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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D2A99C54756 for ; Thu, 22 May 2025 04:30:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=97ruOcxigrpBRwQGdKQtJ+Pl/tpRdk9Whg+hn7cxaFE=; b=A0Dziq2QOoe434FY/PXTcLOCTo S+Zv4hyeoTTt8UM+AeWKaWvnBt3Z5kT8zUWb3xqajygAroSGq9CP438BacvsyrxZHSisDscW7usl4 2QNbdsJNj6W5zQa1vhSxEyLJQth3/OGO3WoR4tsFxFDP04qvkULKv547yqdaiQqAkEB052GanImpE SfUaMLWa62S4s5WjitfSnbxpJeki0OahiU5a4HoTi1W5In7dp2lHtpe1CyDty5B8wPk6+WF2C4aQQ uochqAupMUnWcjGow5sD+pP91RRBQNZAvHrHgifkxD9Mz8+gZ4kZaM3DLQbGjIZSb9pfMbzkj4jiT 78Z+oc1g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHxZF-0000000HPbl-2rMV; Thu, 22 May 2025 04:30:05 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHxZD-0000000HPbL-1HM0 for linux-nvme@lists.infradead.org; Thu, 22 May 2025 04:30:04 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6DEC45C47AE; Thu, 22 May 2025 04:27:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3B7AC4CEE4; Thu, 22 May 2025 04:30:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1747888202; bh=97ruOcxigrpBRwQGdKQtJ+Pl/tpRdk9Whg+hn7cxaFE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fzC84e8n7qnFGZDCleQl2m0oHjiCWVStb4iis69dBCBEb/HqZ0fHXF16IZwEaFyNf B3AJ29YtNOh325PswiP/byoS5PW3gPIyTHYjDCMYKjSlQ3vNjwpwoRQqNINA91Trx8 ygKISCTaPI6HWWSwyCWra5IS7iFet/1GL9SAuWdSQC8lCHrPSfElNlnYdGrFswFsxV KVtPQa0TxRekTxnC4JnwwnGhwNVtCVr+0rOHTjTc3ACjXw1Gmh9AH2TpCWc0EOmU8c XjPseF1QlL3oCbC1sliBfF5bGS5til/PysBKqrKSmHe1kthauL8UTq2L9j70R3T9wf Q0tcr1DtSTI0w== Date: Wed, 21 May 2025 22:29:59 -0600 From: Keith Busch To: Caleb Sander Mateos Cc: Keith Busch , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH 3/5] nvme: add support for copy offload Message-ID: References: <20250521223107.709131-1-kbusch@meta.com> <20250521223107.709131-4-kbusch@meta.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250521_213003_386032_C7616E35 X-CRM114-Status: GOOD ( 10.38 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, May 21, 2025 at 08:41:40PM -0700, Caleb Sander Mateos wrote: > For the record, that change broke Linux hosts sending DSM commands to > our NVMe controller, which was validating that the SGL length exactly > matches the number of data bytes implied by the command. I'm sure > we're in the minority of NVMe controller vendors in aggressively > validating the NVMe command parameters, but it was unfortunate to > discover this change in Linux's behavior. This is a fabrics target you're talking about? I assume so because pci would use PRP for a 4k payload, which doesn't encode transfer lengths. All the offending controllers were pci, so maybe we could have constrained the DSM over-allocation to that transport if we knew this was causing problems for fabrics.