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 382A4C43458 for ; Fri, 26 Jun 2026 17:55:49 +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=ZA6LNO4zZPmcBNly3QOqtFTnOggSxh3G1dGlSf4qG5U=; b=w1XmdgcpGT/YPE/OO0nJmMTYn8 4XejA1AO6L+a0VLf6ULeqSUvxe05lfROFcQJlOT3o3eUzqsV8iSMLiXgNz0sNNPsm3hBKYgCYosrV GEsioYKa02N9+IFCl408S3veOhIHEzSGZ14xV7hoA2oaAjr9Qx0Nh5ViJhomnzZjrLuK/5aq/nMF4 6K2c33de9JG6sUCh+S5yrDZUZhnl3wN1VcKcNbiUWPxv5CnnkQwSnJD9p26NrQXJ7HndAeEGxqYX4 woRCjwVxsRIkhsD+ouHKP+IZyqUH+7RNbdNgqbwBj3NJiuLBnj8+koChM+lgqyW5J1j4Fjb8QeJ3C WGujpn/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdAmI-0000000BjPt-2NQ1; Fri, 26 Jun 2026 17:55:46 +0000 Received: from smtp.missinglinkelectronics.com ([162.55.135.183]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wdAmF-0000000BjOu-29OV for linux-nvme@lists.infradead.org; Fri, 26 Jun 2026 17:55:44 +0000 Received: from ubuntu-server (ppp-88-217-75-1.dynamic.mnet-online.de [88.217.75.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: david) by smtp.missinglinkelectronics.com (Postfix) with ESMTPSA id A0C9320150; Fri, 26 Jun 2026 19:55:38 +0200 (CEST) Date: Fri, 26 Jun 2026 19:55:32 +0200 From: David Epping To: Christoph Hellwig Cc: Keith Busch , linux-nvme@lists.infradead.org, Jens Axboe , Sagi Grimberg , Leon Romanovsky , Joachim Foerster Subject: Re: [PATCH RFC] nvme-ioctl: propagate PRP1 from ioctl to admin cmd Message-ID: References: <20260624074045.GB12649@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260624074045.GB12649@lst.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260626_105543_726539_115A63EC X-CRM114-Status: GOOD ( 17.77 ) 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, Jun 24, 2026 at 09:40:45AM +0200, Christoph Hellwig wrote: > On Tue, Jun 23, 2026 at 06:19:08AM -0600, Keith Busch wrote: > > Partitioning device resources to assign to special purposes should be > > under a well defined framework. Unfortunately the only thing I know of > > approaching this is SIOV. :) Not sure how other maintainers and > > developers feel about it, but that's the route I would go for this. It > > at least provides memory access on a queue granularity and neatly > > separates the control plane. > > Yeah, we can't just hand out queues. I/O to all namespaces can be done > on queue, and any queue can address any IOVA, so this is fundamentally > unsafe. Add to that fun like abort handling and it's just not going > to work at all. We had at least to previous public attempts at such > schemes (Damiens' libvnme back in the day, and the Mellanox nvmet > offloading) that were rejected for the same reason. > Thank you both for your feedback, I get the point. I'll definitely look into using SRIOV or SPDK to migrate the system to an unmodified upstream NVMe driver mid-term. Thank you for such a stable base to build upon, David