From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C641A24EA85 for ; Mon, 9 Jun 2025 09:29:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749461371; cv=none; b=bOFXzNp7hvFlz0+zD8XIyk/dJODT5079uG6W3792qI6nUh/evshhdDbfp17S6G9PpDfd/I9JYjOlJGLZNZisBTDa1ys3xAelr3homDagzGw801ngTf7UYWzt6tsyvBnsRliqrZZlsZgLdxNuDdmqvUKVdLf1w8hd6p8D78g7aWU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749461371; c=relaxed/simple; bh=x/EnJWl/k0jsWW6PMMleDnU0RrJaBN65jDQeKCebf9E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Zvkm92t+5t6JrpRvpqznv3F8L6hcLVLMpUnrKpq+DE0opsap+QhhkQ/NSJOnmxRJmxlx2yGmlw0jZN3KAuD6WTzi8NyVII2Dwp/Q13/cN1Dwu6u0p3fT9BSr+FqfnafmrwVMLc6vgbZ8bbDifa/O2HY1ZY3HivrjxUgLUf8K0Vw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LcCM6Xef; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LcCM6Xef" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4007CC4CEEB; Mon, 9 Jun 2025 09:29:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749461371; bh=x/EnJWl/k0jsWW6PMMleDnU0RrJaBN65jDQeKCebf9E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LcCM6Xef1yXTIWZcPmZjtcgsQzFN2XcKqh4ZFgV/ssN08Df0aKJHSfW//3gGknsq4 WAAVwhOUqvFQIwxv3rTywGa505tQWx/zpxsFsZzwo9mD6MGKmnby8DbAQlAXmp9Xg6 eFXBxwvw6SfZbk/imnjKFjU5HvxLFkcz26baZpWESbsVhgp7wWWAlyj0/HDaCxSdPh AP3oJSH6CU+mTNrtuzcW+tVnuvFC9V8xLGQVhaml2twXc4LLF4iioOMA4i8TBgTU/X NYSq+NV8ws968V9Peb1nASUuJTkJJrWdIqfwfXLb0+9A8RgPkWWgcWgpx6j4vSJWvz +qSltiFz1+BLw== Date: Mon, 9 Jun 2025 11:29:27 +0200 From: Niklas Cassel To: Keith Busch Cc: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Keith Busch 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> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250521223107.709131-4-kbusch@meta.com> Hello Keith, On Wed, May 21, 2025 at 03:31:05PM -0700, Keith Busch wrote: > From: Keith Busch > > Register the nvme namespace copy capablities with the request_queue > limits and implement support for the REQ_OP_COPY operation. Since you never initialize Descriptor Format (DESFMT), you will use Descriptor Format 0 (No SNSID, 16b Guard PI). That is understandable, since your block layer API intentionally does not support cross-device copies. But I would have expected you to somehow mention the descriptor type format used somewhere in the commit message and somewhere in the code (as a comment). I haven't followed all the work that has happened wrt. PI in the block layer recently, so I don't know, but I can see that nvme_set_app_tag() can set a app tag in the request itself, and that nvme_set_ref_tag() supports both 16b Guard PI and 64b Guard PI. Do we ever want to set the ELBT/ELBAT/ELBATM in the nvme_copy_range struct? And if the namespace is using 64b Guard PI, do we want to use Descriptor Format 1 (No SNSID, 32b/64b Guard PI) rather than Descriptor Format 0 ? Kind regards, Niklas