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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E64FAC33CB2 for ; Fri, 31 Jan 2020 06:13:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A27A12082E for ; Fri, 31 Jan 2020 06:13:27 +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 A27A12082E 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) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F8A16B0511; Fri, 31 Jan 2020 01:13:27 -0500 (EST) 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-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-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 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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: =46rom: 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: Bj=C3=B6rn T=C3=B6pel 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-p= ut_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 =3D 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 |=3D FOLL_WRITE; =20 down_read(&mm->mmap_sem); - ret =3D get_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, + ret =3D pin_user_pages_remote(NULL, mm, vaddr, 1, flags | FOLL_LONGTERM, page, NULL, NULL); if (ret =3D=3D 1) { *pfn =3D page_to_pfn(page[0]); _