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 16AB8C433EF for ; Thu, 26 May 2022 18:37:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244864AbiEZShi (ORCPT ); Thu, 26 May 2022 14:37:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345254AbiEZShZ (ORCPT ); Thu, 26 May 2022 14:37:25 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 380DF694A5 for ; Thu, 26 May 2022 11:37:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653590243; 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: in-reply-to:in-reply-to:references:references; bh=iZXZyOBj9K/G+WFDwIrle6dO9n3UzwXZHEEzIr/nzYk=; b=EcN/9lvQ2vCfiG/e2xYWoODYOQEkXUaYtUvRX8268CA1WFkXVfs8Auaql9IoYONSvGMBJ2 6mBRqFgpr/pG17PrvReBn5zLlg5IX/OcoO4i8GXSCQbuDVXT7FP6pM8DtGv6bu6c+vKTFY TgD6/kjuAvbgplcnNHYCZRAbPn5ChMU= Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-302-Ml5Y1yKDO720KnabuZbwxg-1; Thu, 26 May 2022 14:37:22 -0400 X-MC-Unique: Ml5Y1yKDO720KnabuZbwxg-1 Received: by mail-io1-f70.google.com with SMTP id k184-20020a6bbac1000000b0065aeedd4ba8so1472312iof.20 for ; Thu, 26 May 2022 11:37:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=iZXZyOBj9K/G+WFDwIrle6dO9n3UzwXZHEEzIr/nzYk=; b=Qqc7th9LrvUPICPzvNwR8R2tpBP5etMFRS+IplhNBP5NBPNVWfocC/Hce1ccK9SgMu kJOACcj9Y4nGCqsbTaAJf2/6tgSSAm8LluYColEfVSkKJTVCiA7LjxrbnTHDXBJ43+s8 2iV4v4miIpjareF11+2Hbfkpah5tb3jxcJ8vCZ6umn8MfGJJocKW0BWrDkQ1atWvXR+z qAc8Z2z6s30Vp3BY/MdF0Ak4+UImmkEzSTm1NOms2/FehaNY/SZ6hT4fB5zbijFWfe// pzJVxugxQoZR/zrcchEZzRD5dl+AWkvP4HxZ3uyNhUrv3vuwHJcUC2uICzl6WvGWMiod Q44Q== X-Gm-Message-State: AOAM5305A+Wr0v+YB8fO1aSt8gemj83Y3zb8fEzer3DRA/mm1In0PGYF SA+NDyin8YeEULrr9IyJyeCoJPAeT/DfX+VUc49VDzmYCQkcM8pdzmqPH1GVnbfUfE5/Sje7JPz jzDLPFYLAgY+s8Evas2OxtlTG X-Received: by 2002:a05:6638:4901:b0:32f:d52c:924c with SMTP id cx1-20020a056638490100b0032fd52c924cmr6248112jab.8.1653590241277; Thu, 26 May 2022 11:37:21 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzpP2TSvS6e9NpQEMUP3qCECYxWtAnkzb4ugRqwUnJ/Y/Oan//xTqCMVr3HgbEkayorckxxRg== X-Received: by 2002:a05:6638:4901:b0:32f:d52c:924c with SMTP id cx1-20020a056638490100b0032fd52c924cmr6248102jab.8.1653590241044; Thu, 26 May 2022 11:37:21 -0700 (PDT) Received: from xz-m1.local (cpec09435e3e0ee-cmc09435e3e0ec.cpe.net.cable.rogers.com. [99.241.198.116]) by smtp.gmail.com with ESMTPSA id x89-20020a0294e2000000b0032e43cb7344sm575684jah.146.2022.05.26.11.37.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 May 2022 11:37:20 -0700 (PDT) Date: Thu, 26 May 2022 14:37:18 -0400 From: Peter Xu To: Jue Wang Cc: pizhenwei@bytedance.com, Andrew Morton , David Hildenbrand , jasowang@redhat.com, LKML , Linux MM , mst@redhat.com, HORIGUCHI =?utf-8?B?TkFPWUEo5aCA5Y+jIOebtOS5nyk=?= , Paolo Bonzini , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH 0/3] recover hardware corrupted page by virtio balloon Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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, -- Peter Xu