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 0F994C7618E for ; Mon, 24 Apr 2023 06:20:54 +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=7Oc/dQm9V4QmVlQ+yHvyFuNUYsb0WYrwV7eVtNG2VHI=; b=aYS35mHRTVKwPxz8Org2nLJIQZ OlGjqSaQKCysKjyNgRokEi9jvpfmrw2lm2hSMFlW6qEx5vDqunYLQr7wRuz3PJrj26AZj5Ee83ypj fGyELODEM3F8WQOCSUdTGQ93hIfsgr4BNgiiePtYK1spypgpaFbsmjkWhT8CnaVMBpGsSlW2B+wL0 WGdtrFjqPnsRn4QsvoBB15VY1YNwDmnRgVqYLpu4L3gGE8bx2orazqrBIN44jQ5KKHpoPino8e+OU GFWha9B6/6zO7HrOjUrnMHOrWaLNEDjgRESCkESf14HdaCyIzCFzRbQCnNkS18NbnZSyX3eJOv13F jwT3I5sw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pqpZC-00FT4T-0v; Mon, 24 Apr 2023 06:20:50 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pqpZ8-00FT3z-2A for linux-nvme@lists.infradead.org; Mon, 24 Apr 2023 06:20:47 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 5D49968B05; Mon, 24 Apr 2023 08:20:41 +0200 (CEST) Date: Mon, 24 Apr 2023 08:20:41 +0200 From: Christoph Hellwig To: Hannes Reinecke Cc: Christoph Hellwig , Max Gurtovoy , martin.petersen@oracle.com, sagi@grimberg.me, linux-nvme@lists.infradead.org, kbusch@kernel.org, axboe@kernel.dk, linux-block@vger.kernel.org, oren@nvidia.com, oevron@nvidia.com, israelr@nvidia.com Subject: Re: [PATCH v1 0/2] Fix failover to non integrity NVMe path Message-ID: <20230424062040.GA10281@lst.de> References: <20230423141330.40437-1-mgurtovoy@nvidia.com> <20230424051144.GA9288@lst.de> <5b7ca121-2b85-ddd0-d94b-1739cc5dcbec@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5b7ca121-2b85-ddd0-d94b-1739cc5dcbec@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230423_232046_876573_D855C77E X-CRM114-Status: GOOD ( 15.83 ) 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 Mon, Apr 24, 2023 at 08:10:59AM +0200, Hannes Reinecke wrote: > Yeah, I'm slightly unhappy with this whole setup. > If we were just doing DIF I guess the setup could work, but then we have to > disable DIX (as we cannot support integrity data on the non-PI path). > But we would need an additional patch to disable DIX functionality in those > cases. NVMeoF only supports inline integrity data, the remapping from out of line integrity data is always done by the HCA for NVMe over RDMA, and integrity data is not supported without that. Because of that I can't see how we could sensibly support one path with integrity offload and one without. And yes, it might make sense to offer a way to explicitly disable integrity support to allow forming such a multipath setup.