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 DA974C433F5 for ; Wed, 25 May 2022 20:17:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241378AbiEYURQ (ORCPT ); Wed, 25 May 2022 16:17:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345799AbiEYUQs (ORCPT ); Wed, 25 May 2022 16:16:48 -0400 Received: from mail-vk1-xa30.google.com (mail-vk1-xa30.google.com [IPv6:2607:f8b0:4864:20::a30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 804611147D for ; Wed, 25 May 2022 13:16:46 -0700 (PDT) Received: by mail-vk1-xa30.google.com with SMTP id bc42so10390369vkb.12 for ; Wed, 25 May 2022 13:16:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:from:date:message-id:subject:to:cc; bh=sEG0icEbQWzQToljyqBgD3aSPQ/mar2lnW/ygu4neoY=; b=eEqJ7TQi6I6W8fbEV9Ibmb7lons3Vl5rNCaekxwVLzqN0iym/F9GFmW3m8TS31Fe45 ePM+S2RHy/r20laDdii5e9VQiY5RSKaoLD/pgXZ2ghVStHsVV5ugwG8dbXSzeW5nOv7D MC9/aFVH0Dx69kSHo86+3frP64Ss6OcL9dq7i3UzIX7lf9daLy05BVveI+yKZVbFg464 RBO63ztSg2not7N8aYKfyAshrQzRJpnlQfMOl16HBb484uCMYX8FkRSYqNpNIp2ZE1j2 AQJiXPAQQOuoJxAGTQ7Gw+Iev/omSlrkzV5CgbHvyOKaLku4CDlo7dualO3zn2tzIivB nyDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=sEG0icEbQWzQToljyqBgD3aSPQ/mar2lnW/ygu4neoY=; b=i9dvgyFmZldw9uIf6JDOisbDxCvliYXfXkD2sQYPomEqzqw8c6C5PoXqdsFgVKvYir oSyzN5U9oUL+h+B+QdcvWguaIGyJrJytReZsHAaVOemR+vqRaZDgOo1fomrY0C2NCcMN Pfv6n9cS8a0566xnsAkriDsUGaEL1z6/k3GOinnXfJnFj6Huh1X+Fnjrm6fIz0b8up14 dqTE9JPLQORg0OsVpXIYiGn+XhOgIdUlEPcoKNE9eIVOENm/A+SACa29eqQW0iA77lZX BBTHXdeXuMkA3szO9aSrFe/4OxuKw6fAOphS8JGg/xDlnhy8NhCXMlp+2SOZ6SDqPWvt HZrw== X-Gm-Message-State: AOAM530xcqjr3gQG1YfcGThjKPp9EqI6jxmbGqVSEaLskhlz5XIrSY3Q 4aEQ98nx4ZzpPhJ24kyZ97zfe5q7Z53jCBxRWJ/1EA== X-Google-Smtp-Source: ABdhPJxXTD0b0wGt11g6Sf3EIcNgykMMnDOGoXDZJlAhtASlMQY8J+Li2flc5Z6ipSE6ZXPSEPSpTccxmE+am9GnerQ= X-Received: by 2002:ac5:cdec:0:b0:358:269a:8a24 with SMTP id v12-20020ac5cdec000000b00358269a8a24mr2737096vkn.22.1653509805414; Wed, 25 May 2022 13:16:45 -0700 (PDT) MIME-Version: 1.0 From: Jue Wang Date: Wed, 25 May 2022 13:16:34 -0700 Message-ID: Subject: Re: [PATCH 0/3] recover hardware corrupted page by virtio balloon To: pizhenwei@bytedance.com Cc: Andrew Morton , David Hildenbrand , jasowang@redhat.com, LKML , Linux MM , mst@redhat.com, =?UTF-8?B?SE9SSUdVQ0hJIE5BT1lBKOWggOWPoyDnm7TkuZ8p?= , Paolo Bonzini , Peter Xu , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some points to consider: The injected MCE has _done_ the damages to guest workload. Recovering the guest poisoned memory doesn't help with the already happened guest workload memory corruption / loss / interruption due to injected MCEs. 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. Thanks, -Jue