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[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 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Stat-Signature: 3uh8ern3qehrzy1p5s89j5anmj5tahwh Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="EcN/9lvQ"; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf11.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=peterx@redhat.com X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 3B7D24003D X-HE-Tag: 1653590236-87919 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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