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 732C8C28B28 for ; Thu, 13 Mar 2025 06:38:32 +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=z+M7T5+oesBRFEivtacNct45Um0/S+YIRwesyjMdhZ0=; b=2uqGx0fM5HFUUiI1plcuDyLL63 qMB5qkl1SkAseL9e7y2OxS0ZYyhy5BihYlEgihuHnARVUePwix8MAnv+Bdc2IIQBU14Hb9YtoNGvH 2Jx9LXAbt8e3yNASSlMpTEioeEZQu/wUfSaOQ1Q6cAFIXCRKJeM7dA0hHdB3AdzQh2Tws0/73Zi1n o4Pe4Dpc543U/fuwraAV5ll+y3CgeJwRwfElFiHb6lbqdmBLyhD/zHBX2v2bZQe2vcPSAgV5pRrQO ybGd/+zf2uAc0K7QvAMHkWWSu5QP7aypDIBAah8OuwAfZ3xLDfc2ebsnjxWT4zcEL5FWKVejpEnHK YJ4D+8qA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tscD8-0000000AEjq-43hn; Thu, 13 Mar 2025 06:38:30 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tscCD-0000000AEeG-3vmP for linux-nvme@lists.infradead.org; Thu, 13 Mar 2025 06:37:35 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 9503D68C4E; Thu, 13 Mar 2025 07:37:30 +0100 (CET) Date: Thu, 13 Mar 2025 07:37:30 +0100 From: Christoph Hellwig To: Mike Christie Cc: chaitanyak@nvidia.com, kbusch@kernel.org, hch@lst.de, sagi@grimberg.me, joao.m.martins@oracle.com, linux-nvme@lists.infradead.org, kvm@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com, mlevitsk@redhat.com Subject: Re: [PATCH RFC 03/11] nvmet: Add nvmet_fabrics_ops flag to indicate SGLs not supported Message-ID: <20250313063730.GC9967@lst.de> References: <20250313052222.178524-1-michael.christie@oracle.com> <20250313052222.178524-4-michael.christie@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250313052222.178524-4-michael.christie@oracle.com> 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-20250312_233734_230519_3B7FAB86 X-CRM114-Status: GOOD ( 14.04 ) 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 Thu, Mar 13, 2025 at 12:18:04AM -0500, Mike Christie wrote: > The nvmet_mdev_pci driver does not initially support SGLs. In some > prelim testing I don't think there will be a perf gain (the virt related > interface may be the major bottleneck so I may not notice) so I wasn't > sure if they will be required/needed. This adds a nvmet_fabrics_ops flag > so we can tell nvmet core to tell the host we do not supports SGLS. I'd prefer to be able to support SGLs if we can, but if not I could live with a flag of some sort.