Re: [Xen-devel] [PATCH v2 04/14] x86/time.c: Use correct guest TSC frequency in tsc_get_info()
On 12/08/15 13:26, Boris Ostrovsky wrote: > On 12/07/2015 08:08 PM, Haozhong Zhang wrote: > >On 12/07/15 12:53, Boris Ostrovsky wrote: > >>On 12/06/2015 03:58 PM, Haozhong Zhang wrote: > >>>When the TSC mode of a HVM container is TSC_MODE_DEFAULT or > >>>TSC_MODE_PVRDTSCP and no TSC emulation is used, the existing > >>>tsc_get_info() uses the host TSC frequency (cpu_khz) as the guest TSC > >>>frequency. However, tsc_set_info() may set the guest TSC frequency to a > >>>value different than the host. In order to keep consistent to > >>>tsc_set_info(), this patch makes tsc_get_info() use the value set by > >>>tsc_set_info() as the guest TSC frequency. > >>> > >>>Signed-off-by: Haozhong Zhang > >>>--- > >>> xen/arch/x86/time.c | 12 +--- > >>> 1 file changed, 9 insertions(+), 3 deletions(-) > >>> > >>>diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c > >>>index 1091e69..95df4f1 100644 > >>>--- a/xen/arch/x86/time.c > >>>+++ b/xen/arch/x86/time.c > >>>@@ -1749,6 +1749,9 @@ void tsc_get_info(struct domain *d, uint32_t > >>>*tsc_mode, > >>>uint64_t *elapsed_nsec, uint32_t *gtsc_khz, > >>>uint32_t *incarnation) > >>> { > >>>+bool_t enable_tsc_scaling = has_hvm_container_domain(d) && > >>>+cpu_has_tsc_ratio; > >>&& !d->arch.vtsc ? > >> > >>(assuming my comment to the previous patch is correct). > >> > >enable_tsc_scaling in tsc_get_info() is always used in the condition > >!d->arch.vtsc, so it's not necessary to include it again in > >enable_tsc_scaling. > > > >>>+ > >>> *incarnation = d->arch.incarnation; > >>> *tsc_mode = d->arch.tsc_mode; > >>>@@ -1769,7 +1772,7 @@ void tsc_get_info(struct domain *d, uint32_t > >>>*tsc_mode, > >>> } > >>> tsc = rdtsc(); > >>> *elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns); > >>>-*gtsc_khz = cpu_khz; > >>>+*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : cpu_khz; > >>> break; > >>> case TSC_MODE_PVRDTSCP: > >>> if ( d->arch.vtsc ) > >>>@@ -1779,10 +1782,13 @@ void tsc_get_info(struct domain *d, uint32_t > >>>*tsc_mode, > >>> } > >>> else > >>> { > >>>+struct time_scale *scale = enable_tsc_scaling ? > >>>+ &this_cpu(cpu_time).tsc_scale : > >>>+ &d->arch.vtsc_to_ns; > >>IIUIC tsc_scale is host property and so why would it be used if TSC scaling > >>is available to guests? > >> > >scale is used below to convert a host TSC to nanosec. When TSC scaling is > >used, > >d->arch.vtsc_to_ns may not base on the host TSC frequency, so I turn to the > >host > >tsc_scale instead. > > OK. Can we then use tsc_scale for both with and without TSC scaling? (on the > set side too). > Yes, we can, because early_time_init() calculates tsc_scale based on cpu_khz. I'll change it in the next version. > (And as a side note, I think that the comment in include/asm-x86/domain.h > describing vtsc_to_ns as being used for emulated cases is rather misleading. > We use it for both emulated and native) > agree, I'll update those comments in the next version. Haozhong > -boris > > > > > >Haozhong > > > >>-boris > >> > >> > >>> tsc = rdtsc(); > >>>-*elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns) - > >>>+*elapsed_nsec = scale_delta(tsc, scale) - > >>> d->arch.vtsc_offset; > >>>-*gtsc_khz = 0; /* ignored by tsc_set_info */ > >>>+*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : 0; > >>> } > >>> break; > >>> } > > > ___ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v2 04/14] x86/time.c: Use correct guest TSC frequency in tsc_get_info()
On 12/07/2015 08:08 PM, Haozhong Zhang wrote: On 12/07/15 12:53, Boris Ostrovsky wrote: On 12/06/2015 03:58 PM, Haozhong Zhang wrote: When the TSC mode of a HVM container is TSC_MODE_DEFAULT or TSC_MODE_PVRDTSCP and no TSC emulation is used, the existing tsc_get_info() uses the host TSC frequency (cpu_khz) as the guest TSC frequency. However, tsc_set_info() may set the guest TSC frequency to a value different than the host. In order to keep consistent to tsc_set_info(), this patch makes tsc_get_info() use the value set by tsc_set_info() as the guest TSC frequency. Signed-off-by: Haozhong Zhang --- xen/arch/x86/time.c | 12 +--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 