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From: Like Xu <like.xu.linux@gmail.com>
To: Paolo Bonzini <pbonzini@redhat.com>, Jim Mattson <jmattson@google.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Joerg Roedel <joro@8bytes.org>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Like Xu <likexu@tencent.com>
Subject: [PATCH v3 03/11] KVM: x86/pmu: Protect kvm->arch.pmu_event_filter with SRCU
Date: Mon, 11 Apr 2022 17:35:29 +0800	[thread overview]
Message-ID: <20220411093537.11558-4-likexu@tencent.com> (raw)
In-Reply-To: <20220411093537.11558-1-likexu@tencent.com>

From: Like Xu <likexu@tencent.com>

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@tencent.com>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
---
 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 00436933d13c..adbf07695e1f 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -211,8 +211,9 @@ 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;
 
+	srcu_idx = srcu_read_lock(&kvm->srcu);
 	filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu);
 	if (!filter)
 		goto out;
@@ -235,6 +236,7 @@ static bool check_pmu_event_filter(struct kvm_pmc *pmc)
 	}
 
 out:
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
 	return allow_event;
 }
 
-- 
2.35.1


  parent reply	other threads:[~2022-04-11  9:36 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-11  9:35 [PATCH v3 00/11] KVM: x86/pmu: More refactoring to get rid of PERF_TYPE_HARDWAR Like Xu
2022-04-11  9:35 ` [PATCH v3 01/11] KVM: x86/pmu: Update comments for AMD gp counters Like Xu
2022-04-11  9:35 ` [PATCH v3 02/11] KVM: x86/pmu: Extract check_pmu_event_filter() from the same semantics Like Xu
2022-04-11  9:35 ` Like Xu [this message]
2022-04-11  9:35 ` [PATCH v3 04/11] KVM: x86/pmu: Pass only "struct kvm_pmc *pmc" to reprogram_counter() Like Xu
2022-04-11  9:35 ` [PATCH v3 05/11] KVM: x86/pmu: Drop "u64 eventsel" for reprogram_gp_counter() Like Xu
2022-04-11  9:35 ` [PATCH v3 06/11] KVM: x86/pmu: Drop "u8 ctrl, int idx" for reprogram_fixed_counter() Like Xu
2022-04-11  9:35 ` [PATCH v3 07/11] KVM: x86/pmu: Use only the uniformly exported interface reprogram_counter() Like Xu
2022-04-11  9:35 ` [PATCH v3 08/11] KVM: x86/pmu: Use PERF_TYPE_RAW to merge reprogram_{gp,fixed}counter() Like Xu
2022-04-11  9:35 ` [PATCH v3 09/11] perf: x86/core: Add interface to query perfmon_event_map[] directly Like Xu
2022-04-15  8:25   ` Peter Zijlstra
2022-04-11  9:35 ` [PATCH v3 10/11] KVM: x86/pmu: Replace pmc_perf_hw_id() with perf_get_hw_event_config() Like Xu
2022-04-11  9:35 ` [PATCH v3 11/11] KVM: x86/pmu: Drop amd_event_mapping[] in the KVM context Like Xu
2022-04-27 15:02 ` [PATCH v3 00/11] KVM: x86/pmu: More refactoring to get rid of PERF_TYPE_HARDWAR Like Xu

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