From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF24CC433EF for ; Wed, 22 Sep 2021 00:06:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A433E61159 for ; Wed, 22 Sep 2021 00:06:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231635AbhIVAIX (ORCPT ); Tue, 21 Sep 2021 20:08:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231629AbhIVAHx (ORCPT ); Tue, 21 Sep 2021 20:07:53 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 225AEC0613E7 for ; Tue, 21 Sep 2021 17:06:08 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id z6-20020a056214060600b0037a3f6bd9abso8395113qvw.3 for ; Tue, 21 Sep 2021 17:06:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=QkPwm3zvrM5/6qTUHoNNLSAbgPAl2i0gmFlu0epOg4o=; b=d1KD92GmsPFOnc9Voj9I1ga0GeAS7/A1M3Ff0hwfVHHw2F6NmCxAZ84UfNg13BcPCi lG4uDVWzzMX9YcA/y1gf96xoTBNuPhAlxwTx2TA/MtTqi0CKnLCaTn1XKcjET/qIHw/W PFtn2f+5xRKyIIgk8E1s1kBonYCZbxSjMNPx2Pcoaxli0kTn68s/Bp75u+cWhB/zdDT2 joJ0rxsuthSJgBA//ri2dU4acF1OCR0lq3uBlgPA2WynVs0lVsjJioXNEExBFYXBNxT3 Bx/JzoAA/ewtVFiSqKGlN2hvDgXry2asA82RE64+sST1QDa4vg0dMxQ7kXfb5GF5+5GY /rGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=QkPwm3zvrM5/6qTUHoNNLSAbgPAl2i0gmFlu0epOg4o=; b=aypxCy1QoaL8gygpzsjrkPBmpKNrgPJTtymbZwu/F+p+ndL8mFPMtaOBO2G1d222h8 xtfePeBFVphI/2QPkwIpq0ACeRoG5wFUE5Z4C5THIyQyfEMZMavyYuJCsOHlN/Pp2m3q fdzWFu12xmeNeUuzHxY8gZVPKOMtdowXrxFEUJWJ92YYAztiJyhypK5v7E8J+KPAiO4V zX2Lt+/t98DU4p1sAjT53xBE9qgCsmCf41O0cq0MNZGVo35hqEhK7U9cKeJsLBs5bluN b6CeWiWPDe3h0rtbuyC1iocHnO4+nFSFoA4RtRFgufAAH/ydlaRMfxmkcP+IteXSSY30 Zh6A== X-Gm-Message-State: AOAM532FkSIDqzGy3T1/21+3cw2xQ81pr8girZvbo0GPbHPYwV218NgH Q2GH5UrhBoGM9kjNaYj/0Y7DsJ1rm2A= X-Google-Smtp-Source: ABdhPJwFZxN2Kv1ibh5ZHwIVIA/ukWkfcwWerZdycqHkme9lr0IiGpVtUFqWcbWB5ZsvLCpW/DgRz3yzrYw= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:b022:92d6:d37b:686c]) (user=seanjc job=sendgmr) by 2002:ad4:4a93:: with SMTP id h19mr34366283qvx.41.1632269167312; Tue, 21 Sep 2021 17:06:07 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 21 Sep 2021 17:05:28 -0700 In-Reply-To: <20210922000533.713300-1-seanjc@google.com> Message-Id: <20210922000533.713300-12-seanjc@google.com> Mime-Version: 1.0 References: <20210922000533.713300-1-seanjc@google.com> X-Mailer: git-send-email 2.33.0.464.g1972c5931b-goog Subject: [PATCH v3 11/16] KVM: x86: More precisely identify NMI from guest when handling PMI From: Sean Christopherson To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Will Deacon , Mark Rutland , Marc Zyngier , Guo Ren , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Paolo Bonzini , Boris Ostrovsky , Juergen Gross Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , James Morse , Alexandru Elisei , Suzuki K Poulose , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Stefano Stabellini , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Differntiate between IRQ and NMI for KVM's PMC overflow callback, which was originally invoked in response to an NMI that arrived while the guest was running, but was inadvertantly changed to fire on IRQs as well when support for perf without PMU/NMI was added to KVM. In practice, this should be a nop as the PMC overflow callback shouldn't be reached, but it's a cheap and easy fix that also better documents the situation. Note, this also doesn't completely prevent false positives if perf somehow ends up calling into KVM, e.g. an NMI can arrive in host after KVM sets its flag. Fixes: dd60d217062f ("KVM: x86: Fix perf timer mode IP reporting") Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/svm.c | 2 +- arch/x86/kvm/vmx/vmx.c | 4 +++- arch/x86/kvm/x86.c | 2 +- arch/x86/kvm/x86.h | 13 ++++++++++--- 4 files changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1a70e11f0487..0a0c01744b63 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3843,7 +3843,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) } if (unlikely(svm->vmcb->control.exit_code == SVM_EXIT_NMI)) - kvm_before_interrupt(vcpu); + kvm_before_interrupt(vcpu, KVM_HANDLING_NMI); kvm_load_host_xsave_state(vcpu); stgi(); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index f19d72136f77..61a4f5ff2acd 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6344,7 +6344,9 @@ void vmx_do_interrupt_nmi_irqoff(unsigned long entry); static void handle_interrupt_nmi_irqoff(struct kvm_vcpu *vcpu, unsigned long entry) { - kvm_before_interrupt(vcpu); + bool is_nmi = entry == (unsigned long)asm_exc_nmi_noist; + + kvm_before_interrupt(vcpu, is_nmi ? KVM_HANDLING_NMI : KVM_HANDLING_IRQ); vmx_do_interrupt_nmi_irqoff(entry); kvm_after_interrupt(vcpu); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 24a6faa07442..412646b973bb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9676,7 +9676,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) * interrupts on processors that implement an interrupt shadow, the * stat.exits increment will do nicely. */ - kvm_before_interrupt(vcpu); + kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ); local_irq_enable(); ++vcpu->stat.exits; local_irq_disable(); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index a9c107e7c907..9b26f9b09d2a 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -387,9 +387,16 @@ static inline bool kvm_cstate_in_guest(struct kvm *kvm) return kvm->arch.cstate_in_guest; } -static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu) +enum kvm_intr_type { + /* Values are arbitrary, but must be non-zero. */ + KVM_HANDLING_IRQ = 1, + KVM_HANDLING_NMI, +}; + +static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu, + enum kvm_intr_type intr) { - WRITE_ONCE(vcpu->arch.handling_intr_from_guest, 1); + WRITE_ONCE(vcpu->arch.handling_intr_from_guest, (u8)intr); } static inline void kvm_after_interrupt(struct kvm_vcpu *vcpu) @@ -399,7 +406,7 @@ static inline void kvm_after_interrupt(struct kvm_vcpu *vcpu) static inline bool kvm_handling_nmi_from_guest(struct kvm_vcpu *vcpu) { - return !!vcpu->arch.handling_intr_from_guest; + return vcpu->arch.handling_intr_from_guest == KVM_HANDLING_NMI; } static inline bool kvm_pat_valid(u64 data) -- 2.33.0.464.g1972c5931b-goog