diff options
| author | Like Xu <likexu@tencent.com> | 2022-09-23 00:13:54 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-11-09 12:31:36 -0500 |
| commit | 68fb4757e8678894530ee0b15c29a3567207b970 (patch) | |
| tree | 711ba4357bd7d0f1fa7266f7ca36ca1820a3205e /arch/x86/kvm/svm/pmu.c | |
| parent | dcbb816a2842e41d3ec22605c6760837d800b20a (diff) | |
| download | lwn-68fb4757e8678894530ee0b15c29a3567207b970.tar.gz lwn-68fb4757e8678894530ee0b15c29a3567207b970.zip | |
KVM: x86/pmu: Defer reprogram_counter() to kvm_pmu_handle_event()
Batch reprogramming PMU counters by setting KVM_REQ_PMU and thus
deferring reprogramming kvm_pmu_handle_event() to avoid reprogramming
a counter multiple times during a single VM-Exit.
Deferring programming will also allow KVM to fix a bug where immediately
reprogramming a counter can result in sleeping (taking a mutex) while
interrupts are disabled in the VM-Exit fastpath.
Introduce kvm_pmu_request_counter_reprogam() to make it obvious that
KVM is _requesting_ a reprogram and not actually doing the reprogram.
Opportunistically refine related comments to avoid misunderstandings.
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20220831085328.45489-5-likexu@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220923001355.3741194-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm/pmu.c')
| -rw-r--r-- | arch/x86/kvm/svm/pmu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 9d65cd095691..c4b322ffdac4 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -159,7 +159,7 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) data &= ~pmu->reserved_bits; if (data != pmc->eventsel) { pmc->eventsel = data; - reprogram_counter(pmc); + kvm_pmu_request_counter_reprogam(pmc); } return 0; } |