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 smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 7CDB7C43334 for ; Tue, 5 Jul 2022 16:12:55 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 08AC381A81; Tue, 5 Jul 2022 16:12:55 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 08AC381A81 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jEMKAgQxuCNQ; Tue, 5 Jul 2022 16:12:52 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 498A7801EA; Tue, 5 Jul 2022 16:12:52 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 498A7801EA Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1B6C9C0032; Tue, 5 Jul 2022 16:12:52 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 29D39C002D for ; Tue, 5 Jul 2022 16:12:51 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id E3F2F400A8 for ; Tue, 5 Jul 2022 16:12:50 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org E3F2F400A8 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ZbcVCUrAVHzf for ; Tue, 5 Jul 2022 16:12:46 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 1C83740A95 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by smtp2.osuosl.org (Postfix) with ESMTPS id 1C83740A95 for ; Tue, 5 Jul 2022 16:12:45 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B875B67373; Tue, 5 Jul 2022 18:12:40 +0200 (CEST) Date: Tue, 5 Jul 2022 18:12:40 +0200 From: Christoph Hellwig To: Jason Gunthorpe Subject: Re: [PATCH v7 20/21] PCI/P2PDMA: Introduce pci_mmap_p2pmem() Message-ID: <20220705161240.GB13721@lst.de> References: <20220615161233.17527-1-logang@deltatee.com> <20220615161233.17527-21-logang@deltatee.com> <20220629064854.GD17576@lst.de> <99242789-66a6-bbd2-b56a-e47891f4522e@deltatee.com> <20220629175906.GU23621@ziepe.ca> <20220705075108.GB17451@lst.de> <20220705135102.GE23621@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220705135102.GE23621@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: linux-pci@vger.kernel.org, Dave Hansen , linux-nvme@lists.infradead.org, Stephen Bates , linux-mm@kvack.org, Jason Ekstrand , Ira Weiny , Christoph Hellwig , Minturn Dave B , Martin Oliveira , Matthew Wilcox , Chaitanya Kulkarni , Bjorn Helgaas , Daniel Vetter , Ralph Campbell , John Hubbard , linux-block@vger.kernel.org, Bjorn Helgaas , Dan Williams , Xiong Jianxin , Robin Murphy , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Logan Gunthorpe , Christian =?iso-8859-1?Q?K=F6nig?= X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Jul 05, 2022 at 10:51:02AM -0300, Jason Gunthorpe wrote: > > In fact I'm not even sure this should be a character device, it seems > > to fit it way better with the PCI sysfs hierchacy, just like how we > > map MMIO resources, which these are anyway. And once it is on sysfs > > we do have a uniqueue inode and need none of the pseudofs stuff, and > > don't need all the glue code in nvme either. > > Shouldn't there be an allocator here? It feels a bit weird that the > entire CMB is given to a single process, it is a sharable resource, > isn't it? Making the entire area given by the device to the p2p allocator available to user space seems sensible to me. That is what the current series does, and what a sysfs interface would do as well. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu