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=-8.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 74AB7C433F5 for ; Wed, 22 Sep 2021 12:40:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C1786124A for ; Wed, 22 Sep 2021 12:40:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236020AbhIVMmV (ORCPT ); Wed, 22 Sep 2021 08:42:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23800 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236016AbhIVMmU (ORCPT ); Wed, 22 Sep 2021 08:42:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632314450; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oc3Q6F9LHhQ/23Lb3iu0juJPgymyqAuk3iNqpXm8I68=; b=WMuSRZg76k7QJXy8JAFEj+j80Kj1OqdXeMOYe9KnQmrDzN4BB/swrxn5Og0t62INZWrHAI E044MBgehzque42zOYynLDRAxDz43QZ/ZvwpuE0MYpzerXAN9eBFPAtC/CgTyRH2Q2RRIM MKRgEztYoBHGOxcTCAsDOmN4DJdo7c8= Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-533-msUeEGjUM5ePQ5feMfzsTw-1; Wed, 22 Sep 2021 08:40:49 -0400 X-MC-Unique: msUeEGjUM5ePQ5feMfzsTw-1 Received: by mail-ed1-f71.google.com with SMTP id m30-20020a50999e000000b003cdd7680c8cso2911710edb.11 for ; Wed, 22 Sep 2021 05:40:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=oc3Q6F9LHhQ/23Lb3iu0juJPgymyqAuk3iNqpXm8I68=; b=UT5Yog4/OvHYL6g8CdlKFFsyfo+9TjxKgn6rDCvP2mwDOX+pLfwqC/tk89iWa1hRlr +AI6x7OMBPQ7TlcjMJXNEtkYm3Bs5Rvo4IOfdSoKwizTori8j64BpwaYYWI0x1NYCguk vLOqBMg1udKCA/Qc7x75y3w0iMLMG3y4uugj+yKswM1Wg9lDpzz89A/4ICxJrC5hGIB+ F55b6zRwo8oKkyR1ysOuiMs4sAkM8NkCJqReQziYU5+Or/87eM/5If1BOwTv1KOxZ/yZ 1EH1S9cG9Jy5YVKi6t4CiBNiW9txP5tbFqrDZBbUNJvNvJTxQBY8MDI4xjuwK0ZQQMmS lROQ== X-Gm-Message-State: AOAM530k+OBsl+RDtrCU3Q7jAluGXyLemvjsSVwhEbmq8CV8dEjxLRQL b+c1nYjSaz/BWyqm9oiBAURAreFY8+PqXJdIBp+PZfR1iTYsuJq+1LpCSpFEkLwpvWBQrKV3NZ8 x7Hknor7hYjftWsk7iINWXibi X-Received: by 2002:a05:6402:2cd:: with SMTP id b13mr41840756edx.267.1632314448403; Wed, 22 Sep 2021 05:40:48 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyPcohitOYlJxmH82gHsF/0gv1vncG8Sjcah9w2Y9T/wly4AAteK5LpZI/K7wDkwVrBI+hw0A== X-Received: by 2002:a05:6402:2cd:: with SMTP id b13mr41840730edx.267.1632314448163; Wed, 22 Sep 2021 05:40:48 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id u19sm1173524edv.40.2021.09.22.05.40.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Sep 2021 05:40:47 -0700 (PDT) Subject: Re: [PATCH] KVM: VMX: Check if bus lock vmexit was preempted To: Xiaoyao Li , Hao Xiang , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, chenyi.qiang@intel.com, shannon.zhao@linux.alibaba.com, Sean Christopherson References: <1631964600-73707-1-git-send-email-hao.xiang@linux.alibaba.com> <87b411c3-da75-e074-91a4-a73891f9f5f8@redhat.com> <57597778-836c-7bac-7f1d-bcdae0cd6ac4@intel.com> From: Paolo Bonzini Message-ID: Date: Wed, 22 Sep 2021 14:40:45 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <57597778-836c-7bac-7f1d-bcdae0cd6ac4@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/09/21 12:32, Xiaoyao Li wrote: >> > > EXIT_REASON.bus_lock_detected may or may not be set when exit reason == > EXIT_REASON_BUS_LOCK. Intel will update ISE or SDM to state it. > > Maybe we can do below in handle_bus_lock_vmexit handler: > >     if (!to_vmx(vcpu)->exit_reason.bus_lock_detected) >         to_vmx(vcpu)->exit_reason.bus_lock_detected = 1; > > But is manually changing the hardware reported value for software > purpose a good thing? No. That said, Hao's patch is just making the code clearer; there's no behavioral change since the "if" will just redo the same assignments as handle_bus_lock_vmexit. Paolo