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 59BF9C54EE9 for ; Mon, 19 Sep 2022 07:39:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229766AbiISHjO (ORCPT ); Mon, 19 Sep 2022 03:39:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229577AbiISHjM (ORCPT ); Mon, 19 Sep 2022 03:39:12 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 352A81EAEA; Mon, 19 Sep 2022 00:39:09 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id b75so22021489pfb.7; Mon, 19 Sep 2022 00:39:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date; bh=6BbzpneSCd/fog8Z/llAh0YBRR0NTGGPNcaoP0oTmv8=; b=VOiVHDSbwRDnYIfB5vTjxTI5vzhffyTYBtu46285qGH5XdyYmi9H1r8raFz9isX8H8 WVL8MMC1JJQMBkSv9JxyQts8iUskqIaXL0ycoZjcWjafWH3ykpva81ljhI2v+Ql0VQ/n dJQIhI1ePbYnwermbk/av1N5+6XX0dx/p4Wm0Nq6xQmdMYoLxXdIVSDj2BqU8Q19z1f1 tsTkHHxGZOQA5nBs8D5OIqHld4XC9SKyIVT2hVCm1HClSl5S4mPUzjDWM5eq64aVnVA1 cSd3fBAbmlC97PSar1kcmXmu6+UaOIuhue9kIUteI6qssI4wbJ/Diu1uakyvwrktcVzH dJ/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date; bh=6BbzpneSCd/fog8Z/llAh0YBRR0NTGGPNcaoP0oTmv8=; b=YbbRDEmPCxiFMPwc8keMd/T15w9rzy3jFJvbTh2LiPvER3FuPoa2uoez1EhhcOzKdt 2z+dMk1B4mLuf0b3M7rSSlhhCeyA2prTZ4pH+uw5zSolxQl3Kxvdc9HB5fId4slBITO4 JO+wwAIBfKMpLECaZ6uaRrmaMktDUhoDCLW5p12sitYzKwGGUq59TSY45KhjkAXZDwdp UqACG8wVudxAn1/u89hQWFQBreVqxkXDom20y/pwRJzYz5d/P9f775Egw5wbdjph4hdG F9pvDUoykKxXbGV7ji+yKdAws0bzMzDWNbf1HqY1JzXEonMGx7xQQzdY+hKnmzba2lAJ Mn4g== X-Gm-Message-State: ACrzQf2JvMstCs34afOwaVDgYU+crCbr9FqBkdPutkTl8FzfEGzZmCzQ VED21qA8CBo4/a74iq1A5so= X-Google-Smtp-Source: AMsMyM6VXcd32oAHHS8h4UvkKOe1Ubw+usoTz+8u0qNTPfO0fik9WsVLsHzt4VGQxx6aVKgWQ797Tg== X-Received: by 2002:a65:6042:0:b0:439:2032:225 with SMTP id a2-20020a656042000000b0043920320225mr14325350pgp.469.1663573148841; Mon, 19 Sep 2022 00:39:08 -0700 (PDT) Received: from [192.168.255.10] ([103.7.29.32]) by smtp.gmail.com with ESMTPSA id b26-20020a62a11a000000b00540a3252191sm19541622pff.28.2022.09.19.00.39.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 19 Sep 2022 00:39:08 -0700 (PDT) Message-ID: <2a419402-c9ed-02a4-cdf6-00395fffad47@gmail.com> Date: Mon, 19 Sep 2022 15:38:57 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [RFC PATCH 0/9] kvm: implement atomic memslot updates Content-Language: en-US To: Emanuele Giuseppe Esposito , Sean Christopherson Cc: kvm@vger.kernel.org, Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , David Hildenbrand , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org, Maxim Levitsky , Paolo Bonzini References: <20220909104506.738478-1-eesposit@redhat.com> <5f0345d2-d4d1-f4fe-86ba-6e22561cb6bd@redhat.com> From: Like Xu In-Reply-To: <5f0345d2-d4d1-f4fe-86ba-6e22561cb6bd@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/9/2022 12:13 am, Emanuele Giuseppe Esposito wrote: > > Am 09/09/2022 um 16:30 schrieb Sean Christopherson: >> On Fri, Sep 09, 2022, Emanuele Giuseppe Esposito wrote: >>> KVM is currently capable of receiving a single memslot update through >>> the KVM_SET_USER_MEMORY_REGION ioctl. >>> The problem arises when we want to atomically perform multiple updates, >>> so that readers of memslot active list avoid seeing incomplete states. >>> >>> For example, in RHBZhttps://bugzilla.redhat.com/show_bug.cgi?id=1979276 Oh, thanks for stepping up to try to address it. As it turns out, this issue was discovered "long" before https://bugzilla.kernel.org/show_bug.cgi?id=213781 As a comment, relevant selftests are necessary and required.