On Thu, Jan 16, 2014 at 08:18:37PM +1100, Vadim Rozenfeld wrote: > Signed-off: Peter Lieven <pl@xxxxxxx> > Signed-off: Gleb Natapov > Signed-off: Vadim Rozenfeld <vrozenfe@xxxxxxxxxx> > > After some consideration I decided to submit only Hyper-V reference > counters support this time. I will submit iTSC support as a separate > patch as soon as it is ready. > > v1 -> v2 > 1. mark TSC page dirty as suggested by > Eric Northup <digitaleric@xxxxxxxxxx> and Gleb > 2. disable local irq when calling get_kernel_ns, > as it was done by Peter Lieven <pl@xxxxxx> > 3. move check for TSC page enable from second patch > to this one. > > v3 -> v4 > Get rid of ref counter offset. > > v4 -> v5 > replace __copy_to_user with kvm_write_guest > when updateing iTSC page. > > --- > arch/x86/include/asm/kvm_host.h | 1 + > arch/x86/include/uapi/asm/hyperv.h | 13 +++++++++++++ > arch/x86/kvm/x86.c | 28 +++++++++++++++++++++++++++- > include/uapi/linux/kvm.h | 1 + > 4 files changed, 42 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index ae5d783..33fef07 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -605,6 +605,7 @@ struct kvm_arch { > /* fields used by HYPER-V emulation */ > u64 hv_guest_os_id; > u64 hv_hypercall; > + u64 hv_tsc_page; > > #ifdef CONFIG_KVM_MMU_AUDIT > int audit_point; > diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h > index b8f1c01..462efe7 100644 > --- a/arch/x86/include/uapi/asm/hyperv.h > +++ b/arch/x86/include/uapi/asm/hyperv.h > @@ -28,6 +28,9 @@ > /* Partition Reference Counter (HV_X64_MSR_TIME_REF_COUNT) available*/ > #define HV_X64_MSR_TIME_REF_COUNT_AVAILABLE (1 << 1) > > +/* A partition's reference time stamp counter (TSC) page */ > +#define HV_X64_MSR_REFERENCE_TSC 0x40000021 > + > /* > * There is a single feature flag that signifies the presence of the MSR > * that can be used to retrieve both the local APIC Timer frequency as > @@ -198,6 +201,9 @@ > #define HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_MASK \ > (~((1ull << HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT) - 1)) > > +#define HV_X64_MSR_TSC_REFERENCE_ENABLE 0x00000001 > +#define HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT 12 > + > #define HV_PROCESSOR_POWER_STATE_C0 0 > #define HV_PROCESSOR_POWER_STATE_C1 1 > #define HV_PROCESSOR_POWER_STATE_C2 2 > @@ -210,4 +216,11 @@ > #define HV_STATUS_INVALID_ALIGNMENT 4 > #define HV_STATUS_INSUFFICIENT_BUFFERS 19 > > +typedef struct _HV_REFERENCE_TSC_PAGE { > + __u32 tsc_sequence; > + __u32 res1; > + __u64 tsc_scale; > + __s64 tsc_offset; > +} HV_REFERENCE_TSC_PAGE, *PHV_REFERENCE_TSC_PAGE; > + > #endif > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 5d004da..8e685b8 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -836,11 +836,12 @@ EXPORT_SYMBOL_GPL(kvm_rdpmc); > * kvm-specific. Those are put in the beginning of the list. > */ > > -#define KVM_SAVE_MSRS_BEGIN 10 > +#define KVM_SAVE_MSRS_BEGIN 12 > static u32 msrs_to_save[] = { > MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, > MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW, > HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL, > + HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC, > HV_X64_MSR_APIC_ASSIST_PAGE, MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME, > MSR_KVM_PV_EOI_EN, > MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, > @@ -1826,6 +1827,8 @@ static bool kvm_hv_msr_partition_wide(u32 msr) > switch (msr) { > case HV_X64_MSR_GUEST_OS_ID: > case HV_X64_MSR_HYPERCALL: > + case HV_X64_MSR_REFERENCE_TSC: > + case HV_X64_MSR_TIME_REF_COUNT: > r = true; > break; > } > @@ -1867,6 +1870,20 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data) > kvm->arch.hv_hypercall = data; > break; > } > + case HV_X64_MSR_REFERENCE_TSC: { > + u64 gfn; > + HV_REFERENCE_TSC_PAGE tsc_ref; > + memset(&tsc_ref, 0, sizeof(tsc_ref)); > + kvm->arch.hv_tsc_page = data; Comment 1) Is there a reason (that is compliance with spec) to maintain value, for HV_X64_MSR_REFERENCE_TSC wrmsr operation, in case HV_X64_MSR_TSC_REFERENCE_ENABLE is not set? If not, should only assign to kvm->arch.hv_tsc_page after proper checks. > + if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) > + break; > + gfn = data >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT; > + if (kvm_write_guest(kvm, data, > + &tsc_ref, sizeof(tsc_ref))) > + return 1; > + mark_page_dirty(kvm, gfn); > + break; > + } > default: > vcpu_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x " > "data 0x%llx\n", msr, data); > @@ -2291,6 +2308,14 @@ static int get_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) > case HV_X64_MSR_HYPERCALL: > data = kvm->arch.hv_hypercall; > break; > + case HV_X64_MSR_TIME_REF_COUNT: { > + data = > + div_u64(get_kernel_ns() + kvm->arch.kvmclock_offset, 100); Comment 2) Is there any specification related to the initial value of the clock after it is enabled ? > + break; > + } > + case HV_X64_MSR_REFERENCE_TSC: > + data = kvm->arch.hv_tsc_page; > + break; > default: > vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr); > return 1; > @@ -2604,6 +2629,7 @@ int kvm_dev_ioctl_check_extension(long ext) > #ifdef CONFIG_KVM_DEVICE_ASSIGNMENT > case KVM_CAP_ASSIGN_DEV_IRQ: > case KVM_CAP_PCI_2_3: > + case KVM_CAP_HYPERV_TIME: > #endif > r = 1; > break; > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 902f124..686c1ca 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -674,6 +674,7 @@ struct kvm_ppc_smmu_info { > #define KVM_CAP_ARM_EL1_32BIT 93 > #define KVM_CAP_SPAPR_MULTITCE 94 > #define KVM_CAP_EXT_EMUL_CPUID 95 > +#define KVM_CAP_HYPERV_TIME 96 > > #ifdef KVM_CAP_IRQ_ROUTING > > -- > 1.8.1.4 > Comment 3) Missing qemu HV_X64_MSR_REFERENCE_TSC save/restore. 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