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-rw-r--r--arch/x86/include/asm/kvm_host.h5
-rw-r--r--arch/x86/kvm/pmu.c45
-rw-r--r--arch/x86/kvm/pmu.h12
-rw-r--r--arch/x86/kvm/pmu_amd.c1
-rw-r--r--arch/x86/kvm/vmx/pmu_intel.c2
5 files changed, 61 insertions, 4 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6f6b8886a8eb..a87a6c98adee 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -449,6 +449,11 @@ struct kvm_pmc {
u64 eventsel;
struct perf_event *perf_event;
struct kvm_vcpu *vcpu;
+ /*
+ * eventsel value for general purpose counters,
+ * ctrl value for fixed counters.
+ */
+ u64 current_config;
};
struct kvm_pmu {
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 472b69b3b6c3..99565de5410a 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -138,6 +138,35 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
clear_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
}
+static void pmc_pause_counter(struct kvm_pmc *pmc)
+{
+ u64 counter = pmc->counter;
+
+ if (!pmc->perf_event)
+ return;
+
+ /* update counter, reset event value to avoid redundant accumulation */
+ counter += perf_event_pause(pmc->perf_event, true);
+ pmc->counter = counter & pmc_bitmask(pmc);
+}
+
+static bool pmc_resume_counter(struct kvm_pmc *pmc)
+{
+ if (!pmc->perf_event)
+ return false;
+
+ /* recalibrate sample period and check if it's accepted by perf core */
+ if (perf_event_period(pmc->perf_event,
+ (-pmc->counter) & pmc_bitmask(pmc)))
+ return false;
+
+ /* reuse perf_event to serve as pmc_reprogram_counter() does*/
+ perf_event_enable(pmc->perf_event);
+
+ clear_bit(pmc->idx, (unsigned long *)&pmc_to_pmu(pmc)->reprogram_pmi);
+ return true;
+}
+
void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
{
unsigned config, type = PERF_TYPE_RAW;
@@ -152,7 +181,7 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
pmc->eventsel = eventsel;
- pmc_stop_counter(pmc);
+ pmc_pause_counter(pmc);
if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_is_enabled(pmc))
return;
@@ -191,6 +220,12 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
if (type == PERF_TYPE_RAW)
config = eventsel & X86_RAW_EVENT_MASK;
+ if (pmc->current_config == eventsel && pmc_resume_counter(pmc))
+ return;
+
+ pmc_release_perf_event(pmc);
+
+ pmc->current_config = eventsel;
pmc_reprogram_counter(pmc, type, config,
!(eventsel & ARCH_PERFMON_EVENTSEL_USR),
!(eventsel & ARCH_PERFMON_EVENTSEL_OS),
@@ -207,7 +242,7 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
struct kvm_pmu_event_filter *filter;
struct kvm *kvm = pmc->vcpu->kvm;
- pmc_stop_counter(pmc);
+ pmc_pause_counter(pmc);
if (!en_field || !pmc_is_enabled(pmc))
return;
@@ -222,6 +257,12 @@ void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int idx)
return;
}
+ if (pmc->current_config == (u64)ctrl && pmc_resume_counter(pmc))
+ return;
+
+ pmc_release_perf_event(pmc);
+
+ pmc->current_config = (u64)ctrl;
pmc_reprogram_counter(pmc, PERF_TYPE_HARDWARE,
kvm_x86_ops->pmu_ops->find_fixed_event(idx),
!(en_field & 0x2), /* exclude user */
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index b253dd5e56cf..7eba298587dc 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -56,12 +56,20 @@ static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
return counter & pmc_bitmask(pmc);
}
-static inline void pmc_stop_counter(struct kvm_pmc *pmc)
+static inline void pmc_release_perf_event(struct kvm_pmc *pmc)
{
if (pmc->perf_event) {
- pmc->counter = pmc_read_counter(pmc);
perf_event_release_kernel(pmc->perf_event);
pmc->perf_event = NULL;
+ pmc->current_config = 0;
+ }
+}
+
+static inline void pmc_stop_counter(struct kvm_pmc *pmc)
+{
+ if (pmc->perf_event) {
+ pmc->counter = pmc_read_counter(pmc);
+ pmc_release_perf_event(pmc);
}
}
diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
index e8609ccd0b62..e87d34136047 100644
--- a/arch/x86/kvm/pmu_amd.c
+++ b/arch/x86/kvm/pmu_amd.c
@@ -292,6 +292,7 @@ static void amd_pmu_init(struct kvm_vcpu *vcpu)
pmu->gp_counters[i].type = KVM_PMC_GP;
pmu->gp_counters[i].vcpu = vcpu;
pmu->gp_counters[i].idx = i;
+ pmu->gp_counters[i].current_config = 0;
}
}
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index dcde142327ca..9b1ddc42f604 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -340,12 +340,14 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu)
pmu->gp_counters[i].type = KVM_PMC_GP;
pmu->gp_counters[i].vcpu = vcpu;
pmu->gp_counters[i].idx = i;
+ pmu->gp_counters[i].current_config = 0;
}
for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) {
pmu->fixed_counters[i].type = KVM_PMC_FIXED;
pmu->fixed_counters[i].vcpu = vcpu;
pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
+ pmu->fixed_counters[i].current_config = 0;
}
}