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 26E54C982FA for ; Tue, 22 Sep 2026 13:23:25 +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=guohS5YV9dRdJleOQU/qgo9Y8mhsnVIEuBXBuHTgTwM=; b=ABnbTrTM2Bfz92k9SL0Z1sao86 GwmkCp3ObXpvPDVVDWpLmqV0gJfeOXJAV7WdLmimO4jOQz4RSPOg/mX/D7bW3v/cb6qe5TMkg4lus lacxp/TpsZT2IwSEtZKaPwRnZJTI6wcTE+0Slb26DBKDi77ZR+ZLYneh5ibaasQ1VupLnnFp/CECu v7sa9qPlBKKLWTm0PSusMnQ4mzl4lFSwsli2+N4ZkMzXuKw+smp9LlYD/rJ7GcBVCVX584LWvg9nl doiPEFZNmh0fSN15qaJhtNHpRmZKcleslbmjqGIUWEEocpa/CXucLhRQt70+VO0VG63A+mjyh5ooi d3O7mAFA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x90Sv-00000005VTY-2t4m; Tue, 22 Sep 2026 13:23:21 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x90Q3-00000005Ut1-2JOF for linux-nvme@lists.infradead.org; Tue, 22 Sep 2026 13:20:24 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 8030168C7B; Tue, 22 Sep 2026 15:20:17 +0200 (CEST) Date: Tue, 22 Sep 2026 15:20:16 +0200 From: Christoph Hellwig To: Pavel Begunkov Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, Sumit Semwal , Christian =?iso-8859-1?Q?K=F6nig?= , Keith Busch , Sagi Grimberg , Alexander Viro , Christian Brauner , Jan Kara , Andrew Morton , Jens Axboe , Nitesh Shetty , Kanchan Joshi , Anuj Gupta , Tushar Gohad , William Power , Phil Cayton , Matthew Brost , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , dm-devel@lists.linux.dev Subject: Re: [PATCH v6 06/13] nvme-pci: implement dma-buf backed requests Message-ID: <20260922132016.GA30684@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260922_062023_751112_C38261EA X-CRM114-Status: GOOD ( 13.15 ) X-Mailman-Approved-At: Tue, 22 Sep 2026 06:23:21 -0700 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, Sep 21, 2026 at 02:38:50PM +0100, Pavel Begunkov wrote: > Enable BIO_DMABUF_MAP backed requests. On registration we map the This is now REQ_DMABUF. Sashiko had a few comments, which I think are correct - if we use dma_map_sg to map the data, we need to use the sync_sg APIs to transfer ownership. That only matters on non-coherent architectures with MMU, but we need to get it right. And the reset deadlock also looks plausible.