| Message ID | 20191216001922.23008-7-boqun.feng@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vDSO support for Hyper-V guest on ARM64 | expand |
Boqun Feng <boqun.feng@gmail.com> writes: > Similar to x86, add a new vclock_mode VCLOCK_HVCLOCK, and reuse the > hv_read_tsc_page() for userspace to read tsc page clocksource. > > Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com> > --- > arch/arm64/include/asm/clocksource.h | 3 ++- > arch/arm64/include/asm/mshyperv.h | 2 +- > arch/arm64/include/asm/vdso/gettimeofday.h | 19 +++++++++++++++++++ > 3 files changed, 22 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h > index fbe80057468c..c6acd45fe748 100644 > --- a/arch/arm64/include/asm/clocksource.h > +++ b/arch/arm64/include/asm/clocksource.h > @@ -4,7 +4,8 @@ > > #define VCLOCK_NONE 0 /* No vDSO clock available. */ > #define VCLOCK_CNTVCT 1 /* vDSO should use cntvcnt */ > -#define VCLOCK_MAX 1 > +#define VCLOCK_HVCLOCK 2 /* vDSO should use vread_hvclock() */ > +#define VCLOCK_MAX 2 > > struct arch_clocksource_data { > int vclock_mode; > diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h > index 0afb00e3501d..7c85dd816dca 100644 > --- a/arch/arm64/include/asm/mshyperv.h > +++ b/arch/arm64/include/asm/mshyperv.h > @@ -90,7 +90,7 @@ extern void hv_get_vpreg_128(u32 reg, struct hv_get_vp_register_output *result); > #define hv_set_reference_tsc(val) \ > hv_set_vpreg(HV_REGISTER_REFERENCE_TSC, val) > #define hv_set_clocksource_vdso(val) \ > - ((val).archdata.vclock_mode = VCLOCK_NONE) > + ((val).archdata.vclock_mode = VCLOCK_HVCLOCK) > > #if IS_ENABLED(CONFIG_HYPERV) > #define hv_enable_stimer0_percpu_irq(irq) enable_percpu_irq(irq, 0) > diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h > index e6e3fe0488c7..7e689b903f4d 100644 > --- a/arch/arm64/include/asm/vdso/gettimeofday.h > +++ b/arch/arm64/include/asm/vdso/gettimeofday.h > @@ -67,6 +67,20 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) > return ret; > } > > +#ifdef CONFIG_HYPERV_TIMER > +/* This will override the default hv_get_raw_timer() */ > +#define hv_get_raw_timer() __arch_counter_get_cntvct() > +#include <clocksource/hyperv_timer.h> > + > +extern struct ms_hyperv_tsc_page > +_hvclock_page __attribute__((visibility("hidden"))); > + > +static u64 vread_hvclock(void) > +{ > + return hv_read_tsc_page(&_hvclock_page); > +} > +#endif The function is almost the same on x86 (&_hvclock_page -> &hvclock_page), would it maybe make sense to move this to arch neutral clocksource/hyperv_timer.h? > + > static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) > { > u64 res; > @@ -78,6 +92,11 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) > if (clock_mode == VCLOCK_NONE) > return __VDSO_USE_SYSCALL; > > +#ifdef CONFIG_HYPERV_TIMER > + if (likely(clock_mode == VCLOCK_HVCLOCK)) > + return vread_hvclock(); I'm not sure likely() is justified here: it'll make ALL builds which enable CONFIG_HYPERV_TIMER (e.g. distro kernels) to prefer VCLOCK_HVCLOCK, even if the kernel is not running on Hyper-V. > +#endif > + > /* > * This isb() is required to prevent that the counter value > * is speculated.
On Tue, Dec 17, 2019 at 03:10:16PM +0100, Vitaly Kuznetsov wrote: > Boqun Feng <boqun.feng@gmail.com> writes: > > > Similar to x86, add a new vclock_mode VCLOCK_HVCLOCK, and reuse the > > hv_read_tsc_page() for userspace to read tsc page clocksource. > > > > Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com> > > --- > > arch/arm64/include/asm/clocksource.h | 3 ++- > > arch/arm64/include/asm/mshyperv.h | 2 +- > > arch/arm64/include/asm/vdso/gettimeofday.h | 19 +++++++++++++++++++ > > 3 files changed, 22 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h > > index fbe80057468c..c6acd45fe748 100644 > > --- a/arch/arm64/include/asm/clocksource.h > > +++ b/arch/arm64/include/asm/clocksource.h > > @@ -4,7 +4,8 @@ > > > > #define VCLOCK_NONE 0 /* No vDSO clock available. */ > > #define VCLOCK_CNTVCT 1 /* vDSO should use cntvcnt */ > > -#define VCLOCK_MAX 1 > > +#define VCLOCK_HVCLOCK 2 /* vDSO should use vread_hvclock() */ > > +#define VCLOCK_MAX 2 > > > > struct arch_clocksource_data { > > int vclock_mode; > > diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h > > index 0afb00e3501d..7c85dd816dca 100644 > > --- a/arch/arm64/include/asm/mshyperv.h > > +++ b/arch/arm64/include/asm/mshyperv.h > > @@ -90,7 +90,7 @@ extern void hv_get_vpreg_128(u32 reg, struct hv_get_vp_register_output *result); > > #define hv_set_reference_tsc(val) \ > > hv_set_vpreg(HV_REGISTER_REFERENCE_TSC, val) > > #define hv_set_clocksource_vdso(val) \ > > - ((val).archdata.vclock_mode = VCLOCK_NONE) > > + ((val).archdata.vclock_mode = VCLOCK_HVCLOCK) > > > > #if IS_ENABLED(CONFIG_HYPERV) > > #define hv_enable_stimer0_percpu_irq(irq) enable_percpu_irq(irq, 0) > > diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h > > index e6e3fe0488c7..7e689b903f4d 100644 > > --- a/arch/arm64/include/asm/vdso/gettimeofday.h > > +++ b/arch/arm64/include/asm/vdso/gettimeofday.h > > @@ -67,6 +67,20 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) > > return ret; > > } > > > > +#ifdef CONFIG_HYPERV_TIMER > > +/* This will override the default hv_get_raw_timer() */ > > +#define hv_get_raw_timer() __arch_counter_get_cntvct() > > +#include <clocksource/hyperv_timer.h> > > + > > +extern struct ms_hyperv_tsc_page > > +_hvclock_page __attribute__((visibility("hidden"))); > > + > > +static u64 vread_hvclock(void) > > +{ > > + return hv_read_tsc_page(&_hvclock_page); > > +} > > +#endif > > The function is almost the same on x86 (&_hvclock_page -> > &hvclock_page), would it maybe make sense to move this to arch neutral > clocksource/hyperv_timer.h? > I'm not sure whether the underscore matters in the vDSO data symbol, so I follow the architectural name convention. If the leading underscore doesn't have special purpose I'm happy to move this to arch neutral header file. > > + > > static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) > > { > > u64 res; > > @@ -78,6 +92,11 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) > > if (clock_mode == VCLOCK_NONE) > > return __VDSO_USE_SYSCALL; > > > > +#ifdef CONFIG_HYPERV_TIMER > > + if (likely(clock_mode == VCLOCK_HVCLOCK)) > > + return vread_hvclock(); > > I'm not sure likely() is justified here: it'll make ALL builds which > enable CONFIG_HYPERV_TIMER (e.g. distro kernels) to prefer > VCLOCK_HVCLOCK, even if the kernel is not running on Hyper-V. > Make sense. Thanks for pointing this out! I will change it in the next version. Regards, Boqun > > +#endif > > + > > /* > > * This isb() is required to prevent that the counter value > > * is speculated. > > -- > Vitaly >
diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h index fbe80057468c..c6acd45fe748 100644 --- a/arch/arm64/include/asm/clocksource.h +++ b/arch/arm64/include/asm/clocksource.h @@ -4,7 +4,8 @@ #define VCLOCK_NONE 0 /* No vDSO clock available. */ #define VCLOCK_CNTVCT 1 /* vDSO should use cntvcnt */ -#define VCLOCK_MAX 1 +#define VCLOCK_HVCLOCK 2 /* vDSO should use vread_hvclock() */ +#define VCLOCK_MAX 2 struct arch_clocksource_data { int vclock_mode; diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h index 0afb00e3501d..7c85dd816dca 100644 --- a/arch/arm64/include/asm/mshyperv.h +++ b/arch/arm64/include/asm/mshyperv.h @@ -90,7 +90,7 @@ extern void hv_get_vpreg_128(u32 reg, struct hv_get_vp_register_output *result); #define hv_set_reference_tsc(val) \ hv_set_vpreg(HV_REGISTER_REFERENCE_TSC, val) #define hv_set_clocksource_vdso(val) \ - ((val).archdata.vclock_mode = VCLOCK_NONE) + ((val).archdata.vclock_mode = VCLOCK_HVCLOCK) #if IS_ENABLED(CONFIG_HYPERV) #define hv_enable_stimer0_percpu_irq(irq) enable_percpu_irq(irq, 0) diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h index e6e3fe0488c7..7e689b903f4d 100644 --- a/arch/arm64/include/asm/vdso/gettimeofday.h +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -67,6 +67,20 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) return ret; } +#ifdef CONFIG_HYPERV_TIMER +/* This will override the default hv_get_raw_timer() */ +#define hv_get_raw_timer() __arch_counter_get_cntvct() +#include <clocksource/hyperv_timer.h> + +extern struct ms_hyperv_tsc_page +_hvclock_page __attribute__((visibility("hidden"))); + +static u64 vread_hvclock(void) +{ + return hv_read_tsc_page(&_hvclock_page); +} +#endif + static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) { u64 res; @@ -78,6 +92,11 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) if (clock_mode == VCLOCK_NONE) return __VDSO_USE_SYSCALL; +#ifdef CONFIG_HYPERV_TIMER + if (likely(clock_mode == VCLOCK_HVCLOCK)) + return vread_hvclock(); +#endif + /* * This isb() is required to prevent that the counter value * is speculated.
Similar to x86, add a new vclock_mode VCLOCK_HVCLOCK, and reuse the hv_read_tsc_page() for userspace to read tsc page clocksource. Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com> --- arch/arm64/include/asm/clocksource.h | 3 ++- arch/arm64/include/asm/mshyperv.h | 2 +- arch/arm64/include/asm/vdso/gettimeofday.h | 19 +++++++++++++++++++ 3 files changed, 22 insertions(+), 2 deletions(-)