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 EBF99C5B556 for ; Fri, 30 May 2025 09:44:39 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yhyTHW9/iNSmJ3o1/+Kc2KlH+vX1ja7mHJ+mDxpkv9E=; b=HIAtRD9+Nd+IW6jgfFiK2HZZtT fpYMKQutOEhQNLSjzXV14yiKuj+gH7yH2mwhp1ukjWcD6LO/jrjMDmLLRYOTEMBZgGzXUvPVg23+C Tjy40elBeweaQjneH5KhRWVnV1vYOCNRD5xfW6TaaygNmktOdBrQCkNQGoXQtDbbixGpPQm/fI+Nj FYELK7pOhUFs2IzxzUc47CLm5cW4YHbxYiseVRxdNTKjINyutdTkhEC14jB5Bx4dECPepgay5Qta+ 5FHZX/Dyl+AqX6iUaYY3Q86jrVN7nUtfuoNW5Z6tbhf5u2fnRSKLbcx26SZOqhNDMObjipOa/haTc HEfGQgAw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uKwHx-00000000CAl-3aR0; Fri, 30 May 2025 09:44:33 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uKwB5-00000000AB6-3IGm for linux-arm-kernel@lists.infradead.org; Fri, 30 May 2025 09:37:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1748597846; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=yhyTHW9/iNSmJ3o1/+Kc2KlH+vX1ja7mHJ+mDxpkv9E=; b=DY3NG2HjIHrDin4d3KPLRqtKEZs2d0c17bWrS+6pxwaFkhGLp+C86KrCscAKUrD7SHlg3x OHR0BcexiZcKHpI72C/W2QK/0tsEEx2XO0sMbsLsjMGpA//ltVI4udxuxeZNpePL0DzoRz m0PsqlX3vjOA3YmNjcRSw1HaxFvFaMU= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-581-1bWEQT5yNl-iNbThHiEfvQ-1; Fri, 30 May 2025 05:37:25 -0400 X-MC-Unique: 1bWEQT5yNl-iNbThHiEfvQ-1 X-Mimecast-MFC-AGG-ID: 1bWEQT5yNl-iNbThHiEfvQ_1748597844 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-442f4a3851fso15613815e9.1 for ; Fri, 30 May 2025 02:37:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748597844; x=1749202644; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=yhyTHW9/iNSmJ3o1/+Kc2KlH+vX1ja7mHJ+mDxpkv9E=; b=dn9eWh/IMB7d8e9x0hhwk/VVR2e9m5pc2y+z774eCzn4LjNajN5+nBYRQjCL9Xh2WI z5Vvp2qmKVo6qEN8BbbrZtiZBC5ckZgmspGYA3sxDKnEmdeWWh2qOwhJ1fF1bliAvUk/ SZ/vJI83MHlHhCoOnr6A8ZbRyqRK+NazU7qU/yJyKNd1zjn2LzpJKdMtbFAIE7vOUhNz oMnZUkPfS5EKI0jcgzlPzg1PHQWX5nV0nXyuWJSpiunTleNPH+EylPKrkgClv6B0AZi0 NxDY3XGwRK9khmQyYa+d1Cxb1BglPEnTFoGLuYErvjzl55JmUF5Y34S3seTZ3eADNXuS qeqQ== X-Forwarded-Encrypted: i=1; AJvYcCU5aTIn31+vk/qHnJYKRAI6m/VY2tYFPPrkqJDzHwTeDwqHWDmJP1kIiy4dlzrQeMvx8uToITgHWNRhwNnFGtPN@lists.infradead.org X-Gm-Message-State: AOJu0YzgTRI+RM7PHaA5nI5laEDURjCeC0LtUOCV62Es7rjLPCdcBD/g F2W6t/nfFXeAeOf5ZujVZrHRGbFi2eMooA7gs9XCuMGd8D7ONmTRBNwZXvzkTzGElb8LBxOYG5Z i1NGOvJjCfNLVwoyW4+WHsRgS+jWjtwb5iUOPTUFZk27PxlLb0dU8Q9K9J5IvqAm1h2DGtYPAjx UH X-Gm-Gg: ASbGncvH6VvGAVNPaRVPwHCuEX4pDvanSvceGTkNzjiDQDS7eR6V7AH76M5JDb2VGD1 epBswsj+OLvOva3pvMhPuupADay2N4OyB+965z4IlkW+R3f5SsiovFHOSutfz+J0zL0ZFKbpozZ ngbYkmA2x86UAcqJX9+NBGkWCa75tVNfmIKUtIheja4ix1AEaZdPjtaRiRbaMXTuiX/uGXwUIUC LNcsEX4JUXKAAVKjm38hEkcp6hM0ZtUb8T8IVYd1hUbOyaJMWZkUhjmGXjgTXx0K08G5ZlEZ/kZ W8PYWShJRP96tptuSsJn/gzWP0qE9IjGFxgShrvTD24xPIOkQeggSKY4oiMtHtou8nX8zkO5BsX K/uG9PWXD9rTNI0EQSmuPwYn56NAHcZHvPNhBhqE= X-Received: by 2002:a05:600c:6207:b0:43c:ea36:9840 with SMTP id 5b1f17b1804b1-450d885e38amr12675525e9.22.1748597844514; Fri, 30 May 2025 02:37:24 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGccFKRFTCgkkT3ae/QFUuhHOQzucrbv9tCboH5VNdb/K0MlBO6YnvTUAz5zFzNoWT7UAvZNw== X-Received: by 2002:a05:600c:6207:b0:43c:ea36:9840 with SMTP id 5b1f17b1804b1-450d885e38amr12675135e9.22.1748597844047; Fri, 30 May 2025 02:37:24 -0700 (PDT) Received: from ?IPV6:2003:d8:2f03:5b00:f549:a879:b2d3:73ee? (p200300d82f035b00f549a879b2d373ee.dip0.t-ipconnect.de. [2003:d8:2f03:5b00:f549:a879:b2d3:73ee]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-450d800671csm12953125e9.30.2025.05.30.02.37.