diff mbox

[RFC,2/2] Hyper-V iTSC handler

Message ID 1368445517-5496-3-git-send-email-vrozenfe@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vadim Rozenfeld May 13, 2013, 11:45 a.m. UTC 
Signed-off: Vadim Rozenfeld <vrozenfe@redhat.com>

The following patch allows to activate a partition reference 
time enlightenment that is based on the host platform's support 
for an Invariant Time Stamp Counter (iTSC).
NOTE: This code will survive migration due to lack of VM stop/resume
handlers.

---
 arch/x86/include/uapi/asm/hyperv.h | 10 ++++++++++
 arch/x86/kvm/x86.c                 | 18 +++++++++++++-----
 include/uapi/linux/kvm.h           |  1 +
 3 files changed, 24 insertions(+), 5 deletions(-)

Comments

Gleb Natapov May 16, 2013, 8:33 a.m. UTC | #1 
On Mon, May 13, 2013 at 09:45:17PM +1000, Vadim Rozenfeld wrote:
> Signed-off: Vadim Rozenfeld <vrozenfe@redhat.com>
> 
> The following patch allows to activate a partition reference 
> time enlightenment that is based on the host platform's support 
> for an Invariant Time Stamp Counter (iTSC).
> NOTE: This code will survive migration due to lack of VM stop/resume
> handlers.
> 
Do you mean "will _not_ survive migration"?

> ---
>  arch/x86/include/uapi/asm/hyperv.h | 10 ++++++++++
>  arch/x86/kvm/x86.c                 | 18 +++++++++++++-----
>  include/uapi/linux/kvm.h           |  1 +
>  3 files changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> index 9711819..2d9e666 100644
> --- a/arch/x86/include/uapi/asm/hyperv.h
> +++ b/arch/x86/include/uapi/asm/hyperv.h
> @@ -182,6 +182,9 @@
>  #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
> @@ -194,4 +197,11 @@
>  #define HV_STATUS_INVALID_ALIGNMENT		4
>  #define HV_STATUS_INSUFFICIENT_BUFFERS		19
>  
> +typedef struct _HV_REFERENCE_TSC_PAGE {
> +	uint32_t TscSequence;
> +	uint32_t Rserved1;
> +	uint64_t TscScale;
> +	int64_t  TscOffset;
> +} HV_REFERENCE_TSC_PAGE, * PHV_REFERENCE_TSC_PAGE;
> +
Use kernel types: __u32/__u64/__s64.

>  #endif
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 1a4036d..5788e8f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1809,14 +1809,21 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
>  		break;
>  	}
>  	case HV_X64_MSR_REFERENCE_TSC: {
> -		u64 gfn;
>  		unsigned long addr;
> -		u32 tsc_ref;
> -		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
> -		addr = gfn_to_hva(kvm, gfn);
> +		HV_REFERENCE_TSC_PAGE tsc_ref;
> +		tsc_ref.TscSequence =
> +			boot_cpu_has(X86_FEATURE_CONSTANT_TSC) ? 1 : 0;
> +		tsc_ref.TscScale =
> +			((10000LL << 32) /vcpu->arch.virtual_tsc_khz) << 32;
> +		tsc_ref.TscOffset = 0;
> +		if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) {
> +			kvm->arch.hv_tsc_page = data;
> +			break;
> +		}
> +		addr = gfn_to_hva(vcpu->kvm, data >>
> +			HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT);
>  		if (kvm_is_error_hva(addr))
>  			return 1;
> -		tsc_ref = 0;
>  		if(__copy_to_user((void __user *)addr, &tsc_ref, sizeof(tsc_ref)))
>  			return 1;
>  		kvm->arch.hv_tsc_page = data;
> @@ -2553,6 +2560,7 @@ int kvm_dev_ioctl_check_extension(long ext)
>  	case KVM_CAP_HYPERV:
>  	case KVM_CAP_HYPERV_VAPIC:
>  	case KVM_CAP_HYPERV_SPIN:
> +	case KVM_CAP_HYPERV_TSC:
>  	case KVM_CAP_PCI_SEGMENT:
>  	case KVM_CAP_DEBUGREGS:
>  	case KVM_CAP_X86_ROBUST_SINGLESTEP:
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index a5c86fc..8eff540 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -666,6 +666,7 @@ struct kvm_ppc_smmu_info {
>  #define KVM_CAP_IRQ_MPIC 90
>  #define KVM_CAP_PPC_RTAS 91
>  #define KVM_CAP_IRQ_XICS 92
> +#define KVM_CAP_HYPERV_TSC 93
>  
>  #ifdef KVM_CAP_IRQ_ROUTING
>  
> -- 
> 1.8.1.2

