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 D1229C19F37 for ; Sat, 28 Aug 2021 00:37:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAB8460FD9 for ; Sat, 28 Aug 2021 00:37:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233030AbhH1Ah7 (ORCPT ); Fri, 27 Aug 2021 20:37:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232929AbhH1Ahi (ORCPT ); Fri, 27 Aug 2021 20:37:38 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A93ADC061292 for ; Fri, 27 Aug 2021 17:36:46 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id r15-20020a056902154f00b00598b87f197cso96774ybu.13 for ; Fri, 27 Aug 2021 17:36:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=ZqLtQecZGSWC4AA1MNUminuBnJfUTZ97werLGL77udw=; b=W7YW+zmYlqt7RZocpxt+Zt9pY0UpoY2KAKci8cZwj6B9FcylXpzGzQs460J2eCLeO7 teq3g48IMVj8VY2IbRoULnBfpkow62kQ4WR9lSbT6+S3/VfO1mprPaUeR/TGh9eLXRlv Lc3Rfpl3D1r7APNREe18xnEdMpPT4WiL/4dbHUEcReZ3q/7v2SIOWBkUSbCpfx5nigei 7+ogWXDBydp9r/EwqpMZCW2iShx49w75B8rV8caRVnqX3Ryr6RI6XSvcak0ct7nIrRDY DLc6aNoMH3Xu51qkT4HMU2d6imm3Ju+neyD/xf4o05nAqKv3vaT7w7RaHNmHBwGJNnFa GvhQ== X-Google-DKIM-Signature: v=1; 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=ZqLtQecZGSWC4AA1MNUminuBnJfUTZ97werLGL77udw=; b=Xo+KW6V7SItBeLTKA3qZYivHmrARdGQBpvpHqzb0SkCl6cpzTTRS+ZL6lCIQN1A3lT TethR2tSkJCa1Z6PrkLB0cm0P3c65ZMDbC7EjkzrBrB1mrKjIXG7lEXn4mHmqiKBrnde VBSd4cJrH+Hp/b7jnmylghL/UXOMQ+R7saJO2zFQnJ0sj50Yuh9JXdjmqLm6qKDDghv+ 2UjAhmcJlvm9TwP8LCyEs5Lccc2RZGjKVpRR+ooFk9thmTe3ID7pmuLx7inqKq5DXP7+ ckpX5fwvfWWBJOT9E0kaLwiUvBuKCLw/8n05Wu/sTMhBKx30/M8hQoNean5gJOIQQa/9 4zEw== X-Gm-Message-State: AOAM531mTY3a5tYeqAodxZMiMhZQPFmZUvy0wY9KHYhWHjUnx7F8JPdY BHWXd89v7dt1nt0jN1jVwDgrig4GdPw= X-Google-Smtp-Source: ABdhPJypKVd0cLFh8EuRLmmqpexQyXCav+rSvE30xuwBhSiRSkaWIzvoFPoqFTfkE5i16U7H5ekOzDpkr2E= X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:90:200:f66c:b851:7e79:7ed4]) (user=seanjc job=sendgmr) by 2002:a25:f503:: with SMTP id a3mr8148726ybe.501.1630111005865; Fri, 27 Aug 2021 17:36:45 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 27 Aug 2021 17:35:54 -0700 In-Reply-To: <20210828003558.713983-1-seanjc@google.com> Message-Id: <20210828003558.713983-10-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 09/13] 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 , 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 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 6df300c55461..1427ac1fc1f2 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) -- 2.33.0.259.gc128427fd7-goog