1 files changed, 20 insertions, 0 deletions

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index f291d4ac3519..8731dfeced8b 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -8,6 +8,7 @@
 #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>
@@ -442,8 +443,25 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
                                   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);
 
@@ -451,6 +469,8 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
                 kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
                 kvm_vcpu_kick(vcpu);
         }
+
+        cpu_pmu->pmu.start(perf_event, PERF_EF_RELOAD);
 }
 
 /**