From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1BFDF606A326 for ; Wed, 11 Nov 2026 06:16:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=Gb1D4xe5; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=kXAC+krf DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=L0nui5RoS2ttjlEXfgdf2FHBryPRYispg6KfdVODpUg=; b=Gb1D4xe5/hnH51KdZim9vQWOsa kuzU6teP36rDYd28LYdEG0UjFzEeBZXy8aSrXp/4RxhG5zdAg3qo6A0DT0C+4JGaD8D6wVEl8074f ZDy+elzVMfTFpYdC5rMaKjgmEm7Tm/+GqVUCfJGL1HKpg3AzHT/IYjK9NkwP6psVRaBxs73w0ZGZl U7ZRgDA4WgIvkQNgoY3dPRe2CXBKleAW8kLS/2Y3h+huAo2P1zqFsAkpH9qfTXtEkvZvXI3en/zOK HAaJQfNp5Kn0ZHQbikoQ8JgpSEiEJTbl3KeEJKaKm4SbHebQ/HiJ3Yr290H9H4R+RkUfYhEMuQCLi K7pFH4TA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xR1dV-00000005j8A-3AUh; Wed, 11 Nov 2026 06:16:45 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xR1dU-00000005j6e-14A5 for kexec@lists.infradead.org; Wed, 11 Nov 2026 06:16:44 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id AC725612BF; Wed, 11 Nov 2026 06:16:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 264AF1F00A08; Wed, 11 Nov 2026 06:16:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794377803; bh=L0nui5RoS2ttjlEXfgdf2FHBryPRYispg6KfdVODpUg=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=kXAC+krf+Trv7+PS4HAGEVGxJ03mZokL/Vbm1gXYAWDZPzoyylYrFRTxaOK3f6HN0 PPAbIlzuFEsNPunbT3VxPFSSwKUKB0VLGVyKSdRAyiakqwo7dUGUAR5AKUy0GIjgf7 CRfz8UZCxBjI4u6CxrxFosCh5+76hzGfbdu+nKULjrnQHeoa1p7q/t3b3BXE+ovZoF 8JRnkoz54SUvVHYvWBDfR7tka2vIBsbUnh31yAuqH/brnu4fY2RrNPPcUrkGvRXbWC p5GHqDi9kGDOFb2JMUXRI0J50cCEZvDWGZjCJtIrUqc1ECqyvaOdIBjUeSPygpW2d+ pQ9FsGCEamaKg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 09/19] liveupdate: Add feature header to struct luo_ser To: "Tarun Sahu" , "Pasha Tatashin" , "Mike Rapoport" , robin.murphy@arm.com, maz@kernel.org, will@kernel.org, "David Matlack" , "Alexander Graf" , seanjc@google.com, jgg@nvidia.com, loganodell@google.com, arnd@arndb.de, dwmw2@infradead.org, baolu.lu@linux.intel.com, "Bjorn Helgaas" , oupton@kernel.org, alex@shazbot.org, gle.com@google.com, pbonzini@redhat.com, "Andrew Morton" , kevin.tian@intel.com, joro@8bytes.org Cc: linux-pci@vger.kernel.org, "Pratyush Yadav" , kexec@lists.infradead.org, skhawaja@google.com, sagis@google.com In-Reply-To: <20261110050202.529473-10-tarunsahu@google.com> References: <20261110050202.529473-1-tarunsahu@google.com> <20261110050202.529473-10-tarunsahu@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 11 Nov 2026 06:16:41 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > LUO and its file handlers currently rely solely on coarse-grained > compatibility strings (such as luo-v6 and memfd-v3) to validate > handed-over state across kexec. Because compatibility is checked only > at the whole-structure level, any change to a serialized structure, > even an optional additive field, requires bumping the compatibility > string and breaks live update between adjacent kernels. >=20 > Precede the centralized struct luo_ser with struct kho_ser_hdr using > DECLARE_KHO_SER. Subsystems can now evolve their serialized state at > per-feature granularity. Each subsystem groups the fields of its > serialized structure under feature indices, starting with index 0 for the > base fields. When a subsystem adds a new capability, it appends any new > fields to the end of its payload structure under a new feature index. > Retired fields are kept in place so existing field offsets never shift; > if the type or format of a field needs to change, the existing field and > feature are kept intact until retired and a new feature index with an > appended field of the new type is added. Only when a change requires a > complete break in the serialized layout or semantics that feature flags > cannot handle, a new handler can be introduced with an incremented version > number in its compatibility string. >=20 > Signed-off-by: Logan Odell > Signed-off-by: Tarun Sahu Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261110050202.5294= 73-1-tarunsahu@google.com?part=3D9