From patchwork Thu Sep 22 16:39:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12985545 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F21DBC6FA82 for ; Thu, 22 Sep 2022 16:39:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232153AbiIVQjw (ORCPT ); Thu, 22 Sep 2022 12:39:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231783AbiIVQjp (ORCPT ); Thu, 22 Sep 2022 12:39:45 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C19C747B85; Thu, 22 Sep 2022 09:39:40 -0700 (PDT) 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=Xu2yIyQMXVEwJTJBi/e/+Dcdu4SpQWsBgv2SjQYCf/A=; b=KIM9BmSYlsQIvRYsL18F9XObE/ h9K2RvGbiPiu0mHHmMkUhiAqk9yFVgN1wVYbbnrJ+wMgXhIf9tivWOVs+0x4Cm2mtSxt09t9IGMzf qZwCWRkjt5Jt7mb7o/BUrp5yrqOPWcCDLjLeeZj9NaoSlSuB8/0i1yS7YQaAPsG1XSg+8Z/RMlVp1 yg1YzKI4UHt6uViSw3psbwMmrRTBLIEy9FTM6rRXprG69Xz+XYC1H9il/H7q+gYoJV2xjY0KATv0R XKGNkY31WRLGXWmMVcTmzf032nnL5gBkMFZtmZxKGX2ug9Me5TXLuA2FPKztRt/gV5bP6spbeo1PE nyAuTHpw==; 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 1obPEf-00862b-HN; Thu, 22 Sep 2022 10:39:39 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1obPEa-0001rj-Qe; Thu, 22 Sep 2022 10:39:32 -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 Cc: Christoph Hellwig , Greg Kroah-Hartman , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=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 , Stephen Bates , Logan Gunthorpe Date: Thu, 22 Sep 2022 10:39:19 -0600 Message-Id: <20220922163926.7077-2-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220922163926.7077-1-logang@deltatee.com> References: <20220922163926.7077-1-logang@deltatee.com> MIME-Version: 1.0 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, hch@lst.de, gregkh@linuxfoundation.org, 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, sbates@raithlin.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v10 1/8] 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) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.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 Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard --- 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 21f8b27bd9fd..3cea77c8a9ea 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2897,6 +2897,7 @@ 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 5abdaf487460..108848b67f6f 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -601,6 +601,12 @@ 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); @@ -1039,6 +1045,9 @@ 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; @@ -2383,6 +2392,10 @@ 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; @@ -2462,6 +2475,12 @@ 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))) { @@ -2950,7 +2969,8 @@ 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)