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From: drjones@redhat.com (Andrew Jones)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v10 10/21] KVM: ARM64: Add access handler for PMCNTENSET and PMCNTENCLR register
Date: Thu, 28 Jan 2016 19:08:56 +0100	[thread overview]
Message-ID: <20160128180856.GA16453@hawk.localdomain> (raw)
In-Reply-To: <1453866709-20324-11-git-send-email-zhaoshenglong@huawei.com>

On Wed, Jan 27, 2016 at 11:51:38AM +0800, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
> 
> Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use
> reset_unknown for its reset handler. Add a handler to emulate writing
> PMCNTENSET or PMCNTENCLR register.
> 
> When writing to PMCNTENSET, call perf_event_enable to enable the perf
> event. When writing to PMCNTENCLR, call perf_event_disable to disable
> the perf event.
> 
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
>  arch/arm64/kvm/sys_regs.c | 35 +++++++++++++++++++++++---
>  include/kvm/arm_pmu.h     |  9 +++++++
>  virt/kvm/arm/pmu.c        | 63 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 103 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 6a50262..d43a9a4 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -603,6 +603,33 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
>  	return true;
>  }
>  
> +static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
> +			   const struct sys_reg_desc *r)
> +{
> +	u64 val, mask;
> +
> +	if (!kvm_arm_pmu_v3_ready(vcpu))
> +		return trap_raz_wi(vcpu, p, r);
> +
> +	mask = kvm_pmu_valid_counter_mask(vcpu);
> +	if (p->is_write) {
> +		val = p->regval & mask;
> +		if (r->Op2 & 0x1) {
> +			/* accessing PMCNTENSET_EL0 */
> +			vcpu_sys_reg(vcpu, PMCNTENSET_EL0) |= val;
> +			kvm_pmu_enable_counter(vcpu, val);
> +		} else {
> +			/* accessing PMCNTENCLR_EL0 */
> +			vcpu_sys_reg(vcpu, PMCNTENSET_EL0) &= ~val;
> +			kvm_pmu_disable_counter(vcpu, val);
> +		}
> +	} else {
> +		p->regval = vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask;
> +	}
> +
> +	return true;
> +}
> +
>  /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
>  #define DBG_BCR_BVR_WCR_WVR_EL1(n)					\
>  	/* DBGBVRn_EL1 */						\
> @@ -804,10 +831,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	  access_pmcr, reset_pmcr, },
>  	/* PMCNTENSET_EL0 */
>  	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
> -	  trap_raz_wi },
> +	  access_pmcnten, reset_unknown, PMCNTENSET_EL0 },
>  	/* PMCNTENCLR_EL0 */
>  	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010),
> -	  trap_raz_wi },
> +	  access_pmcnten, NULL, PMCNTENSET_EL0 },

I don't think the reg field is needed, as the reset handler isn't
defined and the access handler doesn't use it. Oh, and shouldn't it be
PMCNTENCLR_EL0 anyway?

>  	/* PMOVSCLR_EL0 */
>  	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
>  	  trap_raz_wi },
> @@ -1149,8 +1176,8 @@ static const struct sys_reg_desc cp15_regs[] = {
>  
>  	/* PMU */
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr },
> -	{ Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
> -	{ Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
> +	{ Op1( 0), CRn( 9), CRm(12), Op2( 1), access_pmcnten },
> +	{ Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmcnten },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
> diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
> index ee4b15c..a7e5485 100644
> --- a/include/kvm/arm_pmu.h
> +++ b/include/kvm/arm_pmu.h
> @@ -37,6 +37,9 @@ struct kvm_pmu {
>  
>  #define kvm_arm_pmu_v3_ready(v)		((v)->arch.pmu.ready)
>  u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
> +u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu);
> +void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val);
> +void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val);
>  void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
>  				    u64 select_idx);
>  #else
> @@ -49,6 +52,12 @@ static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
>  {
>  	return 0;
>  }
> +static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
> +{
> +	return 0;
> +}
> +static inline void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) {}
> +static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {}
>  static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
>  						  u64 data, u64 select_idx) {}
>  #endif
> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
> index 673ec55..0873977 100644
> --- a/virt/kvm/arm/pmu.c
> +++ b/virt/kvm/arm/pmu.c
> @@ -68,6 +68,69 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
>  	}
>  }
>  
> +u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
> +{
> +	u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMCR_N_SHIFT;
> +
> +	val &= ARMV8_PMCR_N_MASK;
> +	return GENMASK(val - 1, 0) | BIT(ARMV8_CYCLE_IDX);

val can be zero if PMCR.N is zero (meaning only the cycle counter is
implemented). We should confirm it's not zero before calling GENMASK.

> +}
> +
> +/**
> + * kvm_pmu_enable_counter - enable selected PMU counter
> + * @vcpu: The vcpu pointer
> + * @val: the value guest writes to PMCNTENSET register
> + *
> + * Call perf_event_enable to start counting the perf event
> + */
> +void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val)
> +{
> +	int i;
> +	struct kvm_pmu *pmu = &vcpu->arch.pmu;
> +	struct kvm_pmc *pmc;
> +
> +	if (!(vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMCR_E) || !val)
> +		return;
> +
> +	for (i = 0; i < ARMV8_MAX_COUNTERS; i++) {
> +		if (!(val & BIT(i)))
> +			continue;
> +
> +		pmc = &pmu->pmc[i];
> +		if (pmc->perf_event) {
> +			perf_event_enable(pmc->perf_event);
> +			if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
> +				kvm_debug("fail to enable perf event\n");
> +		}
> +	}
> +}
> +
> +/**
> + * kvm_pmu_disable_counter - disable selected PMU counter
> + * @vcpu: The vcpu pointer
> + * @val: the value guest writes to PMCNTENCLR register
> + *
> + * Call perf_event_disable to stop counting the perf event
> + */
> +void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val)
> +{
> +	int i;
> +	struct kvm_pmu *pmu = &vcpu->arch.pmu;
> +	struct kvm_pmc *pmc;
> +
> +	if (!val)
> +		return;
> +
> +	for (i = 0; i < ARMV8_MAX_COUNTERS; i++) {
> +		if (!(val & BIT(i)))
> +			continue;
> +
> +		pmc = &pmu->pmc[i];
> +		if (pmc->perf_event)
> +			perf_event_disable(pmc->perf_event);
> +	}
> +}
> +
>  static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx)
>  {
>  	return (vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMCR_E) &&
> -- 
> 2.0.4
> 
> 
> --
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  reply	other threads:[~2016-01-28 18:08 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-27  3:51 [PATCH v10 00/21] KVM: ARM64: Add guest PMU support Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 01/21] ARM64: Move PMU register related defines to asm/pmu.h Shannon Zhao
2016-02-10 10:36   ` Will Deacon
2016-01-27  3:51 ` [PATCH v10 02/21] KVM: ARM64: Define PMU data structure for each vcpu Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 03/21] KVM: ARM64: Add offset defines for PMU registers Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 04/21] KVM: ARM64: Add access handler for PMCR register Shannon Zhao
2016-01-28 15:36   ` Andrew Jones
2016-01-28 20:43     ` Andrew Jones
2016-01-29  2:07       ` Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 05/21] KVM: ARM64: Add access handler for PMSELR register Shannon Zhao
2016-01-28 20:10   ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 06/21] KVM: ARM64: Add access handler for PMCEID0 and PMCEID1 register Shannon Zhao
2016-01-28 20:34   ` Andrew Jones
2016-01-29  3:47     ` Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 07/21] KVM: ARM64: PMU: Add perf event map and introduce perf event creating function Shannon Zhao
2016-01-28 16:31   ` Andrew Jones
2016-01-28 16:45     ` Marc Zyngier
2016-01-28 18:06       ` Will Deacon
2016-01-29  6:14         ` Shannon Zhao
2016-01-29  6:26         ` Shannon Zhao
2016-01-29 10:18           ` Will Deacon
2016-01-29 13:11             ` Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 08/21] KVM: ARM64: Add access handler for event type register Shannon Zhao
2016-01-28 20:11   ` Andrew Jones
2016-01-29  1:42     ` Shannon Zhao
2016-01-29 11:25       ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 09/21] KVM: ARM64: Add access handler for event counter register Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 10/21] KVM: ARM64: Add access handler for PMCNTENSET and PMCNTENCLR register Shannon Zhao
2016-01-28 18:08   ` Andrew Jones [this message]
2016-01-28 18:12     ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 11/21] KVM: ARM64: Add access handler for PMINTENSET and PMINTENCLR register Shannon Zhao
2016-01-28 18:18   ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 12/21] KVM: ARM64: Add access handler for PMOVSSET and PMOVSCLR register Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 13/21] KVM: ARM64: Add access handler for PMSWINC register Shannon Zhao
2016-01-28 18:37   ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 14/21] KVM: ARM64: Add helper to handle PMCR register bits Shannon Zhao
2016-01-28 19:15   ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 15/21] KVM: ARM64: Add access handler for PMUSERENR register Shannon Zhao
2016-01-28 19:58   ` Andrew Jones
2016-01-29  7:37     ` Shannon Zhao
2016-01-29 11:08       ` Andrew Jones
2016-01-29 13:17         ` Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 16/21] KVM: ARM64: Add PMU overflow interrupt routing Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 17/21] KVM: ARM64: Reset PMU state when resetting vcpu Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 18/21] KVM: ARM64: Free perf event of PMU when destroying vcpu Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 19/21] KVM: ARM64: Add a new feature bit for PMUv3 Shannon Zhao
2016-01-28 20:54   ` Andrew Jones
2016-01-27  3:51 ` [PATCH v10 20/21] KVM: ARM: Introduce per-vcpu kvm device controls Shannon Zhao
2016-01-27  3:51 ` [PATCH v10 21/21] KVM: ARM64: Add a new vcpu device control group for PMUv3 Shannon Zhao
2016-01-28 21:12   ` Andrew Jones
2016-01-28 21:30 ` [PATCH v10 00/21] KVM: ARM64: Add guest PMU support Andrew Jones

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