1091e69..95df4f1 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -1749,6 +1749,9 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, uint64_t *elapsed_nsec, uint32_t *gtsc_khz, uint32_t *incarnation) { +bool_t enable_tsc_scaling = has_hvm_container_domain(d) && +cpu_has_tsc_ratio; && !d->arch.vtsc ? (assuming my comment to the previous patch is correct). enable_tsc_scaling in tsc_get_info() is always used in the condition !d->arch.vtsc, so it's not necessary to include it again in enable_tsc_scaling. + *incarnation = d->arch.incarnation; *tsc_mode = d->arch.tsc_mode; @@ -1769,7 +1772,7 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } tsc = rdtsc(); *elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns); -*gtsc_khz = cpu_khz; +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : cpu_khz; break; case TSC_MODE_PVRDTSCP: if ( d->arch.vtsc ) @@ -1779,10 +1782,13 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } else { +struct time_scale *scale = enable_tsc_scaling ? + &this_cpu(cpu_time).tsc_scale : + &d->arch.vtsc_to_ns; IIUIC tsc_scale is host property and so why would it be used if TSC scaling is available to guests? scale is used below to convert a host TSC to nanosec. When TSC scaling is used, d->arch.vtsc_to_ns may not base on the host TSC frequency, so I turn to the host tsc_scale instead. OK. Can we then use tsc_scale for both with and without TSC scaling? (on the set side too). (And as a side note, I think that the comment in include/asm-x86/domain.h describing vtsc_to_ns as being used for emulated cases is rather misleading. We use it for both emulated and native) -boris Haozhong -boris tsc = rdtsc(); -*elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns) - +*elapsed_nsec = scale_delta(tsc, scale) - d->arch.vtsc_offset; -*gtsc_khz = 0; /* ignored by tsc_set_info */ +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : 0; } break; } ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v2 04/14] x86/time.c: Use correct guest TSC frequency in tsc_get_info()
On 12/07/15 12:53, Boris Ostrovsky wrote: > On 12/06/2015 03:58 PM, Haozhong Zhang wrote: > >When the TSC mode of a HVM container is TSC_MODE_DEFAULT or > >TSC_MODE_PVRDTSCP and no TSC emulation is used, the existing > >tsc_get_info() uses the host TSC frequency (cpu_khz) as the guest TSC > >frequency. However, tsc_set_info() may set the guest TSC frequency to a > >value different than the host. In order to keep consistent to > >tsc_set_info(), this patch makes tsc_get_info() use the value set by > >tsc_set_info() as the guest TSC frequency. > > > >Signed-off-by: Haozhong Zhang > >--- > > xen/arch/x86/time.c | 12 +--- > > 1 file changed, 9 insertions(+), 3 deletions(-) > > > >diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c > >index 1091e69..95df4f1 100644 > >--- a/xen/arch/x86/time.c > >+++ b/xen/arch/x86/time.c > >@@ -1749,6 +1749,9 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, > >uint64_t *elapsed_nsec, uint32_t *gtsc_khz, > >uint32_t *incarnation) > > { > >+bool_t enable_tsc_scaling = has_hvm_container_domain(d) && > >+cpu_has_tsc_ratio; > > && !d->arch.vtsc ? > > (assuming my comment to the previous patch is correct). > enable_tsc_scaling in tsc_get_info() is always used in the condition !d->arch.vtsc, so it's not necessary to include it again in enable_tsc_scaling. > > >+ > > *incarnation = d->arch.incarnation; > > *tsc_mode = d->arch.tsc_mode; > >@@ -1769,7 +1772,7 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, > > } > > tsc = rdtsc(); > > *elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns); > >-*gtsc_khz = cpu_khz; > >+*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : cpu_khz; > > break; > > case TSC_MODE_PVRDTSCP: > > if ( d->arch.vtsc ) > >@@ -1779,10 +1782,13 @@ void tsc_get_info(struct domain *d, uint32_t > >*tsc_mode, > > } > > else > > { > >+struct time_scale *scale = enable_tsc_scaling ? > >+ &this_cpu(cpu_time).tsc_scale : > >+ &d->arch.vtsc_to_ns; > > IIUIC tsc_scale is host property and so why would it be used if TSC scaling > is available to guests? > scale is used below to convert a host TSC to nanosec. When TSC scaling is used, d->arch.vtsc_to_ns may not base on the host TSC frequency, so I turn to the host tsc_scale instead. Haozhong > -boris > > > > tsc = rdtsc(); > >-*elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns) - > >+*elapsed_nsec = scale_delta(tsc, scale) - > > d->arch.vtsc_offset; > >-*gtsc_khz = 0; /* ignored by tsc_set_info */ > >+*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : 0; > > } > > break; > > } > ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH v2 04/14] x86/time.c: Use correct guest TSC frequency in tsc_get_info()
