From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794200611; b=FAkwNUZ4Tms6vSvOnRH0BkMjtbogUu/XoNfYyB3R+Inp5lsAUWuxscYc0ysubMNv8+2i joaOptultq0749q1+aKJFosKuHXrt+ZqhLBfZDBLLH7H6tcPW19foCty/zBgYukVqgXIJ Lj8ZdPuAlDDzUyfEyrATfLP2xTebJmJAFfNFd0pJr6rWzQ6w78KNNHbGs647KkoSPs676 V69id72bWpM39a8kH4SBuoVVVd7oSPiiwESGOqS9Y0p5Hq9toTpRi9cp/F6TT794ry17D bo+Lm0DR7oeS8TmegogO7tVEX+gS+OnnGKUPCgYEbXCR0xPvn75rJnp6fPhpq81tuGA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794200611; h=Received:DKIM-Signature:X-Mailer:From:To:Cc:Subject:In-Reply-To: References:Date:Message-ID:MIME-Version:Content-Type; bh=WKDYdtIPpXv/RzXHp6m0fnJtTmWjQH/piwGs13om7po=; b=i6DTyae+ZCpmfGzCGchOR5MeqPb2cTjv6nsF+B75NSOMyWIw7Rb2OF6OLJaUq01CCaN6 zo+tQ65KCjVKL1jJ+RAH9sCVmdK8wRRiZ4olfsVW4YwA7wyi0VnKVup6tCqtDmP6mxRzy PQMwIIiF3jTx+W8b1wWk9w41j26X0sG4XsJkD12tZdlDcVTuEpUvzF5ykYNpHDxmPG/3u 7D14x4uaQH+6EV7ohgmmrbbpxLQSKvZg+WlDraODRmq+6fKWpsQciVRh/vlw6ONGRmSvM tKV8SME2Qdx7PNeR0h4Fcfatu7D7mTrZgDWlvIfFciR5ois6bc+jAjsHuKWgOaNFAiA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GD03ukNX; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 762EC606A31C; Mon, 9 Nov 2026 05:03:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GD03ukNX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4746B1F0089F; Mon, 9 Nov 2026 05:03:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794200611; bh=WKDYdtIPpXv/RzXHp6m0fnJtTmWjQH/piwGs13om7po=; h=From:To:Cc:Subject:In-Reply-To:References:Date; 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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain 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