From patchwork Tue Nov 19 08:16:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11251257 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 1EB94109A for ; Tue, 19 Nov 2019 08:17:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DEB4F22313 for ; Tue, 19 Nov 2019 08:17:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="T5IJG+HT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DEB4F22313 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 67E8E6B027B; Tue, 19 Nov 2019 03:17:13 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 60A206B027C; Tue, 19 Nov 2019 03:17:13 -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 51E7C6B027D; Tue, 19 Nov 2019 03:17:13 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id 3952F6B027B for ; Tue, 19 Nov 2019 03:17:13 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id F06AF4DC1 for ; Tue, 19 Nov 2019 08:17:12 +0000 (UTC) X-FDA: 76172321904.24.box94_3ee882dc44612 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,jhubbard@nvidia.com,:akpm@linux-foundation.org:viro@zeniv.linux.org.uk:alex.williamson@redhat.com:benh@kernel.crashing.org:bjorn.topel@intel.com:hch@infradead.org:dan.j.williams@intel.com:daniel@ffwll.ch:david@fromorbit.com:airlied@linux.ie:davem@davemloft.net:ira.weiny@intel.com:jack@suse.cz:jgg@ziepe.ca:axboe@kernel.dk:corbet@lwn.net:jglisse@redhat.com:magnus.karlsson@intel.com:mchehab@kernel.org:mpe@ellerman.id.au:mhocko@suse.com:mike.kravetz@oracle.com:paulus@samba.org:shuah@kernel.org:vbabka@suse.cz:bpf@vger.kernel.org:dri-devel@lists.freedesktop.org:kvm@vger.kernel.org:linux-block@vger.kernel.org:linux-doc@vger.kernel.org:linux-fsdevel@vger.kernel.org:linux-kselftest@vger.kernel.org:linux-media@vger.kernel.org:linux-rdma@vger.kernel.org:linuxppc-dev@lists.ozlabs.org:netdev@vger.kernel.org::linux-kernel@vger.kernel.org:jhubbard@nvidia.com,RULES_HIT:30054:30064:30070:30090,0,RBL:216.228.121.64:@nvidia.com:.lbl8.mailshell.net-62.18.0 .100 64. X-HE-Tag: box94_3ee882dc44612 X-Filterd-Recvd-Size: 5635 Received: from hqemgate15.nvidia.com (hqemgate15.nvidia.com [216.228.121.64]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 Nov 2019 08:17:12 +0000 (UTC) Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 19 Nov 2019 00:17:06 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Tue, 19 Nov 2019 00:17:09 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Tue, 19 Nov 2019 00:17:09 -0800 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 19 Nov 2019 08:17:08 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 19 Nov 2019 08:17:08 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Tue, 19 Nov 2019 00:17:08 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v6 19/24] vfio, mm: pin_user_pages (FOLL_PIN) and put_user_page() conversion Date: Tue, 19 Nov 2019 00:16:38 -0800 Message-ID: <20191119081643.1866232-20-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119081643.1866232-1-jhubbard@nvidia.com> References: <20191119081643.1866232-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1574151426; bh=nI3kBsm1YYmEZh4r0pGrnWMl68q+Rq4M7HG7pTJrYP4=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=T5IJG+HTVygH2u0m0Mv6OczTGUqKtvbpp70aNAgr46Lv/5FUxQCDymEjKoZYchwCS dDGRB6oIAdIGrHPQYgtQKlg/zy/8Hs1T2lBONU/esrJoPaVUeuPcbPKOdv2BkXZfpQ dyDAJHWF9nmptamzAfrPv0+O0sFHqx26NldRXXDr4BwgfNikwHUHxYc1pDkVwWdzBM kt985oOnOiLDoJwYxS7AMFXhNxnAjGQexhRkahAFqPTulf7r3bnkZyfOvTvSGtExEV SclTkXD1WYWEH77uBjlSH8EZ6TY54Ii4shUQ31uCXJyLXAsO47jKu3F2ot93jfU5kd +vpAxtZSl26Zw== 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: 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 Cc: Alex Williamson Signed-off-by: John Hubbard --- drivers/vfio/vfio_iommu_type1.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index c7a111ad9975..18aa36b56896 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -327,9 +327,8 @@ static int put_pfn(unsigned long pfn, int prot) { 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; @@ -347,7 +346,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr, 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]);