summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/pmu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/pmu.c')
-rw-r--r--arch/x86/kvm/pmu.c90
1 files changed, 59 insertions, 31 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index de1fd7369736..684393c22105 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -101,10 +101,6 @@ static inline void __kvm_perf_overflow(struct kvm_pmc *pmc, bool in_pmi)
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
bool skip_pmi = false;
- /* Ignore counters that have been reprogrammed already. */
- if (test_and_set_bit(pmc->idx, pmu->reprogram_pmi))
- return;
-
if (pmc->perf_event && pmc->perf_event->attr.precise_ip) {
if (!in_pmi) {
/*
@@ -122,7 +118,6 @@ static inline void __kvm_perf_overflow(struct kvm_pmc *pmc, bool in_pmi)
} else {
__set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
}
- kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
if (!pmc->intr || skip_pmi)
return;
@@ -147,12 +142,22 @@ static void kvm_perf_overflow(struct perf_event *perf_event,
{
struct kvm_pmc *pmc = perf_event->overflow_handler_context;
+ /*
+ * Ignore overflow events for counters that are scheduled to be
+ * reprogrammed, e.g. if a PMI for the previous event races with KVM's
+ * handling of a related guest WRMSR.
+ */
+ if (test_and_set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi))
+ return;
+
__kvm_perf_overflow(pmc, true);
+
+ kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
}
-static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
- u64 config, bool exclude_user,
- bool exclude_kernel, bool intr)
+static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config,
+ bool exclude_user, bool exclude_kernel,
+ bool intr)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
struct perf_event *event;
@@ -204,14 +209,14 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
if (IS_ERR(event)) {
pr_debug_ratelimited("kvm_pmu: event creation failed %ld for pmc->idx = %d\n",
PTR_ERR(event), pmc->idx);
- return;
+ return PTR_ERR(event);
}
pmc->perf_event = event;
pmc_to_pmu(pmc)->event_count++;
- clear_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
pmc->is_paused = false;
pmc->intr = intr || pebs;
+ return 0;
}
static void pmc_pause_counter(struct kvm_pmc *pmc)
@@ -245,7 +250,6 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc)
perf_event_enable(pmc->perf_event);
pmc->is_paused = false;
- clear_bit(pmc->idx, (unsigned long *)&pmc_to_pmu(pmc)->reprogram_pmi);
return true;
}
@@ -293,7 +297,7 @@ out:
return allow_event;
}
-void reprogram_counter(struct kvm_pmc *pmc)
+static void reprogram_counter(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
u64 eventsel = pmc->eventsel;
@@ -303,10 +307,13 @@ void reprogram_counter(struct kvm_pmc *pmc)
pmc_pause_counter(pmc);
if (!pmc_speculative_in_use(pmc) || !pmc_is_enabled(pmc))
- return;
+ goto reprogram_complete;
if (!check_pmu_event_filter(pmc))
- return;
+ goto reprogram_complete;
+
+ if (pmc->counter < pmc->prev_counter)
+ __kvm_perf_overflow(pmc, false);
if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
printk_once("kvm pmu: pin control bit is ignored\n");
@@ -324,18 +331,29 @@ void reprogram_counter(struct kvm_pmc *pmc)
}
if (pmc->current_config == new_config && pmc_resume_counter(pmc))
- return;
+ goto reprogram_complete;
pmc_release_perf_event(pmc);
pmc->current_config = new_config;
- pmc_reprogram_counter(pmc, PERF_TYPE_RAW,
- (eventsel & pmu->raw_event_mask),
- !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
- !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
- eventsel & ARCH_PERFMON_EVENTSEL_INT);
+
+ /*
+ * If reprogramming fails, e.g. due to contention, leave the counter's
+ * regprogram bit set, i.e. opportunistically try again on the next PMU
+ * refresh. Don't make a new request as doing so can stall the guest
+ * if reprogramming repeatedly fails.
+ */
+ if (pmc_reprogram_counter(pmc, PERF_TYPE_RAW,
+ (eventsel & pmu->raw_event_mask),
+ !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
+ !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
+ eventsel & ARCH_PERFMON_EVENTSEL_INT))
+ return;
+
+reprogram_complete:
+ clear_bit(pmc->idx, (unsigned long *)&pmc_to_pmu(pmc)->reprogram_pmi);
+ pmc->prev_counter = 0;
}
-EXPORT_SYMBOL_GPL(reprogram_counter);
void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
{
@@ -345,10 +363,11 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
for_each_set_bit(bit, pmu->reprogram_pmi, X86_PMC_IDX_MAX) {
struct kvm_pmc *pmc = static_call(kvm_x86_pmu_pmc_idx_to_pmc)(pmu, bit);
- if (unlikely(!pmc || !pmc->perf_event)) {
+ if (unlikely(!pmc)) {
clear_bit(bit, pmu->reprogram_pmi);
continue;
}
+
reprogram_counter(pmc);
}
@@ -522,14 +541,9 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
static void kvm_pmu_incr_counter(struct kvm_pmc *pmc)
{
- u64 prev_count;
-
- prev_count = pmc->counter;
+ pmc->prev_counter = pmc->counter;
pmc->counter = (pmc->counter + 1) & pmc_bitmask(pmc);
-
- reprogram_counter(pmc);
- if (pmc->counter < prev_count)
- __kvm_perf_overflow(pmc, false);
+ kvm_pmu_request_counter_reprogam(pmc);
}
static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
@@ -542,12 +556,15 @@ static inline bool eventsel_match_perf_hw_id(struct kvm_pmc *pmc,
static inline bool cpl_is_matched(struct kvm_pmc *pmc)
{
bool select_os, select_user;
- u64 config = pmc->current_config;
+ u64 config;
if (pmc_is_gp(pmc)) {
+ config = pmc->eventsel;
select_os = config & ARCH_PERFMON_EVENTSEL_OS;
select_user = config & ARCH_PERFMON_EVENTSEL_USR;
} else {
+ config = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl,
+ pmc->idx - INTEL_PMC_IDX_FIXED);
select_os = config & 0x1;
select_user = config & 0x2;
}
@@ -577,6 +594,8 @@ EXPORT_SYMBOL_GPL(kvm_pmu_trigger_event);
int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp)
{
struct kvm_pmu_event_filter tmp, *filter;
+ struct kvm_vcpu *vcpu;
+ unsigned long i;
size_t size;
int r;
@@ -613,9 +632,18 @@ int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp)
mutex_lock(&kvm->lock);
filter = rcu_replace_pointer(kvm->arch.pmu_event_filter, filter,
mutex_is_locked(&kvm->lock));
+ synchronize_srcu_expedited(&kvm->srcu);
+
+ BUILD_BUG_ON(sizeof(((struct kvm_pmu *)0)->reprogram_pmi) >
+ sizeof(((struct kvm_pmu *)0)->__reprogram_pmi));
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ atomic64_set(&vcpu_to_pmu(vcpu)->__reprogram_pmi, -1ull);
+
+ kvm_make_all_cpus_request(kvm, KVM_REQ_PMU);
+
mutex_unlock(&kvm->lock);
- synchronize_srcu_expedited(&kvm->srcu);
r = 0;
cleanup:
kfree(filter);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 21:15:14 +0000