| Message ID | 1501331711-12961-2-git-send-email-dplotnikov@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 29/07/2017 14:35, Denis Plotnikov wrote: > The parameter is a pointer which is used to store cycles stamp value > used for time calulation on pvclock reading. > > This is a part of the work aiming to move to a more simple scheme of > masterclock related values calculation in KVM. > > Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> > --- > arch/x86/include/asm/pvclock.h | 2 +- > arch/x86/kernel/kvmclock.c | 2 +- > arch/x86/kernel/pvclock.c | 12 +++++++++--- > arch/x86/xen/time.c | 2 +- > 4 files changed, 12 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h > index 448cfe1..147b411 100644 > --- a/arch/x86/include/asm/pvclock.h > +++ b/arch/x86/include/asm/pvclock.h > @@ -14,7 +14,7 @@ static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void) > #endif > > /* some helper functions for xen and kvm pv clock sources */ > -u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); > +u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src, u64 *cycles); > u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); > void pvclock_set_flags(u8 flags); > unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index d889676..f5cfc5d 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -91,7 +91,7 @@ static u64 kvm_clock_read(void) > preempt_disable_notrace(); > cpu = smp_processor_id(); > src = &hv_clock[cpu].pvti; > - ret = pvclock_clocksource_read(src); > + ret = pvclock_clocksource_read(src, NULL); > preempt_enable_notrace(); > return ret; > } > diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c > index 5c3f6d6..a2c554a 100644 > --- a/arch/x86/kernel/pvclock.c > +++ b/arch/x86/kernel/pvclock.c > @@ -73,19 +73,24 @@ u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src) > return flags & valid_flags; > } > > -u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) > +u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src, u64 *cycles) > { > unsigned version; > u64 ret; > u64 last; > u8 flags; > + u64 tsc; > > do { > version = pvclock_read_begin(src); > - ret = __pvclock_read_cycles(src, rdtsc_ordered()); > + tsc = rdtsc_ordered(); > + ret = __pvclock_read_cycles(src, tsc); > flags = src->flags; > } while (pvclock_read_retry(src, version)); > > + if (cycles) > + *cycles = tsc; > + > if (unlikely((flags & PVCLOCK_GUEST_STOPPED) != 0)) { > src->flags &= ~PVCLOCK_GUEST_STOPPED; > pvclock_touch_watchdogs(); > @@ -136,7 +141,8 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, > rmb(); /* fetch time before checking version */ > } while ((wall_clock->version & 1) || (version != wall_clock->version)); > > - delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */ > + /* time since system boot */ > + delta = pvclock_clocksource_read(vcpu_time, NULL); > delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; > > now.tv_nsec = do_div(delta, NSEC_PER_SEC); > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > index 1ecb05d..145ac9a 100644 > --- a/arch/x86/xen/time.c > +++ b/arch/x86/xen/time.c > @@ -46,7 +46,7 @@ u64 xen_clocksource_read(void) > > preempt_disable_notrace(); > src = &__this_cpu_read(xen_vcpu)->time; > - ret = pvclock_clocksource_read(src); > + ret = pvclock_clocksource_read(src, NULL); > preempt_enable_notrace(); > return ret; > } > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h index 448cfe1..147b411 100644 --- a/arch/x86/include/asm/pvclock.h +++ b/arch/x86/include/asm/pvclock.h @@ -14,7 +14,7 @@ static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void) #endif /* some helper functions for xen and kvm pv clock sources */ -u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); +u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src, u64 *cycles); u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); void pvclock_set_flags(u8 flags); unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index d889676..f5cfc5d 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -91,7 +91,7 @@ static u64 kvm_clock_read(void) preempt_disable_notrace(); cpu = smp_processor_id(); src = &hv_clock[cpu].pvti; - ret = pvclock_clocksource_read(src); + ret = pvclock_clocksource_read(src, NULL); preempt_enable_notrace(); return ret; } diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 5c3f6d6..a2c554a 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -73,19 +73,24 @@ u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src) return flags & valid_flags; } -u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) +u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src, u64 *cycles) { unsigned version; u64 ret; u64 last; u8 flags; + u64 tsc; do { version = pvclock_read_begin(src); - ret = __pvclock_read_cycles(src, rdtsc_ordered()); + tsc = rdtsc_ordered(); + ret = __pvclock_read_cycles(src, tsc); flags = src->flags; } while (pvclock_read_retry(src, version)); + if (cycles) + *cycles = tsc; + if (unlikely((flags & PVCLOCK_GUEST_STOPPED) != 0)) { src->flags &= ~PVCLOCK_GUEST_STOPPED; pvclock_touch_watchdogs(); @@ -136,7 +141,8 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, rmb(); /* fetch time before checking version */ } while ((wall_clock->version & 1) || (version != wall_clock->version)); - delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */ + /* time since system boot */ + delta = pvclock_clocksource_read(vcpu_time, NULL); delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; now.tv_nsec = do_div(delta, NSEC_PER_SEC); diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 1ecb05d..145ac9a 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -46,7 +46,7 @@ u64 xen_clocksource_read(void) preempt_disable_notrace(); src = &__this_cpu_read(xen_vcpu)->time; - ret = pvclock_clocksource_read(src); + ret = pvclock_clocksource_read(src, NULL); preempt_enable_notrace(); return ret; }
The parameter is a pointer which is used to store cycles stamp value used for time calulation on pvclock reading. This is a part of the work aiming to move to a more simple scheme of masterclock related values calculation in KVM. Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> --- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/kernel/kvmclock.c | 2 +- arch/x86/kernel/pvclock.c | 12 +++++++++--- arch/x86/xen/time.c | 2 +- 4 files changed, 12 insertions(+), 6 deletions(-)