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b=GD03ukNX3qpJy/ulw8mljNcuZ+ffE/s+zMEiPrDEJKEQ+cye+2q2ws/q05r9C/MwA 8lK5saBohFqhyS1SyDBT7NAkEwD8aM3vrlD9P4LPvGRgDSSGrGefVUdGFsWkIN+fho KpZxXNBbAQhXwg6sB5B8D8Vm59TczWTrD2qm7awrv0ZfpqU3B5VLjxjl7H1AjqQp4S i75YS8Qrd7Vyem4PeyW90tc16A0bzx+XMbNpRh3pm5DhqNFrGg/rEHLk/84mg3sQqd qGoOtS7woGspYXn7FCWWhnpfaGDKLNbR/J6K7jjxa7wcob9PfNJ6OsgEBIyHaJT/Ms gyMazdqf0pplA== X-Mailer: emacs 31.1 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Ackerley Tng via B4 Relay , Alexey Kardashevskiy , Christian Brauner , David Hildenbrand , David Woodhouse , Fred Griffoul , Jacob Pan , Jianxiong Gao , John Starks , Michael Roth , Paolo Bonzini , Samiullah Khawaja , Sean Christopherson , Suzuki K Poulose , Tarun Sahu , Vishal Annapurve , Xu Yilun , Fuad Tabba Cc: kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, Ackerley Tng Subject: Re: [PATCH RFC v3 64/88] vfio: Add vfio_device_gmem_revoke helper for guest_memfd In-Reply-To: <20261106-gmem-alternative-providers-v3-64-8484dde66a7e@google.com> References: <20261106-gmem-alternative-providers-v3-0-8484dde66a7e@google.com> <20261106-gmem-alternative-providers-v3-64-8484dde66a7e@google.com> Date: Mon, 09 Nov 2026 10:33:20 +0530 Message-ID: X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 127A0180003 X-Rspamd-Server: rspam12 X-Stat-Signature: gxiy3hshj8ym94b9ww1gys647yit5599 X-Rspam-User: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1794200611-692665 X-HE-Meta: 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 3PU1R8yL 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Ackerley Tng via B4 Relay writes: > From: Ackerley Tng > > When physical device regions backing guest_memfd memory must be revoked > due to hardware reset, power state transitions, or memory decode state > changes, the bus driver must revoke and reclaim the memory ranges from > guest_memfd before modifying hardware state. > Should we prevent such operations while the VFIO fd is attached to guest_memfd? Some of these operations can transition the device to the TDISP error state, and we should avoid host operations that can result in vfio_pci_zap_bars(). -aneesh