| Message ID | 1456664094-5161-3-git-send-email-haozhong.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 28.02.16 at 13:54, <haozhong.zhang@intel.com> wrote: > --- a/xen/arch/x86/hvm/hvm.c > +++ b/xen/arch/x86/hvm/hvm.c > @@ -333,6 +333,23 @@ u64 hvm_get_tsc_scaling_ratio(u32 gtsc_khz) > return ratio > max_ratio ? 0 : ratio; > } > > +u64 hvm_scale_tsc(const struct domain *d, u64 tsc) > +{ > + u64 ratio = d->arch.hvm_domain.tsc_scaling_ratio; > + u64 dummy; > + > + if ( ratio == hvm_default_tsc_scaling_ratio ) > + return tsc; > + > + /* tsc = (tsc * ratio) >> hvm_funcs.tsc_scaling.ratio_frac_bits */ > + asm ( "mulq %[ratio]; shrdq %[frac],%%rdx,%[tsc]" > + : [tsc] "+a" (tsc), "=d" (dummy) Is mixing named and positional asm() operands supported by all gcc versions we care about? Also strictly speaking "=d" needs to be switched to "=&d". Jan
On 02/29/16 06:44, Jan Beulich wrote: > >>> On 28.02.16 at 13:54, <haozhong.zhang@intel.com> wrote: > > --- a/xen/arch/x86/hvm/hvm.c > > +++ b/xen/arch/x86/hvm/hvm.c > > @@ -333,6 +333,23 @@ u64 hvm_get_tsc_scaling_ratio(u32 gtsc_khz) > > return ratio > max_ratio ? 0 : ratio; > > } > > > > +u64 hvm_scale_tsc(const struct domain *d, u64 tsc) > > +{ > > + u64 ratio = d->arch.hvm_domain.tsc_scaling_ratio; > > + u64 dummy; > > + > > + if ( ratio == hvm_default_tsc_scaling_ratio ) > > + return tsc; > > + > > + /* tsc = (tsc * ratio) >> hvm_funcs.tsc_scaling.ratio_frac_bits */ > > + asm ( "mulq %[ratio]; shrdq %[frac],%%rdx,%[tsc]" > > + : [tsc] "+a" (tsc), "=d" (dummy) > > Is mixing named and positional asm() operands supported by all > gcc versions we care about? I see in Config.mk the oldest version is gcc 4.1. I'll test on that version. > Also strictly speaking "=d" needs to be switched to "=&d". > I'll fix in the next version. Thanks, Haozhong
On 02/28/2016 07:54 AM, Haozhong Zhang wrote: > This patch implements a common function hvm_scale_tsc() to scale TSC by > using TSC scaling information collected by architecture code. > > Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> > --- > CC: Keir Fraser <keir@xen.org> > CC: Jan Beulich <jbeulich@suse.com> > CC: Andrew Cooper <andrew.cooper3@citrix.com> > CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> > CC: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> > CC: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> > CC: Kevin Tian <kevin.tian@intel.com> SVM bits: Acked-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 6c32e99..25be45c 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -333,6 +333,23 @@ u64 hvm_get_tsc_scaling_ratio(u32 gtsc_khz) return ratio > max_ratio ? 0 : ratio; } +u64 hvm_scale_tsc(const struct domain *d, u64 tsc) +{ + u64 ratio = d->arch.hvm_domain.tsc_scaling_ratio; + u64 dummy; + + if ( ratio == hvm_default_tsc_scaling_ratio ) + return tsc; + + /* tsc = (tsc * ratio) >> hvm_funcs.tsc_scaling.ratio_frac_bits */ + asm ( "mulq %[ratio]; shrdq %[frac],%%rdx,%[tsc]" + : [tsc] "+a" (tsc), "=d" (dummy) + : [frac] "c" (hvm_funcs.tsc_scaling.ratio_frac_bits), + [ratio] "rm" (ratio) ); + + return tsc; +} + void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc) { uint64_t tsc; @@ -347,7 +364,7 