> -----Original Message----- > From: Roman Kagan [mailto:rkagan@xxxxxxxxxxxxx] > Sent: Tuesday, December 20, 2016 7:56 AM > To: Paolo Bonzini <pbonzini@xxxxxxxxxx>; Radim Krčmář > <rkrcmar@xxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Vitaly > Kuznetsov <vkuznets@xxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>; Ingo Molnar > <mingo@xxxxxxxxxx>; H. Peter Anvin <hpa@xxxxxxxxx>; x86@xxxxxxxxxx; > Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; kvm@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; Denis V . Lunev > <den@xxxxxxxxxx>; Roman Kagan <rkagan@xxxxxxxxxxxxx> > Subject: [PATCH 01/15] hyperv: consolidate TSC ref page definitions > > Consolidate the guest-side and kvm-side definitions for Hyper-V TSC > reference page. > > While at this, rewrite read_hv_clock_tsc using the existing helpers. Why not beak this into separate patches. > > Signed-off-by: Roman Kagan <rkagan@xxxxxxxxxxxxx> > --- > arch/x86/include/asm/kvm_host.h | 2 +- > arch/x86/include/uapi/asm/hyperv.h | 4 +-- > drivers/hv/hyperv_vmbus.h | 8 ------ > arch/x86/kvm/hyperv.c | 4 +-- > drivers/hv/hv.c | 54 +++++++++++++++----------------------- > 5 files changed, 26 insertions(+), 46 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h > b/arch/x86/include/asm/kvm_host.h > index 2e25038..2b85f49 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -713,7 +713,7 @@ struct kvm_hv { > u64 hv_crash_param[HV_X64_MSR_CRASH_PARAMS]; > u64 hv_crash_ctl; > > - HV_REFERENCE_TSC_PAGE tsc_ref; > + struct hv_ref_tsc_page tsc_ref; > }; > > struct kvm_arch { > diff --git a/arch/x86/include/uapi/asm/hyperv.h > b/arch/x86/include/uapi/asm/hyperv.h > index 9b1a918..6098ab5 100644 > --- a/arch/x86/include/uapi/asm/hyperv.h > +++ b/arch/x86/include/uapi/asm/hyperv.h > @@ -252,12 +252,12 @@ > #define HV_STATUS_INVALID_CONNECTION_ID 18 > #define HV_STATUS_INSUFFICIENT_BUFFERS 19 > > -typedef struct _HV_REFERENCE_TSC_PAGE { > +struct hv_ref_tsc_page { > __u32 tsc_sequence; > __u32 res1; > __u64 tsc_scale; > __s64 tsc_offset; > -} HV_REFERENCE_TSC_PAGE, *PHV_REFERENCE_TSC_PAGE; > +}; > > /* Define the number of synthetic interrupt sources. */ > #define HV_SYNIC_SINT_COUNT (16) > diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h > index 0675b39..4516498 100644 > --- a/drivers/hv/hyperv_vmbus.h > +++ b/drivers/hv/hyperv_vmbus.h > @@ -475,14 +475,6 @@ struct hv_context { > > extern struct hv_context hv_context; > > -struct ms_hyperv_tsc_page { > - volatile u32 tsc_sequence; > - u32 reserved1; > - volatile u64 tsc_scale; > - volatile s64 tsc_offset; > - u64 reserved2[509]; > -}; > - > struct hv_ring_buffer_debug_info { > u32 current_interrupt_mask; > u32 current_read_index; > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index 1572c35..c7db112 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -806,7 +806,7 @@ static int kvm_hv_msr_set_crash_data(struct > kvm_vcpu *vcpu, > * These two equivalencies are implemented in this function. > */ > static bool compute_tsc_page_parameters(struct pvclock_vcpu_time_info > *hv_clock, > - HV_REFERENCE_TSC_PAGE *tsc_ref) > + struct hv_ref_tsc_page *tsc_ref) > { > u64 max_mul; > > @@ -847,7 +847,7 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm, > u64 gfn; > > BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv- > >tsc_ref.tsc_sequence)); > - BUILD_BUG_ON(offsetof(HV_REFERENCE_TSC_PAGE, > tsc_sequence) != 0); > + BUILD_BUG_ON(offsetof(struct hv_ref_tsc_page, tsc_sequence) != > 0); > > if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE)) > return; > diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c > index 446802a..a7256ec 100644 > --- a/drivers/hv/hv.c > +++ b/drivers/hv/hv.c > @@ -137,41 +137,29 @@ EXPORT_SYMBOL_GPL(hv_do_hypercall); > #ifdef CONFIG_X86_64 > static cycle_t read_hv_clock_tsc(struct clocksource *arg) > { > - cycle_t current_tick; > - struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page; > + struct hv_ref_tsc_page *tsc_pg = hv_context.tsc_page; > + u32 sequence; > + u64 scale; > + s64 offset; > + > + do { > + sequence = tsc_pg->tsc_sequence; > + virt_rmb(); > + > + if (!sequence) { > + /* fallback to MSR */ > + cycle_t current_tick; > + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, > current_tick); > + return current_tick; > + } > > - if (tsc_pg->tsc_sequence != 0) { > - /* > - * Use the tsc page to compute the value. > - */ > + scale = tsc_pg->tsc_scale; > + offset = tsc_pg->tsc_offset; > > - while (1) { > - cycle_t tmp; > - u32 sequence = tsc_pg->tsc_sequence; > - u64 cur_tsc; > - u64 scale = tsc_pg->tsc_scale; > - s64 offset = tsc_pg->tsc_offset; > - > - rdtscll(cur_tsc); > - /* current_tick = ((cur_tsc *scale) >> 64) + offset */ > - asm("mulq %3" > - : "=d" (current_tick), "=a" (tmp) > - : "a" (cur_tsc), "r" (scale)); > - > - current_tick += offset; > - if (tsc_pg->tsc_sequence == sequence) > - return current_tick; > - > - if (tsc_pg->tsc_sequence != 0) > - continue; > - /* > - * Fallback using MSR method. > - */ > - break; > - } > - } > - rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); > - return current_tick; > + virt_rmb(); > + } while (tsc_pg->tsc_sequence != sequence); > + > + return mul_u64_u64_shr(rdtsc_ordered(), scale, 64) + offset; > } > > static struct clocksource hyperv_cs_tsc = { > -- > 2.9.3 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
