[PATCH v3 07/14] KVM: arm64: PMU: Add counter_index_to_*reg() helpers

Marc Zyngier
2022-11-07T08:55:14Z

In order to reduce the boilerplate code, add two helpers returning
the counter register index (resp. the event register) in the vcpu
register file from the counter index.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/pmu-emul.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 8f6462cbc408..44ad0fdba4db 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -77,6 +77,16 @@ static struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc)
return container_of(vcpu_arch, struct kvm_vcpu, arch);
}

+static u32 counter_index_to_reg(u64 idx)
+{
+ return (idx == ARMV8_PMU_CYCLE_IDX) ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + idx;
+}
+
+static u32 counter_index_to_evtreg(u64 idx)
+{
+ return (idx == ARMV8_PMU_CYCLE_IDX) ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + idx;
+}
+
/**
* kvm_pmu_get_counter_value - get PMU counter value
* @vcpu: The vcpu pointer
@@ -91,8 +101,7 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
if (!kvm_vcpu_has_pmu(vcpu))
return 0;

- reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
+ reg = counter_index_to_reg(select_idx);
counter = __vcpu_sys_reg(vcpu, reg);

/*
@@ -122,8 +131,7 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
if (!kvm_vcpu_has_pmu(vcpu))
return;

- reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
+ reg = counter_index_to_reg(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 */
@@ -158,10 +166,7 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)

val = kvm_pmu_get_counter_value(vcpu, pmc->idx);

- if (pmc->idx == ARMV8_PMU_CYCLE_IDX)
- reg = PMCCNTR_EL0;
- else
- reg = PMEVCNTR0_EL0 + pmc->idx;
+ reg = counter_index_to_reg(pmc->idx);

__vcpu_sys_reg(vcpu, reg) = val;

@@ -406,16 +411,16 @@ static void kvm_pmu_counter_increment(struct kvm_vcpu *vcpu,
u64 type, reg;

/* Filter on event type */
- type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i);
+ type = __vcpu_sys_reg(vcpu, counter_index_to_evtreg(i));
type &= kvm_pmu_event_mask(vcpu->kvm);
if (type != event)
continue;

/* Increment this counter */
- reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1;
+ reg = __vcpu_sys_reg(vcpu, counter_index_to_reg(i)) + 1;
if (!kvm_pmu_idx_is_64bit(vcpu, i))
reg = lower_32_bits(reg);
- __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg;
+ __vcpu_sys_reg(vcpu, counter_index_to_reg(i)) = reg;

/* No overflow? move on */
if (kvm_pmu_idx_has_64bit_overflow(vcpu, i) ? reg : lower_32_bits(reg))
@@ -551,8 +556,7 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
struct perf_event_attr attr;
u64 eventsel, counter, reg, data;

- reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + pmc->idx;
+ reg = counter_index_to_evtreg(select_idx);
data = __vcpu_sys_reg(vcpu, reg);

kvm_pmu_stop_counter(vcpu, pmc);
@@ -634,8 +638,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
mask &= ~ARMV8_PMU_EVTYPE_EVENT;
mask |= kvm_pmu_event_mask(vcpu->kvm);

- reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx;
+ reg = counter_index_to_evtreg(select_idx);

__vcpu_sys_reg(vcpu, reg) = data & mask;

--
2.34.1