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 EDAC8C433F5 for ; Sat, 1 Oct 2022 01:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233099AbiJABDp (ORCPT ); Fri, 30 Sep 2022 21:03:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233027AbiJABCr (ORCPT ); Fri, 30 Sep 2022 21:02:47 -0400 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 43E26F03D for ; Fri, 30 Sep 2022 18:00:28 -0700 (PDT) Received: by mail-pl1-x64a.google.com with SMTP id n10-20020a170902e54a00b001782663dcaeso4220178plf.18 for ; Fri, 30 Sep 2022 18:00:27 -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:subject:date; bh=m33xJ9pBizwrUhfQsmYman/PfJNtqiYZN3F07u+sy1s=; b=doAqyYMrLEzGmhnjgT6yRYK7FatZK4uscBSQzAbeNRy6MapfWpyqdXnFh3wypzCsOr TxoqSN1pxXYXVE9ZgnJD2PS/6pdikSa6RhfSwUtCmulZucCneYFMl1EimC0x9U5NfX9F 2wMhWUgqLM1l+jWiTllRy8PRAMLyhps/RW7pbgQ9vhby954awA8PF9MzpzudnSjGXJjy ewti38RQOPTmHgRWxtymWTcb0W2e0d11sAI5rm4DiuQDCMHdrT1N17ltv+HfwTMDsJGA td6n4ndMZwTN2LEnEVXwvtwQKfxUKYAtfBiXtblqS8PsMxGIg/zL85mD54fFctwlWw/t pa/w== 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:subject:date; bh=m33xJ9pBizwrUhfQsmYman/PfJNtqiYZN3F07u+sy1s=; b=TUMwUsaUoWwBEi4PgO7G3liiFyp5+ue++IyJ39uuf6AflC+09C/3tgktyNnySexenI TMCcLN7V2lx195wcjpYLSDumU+StMgkzEQ5B+aB814ZORbc+tbwUBC0Cid5ARmz9+4oQ AD8U+qmW3GhI0sfhvzVhbpYCAHXtIIWRbe5zZjP9BAnpTj6OBlBQZcu+9isTyKBL/K3I 0GEk5eKDeclemzMFdgAlF5pvs+zrRJDwgrKFXjKXgqCGGanZzkAjSID09EB8T2U3QCCA DgZ/z4sVMkw7zAYfCwdidd+VDcW3F+0h5LEAFAlJsq4HF0NUdq3Qer37Cr6SuXNWwO6H zKJw== X-Gm-Message-State: ACrzQf3fwi18LfSlH+yYH5p37kplqCf4viWijqUGW/43+KR193ADocq7 yG2biLo2/hiachY5kPF276fYUc1+J5A= X-Google-Smtp-Source: AMsMyM7UFxKVxA9e+lSlEe4vjVtsXH9VjJy9Tw0FAaHrLe0l+PQMiOkThtLnqVYDU9iOBTic3GqUzGrzkAQ= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90b:1c8e:b0:205:783b:fe32 with SMTP id oo14-20020a17090b1c8e00b00205783bfe32mr1009086pjb.39.1664586009100; Fri, 30 Sep 2022 18:00:09 -0700 (PDT) Reply-To: Sean Christopherson Date: Sat, 1 Oct 2022 00:59:13 +0000 In-Reply-To: <20221001005915.2041642-1-seanjc@google.com> Mime-Version: 1.0 References: <20221001005915.2041642-1-seanjc@google.com> X-Mailer: git-send-email 2.38.0.rc1.362.ged0d419d3c-goog Message-ID: <20221001005915.2041642-31-seanjc@google.com> Subject: [PATCH v4 30/32] 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, Alejandro Jimenez , 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 Reviewed-by: Maxim Levitsky --- 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 17e64b056e4e..953b1fd14b6d 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -631,6 +631,9 @@ 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; } -- 2.38.0.rc1.362.ged0d419d3c-goog