diff mbox

[v9,19/21] KVM: ARM64: Add a new feature bit for PMUv3

Message ID 1452839275-19368-20-git-send-email-zhaoshenglong@huawei.com
State Superseded
Headers show

Commit Message

Shannon Zhao Jan. 15, 2016, 6:27 a.m. UTC
From: Shannon Zhao <shannon.zhao@linaro.org>


To support guest PMUv3, use one bit of the VCPU INIT feature array.
Initialize the PMU when initialzing the vcpu with that bit and PMU
overflow interrupt set.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>

---
CC: Peter Maydell <peter.maydell@linaro.org>
---
 Documentation/virtual/kvm/api.txt | 2 ++
 arch/arm64/include/asm/kvm_host.h | 2 +-
 arch/arm64/include/uapi/asm/kvm.h | 1 +
 arch/arm64/kvm/reset.c            | 3 +++
 include/kvm/arm_pmu.h             | 2 ++
 include/uapi/linux/kvm.h          | 1 +
 virt/kvm/arm/pmu.c                | 9 +++++++++
 7 files changed, 19 insertions(+), 1 deletion(-)

-- 
2.0.4



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Comments

Andrew Jones Jan. 15, 2016, 11:08 a.m. UTC | #1
On Fri, Jan 15, 2016 at 02:27:53PM +0800, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>

> 

> To support guest PMUv3, use one bit of the VCPU INIT feature array.

> Initialize the PMU when initialzing the vcpu with that bit and PMU

> overflow interrupt set.

> 

> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>

> ---

> CC: Peter Maydell <peter.maydell@linaro.org>

> ---

>  Documentation/virtual/kvm/api.txt | 2 ++

>  arch/arm64/include/asm/kvm_host.h | 2 +-

>  arch/arm64/include/uapi/asm/kvm.h | 1 +

>  arch/arm64/kvm/reset.c            | 3 +++

>  include/kvm/arm_pmu.h             | 2 ++

>  include/uapi/linux/kvm.h          | 1 +

>  virt/kvm/arm/pmu.c                | 9 +++++++++

>  7 files changed, 19 insertions(+), 1 deletion(-)

> 

> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt

> index 053f613..e51fa04 100644

> --- a/Documentation/virtual/kvm/api.txt

> +++ b/Documentation/virtual/kvm/api.txt

> @@ -2577,6 +2577,8 @@ Possible features:

>  	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).

>  	- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU.

>  	  Depends on KVM_CAP_ARM_PSCI_0_2.

> +	- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.

> +	  Depends on KVM_CAP_ARM_PMU_V3.

>  

>  

>  4.83 KVM_ARM_PREFERRED_TARGET

> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h

> index 6bab7fb..cb220b7 100644

> --- a/arch/arm64/include/asm/kvm_host.h

> +++ b/arch/arm64/include/asm/kvm_host.h

> @@ -40,7 +40,7 @@

>  

>  #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS

>  

> -#define KVM_VCPU_MAX_FEATURES 3

> +#define KVM_VCPU_MAX_FEATURES 4

>  

>  int __attribute_const__ kvm_target_cpu(void);

>  int kvm_reset_vcpu(struct kvm_vcpu *vcpu);

> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h

> index 2d4ca4b..6aedbe3 100644

> --- a/arch/arm64/include/uapi/asm/kvm.h

> +++ b/arch/arm64/include/uapi/asm/kvm.h

> @@ -94,6 +94,7 @@ struct kvm_regs {

>  #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */

>  #define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */

>  #define KVM_ARM_VCPU_PSCI_0_2		2 /* CPU uses PSCI v0.2 */

> +#define KVM_ARM_VCPU_PMU_V3		3 /* Support guest PMUv3 */

>  

>  struct kvm_vcpu_init {

>  	__u32 target;

> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c

> index dfbce78..cf4f28a 100644

> --- a/arch/arm64/kvm/reset.c

> +++ b/arch/arm64/kvm/reset.c

> @@ -77,6 +77,9 @@ int kvm_arch_dev_ioctl_check_extension(long ext)

>  	case KVM_CAP_GUEST_DEBUG_HW_WPS:

>  		r = get_num_wrps();

>  		break;

> +	case KVM_CAP_ARM_PMU_V3:

> +		r = kvm_arm_support_pmu_v3();

> +		break;

>  	case KVM_CAP_SET_GUEST_DEBUG:

>  		r = 1;

>  		break;

> diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h

> index d90fc65..c35b11d 100644

> --- a/include/kvm/arm_pmu.h

> +++ b/include/kvm/arm_pmu.h

> @@ -48,6 +48,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);

>  void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);

>  void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,

>  				    u64 select_idx);

> +int kvm_arm_support_pmu_v3(void);