--
			Gleb.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Vadim Rozenfeld May 16, 2013, 8:58 a.m. UTC | #2 
On Thu, 2013-05-16 at 11:33 +0300, Gleb Natapov wrote:
> On Mon, May 13, 2013 at 09:45:17PM +1000, Vadim Rozenfeld wrote:
> > Signed-off: Vadim Rozenfeld <vrozenfe@redhat.com>
> > 
> > The following patch allows to activate a partition reference 
> > time enlightenment that is based on the host platform's support 
> > for an Invariant Time Stamp Counter (iTSC).
> > NOTE: This code will survive migration due to lack of VM stop/resume
> > handlers.
> > 
> Do you mean "will _not_ survive migration"?
Sorry for typo. Yes, it will not,
because offset, scale and sequence must be
readjusted. 
 
> 
> > ---
> >  arch/x86/include/uapi/asm/hyperv.h | 10 ++++++++++
> >  arch/x86/kvm/x86.c                 | 18 +++++++++++++-----
> >  include/uapi/linux/kvm.h           |  1 +
> >  3 files changed, 24 insertions(+), 5 deletions(-)
> > 
> > diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
> > index 9711819..2d9e666 100644
> > --- a/arch/x86/include/uapi/asm/hyperv.h
> > +++ b/arch/x86/include/uapi/asm/hyperv.h
> > @@ -182,6 +182,9 @@
> >  #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
> > @@ -194,4 +197,11 @@
> >  #define HV_STATUS_INVALID_ALIGNMENT		4
> >  #define HV_STATUS_INSUFFICIENT_BUFFERS		19
> >  
> > +typedef struct _HV_REFERENCE_TSC_PAGE {
> > +	uint32_t TscSequence;
> > +	uint32_t Rserved1;
> > +	uint64_t TscScale;
> > +	int64_t  TscOffset;
> > +} HV_REFERENCE_TSC_PAGE, * PHV_REFERENCE_TSC_PAGE;
> > +
> Use kernel types: __u32/__u64/__s64.
> 
> >  #endif
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 1a4036d..5788e8f 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -1809,14 +1809,21 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
> >  		break;
> >  	}
> >  	case HV_X64_MSR_REFERENCE_TSC: {
> > -		u64 gfn;
> >  		unsigned long addr;
> > -		u32 tsc_ref;
> > -		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
> > -		addr = gfn_to_hva(kvm, gfn);
> > +		HV_REFERENCE_TSC_PAGE tsc_ref;
> > +		tsc_ref.TscSequence =
> > +			boot_cpu_has(X86_FEATURE_CONSTANT_TSC) ? 1 : 0;
> > +		tsc_ref.TscScale =
> > +			((10000LL << 32) /vcpu->arch.virtual_tsc_khz) << 32;
> > +		tsc_ref.TscOffset = 0;
> > +		if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) {
> > +			kvm->arch.hv_tsc_page = data;
> > +			break;
> > +		}
> > +		addr = gfn_to_hva(vcpu->kvm, data >>
> > +			HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT);
> >  		if (kvm_is_error_hva(addr))
> >  			return 1;
> > -		tsc_ref = 0;
> >  		if(__copy_to_user((void __user *)addr, &tsc_ref, sizeof(tsc_ref)))
> >  			return 1;
> >  		kvm->arch.hv_tsc_page = data;
> > @@ -2553,6 +2560,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> >  	case KVM_CAP_HYPERV:
> >  	case KVM_CAP_HYPERV_VAPIC:
> >  	case KVM_CAP_HYPERV_SPIN:
> > +	case KVM_CAP_HYPERV_TSC:
> >  	case KVM_CAP_PCI_SEGMENT:
> >  	case KVM_CAP_DEBUGREGS:
> >  	case KVM_CAP_X86_ROBUST_SINGLESTEP:
> > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> > index a5c86fc..8eff540 100644
> > --- a/include/uapi/linux/kvm.h
> > +++ b/include/uapi/linux/kvm.h
> > @@ -666,6 +666,7 @@ struct kvm_ppc_smmu_info {
> >  #define KVM_CAP_IRQ_MPIC 90
> >  #define KVM_CAP_PPC_RTAS 91
> >  #define KVM_CAP_IRQ_XICS 92
> > +#define KVM_CAP_HYPERV_TSC 93
> >  
> >  #ifdef KVM_CAP_IRQ_ROUTING
> >  
> > -- 
> > 1.8.1.2
> 
> --
> 			Gleb.


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 9711819..2d9e666 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -182,6 +182,9 @@ 
 #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
@@ -194,4 +197,11 @@ 
 #define HV_STATUS_INVALID_ALIGNMENT		4
 #define HV_STATUS_INSUFFICIENT_BUFFERS		19
 
+typedef struct _HV_REFERENCE_TSC_PAGE {
+	uint32_t TscSequence;
+	uint32_t Rserved1;
+	uint64_t TscScale;
+	int64_t  TscOffset;
+} HV_REFERENCE_TSC_PAGE, * PHV_REFERENCE_TSC_PAGE;
+
 #endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1a4036d..5788e8f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1809,14 +1809,21 @@  static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data)
 		break;
 	}
 	case HV_X64_MSR_REFERENCE_TSC: {
-		u64 gfn;
 		unsigned long addr;
-		u32 tsc_ref;
-		gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT;
-		addr = gfn_to_hva(kvm, gfn);
+		HV_REFERENCE_TSC_PAGE tsc_ref;
+		tsc_ref.TscSequence =
+			boot_cpu_has(X86_FEATURE_CONSTANT_TSC) ? 1 : 0;
+		tsc_ref.TscScale =
+			((10000LL << 32) /vcpu->arch.virtual_tsc_khz) << 32;
+		tsc_ref.TscOffset = 0;
+		if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) {
+			kvm->arch.hv_tsc_page = data;
+			break;
+		}
+		addr = gfn_to_hva(vcpu->kvm, data >>
+			HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT);
 		if (kvm_is_error_hva(addr))
 			return 1;
-		tsc_ref = 0;
 		if(__copy_to_user((void __user *)addr, &tsc_ref, sizeof(tsc_ref)))
 			return 1;
 		kvm->arch.hv_tsc_page = data;
@@ -2553,6 +2560,7 @@  int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_HYPERV:
 	case KVM_CAP_HYPERV_VAPIC:
 	case KVM_CAP_HYPERV_SPIN:
+	case KVM_CAP_HYPERV_TSC:
 	case KVM_CAP_PCI_SEGMENT:
 	case KVM_CAP_DEBUGREGS:
 	case KVM_CAP_X86_ROBUST_SINGLESTEP:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a5c86fc..8eff540 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -666,6 +666,7 @@  struct kvm_ppc_smmu_info {
 #define KVM_CAP_IRQ_MPIC 90
 #define KVM_CAP_PPC_RTAS 91
 #define KVM_CAP_IRQ_XICS 92
+#define KVM_CAP_HYPERV_TSC 93
 
 #ifdef KVM_CAP_IRQ_ROUTING