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 BF977ECAAA1 for ; Wed, 31 Aug 2022 00:38:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232341AbiHaAim (ORCPT ); Tue, 30 Aug 2022 20:38:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232013AbiHaAhx (ORCPT ); Tue, 30 Aug 2022 20:37:53 -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 C1502AE232 for ; Tue, 30 Aug 2022 17:36:23 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id e187-20020a6369c4000000b0041c8dfb8447so6289993pgc.23 for ; Tue, 30 Aug 2022 17:36:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc; bh=COtQNDmyFMKiUnG0r6DP8wnDX53zfdZyDRmbDYIlONY=; b=lv67W+znzN/46x7oLehYcakVQyriJLYBfxgch3FDtG3+6DalnO4gEwMnCOeXlh3RsV QL1VXkz2olPy3veCJ8XWGpnGwzQLCt8bKiqiAZQ6pjj0ImImEt0lD+qsuj/KSitJmtrt r+Yq7rr7LFmnXuHZbUAYDmwESgLTHohJHspdlcwms+caDyxgUS2/RgIuiH4VrW0Ry/bM 6PMkkR3Ose6LKPEoEZfmTGpmfkOAO2HmAmLmGUZL2xHfpb4vCJE9eeoAUpuMOLJknLaH Hm6X+HjPjR+JCRhkDKOdrunS5EEPGwg6wzsQN4OIRJYOvPtBDFFkENzCfVWNMs17qam3 nJmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc; bh=COtQNDmyFMKiUnG0r6DP8wnDX53zfdZyDRmbDYIlONY=; b=20G9i8Iwv5QC6mmU5C3p4MQc0hDx8PiLxhl2MAUbJa50bwptaobcphTF1GIn6RNCsA 6+gPpwZyp17QFGh+7ensGrdCrrmmjLPG1GU98B/+q9uHPJaI3iahQQ6eJu3V+8DyFEdo 8eSXNkF3eKS34iPB5SjheUlRJh1QSUE/og4laMiXrXYpjbOcZdWVnopNxFhmB5fIP/R/ /cBREUx5XV6WI4Rm2R+O/GlvLzgBW/V4vkfC3H4LO7ZDF2bmxzDUvFT+1yJMbrbg+Ea7 GpH3ipqWSNtpk+m5kIApsKy1COzGCr9XfqkAj3Z4yYHYtyRunyR5ElJpVEvRAlqrgwKC aSRw== X-Gm-Message-State: ACgBeo3kXL7sVcw8bssHykq+jwY4nqHRkA5/7PIbXG5oH1chBSkD5Bya iSRDDsOhbvtCiV1DLeSD2mlxBfUvsYw= X-Google-Smtp-Source: AA6agR53jSxsmlnw8Vqq0VWR0l6XXD330eDCt8c05joJrhe9CCBHlg9c14qWUc1wmSjGkMR7ljsa45TWru4= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:a19:b0:535:49ee:da43 with SMTP id p25-20020a056a000a1900b0053549eeda43mr23874432pfh.53.1661906139729; Tue, 30 Aug 2022 17:35:39 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 31 Aug 2022 00:35:05 +0000 In-Reply-To: <20220831003506.4117148-1-seanjc@google.com> Mime-Version: 1.0 References: <20220831003506.4117148-1-seanjc@google.com> X-Mailer: git-send-email 2.37.2.672.g94769d06f0-goog Message-ID: <20220831003506.4117148-19-seanjc@google.com> Subject: [PATCH 18/19] KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Suravee Suthikulpanit , Maxim Levitsky , Li RongQing Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Drop writes to APIC_RRR, a.k.a. Remote Read Data Register, on AVIC unaccelerated write traps. The register is read-only and isn't emulated by KVM. Sending the register through kvm_apic_write_nodecode() will result in screaming when x2APIC is enabled due to the unexpected failure to retrieve the MSR (KVM expects that only "legal" accesses will trap). Fixes: 4d1d7942e36a ("KVM: SVM: Introduce logic to (de)activate x2AVIC mode") Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/avic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index dad5affe44c1..b2033a56010c 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -675,6 +675,9 @@ static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu) case APIC_DFR: avic_handle_dfr_update(vcpu); break; + case APIC_RRR: + /* Ignore writes to Read Remote Data, it's read-only. */ + return 1; default: break; } -- 2.37.2.672.g94769d06f0-goog