -1330,4 +1319,5 @@ 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(); > } > diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c > index 6ff9665..0774c67 100644 > --- a/arch/x86/xen/suspend.c > +++ b/arch/x86/xen/suspend.c > @@ -28,8 +28,12 @@ void xen_pre_suspend(void) > > void xen_hvm_post_suspend(int suspend_cancelled) > { > + int cpu; > xen_hvm_init_shared_info(); > xen_callback_vector(); > + for_each_online_cpu(cpu) { > + xen_setup_runstate_info(cpu); > + } > } > As I found out on older xen (non 'modern Xen version' ;-) ) w/o XENFEAT_hvm_safe_pvclock, the above patch should look like: if (xen_feature(XENFEAT_hvm_safe_pvclock)) { int cpu; for_each_online_cpu(cpu) { xen_setup_runstate_info(cpu); } } - Don > void xen_post_suspend(int suspend_cancelled) > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > index 32764b8..2d76c28 100644 > --- a/arch/x86/xen/time.c > +++ b/arch/x86/xen/time.c > @@ -20,6 +20,7 @@ > #include <asm/xen/hypercall.h> > > #include <xen/events.h> > +#include <xen/features.h> > #include <xen/interface/xen.h> > #include <xen/interface/vcpu.h> > > @@ -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(); > > @@ -497,3 +502,47 @@ __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.timer_init = xen_time_init; > + x86_init.timers.setup_percpu_clockev = x86_init_noop; > + 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 01c9dd3..089d189 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 8ab08b9..70d2563 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__ */ _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |