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 v10 4/5] KVM: arm/arm64: remove pmc->bitmask Date: Mon, 17 Jun 2019 20:01:04 +0100 [thread overview] Message-ID: <20190617190105.4662-5-andrew.murray@arm.com> (raw) In-Reply-To: <20190617190105.4662-1-andrew.murray@arm.com> We currently use pmc->bitmask to determine the width of the pmc - however it's superfluous as the pmc index already describes if the pmc is a cycle counter or event counter. The architecture clearly describes the widths of these counters. Let's remove the bitmask to simplify the code. Signed-off-by: Andrew Murray <andrew.murray@arm.com> --- include/kvm/arm_pmu.h | 1 - virt/kvm/arm/pmu.c | 30 ++++++++++++++++++++---------- 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index b73f31baca52..2f0e28dc5a9e 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -28,7 +28,6 @@ struct kvm_pmc { u8 idx; /* index into the pmu->pmc array */ struct perf_event *perf_event; - u64 bitmask; }; struct kvm_pmu { diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index ae1e886d4a1a..0588ad0ddb77 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -25,6 +25,18 @@ #include <kvm/arm_vgic.h> static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); + +/** + * kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter + * @vcpu: The vcpu pointer + * @select_idx: The counter index + */ +static bool kvm_pmu_idx_is_64bit(struct kvm_vcpu *vcpu, u64 select_idx) +{ + return (select_idx == ARMV8_PMU_CYCLE_IDX && + __vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_LC); +} + /** * kvm_pmu_get_counter_value - get PMU counter value * @vcpu: The vcpu pointer @@ -47,7 +59,10 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx) counter += perf_event_read_value(pmc->perf_event, &enabled, &running); - return counter & pmc->bitmask; + if (!kvm_pmu_idx_is_64bit(vcpu, select_idx)) + counter = lower_32_bits(counter); + + return counter; } /** @@ -113,7 +128,6 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) { kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]); pmu->pmc[i].idx = i; - pmu->pmc[i].bitmask = 0xffffffffUL; } } @@ -348,8 +362,6 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) */ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) { - struct kvm_pmu *pmu = &vcpu->arch.pmu; - struct kvm_pmc *pmc; u64 mask; int i; @@ -368,11 +380,6 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) kvm_pmu_set_counter_value(vcpu, i, 0); } - - if (val & ARMV8_PMU_PMCR_LC) { - pmc = &pmu->pmc[ARMV8_PMU_CYCLE_IDX]; - pmc->bitmask = 0xffffffffffffffffUL; - } } static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) @@ -420,7 +427,10 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) counter = kvm_pmu_get_counter_value(vcpu, select_idx); /* The initial sample period (overflow count) of an event. */ - attr.sample_period = (-counter) & pmc->bitmask; + if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx)) + attr.sample_period = (-counter) & GENMASK(63, 0); + else + attr.sample_period = (-counter) & GENMASK(31, 0); event = perf_event_create_kernel_counter(&attr, -1, current, kvm_pmu_perf_overflow, pmc); -- 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 v10 4/5] KVM: arm/arm64: remove pmc->bitmask Date: Mon, 17 Jun 2019 20:01:04 +0100 [thread overview] Message-ID: <20190617190105.4662-5-andrew.murray@arm.com> (raw) In-Reply-To: <20190617190105.4662-1-andrew.murray@arm.com> We currently use pmc->bitmask to determine the width of the pmc - however it's superfluous as the pmc index already describes if the pmc is a cycle counter or event counter. The architecture clearly describes the widths of these counters. Let's remove the bitmask to simplify the code. Signed-off-by: Andrew Murray <andrew.murray@arm.com> --- include/kvm/arm_pmu.h | 1 - virt/kvm/arm/pmu.c | 30 ++++++++++++++++++++---------- 2 files changed, 20 insertions(+), 11 deletions(-) diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index b73f31baca52..2f0e28dc5a9e 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -28,7 +28,6 @@ struct kvm_pmc { u8 idx; /* index into the pmu->pmc array */ struct perf_event *perf_event; - u64 bitmask; }; struct kvm_pmu { diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index ae1e886d4a1a..0588ad0ddb77 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -25,6 +25,18 @@ #include <kvm/arm_vgic.h> static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); + +/** + * kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter + * @vcpu: The vcpu pointer + * @select_idx: The counter index + */ +static bool kvm_pmu_idx_is_64bit(struct kvm_vcpu *vcpu, u64 select_idx) +{ + return (select_idx == ARMV8_PMU_CYCLE_IDX && + __vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_LC); +} + /** * kvm_pmu_get_counter_value - get PMU counter value * @vcpu: The vcpu pointer @@ -47,7 +59,10 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx) counter += perf_event_read_value(pmc->perf_event, &enabled, &running); - return counter & pmc->bitmask; + if (!kvm_pmu_idx_is_64bit(vcpu, select_idx)) + counter = lower_32_bits(counter); + + return counter; } /** @@ -113,7 +128,6 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) { kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]); pmu->pmc[i].idx = i; - pmu->pmc[i].bitmask = 0xffffffffUL; } } @@ -348,8 +362,6 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) */ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) { - struct kvm_pmu *pmu = &vcpu->arch.pmu; - struct kvm_pmc *pmc; u64 mask; int i; @@ -368,11 +380,6 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) kvm_pmu_set_counter_value(vcpu, i, 0); } - - if (val & ARMV8_PMU_PMCR_LC) { - pmc = &pmu->pmc[ARMV8_PMU_CYCLE_IDX]; - pmc->bitmask = 0xffffffffffffffffUL; - } } static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) @@ -420,7 +427,10 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) counter = kvm_pmu_get_counter_value(vcpu, select_idx); /* The initial sample period (overflow count) of an event. */ - attr.sample_period = (-counter) & pmc->bitmask; + if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx)) + attr.sample_period = (-counter) & GENMASK(63, 0); + else + attr.sample_period = (-counter) & GENMASK(31, 0); event = perf_event_create_kernel_counter(&attr, -1, current, kvm_pmu_perf_overflow, pmc); -- 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:[~2019-06-17 19:01 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-06-17 19:01 [PATCH v10 0/5] KVM: arm/arm64: add support for chained counters Andrew Murray 2019-06-17 19:01 ` Andrew Murray 2019-06-17 19:01 ` [PATCH v10 1/5] KVM: arm/arm64: rename kvm_pmu_{enable/disable}_counter functions Andrew Murray 2019-06-17 19:01 ` Andrew Murray 2019-06-17 19:01 ` [PATCH v10 2/5] KVM: arm/arm64: extract duplicated code to own function Andrew Murray 2019-06-17 19:01 ` Andrew Murray 2019-06-17 19:01 ` [PATCH v10 3/5] KVM: arm/arm64: re-create event when setting counter value Andrew Murray 2019-06-17 19:01 ` Andrew Murray 2019-06-17 19:01 ` Andrew Murray [this message] 2019-06-17 19:01 ` [PATCH v10 4/5] KVM: arm/arm64: remove pmc->bitmask Andrew Murray 2019-06-17 19:01 ` [PATCH v10 5/5] KVM: arm/arm64: support chained PMU counters Andrew Murray 2019-06-17 19:01 ` Andrew Murray
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