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Peter Anvin" , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Stefano Stabellini , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-csky@vger.kernel.org, linux-riscv@lists.infradead.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org, Artem Kashkanov , Like Xu , Zhu Lingshan X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210827_173645_340544_C2EA2C75 X-CRM114-Status: GOOD ( 20.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Use the generic kvm_running_vcpu plus a new 'handling_intr_from_guest' variable in kvm_arch_vcpu instead of the semi-redundant current_vcpu. kvm_before/after_interrupt() must be called while the vCPU is loaded, (which protects against preemption), thus kvm_running_vcpu is guaranteed to be non-NULL when handling_intr_from_guest is non-zero. Switching to kvm_get_running_vcpu() will allows moving KVM's perf callbacks to generic code, and the new flag will be used in a future patch to more precisely identify the "NMI from guest" case. Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 3 +-- arch/x86/kvm/pmu.c | 2 +- arch/x86/kvm/x86.c | 21 ++++++++++++--------- arch/x86/kvm/x86.h | 10 ++++++---- 4 files changed, 20 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1080166fc0cf..2d86a2dfc775 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -763,6 +763,7 @@ struct kvm_vcpu_arch { unsigned nmi_pending; /* NMI queued after currently running handler */ bool nmi_injected; /* Trying to inject an NMI this entry */ bool smi_pending; /* SMI queued after currently running handler */ + u8 handling_intr_from_guest; struct kvm_mtrr mtrr_state; u64 pat; @@ -1874,8 +1875,6 @@ int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu); int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err); void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu); -unsigned int kvm_guest_state(void); - void __user *__x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size); bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 5b68d4188de0..eef48258e50f 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -87,7 +87,7 @@ static void kvm_perf_overflow_intr(struct perf_event *perf_event, * woken up. So we should wake it, but this is impossible from * NMI context. Do it from irq work instead. */ - if (!kvm_guest_state()) + if (!kvm_handling_nmi_from_guest(pmc->vcpu)) irq_work_queue(&pmc_to_pmu(pmc)->irq_work); else kvm_make_request(KVM_REQ_PMI, pmc->vcpu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b2a4d085aa4f..6df300c55461 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8264,15 +8264,17 @@ static void kvm_timer_init(void) kvmclock_cpu_online, kvmclock_cpu_down_prep); } -DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu); -EXPORT_PER_CPU_SYMBOL_GPL(current_vcpu); +static inline bool kvm_pmi_in_guest(struct kvm_vcpu *vcpu) +{ + return vcpu && vcpu->arch.handling_intr_from_guest; +} -unsigned int kvm_guest_state(void) +static unsigned int kvm_guest_state(void) { - struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); unsigned int state; - if (!vcpu) + if (!kvm_pmi_in_guest(vcpu)) return 0; state = PERF_GUEST_ACTIVE; @@ -8284,9 +8286,10 @@ unsigned int kvm_guest_state(void) static unsigned long kvm_guest_get_ip(void) { - struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); - if (WARN_ON_ONCE(!vcpu)) + /* Retrieving the IP must be guarded by a call to kvm_guest_state(). */ + if (WARN_ON_ONCE(!kvm_pmi_in_guest(vcpu))) return 0; return kvm_rip_read(vcpu); @@ -8294,10 +8297,10 @@ static unsigned long kvm_guest_get_ip(void) static unsigned int kvm_handle_intel_pt_intr(void) { - struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); /* '0' on failure so that the !PT case can use a RET0 static call. */ - if (!vcpu) + if (!kvm_pmi_in_guest(vcpu)) return 0; kvm_make_request(KVM_REQ_PMI, vcpu); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 7d66d63dc55a..a9c107e7c907 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -387,18 +387,20 @@ static inline bool kvm_cstate_in_guest(struct kvm *kvm) return kvm->arch.cstate_in_guest; } -DECLARE_PER_CPU(struct kvm_vcpu *, current_vcpu); - static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu) { - __this_cpu_write(current_vcpu, vcpu); + WRITE_ONCE(vcpu->arch.handling_intr_from_guest, 1); } static inline void kvm_after_interrupt(struct kvm_vcpu *vcpu) { - __this_cpu_write(current_vcpu, NULL); + WRITE_ONCE(vcpu->arch.handling_intr_from_guest, 0); } +static inline bool kvm_handling_nmi_from_guest(struct kvm_vcpu *vcpu) +{ + return !!vcpu->arch.handling_intr_from_guest; +} static inline bool kvm_pat_valid(u64 data) {