On 12/06/2015 03:58 PM, Haozhong Zhang wrote: When the TSC mode of a HVM container is TSC_MODE_DEFAULT or TSC_MODE_PVRDTSCP and no TSC emulation is used, the existing tsc_get_info() uses the host TSC frequency (cpu_khz) as the guest TSC frequency. However, tsc_set_info() may set the guest TSC frequency to a value different than the host. In order to keep consistent to tsc_set_info(), this patch makes tsc_get_info() use the value set by tsc_set_info() as the guest TSC frequency. Signed-off-by: Haozhong Zhang --- xen/arch/x86/time.c | 12 +--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 1091e69..95df4f1 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -1749,6 +1749,9 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, uint64_t *elapsed_nsec, uint32_t *gtsc_khz, uint32_t *incarnation) { +bool_t enable_tsc_scaling = has_hvm_container_domain(d) && +cpu_has_tsc_ratio; && !d->arch.vtsc ? (assuming my comment to the previous patch is correct). + *incarnation = d->arch.incarnation; *tsc_mode = d->arch.tsc_mode; @@ -1769,7 +1772,7 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } tsc = rdtsc(); *elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns); -*gtsc_khz = cpu_khz; +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : cpu_khz; break; case TSC_MODE_PVRDTSCP: if ( d->arch.vtsc ) @@ -1779,10 +1782,13 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } else { +struct time_scale *scale = enable_tsc_scaling ? + &this_cpu(cpu_time).tsc_scale : + &d->arch.vtsc_to_ns; IIUIC tsc_scale is host property and so why would it be used if TSC scaling is available to guests? -boris tsc = rdtsc(); -*elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns) - +*elapsed_nsec = scale_delta(tsc, scale) - d->arch.vtsc_offset; -*gtsc_khz = 0; /* ignored by tsc_set_info */ +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : 0; } break; } ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
[Xen-devel] [PATCH v2 04/14] x86/time.c: Use correct guest TSC frequency in tsc_get_info()
When the TSC mode of a HVM container is TSC_MODE_DEFAULT or TSC_MODE_PVRDTSCP and no TSC emulation is used, the existing tsc_get_info() uses the host TSC frequency (cpu_khz) as the guest TSC frequency. However, tsc_set_info() may set the guest TSC frequency to a value different than the host. In order to keep consistent to tsc_set_info(), this patch makes tsc_get_info() use the value set by tsc_set_info() as the guest TSC frequency. Signed-off-by: Haozhong Zhang --- xen/arch/x86/time.c | 12 +--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index 1091e69..95df4f1 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -1749,6 +1749,9 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, uint64_t *elapsed_nsec, uint32_t *gtsc_khz, uint32_t *incarnation) { +bool_t enable_tsc_scaling = has_hvm_container_domain(d) && +cpu_has_tsc_ratio; + *incarnation = d->arch.incarnation; *tsc_mode = d->arch.tsc_mode; @@ -1769,7 +1772,7 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } tsc = rdtsc(); *elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns); -*gtsc_khz = cpu_khz; +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : cpu_khz; break; case TSC_MODE_PVRDTSCP: if ( d->arch.vtsc ) @@ -1779,10 +1782,13 @@ void tsc_get_info(struct domain *d, uint32_t *tsc_mode, } else { +struct time_scale *scale = enable_tsc_scaling ? + &this_cpu(cpu_time).tsc_scale : + &d->arch.vtsc_to_ns; tsc = rdtsc(); -*elapsed_nsec = scale_delta(tsc, &d->arch.vtsc_to_ns) - +*elapsed_nsec = scale_delta(tsc, scale) - d->arch.vtsc_offset; -*gtsc_khz = 0; /* ignored by tsc_set_info */ +*gtsc_khz = enable_tsc_scaling ? d->arch.tsc_khz : 0; } break; } -- 2.6.3 ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel