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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 0A7CDC65BAF for ; Wed, 12 Dec 2018 22:12:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C146D2084E for ; Wed, 12 Dec 2018 22:12:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="mWsub9UF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C146D2084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728442AbeLLWMJ (ORCPT ); Wed, 12 Dec 2018 17:12:09 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:55684 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726297AbeLLWMI (ORCPT ); Wed, 12 Dec 2018 17:12:08 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=W2fEIyrU1wrlDtrW8W/ltkOSVlOXSPi8GBo0cdyRpRc=; b=mWsub9UFPFV6lxLcMWsnRKjaF REBW7Q6vh3C5vXpn3V/f9Sc2XL9VGvrsQ0AAPB3YhkZSOaw39ARGcxeP+A9rgcGJZgQKnDAR8H/eX ABOYvIXx1rrH2TJTtT029rRO/DWBb+FzmPnsjwkeZMCy/3bRI4xqZ78xQV3D5fl6WsyWhI9VtgVpC uHGmRGlakoIH6zGoJYHCFr4Cs3zYMOReq9zvnzAG5UhUN8XStCB9F48TYj/qARBfgWXBoN7QKcnda ioXfqN76eOPIpyX4Qn/antjpXLCln5ZupA3t+TQmlRkhu3mC3z1KhFBgUwL280VqhcrRDnRTbvcde JSfFvg6nw==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXCjV-0004Pf-Sd; Wed, 12 Dec 2018 22:11:57 +0000 Date: Wed, 12 Dec 2018 14:11:57 -0800 From: Matthew Wilcox To: Jerome Glisse Cc: Dan Williams , Jan Kara , John Hubbard , John Hubbard , Andrew Morton , Linux MM , tom@talpey.com, Al Viro , benve@cisco.com, Christoph Hellwig , Christopher Lameter , "Dalessandro, Dennis" , Doug Ledford , Jason Gunthorpe , Michal Hocko , Mike Marciniszyn , rcampbell@nvidia.com, Linux Kernel Mailing List , linux-fsdevel , "Weiny, Ira" Subject: Re: [PATCH 1/2] mm: introduce put_user_page*(), placeholder versions Message-ID: <20181212221157.GL6830@bombadil.infradead.org> References: <7b4733be-13d3-c790-ff1b-ac51b505e9a6@nvidia.com> <20181207191620.GD3293@redhat.com> <3c4d46c0-aced-f96f-1bf3-725d02f11b60@nvidia.com> <20181208022445.GA7024@redhat.com> <20181210102846.GC29289@quack2.suse.cz> <20181212150319.GA3432@redhat.com> <20181212213005.GE5037@redhat.com> <20181212215348.GF5037@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181212215348.GF5037@redhat.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 12, 2018 at 04:53:49PM -0500, Jerome Glisse wrote: > The mmu notifier i put forward is the emergency revoke ie last > resort after driver have done everything it could to inform user- > space and release the pages. So doing thing brutaly in it like > reprogramming driver page table (which AFAIK is something you > can do on any hardware wether the hardware will like it or not > is a different question). You can't do it to an NVMe device. You submit the DMA addresses in the command, and the device reads the command at submission time. There's no way to change the DMA addresses for an in-flight command.