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 May 2025 02:37:22 -0700 (PDT) Message-ID: <371b8fdd-129d-4fe3-bbc7-f0a1bc433b30@redhat.com> Date: Fri, 30 May 2025 11:37:21 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 02/12] mm: Convert pXd_devmap checks to vma_is_dax To: Alistair Popple , linux-mm@kvack.org Cc: gerald.schaefer@linux.ibm.com, dan.j.williams@intel.com, jgg@ziepe.ca, willy@infradead.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, zhang.lyra@gmail.com, debug@rivosinc.com, bjorn@kernel.org, balbirs@nvidia.com, lorenzo.stoakes@oracle.com, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-cxl@vger.kernel.org, dri-devel@lists.freedesktop.org, John@Groves.net References: <224f0265027a9578534586fa1f6ed80270aa24d5.1748500293.git-series.apopple@nvidia.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <224f0265027a9578534586fa1f6ed80270aa24d5.1748500293.git-series.apopple@nvidia.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: vhFHby9IoRvND5miVQH2-ratK0zj2yKdo_GHqji8oe4_1748597844 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250530_023727_893108_FC26CE4F X-CRM114-Status: GOOD ( 18.21 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 29.05.25 08:32, Alistair Popple wrote: > Currently dax is the only user of pmd and pud mapped ZONE_DEVICE > pages. Therefore page walkers that want to exclude DAX pages can check > pmd_devmap or pud_devmap. However soon dax will no longer set PFN_DEV, > meaning dax pages are mapped as normal pages. > > Ensure page walkers that currently use pXd_devmap to skip DAX pages > continue to do so by adding explicit checks of the VMA instead. > > Signed-off-by: Alistair Popple > --- > fs/userfaultfd.c | 2 +- > mm/hmm.c | 2 +- > mm/userfaultfd.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index 22f4bf9..de671d3 100644 > --- a/fs/userfaultfd.c > +++ b/fs/userfaultfd.c > @@ -304,7 +304,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx, > goto out; > > ret = false; > - if (!pmd_present(_pmd) || pmd_devmap(_pmd)) > + if (!pmd_present(_pmd) || vma_is_dax(vmf->vma)) > goto out; > > if (pmd_trans_huge(_pmd)) { > diff --git a/mm/hmm.c b/mm/hmm.c > index 082f7b7..db12c0a 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -429,7 +429,7 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, > return hmm_vma_walk_hole(start, end, -1, walk); > } > > - if (pud_leaf(pud) && pud_devmap(pud)) { > + if (pud_leaf(pud) && vma_is_dax(walk->vma)) { > unsigned long i, npages, pfn; > unsigned int required_fault; > unsigned long *hmm_pfns; > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index e0db855..133f750 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -1791,7 +1791,7 @@ ssize_t move_pages(struct userfaultfd_ctx *ctx, unsigned long dst_start, > > ptl = pmd_trans_huge_lock(src_pmd, src_vma); > if (ptl) { > - if (pmd_devmap(*src_pmd)) { > + if (vma_is_dax(src_vma)) { > spin_unlock(ptl); > err = -ENOENT; > break; I assume we could also just refuse dax folios, right? If we decide to check VMAs, we should probably check earlier. But I wonder, what about anonymous non-dax pages in COW mappings? Is it possible? Not supported? If supported, checking the actual folio would be the right thing to do. -- Cheers, David / dhildenb