>  #else

>  struct kvm_pmu {

>  };

> @@ -72,6 +73,7 @@ static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}

>  static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}

>  static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,

>  						  u64 data, u64 select_idx) {}

> +static inline int kvm_arm_support_pmu_v3(void) { return 0; }

>  #endif

>  

>  #endif

> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h

> index 9da9051..dc16d30 100644

> --- a/include/uapi/linux/kvm.h

> +++ b/include/uapi/linux/kvm.h

> @@ -850,6 +850,7 @@ struct kvm_ppc_smmu_info {

>  #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122

>  #define KVM_CAP_HYPERV_SYNIC 123

>  #define KVM_CAP_S390_RI 124

> +#define KVM_CAP_ARM_PMU_V3 125

>  

>  #ifdef KVM_CAP_IRQ_ROUTING

>  

> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c

> index 45d4d91..cb373d4 100644

> --- a/virt/kvm/arm/pmu.c

> +++ b/virt/kvm/arm/pmu.c

> @@ -374,3 +374,12 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,

>  

>  	pmc->perf_event = event;

>  }

> +

> +int kvm_arm_support_pmu_v3(void)

> +{

> +	/* Check if HW_PERF_EVENTS are supported by checking the number of

> +	 * hardware performance counters. This could ensure physical PMU and

> +	 * PERF_EVENT driver existing.

> +	 */

> +	return perf_num_counters();


This returns the number of counters, but the CAP name and function name imply
a true/false response. Is it useful to userspace to return the number of
counters? Or should this just be a bool function and instead return
perf_num_counters() != 0

drew

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Peter Maydell Jan. 25, 2016, 4:47 p.m. UTC | #2
On 19 January 2016 at 07:10, Shannon Zhao <zhaoshenglong@huawei.com> wrote:
> Yes, for checking the CAP true/false is enough. Maybe I think the number

> of host counters could be useful for QEMU to know the number and for

> supporting cross-type vcpu, but I'm not sure. If someone else has no

> other suggestion, I will change it to what you suggest.


Do we care about the number of host counters? We might want to
know how many counters the guest sees, but we can do that by
using KVM_GET_ONE_REG to look at the guest PMCR_EL0, right?

thanks
-- PMM

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diff mbox

Patch

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 053f613..e51fa04 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2577,6 +2577,8 @@  Possible features:
 	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
 	- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU.
 	  Depends on KVM_CAP_ARM_PSCI_0_2.
+	- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
+	  Depends on KVM_CAP_ARM_PMU_V3.
 
 
 4.83 KVM_ARM_PREFERRED_TARGET
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 6bab7fb..cb220b7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -40,7 +40,7 @@ 
 
 #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
 
-#define KVM_VCPU_MAX_FEATURES 3
+#define KVM_VCPU_MAX_FEATURES 4
 
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 2d4ca4b..6aedbe3 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -94,6 +94,7 @@  struct kvm_regs {
 #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
 #define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
 #define KVM_ARM_VCPU_PSCI_0_2		2 /* CPU uses PSCI v0.2 */
+#define KVM_ARM_VCPU_PMU_V3		3 /* Support guest PMUv3 */
 
 struct kvm_vcpu_init {
 	__u32 target;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index dfbce78..cf4f28a 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -77,6 +77,9 @@  int kvm_arch_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_GUEST_DEBUG_HW_WPS:
 		r = get_num_wrps();
 		break;
+	case KVM_CAP_ARM_PMU_V3:
+		r = kvm_arm_support_pmu_v3();
+		break;
 	case KVM_CAP_SET_GUEST_DEBUG:
 		r = 1;
 		break;
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index d90fc65..c35b11d 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -48,6 +48,7 @@  void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
 				    u64 select_idx);
+int kvm_arm_support_pmu_v3(void);
 #else
 struct kvm_pmu {
 };
@@ -72,6 +73,7 @@  static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
 						  u64 data, u64 select_idx) {}
+static inline int kvm_arm_support_pmu_v3(void) { return 0; }
 #endif
 
 #endif
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9da9051..dc16d30 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -850,6 +850,7 @@  struct kvm_ppc_smmu_info {
 #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122
 #define KVM_CAP_HYPERV_SYNIC 123
 #define KVM_CAP_S390_RI 124
+#define KVM_CAP_ARM_PMU_V3 125
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 45d4d91..cb373d4 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -374,3 +374,12 @@  void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
 
 	pmc->perf_event = event;
 }
+
+int kvm_arm_support_pmu_v3(void)
+{
+	/* Check if HW_PERF_EVENTS are supported by checking the number of
+	 * hardware performance counters. This could ensure physical PMU and
+	 * PERF_EVENT driver existing.
+	 */
+	return perf_num_counters();
+}