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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 4E66CC0044D for ; Mon, 16 Mar 2020 18:20:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1A49F20409 for ; Mon, 16 Mar 2020 18:20:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A49F20409 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9D7376B0003; Mon, 16 Mar 2020 14:20:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 987AD6B0005; Mon, 16 Mar 2020 14:20:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8C4626B0007; Mon, 16 Mar 2020 14:20:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 7266A6B0003 for ; Mon, 16 Mar 2020 14:20:43 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 1B7215DD7 for ; Mon, 16 Mar 2020 18:20:43 +0000 (UTC) X-FDA: 76602041166.06.water20_7aa563131b632 X-HE-Tag: water20_7aa563131b632 X-Filterd-Recvd-Size: 2114 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Mon, 16 Mar 2020 18:20:42 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id E7A4568BFE; Mon, 16 Mar 2020 19:20:39 +0100 (CET) Date: Mon, 16 Mar 2020 19:20:39 +0100 From: Christoph Hellwig To: Jason Gunthorpe Cc: Christoph Hellwig , Dan Williams , Bharata B Rao , Christian =?iso-8859-1?Q?K=F6nig?= , Ben Skeggs , Jerome Glisse , kvm-ppc@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: [PATCH 1/2] mm: handle multiple owners of device private pages in migrate_vma Message-ID: <20200316182039.GA24736@lst.de> References: <20200316175259.908713-1-hch@lst.de> <20200316175259.908713-2-hch@lst.de> <20200316181707.GJ20941@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200316181707.GJ20941@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Mar 16, 2020 at 03:17:07PM -0300, Jason Gunthorpe wrote: > On Mon, Mar 16, 2020 at 06:52:58PM +0100, Christoph Hellwig wrote: > > Add a new opaque owner field to struct dev_pagemap, which will allow > > the hmm and migrate_vma code to identify who owns ZONE_DEVICE memory, > > and refuse to work on mappings not owned by the calling entity. > > Using a pointer seems like a good solution to me. > > Is this a bug fix? What is the downside for migrate on pages it > doesn't work? I'm not up to speed on migrate.. migrating private pages not owned by driver simply won't work, as the device can't access it. Even inside the same driver say GPU A can't just migrate CPU B's memory. In that sense it is a bug fix for the rather unlikely case of using the experimental nouveau with multiple GPUs, or in a power secure VM (if that is even possible). 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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 04F4CC0044D for ; Mon, 16 Mar 2020 18:22:37 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 D31FF20409 for ; Mon, 16 Mar 2020 18:22:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D31FF20409 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=amd-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8588C89DA3; Mon, 16 Mar 2020 18:22:36 +0000 (UTC) Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by gabe.freedesktop.org (Postfix) with ESMTPS id E96326E49D; Mon, 16 Mar 2020 18:20:42 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id E7A4568BFE; Mon, 16 Mar 2020 19:20:39 +0100 (CET) Date: Mon, 16 Mar 2020 19:20:39 +0100 From: Christoph Hellwig To: Jason Gunthorpe Subject: Re: [PATCH 1/2] mm: handle multiple owners of device private pages in migrate_vma Message-ID: <20200316182039.GA24736@lst.de> References: <20200316175259.908713-1-hch@lst.de> <20200316175259.908713-2-hch@lst.de> <20200316181707.GJ20941@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200316181707.GJ20941@ziepe.ca> User-Agent: Mutt/1.5.17 (2007-11-01) X-Mailman-Approved-At: Mon, 16 Mar 2020 18:22:35 +0000 X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: amd-gfx@lists.freedesktop.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kvm-ppc@vger.kernel.org, Christoph Hellwig , linux-mm@kvack.org, Jerome Glisse , Ben Skeggs , Dan Williams , Bharata B Rao , Christian =?iso-8859-1?Q?K=F6nig?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Mon, Mar 16, 2020 at 03:17:07PM -0300, Jason Gunthorpe wrote: > On Mon, Mar 16, 2020 at 06:52:58PM +0100, Christoph Hellwig wrote: > > Add a new opaque owner field to struct dev_pagemap, which will allow > > the hmm and migrate_vma code to identify who owns ZONE_DEVICE memory, > > and refuse to work on mappings not owned by the calling entity. > > Using a pointer seems like a good solution to me. > > Is this a bug fix? What is the downside for migrate on pages it > doesn't work? I'm not up to speed on migrate.. migrating private pages not owned by driver simply won't work, as the device can't access it. Even inside the same driver say GPU A can't just migrate CPU B's memory. In that sense it is a bug fix for the rather unlikely case of using the experimental nouveau with multiple GPUs, or in a power secure VM (if that is even possible). _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Mon, 16 Mar 2020 18:20:39 +0000 Subject: Re: [PATCH 1/2] mm: handle multiple owners of device private pages in migrate_vma Message-Id: <20200316182039.GA24736@lst.de> List-Id: References: <20200316175259.908713-1-hch@lst.de> <20200316175259.908713-2-hch@lst.de> <20200316181707.GJ20941@ziepe.ca> In-Reply-To: <20200316181707.GJ20941@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jason Gunthorpe Cc: Christoph Hellwig , Dan Williams , Bharata B Rao , Christian =?iso-8859-1?Q?K=F6nig?= , Ben Skeggs , Jerome Glisse , kvm-ppc@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-mm@kvack.org On Mon, Mar 16, 2020 at 03:17:07PM -0300, Jason Gunthorpe wrote: > On Mon, Mar 16, 2020 at 06:52:58PM +0100, Christoph Hellwig wrote: > > Add a new opaque owner field to struct dev_pagemap, which will allow > > the hmm and migrate_vma code to identify who owns ZONE_DEVICE memory, > > and refuse to work on mappings not owned by the calling entity. > > Using a pointer seems like a good solution to me. > > Is this a bug fix? What is the downside for migrate on pages it > doesn't work? I'm not up to speed on migrate.. migrating private pages not owned by driver simply won't work, as the device can't access it. Even inside the same driver say GPU A can't just migrate CPU B's memory. In that sense it is a bug fix for the rather unlikely case of using the experimental nouveau with multiple GPUs, or in a power secure VM (if that is even possible).