From nobody Thu Feb 12 02:43:21 2026 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 85FE8C77B78 for ; Wed, 3 May 2023 18:29:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229970AbjECS3X (ORCPT ); Wed, 3 May 2023 14:29:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230096AbjECS3N (ORCPT ); Wed, 3 May 2023 14:29:13 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 767E47DAA for ; Wed, 3 May 2023 11:29:05 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id 41be03b00d2f7-51f10bda596so2392217a12.1 for ; Wed, 03 May 2023 11:29:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683138545; x=1685730545; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=+XG9Kzlllq+ti/90Z+KsBtO7J9NFYimJbVN3QRxLOvk=; b=X29uNydOzy9esvjDZDAzmyJGWiaC/8bpqbk2Hn15itn/w45LOQd8JmRA/zpwjar7/G zCfOqNS1PuER3kG90LJ6+faebHsfrBZgI3Gsk9OaOkOjzz+YCncaAaFKFeTjGucnaL82 uV7amdMIE8zdLVIe+qP+XpQmBGhhs/EAOzrLAGU80Lo+kOudelqPKzbSbQ0oQyHVyBMa g50Ev7JfwzCubGHAIE+UmozkyzUX0bVgS5oags8b6FO52NSnPSqiB4IVtTSmtj6QDYHg smF9mSD6ucU4qYrBtDkwQqJSfLnkmTSjv+y/jwtO8cHVaC2OS6dmMMoRczVPyJn910iP gUIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683138545; x=1685730545; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=+XG9Kzlllq+ti/90Z+KsBtO7J9NFYimJbVN3QRxLOvk=; b=OhzirQdsgOoNgJnJDx/lvZuY84X6myN2HB2J8DJCg8jqEVO/oJq0mtKbBnmPl1KSCK hHERbxET+YyBUWI5P5GDg799IukdENzIiTkmflHChOXNdkIsN3hD6H213E2xoVyAWoT8 KGt3w1z7E3dXrVtfJu+chEWoNI+Q1eTiIkRAF5fPY6x0SGU+LEfDfflUb8as/JxRG/+J VQ7WQ0SkEy0oM6phjqsh/pcFGMnJE+HBdkom9xR7saVevSij+W7DB2gDikp0gGLBRUp+ 95Llf/+hIVBRrr5lPSr9B4k9+RBAIPehZ4o0+5RWgxHpZQxHyL8GXwEq66CU+KFbPlG+ 13oA== X-Gm-Message-State: AC+VfDwZ0RPjezaCuVQtuJZrn56Tj+t90WtNHRNXsArBxgEQ2p6K2ia5 5Dxy/lageqn4MSjN6XcpTgt0UYhu79o= X-Google-Smtp-Source: ACHHUZ4g8LojGEmZCmmMffo7tSPFux1H2U6OuRHLfTAyx56VmnpckmGnA7nYKNUzNHB30VgOIXF/ETeNQoc= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a63:8142:0:b0:520:53db:fbf with SMTP id t63-20020a638142000000b0052053db0fbfmr760255pgd.6.1683138545003; Wed, 03 May 2023 11:29:05 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 3 May 2023 11:28:51 -0700 In-Reply-To: <20230503182852.3431281-1-seanjc@google.com> Mime-Version: 1.0 References: <20230503182852.3431281-1-seanjc@google.com> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog Message-ID: <20230503182852.3431281-5-seanjc@google.com> Subject: [PATCH 4/5] KVM: x86: WARN if writes to PAT MSR are handled by common KVM code From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Wenyao Hai , Ke Guo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" WARN and continue if a write to the PAT MSR reaches kvm_set_msr_common() now that both VMX and SVM handle PAT writes entirely on their own. Keep the case statement with a WARN instead of dropping it entirely to document why KVM's handling of reads and writes isn't symmetrical (reads are still handled by kvm_get_msr_common(). Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8b356c9d8a81..c36256d00250 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3701,6 +3701,12 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct= msr_data *msr_info) } break; case MSR_IA32_CR_PAT: + /* + * Writes to PAT should be handled by vendor code as both SVM + * and VMX track the guest's PAT in the VMCB/VMCS. + */ + WARN_ON_ONCE(1); + fallthrough; case MTRRphysBase_MSR(0) ... MSR_MTRRfix4K_F8000: case MSR_MTRRdefType: return kvm_mtrr_set_msr(vcpu, msr, data); --=20 2.40.1.495.gc816e09b53d-goog