diff mbox series

[2/5] KVM: x86/pmu: Add a helper to check if pmc has PEBS mode enabled

Message ID 20230310105346.12302-3-likexu@tencent.com
State New
Headers
Series KVM: x86/pmu: Hide guest counter updates from the VMRUN instruction |

Commit Message

Like Xu March 10, 2023, 10:53 a.m. UTC 
  From: Like Xu <likexu@tencent.com>

Add a helper to check if pmc has PEBS mode enabled so that more new
code may reuse this part and opportunistically drop a pmu reference.

No functional change intended.

Signed-off-by: Like Xu <likexu@tencent.com>
---
 arch/x86/kvm/pmu.c | 3 +--
 arch/x86/kvm/pmu.h | 7 +++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

Comments

Sean Christopherson May 24, 2023, 8:54 p.m. UTC | #1 
On Fri, Mar 10, 2023, Like Xu wrote:
> From: Like Xu <likexu@tencent.com>
> 
> Add a helper to check if pmc has PEBS mode enabled so that more new
> code may reuse this part and opportunistically drop a pmu reference.
> 
> No functional change intended.
> 
> Signed-off-by: Like Xu <likexu@tencent.com>
> ---
>  arch/x86/kvm/pmu.c | 3 +--
>  arch/x86/kvm/pmu.h | 7 +++++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
> index d1c89a6625a0..01a6b7ffa9b1 100644
> --- a/arch/x86/kvm/pmu.c
> +++ b/arch/x86/kvm/pmu.c
> @@ -191,7 +191,6 @@ static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
>  				 bool exclude_user, bool exclude_kernel,
>  				 bool intr)
>  {
> -	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
>  	struct perf_event *event;
>  	struct perf_event_attr attr = {
>  		.type = type,
> @@ -203,7 +202,7 @@ static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
>  		.exclude_kernel = exclude_kernel,
>  		.config = config,
>  	};
> -	bool pebs = test_bit(pmc->idx, (unsigned long *)&pmu->pebs_enable);
> +	bool pebs = pebs_is_enabled(pmc);
>  
>  	attr.sample_period = get_sample_period(pmc, pmc->counter);
>  
> diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
> index cff0651b030b..db4262fe8814 100644
> --- a/arch/x86/kvm/pmu.h
> +++ b/arch/x86/kvm/pmu.h
> @@ -189,6 +189,13 @@ static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
>  	kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
>  }
>  
> +static inline bool pebs_is_enabled(struct kvm_pmc *pmc)

pebs_is_enabled() is a bit too generic, e.g. at a glance I would expect it to return
true if PEBS as a whole is enabled.  What about something like pmc_is_pebs() or
pmc_is_pebs_enabled()?
diff mbox series

Patch

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index d1c89a6625a0..01a6b7ffa9b1 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -191,7 +191,6 @@  static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
 				 bool exclude_user, bool exclude_kernel,
 				 bool intr)
 {
-	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 	struct perf_event *event;
 	struct perf_event_attr attr = {
 		.type = type,
@@ -203,7 +202,7 @@  static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
 		.exclude_kernel = exclude_kernel,
 		.config = config,
 	};
-	bool pebs = test_bit(pmc->idx, (unsigned long *)&pmu->pebs_enable);
+	bool pebs = pebs_is_enabled(pmc);
 
 	attr.sample_period = get_sample_period(pmc, pmc->counter);
 
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index cff0651b030b..db4262fe8814 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -189,6 +189,13 @@  static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
 	kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
 }
 
+static inline bool pebs_is_enabled(struct kvm_pmc *pmc)
+{
+	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
+
+	return test_bit(pmc->idx, (unsigned long *)&pmu->pebs_enable);
+}
+
 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
 void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
 int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);