linux-kernel - [PATCH v1 8/8] KVM/x86/vPMU: return the counters to host if guest is torn down

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Date:   Thu,  1 Nov 2018 18:04:08 +0800
From:   Wei Wang <wei.w.wang@...el.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        pbonzini@...hat.com, ak@...ux.intel.com, peterz@...radead.org
Cc:     mingo@...hat.com, rkrcmar@...hat.com, like.xu@...el.com,
        wei.w.wang@...el.com
Subject: [PATCH v1 8/8] KVM/x86/vPMU: return the counters to host if guest is torn down

Return the assigned counters to host in the case the guest is torn down
unexpectedly.

Signed-off-by: Wei Wang <wei.w.wang@...el.com>
Cc: Andi Kleen <ak@...ux.intel.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
---
 arch/x86/kvm/pmu_intel.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
index 9eb5230..30fa8eb 100644
--- a/arch/x86/kvm/pmu_intel.c
+++ b/arch/x86/kvm/pmu_intel.c
@@ -410,7 +410,7 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 	struct kvm_pmc *pmc;
-	int i;
+	u32 i, bit;
 
 	for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 		pmc = &pmu->gp_counters[i];
@@ -422,6 +422,10 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 		pmc->counter = 0;
 	}
 
+	for_each_set_bit(bit, (unsigned long *)&pmu->assigned_pmc_bitmap,
+			 X86_PMC_IDX_MAX)
+		intel_pmu_put_pmc(pmu, bit);
+
 	pmu->fixed_ctr_ctrl = 0;
 	pmu->global_ctrl = 0;
 	pmu->global_status = 0;
-- 
2.7.4