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[209.132.180.67]) by mx.google.com with ESMTP id q24si9820071ejr.128.2019.11.03.13.22.18; Sun, 03 Nov 2019 13:22:41 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=OAyRSW4f; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728607AbfKCVS0 (ORCPT + 99 others); Sun, 3 Nov 2019 16:18:26 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:17504 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728330AbfKCVSU (ORCPT ); Sun, 3 Nov 2019 16:18:20 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Sun, 03 Nov 2019 13:18:23 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Sun, 03 Nov 2019 13:18:18 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Sun, 03 Nov 2019 13:18:18 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Sun, 3 Nov 2019 21:18:18 +0000 Received: from hqnvemgw01.nvidia.com (172.20.150.20) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Sun, 3 Nov 2019 21:18:18 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by hqnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Sun, 03 Nov 2019 13:18:17 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , 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?q?J=C3=A9r=C3=B4me=20Glisse?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v2 14/18] vfio, mm: pin_longterm_pages (FOLL_PIN) and put_user_page() conversion Date: Sun, 3 Nov 2019 13:18:09 -0800 Message-ID: <20191103211813.213227-15-jhubbard@nvidia.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191103211813.213227-1-jhubbard@nvidia.com> References: <20191103211813.213227-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public Content-Transfer-Encoding: quoted-printable Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1572815904; bh=1iOGN4TRt8PvqjiLdwM6f6zOKk3A3b0FSz4UPjmoAC4=; 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=OAyRSW4fz9UjixnJPOQaglpLfSXgi7hZ6p50OoOhrLZfb106XYVyWfNelOGyOefln 4Xf4SxQgL5HfXtUn5ZluPWd49rtAZPWLpP38mGIQrFtKjFzur2WF8ZuraePQI8ImgT EGXdW1OXicEbqsELOmkgg2iKfHyO0JV2kCE6oBgl5EZnTOiPdBptLS0mRdNxS8xcbm +PUEHlLAjGdEon1mRW51BRYPtc//WiHuZwc3shxSnuSODuNefZNmXSZ1aNdRq8tjjl S+8nLOg7/Xt76GP87RNiwGivmY98faMDXIItZR+tvODSGWV/Ef1Gjiov8uMVg5dZCl o1rjs1yN+iGCQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 1. Change vfio from get_user_pages(FOLL_LONGTERM), to pin_longterm_pages(), which sets both FOLL_LONGTERM and FOLL_PIN. 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(). 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 | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type= 1.c index d864277ea16f..795e13f3ef08 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 =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; @@ -349,11 +348,11 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsign= ed long vaddr, =20 down_read(&mm->mmap_sem); if (mm =3D=3D current->mm) { - ret =3D get_user_pages(vaddr, 1, flags | FOLL_LONGTERM, page, - vmas); + ret =3D pin_longterm_pages(vaddr, 1, flags, page, vmas); } else { - ret =3D get_user_pages_remote(NULL, mm, vaddr, 1, flags, page, - vmas, NULL); + ret =3D pin_longterm_pages_remote(NULL, mm, vaddr, 1, + flags, page, vmas, + NULL); /* * The lifetime of a vaddr_get_pfn() page pin is * userspace-controlled. In the fs-dax case this could @@ -363,7 +362,7 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned= long vaddr, */ if (ret > 0 && vma_is_fsdax(vmas[0])) { ret =3D -EOPNOTSUPP; - put_page(page[0]); + put_user_page(page[0]); } } up_read(&mm->mmap_sem); --=20 2.23.0