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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 58C01C433EF for ; Wed, 15 Jun 2022 16:13:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Subject: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id:Date :Cc:To:From:Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=cy9XTpt2FU24C9e+HkFSboKSQbqr83R/V0hLrLGYdpk=; b=mr8k8O8goCUbqCmZFVbeUbXCV3 dKYE5I+W4fjRKFcWyqOXRRRHELbHUvuSHxTvd6NjDdTnMiJnziosMlUS39w/Hje0m6cuA1Y93bf2q 2Tocv5WDYpgUDnp2ACU4Bzq/L+Cpz41HDRbYIjNUWyjdzFV8WrnfrF92K6+ixoMoyNQDTNIMXyKzn c+FoztfShPYds/J2374Jipskcalbf9Oih7MQhNzOoCgFM38DShjMxH4t1Bfg6ZabYgJrKmaQzwR5d lYoP0cqvSTtXMVAC45DFjhHlPhctdJgLRbRrW07fMYaJgSFKmfjVl8ptJaEbwIzd4665g48E2gnMJ DzQvG6aw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o1VeI-00FKN7-JU; Wed, 15 Jun 2022 16:13:42 +0000 Received: from ale.deltatee.com ([204.191.154.188]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o1VdU-00FJZI-L0 for linux-nvme@lists.infradead.org; Wed, 15 Jun 2022 16:12:55 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=cy9XTpt2FU24C9e+HkFSboKSQbqr83R/V0hLrLGYdpk=; b=pd2HZB3bg2LSWZzj9EZpMOVi0s nG+iNfaXYF8eeuTEDUoZ0U8qSJTVi7vDWTdy/zmTG7/s7iE+8risFdqTCofKryO67JiCPS74QcN/D HXxUH4ZrFy8nPMUav1tnD1IuJGBOOuZbWG4zPMBXQZ2V7cHVbV5AqG0TMDbRmoolQZ69rWlMCuV15 T0Af4nUJnITfvcQU/YUlR3K/EW+r0rHA597WJEYgSPeOHyZlIYcSs4Bbe8tDPRZnOXOQJ6SUYYLig neTok2Gg7BE33rdf0OLJdVOtUp3HtDwt/bScL/0+Sc/BKuSD5YbYRxFJoenJ2Ctdtlk2YGexdDvOk vCLIivzA==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1o1VdQ-0084iT-KT; Wed, 15 Jun 2022 10:12:49 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1o1VdI-0004ac-LN; Wed, 15 Jun 2022 10:12:40 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?UTF-8?q?Christian=20K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell , Logan Gunthorpe Date: Wed, 15 Jun 2022 10:12:26 -0600 Message-Id: <20220615161233.17527-15-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220615161233.17527-1-logang@deltatee.com> References: <20220615161233.17527-1-logang@deltatee.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, jason@jlekstrand.net, dave.hansen@linux.intel.com, helgaas@kernel.org, dan.j.williams@intel.com, dave.b.minturn@intel.com, jianxin.xiong@intel.com, ira.weiny@intel.com, robin.murphy@arm.com, martin.oliveira@eideticom.com, ckulkarnilinux@gmail.com, jhubbard@nvidia.com, rcampbell@nvidia.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v7 14/21] mm: introduce FOLL_PCI_P2PDMA to gate getting PCI P2PDMA pages X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220615_091252_776464_C1CA3B64 X-CRM114-Status: GOOD ( 15.38 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org GUP Callers that expect PCI P2PDMA pages can now set FOLL_PCI_P2PDMA to allow obtaining P2PDMA pages. If GUP is called without the flag and a P2PDMA page is found, it will return an error. FOLL_PCI_P2PDMA cannot be set if FOLL_LONGTERM is set. Signed-off-by: Logan Gunthorpe --- include/linux/mm.h | 1 + mm/gup.c | 22 +++++++++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index bc8f326be0ce..0bcb54ea503c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2941,6 +2941,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */ #define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */ #define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */ +#define FOLL_PCI_P2PDMA 0x100000 /* allow returning PCI P2PDMA pages */ /* * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each diff --git a/mm/gup.c b/mm/gup.c index 551264407624..f15f01d06a09 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -564,6 +564,12 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, goto out; } + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && + is_pci_p2pdma_page(page))) { + page = ERR_PTR(-EREMOTEIO); + goto out; + } + VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && !PageAnonExclusive(page), page); @@ -994,6 +1000,9 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) if ((gup_flags & FOLL_LONGTERM) && vma_is_fsdax(vma)) return -EOPNOTSUPP; + if ((gup_flags & FOLL_LONGTERM) && (gup_flags & FOLL_PCI_P2PDMA)) + return -EOPNOTSUPP; + if (vma_is_secretmem(vma)) return -EFAULT; @@ -2289,6 +2298,10 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); page = pte_page(pte); + if (unlikely(!(flags & FOLL_PCI_P2PDMA) && + is_pci_p2pdma_page(page))) + goto pte_unmap; + folio = try_grab_folio(page, 1, flags); if (!folio) goto pte_unmap; @@ -2368,6 +2381,12 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, undo_dev_pagemap(nr, nr_start, flags, pages); break; } + + if (!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page)) { + undo_dev_pagemap(nr, nr_start, flags, pages); + break; + } + SetPageReferenced(page); pages[*nr] = page; if (unlikely(!try_grab_page(page, flags))) { @@ -2856,7 +2875,8 @@ static int internal_get_user_pages_fast(unsigned long start, if (WARN_ON_ONCE(gup_flags & ~(FOLL_WRITE | FOLL_LONGTERM | FOLL_FORCE | FOLL_PIN | FOLL_GET | - FOLL_FAST_ONLY | FOLL_NOFAULT))) + FOLL_FAST_ONLY | FOLL_NOFAULT | + FOLL_PCI_P2PDMA))) return -EINVAL; if (gup_flags & FOLL_PIN) -- 2.30.2