From patchwork Fri Jan 31 06:13:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11359201 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2BFBA13A4 for ; Fri, 31 Jan 2020 06:13:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ECC4E24682 for ; Fri, 31 Jan 2020 06:13:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="zwCkOkuO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECC4E24682 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 521636B050F; Fri, 31 Jan 2020 01:13:27 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 4F8A16B0511; Fri, 31 Jan 2020 01:13:27 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3E7BE6B0512; Fri, 31 Jan 2020 01:13:27 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) by kanga.kvack.org (Postfix) with ESMTP id 29F8B6B050F for ; Fri, 31 Jan 2020 01:13:27 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D5128180AD802 for ; Fri, 31 Jan 2020 06:13:26 +0000 (UTC) X-FDA: 76436912412.10.paper63_1e09338dc9f3f X-Spam-Summary: 2,0,0,fb07288a0cfc2187,d41d8cd98f00b204,akpm@linux-foundation.org,:akpm@linux-foundation.org:alex.williamson@redhat.com:aneesh.kumar@linux.ibm.com:axboe@kernel.dk:bjorn.topel@intel.com:corbet@lwn.net:dan.j.williams@intel.com:daniel.vetter@ffwll.ch:hch@lst.de:hverkuil-cisco@xs4all.nl:ira.weiny@intel.com:jack@suse.cz:jgg@mellanox.com:jgg@ziepe.ca:jglisse@redhat.com:jhubbard@nvidia.com:kirill@shutemov.name:leonro@mellanox.com::mchehab@kernel.org:mm-commits@vger.kernel.org:rppt@linux.ibm.com:torvalds@linux-foundation.org,RULES_HIT:41:152:355:379:800:960:967:973:988:989:1260:1263:1277:1311:1313:1314:1345:1359:1381:1431:1437:1513:1515:1516:1518:1521:1534:1542:1593:1594:1711:1730:1747:1777:1792:2194:2199:2393:2525:2553:2559:2564:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6119:6261:6653:6737:6738:7576:8599:8660:8957:90 25:9545: X-HE-Tag: paper63_1e09338dc9f3f X-Filterd-Recvd-Size: 4559 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Fri, 31 Jan 2020 06:13:26 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EA830206A2; Fri, 31 Jan 2020 06:13:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580451205; bh=RgEbi8/JcHjN66ff7d5rjoLwmtPH3upDL3IGbdiEP+k=; h=Date:From:To:Subject:In-Reply-To:From; b=zwCkOkuOtCQ852hqUNO6GIp1luHBFXP7vJKAEuVHHpsHeiHvLHCcwheCN3R+QGyC2 ugu8uHjPhTwP9/eNvMzEmHgVqNl5CWatYdhYOkjgzMvFxe15OPe4qWJI93QDNLpSXf iNRfosKKAnxoXDrRveWIwcC96BzUUGYX3gXtwRj0= Date: Thu, 30 Jan 2020 22:13:24 -0800 From: Andrew Morton To: akpm@linux-foundation.org, alex.williamson@redhat.com, aneesh.kumar@linux.ibm.com, axboe@kernel.dk, bjorn.topel@intel.com, corbet@lwn.net, dan.j.williams@intel.com, daniel.vetter@ffwll.ch, hch@lst.de, hverkuil-cisco@xs4all.nl, ira.weiny@intel.com, jack@suse.cz, jgg@mellanox.com, jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com, kirill@shutemov.name, leonro@mellanox.com, linux-mm@kvack.org, mchehab@kernel.org, mm-commits@vger.kernel.org, rppt@linux.ibm.com, torvalds@linux-foundation.org Subject: [patch 042/118] vfio, mm: pin_user_pages (FOLL_PIN) and put_user_page() conversion Message-ID: <20200131061324.AO72PHl35%akpm@linux-foundation.org> In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 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: From: John Hubbard Subject: vfio, mm: pin_user_pages (FOLL_PIN) and put_user_page() conversion 1. Change vfio from get_user_pages_remote(), to pin_user_pages_remote(). 2. Because all FOLL_PIN-acquired pages must be released via put_user_page(), also convert the put_page() call over to put_user_pages_dirty_lock(). Note that this effectively changes the code's behavior in vfio_iommu_type1.c: put_pfn(): it now ultimately calls set_page_dirty_lock(), instead of set_page_dirty(). This is probably more accurate. As Christoph Hellwig put it, "set_page_dirty() is only safe if we are dealing with a file backed page where we have reference on the inode it hangs off." [1] [1] https://lore.kernel.org/r/20190723153640.GB720@lst.de Link: http://lkml.kernel.org/r/20200107224558.2362728-20-jhubbard@nvidia.com Signed-off-by: John Hubbard Tested-by: Alex Williamson Acked-by: Alex Williamson Cc: Aneesh Kumar K.V Cc: Björn Töpel Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Dan Williams Cc: Hans Verkuil Cc: Ira Weiny Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Jerome Glisse Cc: Jonathan Corbet Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mauro Carvalho Chehab Cc: Mike Rapoport Signed-off-by: Andrew Morton --- drivers/vfio/vfio_iommu_type1.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/vfio/vfio_iommu_type1.c~vfio-mm-pin_user_pages-foll_pin-and-put_user_page-conversion +++ a/drivers/vfio/vfio_iommu_type1.c @@ -309,9 +309,8 @@ static int put_pfn(unsigned long pfn, in { if (!is_invalid_reserved_pfn(pfn)) { struct page *page = pfn_to_page(pfn); - if (prot & IOMMU_WRITE) - SetPageDirty(page); - put_page(page); + + put_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE); return 1; } return 0; @@ -329,7 +328,7 @@ static int vaddr_get_pfn(struct mm_struc flags |= FOLL_WRITE; down_read(&mm->mmap_sem); - ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, + ret = pin_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, page, NULL, NULL); if (ret == 1) { *pfn = page_to_pfn(page[0]);