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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E936CC55178 for ; Thu, 5 Nov 2020 17:29:29 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 669E02083B for ; Thu, 5 Nov 2020 17:29:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 669E02083B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id C0FD4859BA; Thu, 5 Nov 2020 17:29:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id duSJ5wrYssA0; Thu, 5 Nov 2020 17:29:28 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 5E96085580; Thu, 5 Nov 2020 17:29:28 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 47945C088B; Thu, 5 Nov 2020 17:29:28 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 93D84C0889 for ; Thu, 5 Nov 2020 17:29:27 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 79919870A7 for ; Thu, 5 Nov 2020 17:29:27 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id binxHTY2FZIl for ; Thu, 5 Nov 2020 17:29:26 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by hemlock.osuosl.org (Postfix) with ESMTPS id 4F5738666D for ; Thu, 5 Nov 2020 17:29:26 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B7E4D68C4E; Thu, 5 Nov 2020 18:29:21 +0100 (CET) Date: Thu, 5 Nov 2020 18:29:21 +0100 From: Christoph Hellwig To: Jason Gunthorpe Subject: Re: [PATCH 4/6] PCI/P2PDMA: Remove the DMA_VIRT_OPS hacks Message-ID: <20201105172921.GA9537@lst.de> References: <20201105074205.1690638-1-hch@lst.de> <20201105074205.1690638-5-hch@lst.de> <20201105143418.GA4142106@ziepe.ca> <20201105170816.GC7502@lst.de> <20201105172357.GE36674@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201105172357.GE36674@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Zhu Yanjun , Dennis Dalessandro , linux-rdma@vger.kernel.org, linux-pci@vger.kernel.org, Mike Marciniszyn , iommu@lists.linux-foundation.org, Bjorn Helgaas , Bernard Metzler , Logan Gunthorpe , Christoph Hellwig 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 Thu, Nov 05, 2020 at 01:23:57PM -0400, Jason Gunthorpe wrote: > But that depends on the calling driver doing this properly, and we > don't expose an API to get the PCI device of the struct ib_device > .. how does nvme even work here? The PCI p2pdma APIs walk the parent chains of a struct device until they find a PCI device. And the ib_device eventually ends up there. > > If we can't get here then why did you add the check to the unmap side? Because I added them to the map and unmap side, but forgot to commit the map side. Mostly to be prepared for the case where we could end up there. And thinking out loud I actually need to double check rdmavt if that is true there as well. It certainly is for rxe and siw as I checked it on a live system. > The SW drivers can't handle PCI pages at all, they are going to try to > memcpy them or something else not __iomem, so we really do need to > prevent P2P pages going into them. Ok, let's prevent it for now. And if someone wants to do it there they have to do all the work. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu