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Commit e984097b authored by Vadim Rozenfeld's avatar Vadim Rozenfeld Committed by Paolo Bonzini
Browse files

add support for Hyper-V reference time counter 



Signed-off: Peter Lieven <pl@kamp.de>
Signed-off: Gleb Natapov
Signed-off: Vadim Rozenfeld <vrozenfe@redhat.com>

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@google.com> and Gleb
2. disable local irq when calling get_kernel_ns,
    as it was done by Peter Lieven <pl@amp.de>
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: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent aab6d7ce

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/include/uapi/asm/hyperv.h

+13 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/x86.c

+27 −1
Original line number Diff line number Diff line
@@ -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;

include/uapi/linux/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -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