From: Like Xu <likexu@xxxxxxxxxxx>
Similar to "kvm->arch.msr_filter", KVM should guarantee that vCPUs will
see either the previous filter or the new filter when user space calls
KVM_SET_PMU_EVENT_FILTER ioctl with the vCPU running so that guest
pmu events with identical settings in both the old and new filter have
deterministic behavior.
Fixes: 66bb8a065f5a ("KVM: x86: PMU Event Filter")
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Reviewed-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
---
arch/x86/kvm/pmu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 40a6e778b3d9..84f0fcbba820 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -183,11 +183,12 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc)
struct kvm *kvm = pmc->vcpu->kvm;
bool allow_event = true;
__u64 key;
- int idx;
+ int idx, srcu_idx;
if (kvm_x86_ops.pmu_ops->hw_event_is_unavail(pmc))
return false;
+ srcu_idx = srcu_read_lock(&kvm->srcu);
filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
if (!filter)
goto out;
@@ -210,6 +211,7 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc)
}
out:
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
return allow_event;
}
--
2.35.0
