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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/arch/arm64/kvm/pmu-emul.c

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C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 Linaro Ltd.
* Author: Shannon Zhao <shannon.zhao@linaro.org>
*/
#include <linux/cpu.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/perf_event.h>
#include <linux/perf/arm_pmu.h>
#include <linux/uaccess.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_pmu.h>
#include <kvm/arm_vgic.h>
static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx);
static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx);
static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc);
#define PERF_ATTR_CFG1_KVM_PMU_CHAINED 0x1
static u32 kvm_pmu_event_mask(struct kvm *kvm)
{
switch (kvm->arch.pmuver) {
case ID_AA64DFR0_PMUVER_8_0:
return GENMASK(9, 0);
case ID_AA64DFR0_PMUVER_8_1:
case ID_AA64DFR0_PMUVER_8_4:
case ID_AA64DFR0_PMUVER_8_5:
return GENMASK(15, 0);
default: /* Shouldn't be here, just for sanity */
WARN_ONCE(1, "Unknown PMU version %d\n", kvm->arch.pmuver);
return 0;
}
}
/**
* 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);
}
static struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu;
struct kvm_vcpu_arch *vcpu_arch;
pmc -= pmc->idx;
pmu = container_of(pmc, struct kvm_pmu, pmc[0]);
vcpu_arch = container_of(pmu, struct kvm_vcpu_arch, pmu);
return container_of(vcpu_arch, struct kvm_vcpu, arch);
}
/**
* kvm_pmu_pmc_is_chained - determine if the pmc is chained
* @pmc: The PMU counter pointer
*/
static bool kvm_pmu_pmc_is_chained(struct kvm_pmc *pmc)
{
struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
return test_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
}
/**
* kvm_pmu_idx_is_high_counter - determine if select_idx is a high/low counter
* @select_idx: The counter index
*/
static bool kvm_pmu_idx_is_high_counter(u64 select_idx)
{
return select_idx & 0x1;
}
/**
* kvm_pmu_get_canonical_pmc - obtain the canonical pmc
* @pmc: The PMU counter pointer
*
* When a pair of PMCs are chained together we use the low counter (canonical)
* to hold the underlying perf event.
*/
static struct kvm_pmc *kvm_pmu_get_canonical_pmc(struct kvm_pmc *pmc)
{
if (kvm_pmu_pmc_is_chained(pmc) &&
kvm_pmu_idx_is_high_counter(pmc->idx))
return pmc - 1;
return pmc;
}
static struct kvm_pmc *kvm_pmu_get_alternate_pmc(struct kvm_pmc *pmc)
{
if (kvm_pmu_idx_is_high_counter(pmc->idx))
return pmc - 1;
else
return pmc + 1;
}
/**
* kvm_pmu_idx_has_chain_evtype - determine if the event type is chain
* @vcpu: The vcpu pointer
* @select_idx: The counter index
*/
static bool kvm_pmu_idx_has_chain_evtype(struct kvm_vcpu *vcpu, u64 select_idx)
{
u64 eventsel, reg;
select_idx |= 0x1;
if (select_idx == ARMV8_PMU_CYCLE_IDX)
return false;
reg = PMEVTYPER0_EL0 + select_idx;
eventsel = __vcpu_sys_reg(vcpu, reg) & kvm_pmu_event_mask(vcpu->kvm);
return eventsel == ARMV8_PMUV3_PERFCTR_CHAIN;
}
/**
* kvm_pmu_get_pair_counter_value - get PMU counter value
* @vcpu: The vcpu pointer
* @pmc: The PMU counter pointer
*/
static u64 kvm_pmu_get_pair_counter_value(struct kvm_vcpu *vcpu,
struct kvm_pmc *pmc)
{
u64 counter, counter_high, reg, enabled, running;
if (kvm_pmu_pmc_is_chained(pmc)) {
pmc = kvm_pmu_get_canonical_pmc(pmc);
reg = PMEVCNTR0_EL0 + pmc->idx;
counter = __vcpu_sys_reg(vcpu, reg);
counter_high = __vcpu_sys_reg(vcpu, reg + 1);
counter = lower_32_bits(counter) | (counter_high << 32);
} else {
reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
counter = __vcpu_sys_reg(vcpu, reg);
}
/*
* The real counter value is equal to the value of counter register plus
* the value perf event counts.