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc) { tsc = at_tsc ?: rdtsc(); if ( hvm_tsc_scaling_supported ) - tsc = hvm_funcs.tsc_scaling.scale_tsc(v, tsc); + tsc = hvm_scale_tsc(v->domain, tsc); } delta_tsc = guest_tsc - tsc; @@ -379,7 +396,7 @@ u64 hvm_get_guest_tsc_fixed(struct vcpu *v, uint64_t at_tsc) { tsc = at_tsc ?: rdtsc(); if ( hvm_tsc_scaling_supported ) - tsc = hvm_funcs.tsc_scaling.scale_tsc(v, tsc); + tsc = hvm_scale_tsc(v->domain, tsc); } return tsc + v->arch.hvm_vcpu.cache_tsc_offset; diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 7172f25..979d226 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -819,13 +819,6 @@ static uint64_t scale_tsc(uint64_t host_tsc, uint64_t ratio) return scaled_host_tsc; } -static uint64_t svm_scale_tsc(const struct vcpu *v, uint64_t tsc) -{ - ASSERT(cpu_has_tsc_ratio && !v->domain->arch.vtsc); - - return scale_tsc(tsc, hvm_tsc_scaling_ratio(v->domain)); -} - static uint64_t svm_get_tsc_offset(uint64_t host_tsc, uint64_t guest_tsc, uint64_t ratio) { @@ -2291,7 +2284,6 @@ static struct hvm_function_table __initdata svm_function_table = { .tsc_scaling = { .max_ratio = ~TSC_RATIO_RSVD_BITS, - .scale_tsc = svm_scale_tsc, }, }; diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index fda9692..687e39b 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -816,8 +816,7 @@ static void __update_vcpu_system_time(struct vcpu *v, int force) { if ( has_hvm_container_domain(d) && hvm_tsc_scaling_supported ) { - tsc_stamp = - hvm_funcs.tsc_scaling.scale_tsc(v, t->local_tsc_stamp); + tsc_stamp = hvm_scale_tsc(d, t->local_tsc_stamp); _u.tsc_to_system_mul = d->arch.vtsc_to_ns.mul_frac; _u.tsc_shift = d->arch.vtsc_to_ns.shift; } diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index ddb1e33..c5c9328 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -231,8 +231,6 @@ struct hvm_function_table { uint8_t ratio_frac_bits; /* maximum-allowed TSC scaling ratio */ uint64_t max_ratio; - - uint64_t (*scale_tsc)(const struct vcpu *v, uint64_t tsc); } tsc_scaling; }; @@ -278,6 +276,7 @@ u64 hvm_get_guest_tsc_fixed(struct vcpu *v, u64 at_tsc); #define hvm_tsc_scaling_ratio(d) \ ((d)->arch.hvm_domain.tsc_scaling_ratio) +u64 hvm_scale_tsc(const struct domain *d, u64 tsc); u64 hvm_get_tsc_scaling_ratio(u32 gtsc_khz); int hvm_set_mode(struct vcpu *v, int mode);
This patch implements a common function hvm_scale_tsc() to scale TSC by using TSC scaling information collected by architecture code. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> --- CC: Keir Fraser <keir@xen.org> CC: Jan Beulich <jbeulich@suse.com> CC: Andrew Cooper <andrew.cooper3@citrix.com> CC: Boris Ostrovsky <boris.ostrovsky@oracle.com> CC: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> CC: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> CC: Kevin Tian <kevin.tian@intel.com> --- Changes in v6: * Turn to named arguments for inline assembly in hvm_scale_tsc(). * I don't take R-b from Jan Beulich and Kevin Tian because of above changes. --- xen/arch/x86/hvm/hvm.c | 21 +++++++++++++++++++-- xen/arch/x86/hvm/svm/svm.c | 8 -------- xen/arch/x86/time.c | 3 +-- xen/include/asm-x86/hvm/hvm.h | 3 +-- 4 files changed, 21 insertions(+), 14 deletions(-)