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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=DHvdKUJPhOfdwKYi3gDlAxqlqPxsEI3eu21bt3UUIpQ=; b=JTFo0W3HGt5Taf0zWvFmmXZ57uevcWK1cBMM8QQ8LglLApMBm4aGt8T/nE3xmqiMiN xY1UWmUfD3+qDY7Q1f7H2h9tkqyGGpCi1WwKhpRl3QbmiImJmDvK8CCZea1OIrAXLh/j obvzXfePJVl6HrQeQzil2RX1WAiCziPtegr1WZwTSGlWajWx2LPRtxElyiJGUSL/O0FN 6+h8OfDuKJHxA4y+6uk4Qsh6hpxuwp3j7M7wb4cnUtWcy0zhp9oRczRRkX8t+Jj/QTJR X1ThhxZU56tGAExQpkV4WP7tGuO2ISQw1aM8OWuUCFXeqxn49ODq+Lj/2w3SFH+4T/QI hv6g== X-Gm-Message-State: AOAM533vDQkHCXqxUGl9MYMwI4YEGnXzNCmARuDze67t7h3y85fQvX6K iSqPTLgsUlFnwtA2BF8fcGsLWOr4mc8= X-Google-Smtp-Source: ABdhPJwPL5V/RrJYzEwuqQz/lpqtoTngCSsfC6hM7seqpt+XgOfCSrLYZLMKAACl21hF27dX3suwlB0z88Y= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:f66c:b851:7e79:7ed4]) (user=seanjc job=sendgmr) by 2002:ad4:5346:: with SMTP id v6mr12225725qvs.40.1630111003639; Fri, 27 Aug 2021 17:36:43 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 27 Aug 2021 17:35:53 -0700 In-Reply-To: <20210828003558.713983-1-seanjc@google.com> Message-Id: <20210828003558.713983-9-seanjc@google.com> Mime-Version: 1.0 References: <20210828003558.713983-1-seanjc@google.com> X-Mailer: git-send-email 2.33.0.259.gc128427fd7-goog Subject: [PATCH v2 08/13] KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable From: Sean Christopherson To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Will Deacon , Mark Rutland , Catalin Marinas , Marc Zyngier , Guo Ren , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Borislav Petkov , x86@kernel.org, Paolo Bonzini , Boris Ostrovsky , Juergen Gross Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , James Morse , Alexandru Elisei , Suzuki K Poulose , "H. 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 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) {