*/
if (pmc->perf_event)
counter += perf_event_read_value(pmc->perf_event, &enabled,
&running);
return counter;
}
/**
* kvm_pmu_get_counter_value - get PMU counter value
* @vcpu: The vcpu pointer
* @select_idx: The counter index
*/
u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
{
u64 counter;
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc = &pmu->pmc[select_idx];
counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
if (kvm_pmu_pmc_is_chained(pmc) &&
kvm_pmu_idx_is_high_counter(select_idx))
counter = upper_32_bits(counter);
else if (select_idx != ARMV8_PMU_CYCLE_IDX)
counter = lower_32_bits(counter);
return counter;
}
/**
* kvm_pmu_set_counter_value - set PMU counter value
* @vcpu: The vcpu pointer
* @select_idx: The counter index
* @val: The counter value
*/
void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
{
u64 reg;
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);
}
/**
* kvm_pmu_release_perf_event - remove the perf event
* @pmc: The PMU counter pointer
*/
static void kvm_pmu_release_perf_event(struct kvm_pmc *pmc)
{
pmc = kvm_pmu_get_canonical_pmc(pmc);
if (pmc->perf_event) {
perf_event_disable(pmc->perf_event);
perf_event_release_kernel(pmc->perf_event);
pmc->perf_event = NULL;
}
}
/**
* kvm_pmu_stop_counter - stop PMU counter
* @pmc: The PMU counter pointer
*
* If this counter has been configured to monitor some event, release it here.
*/
static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
{
u64 counter, reg, val;
pmc = kvm_pmu_get_canonical_pmc(pmc);
if (!pmc->perf_event)
return;
counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
if (pmc->idx == ARMV8_PMU_CYCLE_IDX) {
reg = PMCCNTR_EL0;
val = counter;
} else {
reg = PMEVCNTR0_EL0 + pmc->idx;
val = lower_32_bits(counter);
}
__vcpu_sys_reg(vcpu, reg) = val;
if (kvm_pmu_pmc_is_chained(pmc))
__vcpu_sys_reg(vcpu, reg + 1) = upper_32_bits(counter);
kvm_pmu_release_perf_event(pmc);
}
/**
* kvm_pmu_vcpu_init - assign pmu counter idx for cpu
* @vcpu: The vcpu pointer
*
*/
void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu)
{
int i;
struct kvm_pmu *pmu = &vcpu->arch.pmu;
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++)
pmu->pmc[i].idx = i;
}
/**
* kvm_pmu_vcpu_reset - reset pmu state for cpu
* @vcpu: The vcpu pointer
*
*/
void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu)
{
unsigned long mask = kvm_pmu_valid_counter_mask(vcpu);
struct kvm_pmu *pmu = &vcpu->arch.pmu;
int i;
for_each_set_bit(i, &mask, 32)
kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]);
bitmap_zero(vcpu->arch.pmu.chained, ARMV8_PMU_MAX_COUNTER_PAIRS);
}
/**
* kvm_pmu_vcpu_destroy - free perf event of PMU for cpu
* @vcpu: The vcpu pointer
*
*/
void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu)
{
int i;
struct kvm_pmu *pmu = &vcpu->arch.pmu;
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++)
kvm_pmu_release_perf_event(&pmu->pmc[i]);
irq_work_sync(&vcpu->arch.pmu.overflow_work);
}
u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
{
u64 val = __vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT;
val &= ARMV8_PMU_PMCR_N_MASK;
if (val == 0)
return BIT(ARMV8_PMU_CYCLE_IDX);
else
return GENMASK(val - 1, 0) | BIT(ARMV8_PMU_CYCLE_IDX);
}
/**
* kvm_pmu_enable_counter_mask - enable selected PMU counters
* @vcpu: The vcpu pointer
* @val: the value guest writes to PMCNTENSET register
*
* Call perf_event_enable to start counting the perf event
*/
void kvm_pmu_enable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
{
int i;
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc;
if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) || !val)
return;
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
if (!(val & BIT(i)))
continue;
pmc = &pmu->pmc[i];
/* A change in the enable state may affect the chain state */
kvm_pmu_update_pmc_chained(vcpu, i);
kvm_pmu_create_perf_event(vcpu, i);
/* At this point, pmc must be the canonical */
if (pmc->perf_event) {
perf_event_enable(pmc->perf_event);
if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
kvm_debug("fail to enable perf event\n");
}
}
}
/**
* kvm_pmu_disable_counter_mask - disable selected PMU counters
* @vcpu: The vcpu pointer
* @val: the value guest writes to PMCNTENCLR register
*
* Call perf_event_disable to stop counting the perf event
*/
void kvm_pmu_disable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
{
int i;
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc;
if (!val)
return;
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
if (!(val & BIT(i)))
continue;
pmc = &pmu->pmc[i];
/* A change in the enable state may affect the chain state */
kvm_pmu_update_pmc_chained(vcpu, i);
kvm_pmu_create_perf_event(vcpu, i);
/* At this point, pmc must be the canonical */
if (pmc->perf_event)
perf_event_disable(pmc->perf_event);
}
}
static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
{
u64 reg = 0;
if ((__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E)) {
reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0);
reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1);
reg &= kvm_pmu_valid_counter_mask(vcpu);
}
return reg;
}
static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
bool overflow;
if (!kvm_vcpu_has_pmu(vcpu))
return;
overflow = !!kvm_pmu_overflow_status(vcpu);
if (pmu->irq_level == overflow)
return;
pmu->irq_level = overflow;
if (likely(irqchip_in_kernel(vcpu->kvm))) {
int ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
pmu->irq_num, overflow, pmu);
WARN_ON(ret);
}
}
bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_sync_regs *sregs = &vcpu->run->s.regs;
bool run_level = sregs->device_irq_level & KVM_ARM_DEV_PMU;
if (likely(irqchip_in_kernel(vcpu->kvm)))
return false;
return pmu->irq_level != run_level;
}
/*
* Reflect the PMU overflow interrupt output level into the kvm_run structure
*/
void kvm_pmu_update_run(struct kvm_vcpu *vcpu)
{
struct kvm_sync_regs *regs = &vcpu->run->s.regs;
/* Populate the timer bitmap for user space */
regs->device_irq_level &= ~KVM_ARM_DEV_PMU;
if (vcpu->arch.pmu.irq_level)
regs->device_irq_level |= KVM_ARM_DEV_PMU;
}
/**
* kvm_pmu_flush_hwstate - flush pmu state to cpu
* @vcpu: The vcpu pointer
*
* Check if the PMU has overflowed while we were running in the host, and inject
* an interrupt if that was the case.
*/
void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu)
{
kvm_pmu_update_state(vcpu);
}
/**
* kvm_pmu_sync_hwstate - sync pmu state from cpu
* @vcpu: The vcpu pointer
*
* Check if the PMU has overflowed while we were running in the guest, and
* inject an interrupt if that was the case.
*/
void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu)
{
kvm_pmu_update_state(vcpu);
}
/**
* When perf interrupt is an NMI, we cannot safely notify the vcpu corresponding
* to the event.
* This is why we need a callback to do it once outside of the NMI context.
*/
static void kvm_pmu_perf_overflow_notify_vcpu(struct irq_work *work)
{
struct kvm_vcpu *vcpu;
struct kvm_pmu *pmu;
pmu = container_of(work, struct kvm_pmu, overflow_work);
vcpu = kvm_pmc_to_vcpu(pmu->pmc);
kvm_vcpu_kick(vcpu);
}
/**
* When the perf event overflows, set the overflow status and inform the vcpu.
*/
static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
struct perf_sample_data *data,
struct pt_regs *regs)
{
struct kvm_pmc *pmc = perf_event->overflow_handler_context;
struct arm_pmu *cpu_pmu = to_arm_pmu(perf_event->pmu);
struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
int idx = pmc->idx;
u64 period;
cpu_pmu->pmu.stop(perf_event, PERF_EF_UPDATE);
/*
* Reset the sample period to the architectural limit,
* i.e. the point where the counter overflows.
*/
period = -(local64_read(&perf_event->count));
if (!kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
period &= GENMASK(31, 0);
local64_set(&perf_event->hw.period_left, 0);
perf_event->attr.sample_period = period;
perf_event->hw.sample_period = period;
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(idx);
if (kvm_pmu_overflow_status(vcpu)) {
kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
if (!in_nmi())
kvm_vcpu_kick(vcpu);
else
irq_work_queue(&vcpu->arch.pmu.overflow_work);
}
cpu_pmu->pmu.start(perf_event, PERF_EF_RELOAD);
}
/**
* 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)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
int i;
if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E))
return;
/* Weed out disabled counters */
val &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) {
u64 type, reg;
if (!(val & BIT(i)))
continue;
/* PMSWINC only applies to ... SW_INC! */
type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i);
type &= kvm_pmu_event_mask(vcpu->kvm);
if (type != ARMV8_PMUV3_PERFCTR_SW_INCR)
continue;
/* increment this even SW_INC counter */
reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1;
reg = lower_32_bits(reg);
__vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg;
if (reg) /* no overflow on the low part */
continue;
if (kvm_pmu_pmc_is_chained(&pmu->pmc[i])) {
/* increment the high counter */
reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) + 1;
reg = lower_32_bits(reg);
__vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) = reg;
if (!reg) /* mark overflow on the high counter */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i + 1);
} else {
/* mark overflow on low counter */
__vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i);
}
}
}
/**
* kvm_pmu_handle_pmcr - handle PMCR register
* @vcpu: The vcpu pointer
* @val: the value guest writes to PMCR register
*/
void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
{
unsigned long mask = kvm_pmu_valid_counter_mask(vcpu);
int i;
if (val & ARMV8_PMU_PMCR_E) {
kvm_pmu_enable_counter_mask(vcpu,
__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask);
} else {
kvm_pmu_disable_counter_mask(vcpu, mask);
}
if (val & ARMV8_PMU_PMCR_C)
kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0);
if (val & ARMV8_PMU_PMCR_P) {
for_each_set_bit(i, &mask, 32)
kvm_pmu_set_counter_value(vcpu, i, 0);
}
}
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) &&
(__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & BIT(select_idx));
}
/**
* kvm_pmu_create_perf_event - create a perf event for a counter
* @vcpu: The vcpu pointer
* @select_idx: The number of selected counter
*/
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;
struct perf_event *event;
struct perf_event_attr attr;
u64 eventsel, counter, reg, data;
/*
* For chained counters the event type and filtering attributes are
* obtained from the low/even counter. We also use this counter to
* determine if the event is enabled/disabled.
*/
pmc = kvm_pmu_get_canonical_pmc(&pmu->pmc[select_idx]);
reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + pmc->idx;
data = __vcpu_sys_reg(vcpu, reg);
kvm_pmu_stop_counter(vcpu, pmc);
if (pmc->idx == ARMV8_PMU_CYCLE_IDX)
eventsel = ARMV8_PMUV3_PERFCTR_CPU_CYCLES;
else
eventsel = data & kvm_pmu_event_mask(vcpu->kvm);
/* Software increment event doesn't need to be backed by a perf event */
if (eventsel == ARMV8_PMUV3_PERFCTR_SW_INCR)
return;
/*
* If we have a filter in place and that the event isn't allowed, do
* not install a perf event either.
*/
if (vcpu->kvm->arch.pmu_filter &&
!test_bit(eventsel, vcpu->kvm->arch.pmu_filter))
return;
memset(&attr, 0, sizeof(struct perf_event_attr));
attr.type = PERF_TYPE_RAW;
attr.size = sizeof(attr);
attr.pinned = 1;
attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, pmc->idx);
attr.exclude_user = data & ARMV8_PMU_EXCLUDE_EL0 ? 1 : 0;
attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0;
attr.exclude_hv = 1; /* Don't count EL2 events */
attr.exclude_host = 1; /* Don't count host events */
attr.config = eventsel;
counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
if (kvm_pmu_pmc_is_chained(pmc)) {
/**
* The initial sample period (overflow count) of an event. For
* chained counters we only support overflow interrupts on the
* high counter.
*/
attr.sample_period = (-counter) & GENMASK(63, 0);
attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED;
event = perf_event_create_kernel_counter(&attr, -1, current,
kvm_pmu_perf_overflow,
pmc + 1);
} else {
/* The initial sample period (overflow count) of an event. */
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);
}
if (IS_ERR(event)) {
pr_err_once("kvm: pmu event creation failed %ld\n",
PTR_ERR(event));
return;
}
pmc->perf_event = event;
}
/**
* kvm_pmu_update_pmc_chained - update chained bitmap
* @vcpu: The vcpu pointer
* @select_idx: The number of selected counter
*
* Update the chained bitmap based on the event type written in the
* typer register and the enable state of the odd register.
