From 7a0adc7064b88609e2917446af8789fac1d4fdd1 Mon Sep 17 00:00:00 2001 From: Shannon Zhao Date: Tue, 8 Sep 2015 15:49:39 +0800 Subject: [PATCH] arm64: KVM: Add access handler for PMSWINC register Add access handler which emulates writing and reading PMSWINC register and add support for creating software increment event. Signed-off-by: Shannon Zhao Reviewed-by: Andrew Jones Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/include/asm/kvm_perf_event.h | 2 ++ arch/arm64/kvm/sys_regs.c | 20 ++++++++++++++- include/kvm/arm_pmu.h | 2 ++ virt/kvm/arm/pmu.c | 34 +++++++++++++++++++++++++ 5 files changed, 58 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 6c61a2bda6de..4001e85b4818 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -129,6 +129,7 @@ enum vcpu_sysreg { PMCNTENSET_EL0, /* Count Enable Set Register */ PMINTENSET_EL1, /* Interrupt Enable Set Register */ PMOVSSET_EL0, /* Overflow Flag Status Set Register */ + PMSWINC_EL0, /* Software Increment Register */ /* 32bit specific registers. Keep them at the end of the range */ DACR32_EL2, /* Domain Access Control Register */ diff --git a/arch/arm64/include/asm/kvm_perf_event.h b/arch/arm64/include/asm/kvm_perf_event.h index d1c9d504f928..62fa60fbc0b3 100644 --- a/arch/arm64/include/asm/kvm_perf_event.h +++ b/arch/arm64/include/asm/kvm_perf_event.h @@ -45,6 +45,8 @@ #define ARMV8_PMU_EVTYPE_MASK 0xc80003ff /* Mask for writable bits */ #define ARMV8_PMU_EVTYPE_EVENT 0x3ff /* Mask for EVENT bits */ +#define ARMV8_PMU_EVTYPE_EVENT_SW_INCR 0 /* Software increment event */ + /* * Event filters for PMUv3 */ diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 6a774f9b9cca..10e53796926c 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -672,6 +672,23 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return true; } +static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 mask; + + if (!kvm_arm_pmu_v3_ready(vcpu)) + return trap_raz_wi(vcpu, p, r); + + if (p->is_write) { + mask = kvm_pmu_valid_counter_mask(vcpu); + kvm_pmu_software_increment(vcpu, p->regval & mask); + return true; + } + + return false; +} + /* 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 */ \ @@ -882,7 +899,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { access_pmovs, NULL, PMOVSSET_EL0 }, /* PMSWINC_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b100), - trap_raz_wi }, + access_pmswinc, reset_unknown, PMSWINC_EL0 }, /* PMSELR_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101), access_pmselr, reset_unknown, PMSELR_EL0 }, @@ -1221,6 +1238,7 @@ static const struct sys_reg_desc cp15_regs[] = { { 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), access_pmovs }, + { Op1( 0), CRn( 9), CRm(12), Op2( 4), access_pmswinc }, { Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr }, { Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid }, { Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid }, diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 60061dabe881..348c4c9d763a 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -44,6 +44,7 @@ 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_overflow_set(struct kvm_vcpu *vcpu, u64 val); +void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val); void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, u64 select_idx); #else @@ -65,6 +66,7 @@ static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu) 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_overflow_set(struct kvm_vcpu *vcpu, u64 val) {} +static inline void kvm_pmu_software_increment(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 023286101fef..9fc775ef03ec 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -180,6 +180,36 @@ void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) kvm_vcpu_kick(vcpu); } +/** + * kvm_pmu_software_increment - do software increment + * @vcpu: The vcpu pointer + * @val: the value guest writes to PMSWINC register + */ +void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) +{ + int i; + u64 type, enable, reg; + + if (val == 0) + return; + + enable = vcpu_sys_reg(vcpu, PMCNTENSET_EL0); + for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) { + if (!(val & BIT(i))) + continue; + type = vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i) + & ARMV8_PMU_EVTYPE_EVENT; + if ((type == ARMV8_PMU_EVTYPE_EVENT_SW_INCR) + && (enable & BIT(i))) { + reg = vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1; + reg = lower_32_bits(reg); + vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; + if (!reg) + kvm_pmu_overflow_set(vcpu, BIT(i)); + } + } +} + static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) { return (vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) && @@ -208,6 +238,10 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, kvm_pmu_stop_counter(vcpu, pmc); eventsel = data & ARMV8_PMU_EVTYPE_EVENT; + /* Software increment event does't need to be backed by a perf event */ + if (eventsel == ARMV8_PMU_EVTYPE_EVENT_SW_INCR) + return; + memset(&attr, 0, sizeof(struct perf_event_attr)); attr.type = PERF_TYPE_RAW; attr.size = sizeof(attr); -- 2.20.1