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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61F51C10DC1 for ; Mon, 4 Dec 2023 16:46:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229887AbjLDQqk (ORCPT ); Mon, 4 Dec 2023 11:46:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234862AbjLDPzl (ORCPT ); Mon, 4 Dec 2023 10:55:41 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B250C6 for ; Mon, 4 Dec 2023 07:55:48 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id d9443c01a7336-1d03cf821e3so17851605ad.3 for ; Mon, 04 Dec 2023 07:55:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701705347; x=1702310147; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=cecZouhBWGt/EiQ/BWaOcGVIY9+Efnff7UOIt4tvjVY=; b=gQpqaiFZvwjF5lML5pOBG3hzEY5fPSxeti7yiKg9RP4QeNItmvK+wMfwJ8dnlxdMm4 lz61qnxgsmQQwHxncM+OOyIrv7q5ofLHdANnTuQbN4sWX+ErSan+80V6DIl/mqD/AKYo zHoIxnLNdt2397TO4q5zz/vFhQ5NKJMJJu1IZmcRad7G6rSoQUb9Y7YcZsfvj+jHxxQi PnhZPv42js7jfdw8yqtuy6p0qWg5lZE41MMh2rHy6XuOFu0M+7u1nPmue74ESu7PB/gc i13t4eCMGbC9MI0lqf3kq6i0wP0GmRKDVkrujF8iJM6E1zWPC9EafLQhj7uIMPom5rm6 7pjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701705347; x=1702310147; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cecZouhBWGt/EiQ/BWaOcGVIY9+Efnff7UOIt4tvjVY=; b=VhVvqb/b1tCh4pX40Wqynr3qrS24SrpyBuXxonNfOXEutv6WK8KlNrU5vxHwouglO8 2Coo1u7kKzFXpjXpjDQtCguYd+g6+7JnhwOECubF3Zzz4kz4fMUNnT2pLxHJk1EbRw5M JDKP788BH2SDBp4ZvW3n3GjGBwV0jva0+VMWODP3hAmXB75avW7ZXtLGK/u9nfzEzxO1 dMl1zVNkVhpJm31QTWMsKkp4lfjLTWfEeTcVvk3Jm6CLm+WNMNSr1bDAUPXqYuIiHbtW Dvd9gRnncQ/PgDR5bDjs2Q/y9wpKpJMAHj3mw+KgxcdyX8fJON2Ejx5D6e3DXsz0u3ay 19Fw== X-Gm-Message-State: AOJu0Yw+hpwcto0R7VPs9tTdDVK5Td9vMP9MjODU0CIOwAIT6zDi9lWW pQ60/kkhoPgsDzRU4glI8BwH47UFjaQ= X-Google-Smtp-Source: AGHT+IHT4+rKE00OMxlkVtbzFGfm42rAMwZxQGGjiqdlMrT/HQOS0qnitbvkIE3fzrfrjz38aunT4qZzoAA= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:903:2581:b0:1d0:737b:2850 with SMTP id jb1-20020a170903258100b001d0737b2850mr129810plb.11.1701705347469; Mon, 04 Dec 2023 07:55:47 -0800 (PST) Date: Mon, 4 Dec 2023 07:55:45 -0800 In-Reply-To: <20231204074535.9567-1-likexu@tencent.com> Mime-Version: 1.0 References: <20231204074535.9567-1-likexu@tencent.com> Message-ID: Subject: Re: [PATCH] KVM: x86/intr: Explicitly check NMI from guest to eliminate false positives From: Sean Christopherson To: Like Xu Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 04, 2023, Like Xu wrote: > From: Like Xu > > Explicitly checking the source of external interrupt is indeed NMI and not > other types in the kvm_arch_pmi_in_guest(), which prevents perf-kvm false > positive samples generated after vm-exit but before kvm_before_interrupt() > from being incorrectly labelled as guest samples: ... > Fixes: 73cd107b9685 ("KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable") The behavior is deliberate, and was added by commit dd60d217062f ("KVM: x86: Fix perf timer mode IP reporting"). *If* we want to undo that, then the best "fix" would be to effective reverting that commit by dropping the IRQ usage of kvm_before_interrupt() and renaming the helpers kvm_{before,after}_nmi(). But my understanding is that the behavior is necessary for select PMU usage.