*/
static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc = &pmu->pmc[select_idx], *canonical_pmc;
bool new_state, old_state;
old_state = kvm_pmu_pmc_is_chained(pmc);
new_state = kvm_pmu_idx_has_chain_evtype(vcpu, pmc->idx) &&
kvm_pmu_counter_is_enabled(vcpu, pmc->idx | 0x1);
if (old_state == new_state)
return;
canonical_pmc = kvm_pmu_get_canonical_pmc(pmc);
kvm_pmu_stop_counter(vcpu, canonical_pmc);
if (new_state) {
/*
* During promotion from !chained to chained we must ensure
* the adjacent counter is stopped and its event destroyed
*/
kvm_pmu_stop_counter(vcpu, kvm_pmu_get_alternate_pmc(pmc));
set_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
return;
}
clear_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
}
/**
* 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, mask;
mask = ARMV8_PMU_EVTYPE_MASK;
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;
__vcpu_sys_reg(vcpu, reg) = data & mask;
kvm_pmu_update_pmc_chained(vcpu, select_idx);
kvm_pmu_create_perf_event(vcpu, select_idx);
}
static int kvm_pmu_probe_pmuver(void)
{
struct perf_event_attr attr = { };
struct perf_event *event;
struct arm_pmu *pmu;
int pmuver = 0xf;
/*
* Create a dummy event that only counts user cycles. As we'll never
* leave this function with the event being live, it will never
* count anything. But it allows us to probe some of the PMU
* details. Yes, this is terrible.
*/
attr.type = PERF_TYPE_RAW;
attr.size = sizeof(attr);
attr.pinned = 1;
attr.disabled = 0;
attr.exclude_user = 0;
attr.exclude_kernel = 1;
attr.exclude_hv = 1;
attr.exclude_host = 1;
attr.config = ARMV8_PMUV3_PERFCTR_CPU_CYCLES;
attr.sample_period = GENMASK(63, 0);
event = perf_event_create_kernel_counter(&attr, -1, current,
kvm_pmu_perf_overflow, &attr);
if (IS_ERR(event)) {
pr_err_once("kvm: pmu event creation failed %ld\n",
PTR_ERR(event));
return 0xf;
}
if (event->pmu) {
pmu = to_arm_pmu(event->pmu);
if (pmu->pmuver)
pmuver = pmu->pmuver;
}
perf_event_disable(event);
perf_event_release_kernel(event);
return pmuver;
}
u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
{
unsigned long *bmap = vcpu->kvm->arch.pmu_filter;
u64 val, mask = 0;
int base, i, nr_events;
if (!pmceid1) {
val = read_sysreg(pmceid0_el0);
base = 0;
} else {
val = read_sysreg(pmceid1_el0);
/*
* Don't advertise STALL_SLOT, as PMMIR_EL0 is handled
* as RAZ
*/
if (vcpu->kvm->arch.pmuver >= ID_AA64DFR0_PMUVER_8_4)
val &= ~BIT_ULL(ARMV8_PMUV3_PERFCTR_STALL_SLOT - 32);
base = 32;
}
if (!bmap)
return val;
nr_events = kvm_pmu_event_mask(vcpu->kvm) + 1;
for (i = 0; i < 32; i += 8) {
u64 byte;
byte = bitmap_get_value8(bmap, base + i);
mask |= byte << i;
if (nr_events >= (0x4000 + base + 32)) {
byte = bitmap_get_value8(bmap, 0x4000 + base + i);
mask |= byte << (32 + i);
}
}
return val & mask;
}
int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
{
if (!kvm_vcpu_has_pmu(vcpu))
return 0;
if (!vcpu->arch.pmu.created)
return -EINVAL;
/*
* A valid interrupt configuration for the PMU is either to have a
* properly configured interrupt number and using an in-kernel
* irqchip, or to not have an in-kernel GIC and not set an IRQ.
*/
if (irqchip_in_kernel(vcpu->kvm)) {
int irq = vcpu->arch.pmu.irq_num;
/*
* If we are using an in-kernel vgic, at this point we know
* the vgic will be initialized, so we can check the PMU irq
* number against the dimensions of the vgic and make sure
* it's valid.
*/
if (!irq_is_ppi(irq) && !vgic_valid_spi(vcpu->kvm, irq))
return -EINVAL;
} else if (kvm_arm_pmu_irq_initialized(vcpu)) {
return -EINVAL;
}
return 0;
}
static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
{
if (irqchip_in_kernel(vcpu->kvm)) {
int ret;
/*
* If using the PMU with an in-kernel virtual GIC
* implementation, we require the GIC to be already
* initialized when initializing the PMU.
*/
if (!vgic_initialized(vcpu->kvm))
return -ENODEV;
if (!kvm_arm_pmu_irq_initialized(vcpu))
return -ENXIO;
ret = kvm_vgic_set_owner(vcpu, vcpu->arch.pmu.irq_num,
&vcpu->arch.pmu);
if (ret)
return ret;
}
init_irq_work(&vcpu->arch.pmu.overflow_work,
kvm_pmu_perf_overflow_notify_vcpu);
vcpu->arch.pmu.created = true;
return 0;
}
/*
* For one VM the interrupt type must be same for each vcpu.
