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 30B85C433EF for ; Fri, 27 May 2022 06:36:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239662AbiE0Gg5 (ORCPT ); Fri, 27 May 2022 02:36:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229561AbiE0Ggz (ORCPT ); Fri, 27 May 2022 02:36:55 -0400 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B3867C166 for ; Thu, 26 May 2022 23:36:54 -0700 (PDT) Received: by mail-pl1-x62a.google.com with SMTP id n8so3369366plh.1 for ; Thu, 26 May 2022 23:36:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=SuokLXZBT769hHza25K/JKzYPz4okNLCTIvug/IPsOQ=; b=w/Dtt17bexhMQfEO6bZdS8g76rcXfd1fCxzoZiPupXvbG6D1PCjYICkTcZoXMchs33 XwQDdljexH8C7HWpuWkcd0aabZDZmfOs37/pSWL2o/Ma2ckuRkSN4tVLxE3BGT8SjmmZ /JHpZM9duuHTTZ/hqxVnt4BMWzchBWwfjfx1TZXxxn3s7cEvgS8S/aWR+aakyvAW8LGi BUHH0av/nN3KGi26NcaMjBdfZ6bmAo2QAxjbYMkVFw675/L/X8gkdLIELP7ZP9Myzhz7 vQ/X1Rz9UX2xuO+xfYfn6QqA/MsysGxlfvyPQco5aSoo19c6jl7B2GTMxIfcgqs9i2YR xeyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=SuokLXZBT769hHza25K/JKzYPz4okNLCTIvug/IPsOQ=; b=se6oU5/Y/3KXFfwtaZSIHnP5MkqIjVNwlJLIbTjHlZcYizRrcomAbk0nrLq1lETqHA RewdVWtua3tDLwtnWk+nOZ09VEVRs+jRpjIJT9UA8UvIMTysz3bSB4fupzNQ700hhiqk nHd0hXUlUrrqBp3Qu66G6vLIhyb19bhzta6LMVRtnQ8XuSZnxvwYigdCZTyKb8mdSMfz 7bxv4PJCH8eBH0EPNMzTGhkuumsOEpZqEWD2K+i5U8ZvXsji1/WFM5i0sMGs8OkjoKod OURNkz6Yfy+eGuOqR2z1w5HZHnyHX7ye5AC4+sKi6nsHzvv1sDd/yf0fWorf1jbJIh56 FHSg== X-Gm-Message-State: AOAM533KWrLHF/EXCeIwvXsNql8qZGWKwALn59Wq+NXdxq5RqnIY1GCe qaPPl4zdChiOzM3nl0Jx0DDjow== X-Google-Smtp-Source: ABdhPJxOPiXIhe6VKd4CALjITeyKD3bUphXadgcUtVKUa901LvCRw8JDURlFy6QfYahvehfnBi6M3g== X-Received: by 2002:a17:90a:bb17:b0:1e0:ab18:4491 with SMTP id u23-20020a17090abb1700b001e0ab184491mr6583871pjr.120.1653633413656; Thu, 26 May 2022 23:36:53 -0700 (PDT) Received: from [10.255.70.20] ([139.177.225.235]) by smtp.gmail.com with ESMTPSA id m9-20020a63ed49000000b003f9d1c020cbsm2619464pgk.51.2022.05.26.23.36.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 May 2022 23:36:52 -0700 (PDT) Message-ID: <24a95dea-9ea6-a904-7c0b-197961afa1d1@bytedance.com> Date: Fri, 27 May 2022 14:32:52 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: Re: [PATCH 0/3] recover hardware corrupted page by virtio balloon Content-Language: en-US To: Peter Xu , Jue Wang Cc: Andrew Morton , David Hildenbrand , jasowang@redhat.com, LKML , Linux MM , mst@redhat.com, =?UTF-8?B?SE9SSUdVQ0hJIE5BT1lBKOWggOWPoyDnm7TkuZ8p?= , Paolo Bonzini , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org References: From: zhenwei pi In-Reply-To: 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 5/27/22 02:37, Peter Xu wrote: > On Wed, May 25, 2022 at 01:16:34PM -0700, Jue Wang wrote: >> The hypervisor _must_ emulate poisons identified in guest physical >> address space (could be transported from the source VM), this is to >> prevent silent data corruption in the guest. With a paravirtual >> approach like this patch series, the hypervisor can clear some of the >> poisoned HVAs knowing for certain that the guest OS has isolated the >> poisoned page. I wonder how much value it provides to the guest if the >> guest and workload are _not_ in a pressing need for the extra KB/MB >> worth of memory. > > I'm curious the same on how unpoisoning could help here. The reasoning > behind would be great material to be mentioned in the next cover letter. > > Shouldn't we consider migrating serious workloads off the host already > where there's a sign of more severe hardware issues, instead? > > Thanks, > I'm maintaining 1000,000+ virtual machines, from my experience: UE is quite unusual and occurs randomly, and I did not hit UE storm case in the past years. The memory also has no obvious performance drop after hitting UE. I hit several CE storm case, the performance memory drops a lot. But I can't find obvious relationship between UE and CE. So from the point of my view, to fix the corrupted page for VM seems good enough. And yes, unpoisoning several pages does not help significantly, but it is still a chance to make the virtualization better. -- zhenwei pi