From: Andrew Murray <andrew.murray@arm.com> To: Christoffer Dall <christoffer.dall@arm.com>, Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Subject: [PATCH v9 3/5] KVM: arm/arm64: re-create event when setting counter value Date: Wed, 12 Jun 2019 20:04:48 +0100 [thread overview] Message-ID: <20190612190450.7085-4-andrew.murray@arm.com> (raw) In-Reply-To: <20190612190450.7085-1-andrew.murray@arm.com> The perf event sample_period is currently set based upon the current counter value, when PMXEVTYPER is written to and the perf event is created. However the user may choose to write the type before the counter value in which case sample_period will be set incorrectly. Let's instead decouple event creation from PMXEVTYPER and (re)create the event in either suitation. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- virt/kvm/arm/pmu.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 6e7c179103a6..ae1e886d4a1a 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -24,6 +24,7 @@ #include <kvm/arm_pmu.h> #include <kvm/arm_vgic.h> +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); /** * kvm_pmu_get_counter_value - get PMU counter value * @vcpu: The vcpu pointer @@ -62,6 +63,9 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) reg = (select_idx == ARMV8_PMU_CYCLE_IDX) ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx; __vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx); + + /* Recreate the perf event to reflect the updated sample_period */ + kvm_pmu_create_perf_event(vcpu, select_idx); } /** @@ -378,23 +382,21 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) } /** - * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * kvm_pmu_create_perf_event - create a perf event for a counter * @vcpu: The vcpu pointer - * @data: The data guest writes to PMXEVTYPER_EL0 * @select_idx: The number of selected counter - * - * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an - * event with given hardware event number. Here we call perf_event API to - * emulate this action and create a kernel perf event for it. */ -void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, - u64 select_idx) +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) { struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_pmc *pmc = &pmu->pmc[select_idx]; struct perf_event *event; struct perf_event_attr attr; - u64 eventsel, counter; + u64 eventsel, counter, reg, data; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + data = __vcpu_sys_reg(vcpu, reg); kvm_pmu_stop_counter(vcpu, pmc); eventsel = data & ARMV8_PMU_EVTYPE_EVENT; @@ -431,6 +433,28 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, pmc->perf_event = event; } +/** + * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * @vcpu: The vcpu pointer + * @data: The data guest writes to PMXEVTYPER_EL0 + * @select_idx: The number of selected counter + * + * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an + * event with given hardware event number. Here we call perf_event API to + * emulate this action and create a kernel perf event for it. + */ +void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, + u64 select_idx) +{ + u64 reg, event_type = data & ARMV8_PMU_EVTYPE_MASK; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + + __vcpu_sys_reg(vcpu, reg) = event_type; + kvm_pmu_create_perf_event(vcpu, select_idx); +} + bool kvm_arm_support_pmu_v3(void) { /* -- 2.21.0 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Murray <andrew.murray@arm.com> To: Christoffer Dall <christoffer.dall@arm.com>, Marc Zyngier <marc.zyngier@arm.com> Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>, James Morse <james.morse@arm.com>, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Julien Thierry <julien.thierry@arm.com> Subject: [PATCH v9 3/5] KVM: arm/arm64: re-create event when setting counter value Date: Wed, 12 Jun 2019 20:04:48 +0100 [thread overview] Message-ID: <20190612190450.7085-4-andrew.murray@arm.com> (raw) In-Reply-To: <20190612190450.7085-1-andrew.murray@arm.com> The perf event sample_period is currently set based upon the current counter value, when PMXEVTYPER is written to and the perf event is created. However the user may choose to write the type before the counter value in which case sample_period will be set incorrectly. Let's instead decouple event creation from PMXEVTYPER and (re)create the event in either suitation. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- virt/kvm/arm/pmu.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 6e7c179103a6..ae1e886d4a1a 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -24,6 +24,7 @@ #include <kvm/arm_pmu.h> #include <kvm/arm_vgic.h> +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); /** * kvm_pmu_get_counter_value - get PMU counter value * @vcpu: The vcpu pointer @@ -62,6 +63,9 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) reg = (select_idx == ARMV8_PMU_CYCLE_IDX) ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx; __vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx); + + /* Recreate the perf event to reflect the updated sample_period */ + kvm_pmu_create_perf_event(vcpu, select_idx); } /** @@ -378,23 +382,21 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) } /** - * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * kvm_pmu_create_perf_event - create a perf event for a counter * @vcpu: The vcpu pointer - * @data: The data guest writes to PMXEVTYPER_EL0 * @select_idx: The number of selected counter - * - * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an - * event with given hardware event number. Here we call perf_event API to - * emulate this action and create a kernel perf event for it. */ -void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, - u64 select_idx) +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) { struct kvm_pmu *pmu = &vcpu->arch.pmu; struct kvm_pmc *pmc = &pmu->pmc[select_idx]; struct perf_event *event; struct perf_event_attr attr; - u64 eventsel, counter; + u64 eventsel, counter, reg, data; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + data = __vcpu_sys_reg(vcpu, reg); kvm_pmu_stop_counter(vcpu, pmc); eventsel = data & ARMV8_PMU_EVTYPE_EVENT; @@ -431,6 +433,28 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, pmc->perf_event = event; } +/** + * kvm_pmu_set_counter_event_type - set selected counter to monitor some event + * @vcpu: The vcpu pointer + * @data: The data guest writes to PMXEVTYPER_EL0 + * @select_idx: The number of selected counter + * + * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an + * event with given hardware event number. Here we call perf_event API to + * emulate this action and create a kernel perf event for it. + */ +void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, + u64 select_idx) +{ + u64 reg, event_type = data & ARMV8_PMU_EVTYPE_MASK; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + + __vcpu_sys_reg(vcpu, reg) = event_type; + kvm_pmu_create_perf_event(vcpu, select_idx); +} + bool kvm_arm_support_pmu_v3(void) { /* -- 2.21.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-06-12 19:05 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-12 19:04 [PATCH v9 0/5] KVM: arm/arm64: add support for chained counters Andrew Murray 2019-06-12 19:04 ` Andrew Murray 2019-06-12 19:04 ` [PATCH v9 1/5] KVM: arm/arm64: rename kvm_pmu_{enable/disable}_counter functions Andrew Murray 2019-06-12 19:04 ` Andrew Murray 2019-06-12 19:04 ` [PATCH v9 2/5] KVM: arm/arm64: extract duplicated code to own function Andrew Murray 2019-06-12 19:04 ` Andrew Murray 2019-06-12 19:04 ` Andrew Murray [this message] 2019-06-12 19:04 ` [PATCH v9 3/5] KVM: arm/arm64: re-create event when setting counter value Andrew Murray 2019-06-12 19:04 ` [PATCH v9 4/5] KVM: arm/arm64: remove pmc->bitmask Andrew Murray 2019-06-12 19:04 ` Andrew Murray 2019-06-13 7:30 ` Julien Thierry 2019-06-13 7:30 ` Julien Thierry 2019-06-13 9:39 ` Andrew Murray 2019-06-13 9:39 ` Andrew Murray 2019-06-13 16:50 ` Suzuki K Poulose 2019-06-13 16:50 ` Suzuki K Poulose 2019-06-17 15:43 ` Andrew Murray 2019-06-17 15:43 ` Andrew Murray 2019-06-17 16:33 ` Suzuki K Poulose 2019-06-17 16:33 ` Suzuki K Poulose 2019-06-17 18:06 ` Andrew Murray 2019-06-17 18:06 ` Andrew Murray 2019-06-12 19:04 ` [PATCH v9 5/5] KVM: arm/arm64: support chained PMU counters Andrew Murray 2019-06-12 19:04 ` Andrew Murray 2019-06-14 12:08 ` Suzuki K Poulose 2019-06-14 12:08 ` Suzuki K Poulose
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