* As a PPI, the interrupt number is the same for all vcpus,
* while as an SPI it must be a separate number per vcpu.
*/
static bool pmu_irq_is_valid(struct kvm *kvm, int irq)
{
int i;
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!kvm_arm_pmu_irq_initialized(vcpu))
continue;
if (irq_is_ppi(irq)) {
if (vcpu->arch.pmu.irq_num != irq)
return false;
} else {
if (vcpu->arch.pmu.irq_num == irq)
return false;
}
}
return true;
}
int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
{
if (!kvm_vcpu_has_pmu(vcpu))
return -ENODEV;
if (vcpu->arch.pmu.created)
return -EBUSY;
if (!vcpu->kvm->arch.pmuver)
vcpu->kvm->arch.pmuver = kvm_pmu_probe_pmuver();
if (vcpu->kvm->arch.pmuver == 0xf)
return -ENODEV;
switch (attr->attr) {
case KVM_ARM_VCPU_PMU_V3_IRQ: {
int __user *uaddr = (int __user *)(long)attr->addr;
int irq;
if (!irqchip_in_kernel(vcpu->kvm))
return -EINVAL;
if (get_user(irq, uaddr))
return -EFAULT;
/* The PMU overflow interrupt can be a PPI or a valid SPI. */
if (!(irq_is_ppi(irq) || irq_is_spi(irq)))
return -EINVAL;
if (!pmu_irq_is_valid(vcpu->kvm, irq))
return -EINVAL;
if (kvm_arm_pmu_irq_initialized(vcpu))
return -EBUSY;
kvm_debug("Set kvm ARM PMU irq: %d\n", irq);
vcpu->arch.pmu.irq_num = irq;
return 0;
}
case KVM_ARM_VCPU_PMU_V3_FILTER: {
struct kvm_pmu_event_filter __user *uaddr;
struct kvm_pmu_event_filter filter;
int nr_events;
nr_events = kvm_pmu_event_mask(vcpu->kvm) + 1;
uaddr = (struct kvm_pmu_event_filter __user *)(long)attr->addr;
if (copy_from_user(&filter, uaddr, sizeof(filter)))
return -EFAULT;
if (((u32)filter.base_event + filter.nevents) > nr_events ||
(filter.action != KVM_PMU_EVENT_ALLOW &&
filter.action != KVM_PMU_EVENT_DENY))
return -EINVAL;
mutex_lock(&vcpu->kvm->lock);
if (!vcpu->kvm->arch.pmu_filter) {
vcpu->kvm->arch.pmu_filter = bitmap_alloc(nr_events, GFP_KERNEL);
if (!vcpu->kvm->arch.pmu_filter) {
mutex_unlock(&vcpu->kvm->lock);
return -ENOMEM;
}
/*
* The default depends on the first applied filter.
* If it allows events, the default is to deny.
* Conversely, if the first filter denies a set of
* events, the default is to allow.
*/
if (filter.action == KVM_PMU_EVENT_ALLOW)
bitmap_zero(vcpu->kvm->arch.pmu_filter, nr_events);
else
bitmap_fill(vcpu->kvm->arch.pmu_filter, nr_events);
}
if (filter.action == KVM_PMU_EVENT_ALLOW)
bitmap_set(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents);
else
bitmap_clear(vcpu->kvm->arch.pmu_filter, filter.base_event, filter.nevents);
mutex_unlock(&vcpu->kvm->lock);
return 0;
}
case KVM_ARM_VCPU_PMU_V3_INIT:
return kvm_arm_pmu_v3_init(vcpu);
}
return -ENXIO;
}
int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
{
switch (attr->attr) {
case KVM_ARM_VCPU_PMU_V3_IRQ: {
int __user *uaddr = (int __user *)(long)attr->addr;
int irq;
if (!irqchip_in_kernel(vcpu->kvm))
return -EINVAL;
if (!kvm_vcpu_has_pmu(vcpu))
return -ENODEV;
if (!kvm_arm_pmu_irq_initialized(vcpu))
return -ENXIO;
irq = vcpu->arch.pmu.irq_num;
return put_user(irq, uaddr);
}
}
return -ENXIO;
}
int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
{
switch (attr->attr) {
case KVM_ARM_VCPU_PMU_V3_IRQ:
case KVM_ARM_VCPU_PMU_V3_INIT:
case KVM_ARM_VCPU_PMU_V3_FILTER:
if (kvm_vcpu_has_pmu(vcpu))
return 0;
}
return -ENXIO;
}
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