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arm64: KVM: Add access handler for PMSWINC register

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Add access handler which emulates writing and reading PMSWINC
register and add support for creating software increment event.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Shannon Zhao 2015-09-08 15:49:39 +08:00 committed by Marc Zyngier
parent 76d883c4e6
commit 7a0adc7064
5 changed files with 58 additions and 1 deletions
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1
arch/arm64/include/asm/kvm_host.h
View File

@ -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 */

2
arch/arm64/include/asm/kvm_perf_event.h
View File

@ -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
*/

20
arch/arm64/kvm/sys_regs.c
View File

@ -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 },

2
include/kvm/arm_pmu.h
View File

@ -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

34
virt/kvm/arm/pmu.c
View File

@ -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);