From e984097b553ed2d6551c805223e4057421370f00 Mon Sep 17 00:00:00 2001 From: Vadim Rozenfeld Date: Thu, 16 Jan 2014 20:18:37 +1100 Subject: [PATCH] add support for Hyper-V reference time counter MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off: Peter Lieven Signed-off: Gleb Natapov Signed-off: Vadim Rozenfeld 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 and Gleb 2. disable local irq when calling get_kernel_ns, as it was done by Peter Lieven 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. Signed-off-by: Paolo Bonzini --- 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 ae5d7830855c..33fef0738a29 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 b8f1c0176cbc..462efe746d77 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 0fbdced78737..0b3fd809a3c7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -839,11 +839,12 @@ 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, @@ -1788,6 +1789,8 @@ 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; } @@ -1829,6 +1832,20 @@ 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; + 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); @@ -2253,6 +2270,14 @@ 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); + 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; @@ -2566,6 +2591,7 @@ 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 b647c2917391..932d7f2637d6 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