From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CDE9A292B22 for ; Tue, 17 Jun 2025 09:19:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750151983; cv=none; b=cab8cUbtNMbQQv0mTJVRjLifutv2Jusu2IhZn6KkTNk6KOlZtgGKQ4Vyqg62lGjrBumztmbFfd6BevnvzqLK/W+OJENZJSS9diOXIk1uFenyJabcttO6rvBGplcwxMG8bwF/y97vFal0YnNlmE65faCQTHB7DX0/Gndl2Spu6Cw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750151983; c=relaxed/simple; bh=+5SWU1o8juSDYZoOuyQJC1B+OKlGQ52mSspkNeSUazk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KkiacB2S7kxS0J029OU1b1VwlmocQC2eWDYMQTsfz2jhcgyjRXyuS8l+BFy7LxV52I/JUZJbmm/8woSADTI0uBWWB1CapePPzZ+U/5wp7nzowxnFSvWsp6zOqMQe5OJezYH09zH8GjJ3WMUHaj2Rq97FCVKZmIealrqU3snj9fw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Hpyv6nxu; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Hpyv6nxu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750151979; 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=Pl6PxwbpUS7ADU1xqvtXXrf/iKUynSR5SAu+83BnGX4=; b=Hpyv6nxuUkYyaiSPWyTENXhMPXmMziP5LWCNJqk+SV/gM4mOWMsHPPHyk8T1g1LZ+wvtp6 VDeDiWzC2xAxN6S+QkgrSoYDOIFb0O5R0EhqmeWfP7XfVtCc+5cL2pcU31a/IyOlsEzGpE +ORyZjkGIviB99mAWsh5xEXPqt6iQKg= 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-389-Gi03rvpePC6QSdp0sCg9sw-1; Tue, 17 Jun 2025 05:19:38 -0400 X-MC-Unique: Gi03rvpePC6QSdp0sCg9sw-1 X-Mimecast-MFC-AGG-ID: Gi03rvpePC6QSdp0sCg9sw_1750151977 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-451d2037f1eso33772105e9.0 for ; Tue, 17 Jun 2025 02:19:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750151977; x=1750756777; 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=Pl6PxwbpUS7ADU1xqvtXXrf/iKUynSR5SAu+83BnGX4=; b=T35znfAQF/83lUhlJwpxjPyVSqDwOOLc/ofelGEydCXEjSTaLgEN8JTIiegFplTzSK 5qOtrlayaa6CeqgWBvEKm1ESS7uzZRFJll61WrltBpENf3z4xTQ9KpwvTYuzjPbR7VxL oa1wC8XbZemsKN7j1KDrGzTrJWEpJsviuLrC5F7Sa+KKqSSAd+8DhR42yJ2DyZLdxkPS 3AN+ACNz2TWQIYZDu6J6a28TiykPhcyicRviqge6r7KSxNj7QJX3CJDJDLbmUYmohm/l 9dV4baDtON28EoDsQEYLHSQUhAJUElFlTRtEgR/+v15sNGo5Zs+MluZDLYlnGL+jDEHK FSAg== X-Forwarded-Encrypted: i=1; AJvYcCWeRbBUaJxhRjcwTKWzNmq5C6n0t1d81RKqnH10y4C6fjBLOdb5fKtS5dM0iM9qaajXV8TbaEs=@lists.linux.dev X-Gm-Message-State: AOJu0YyKpYcJLqOcqcFSpSLNImGzJhcV2FvvxmVCvDPG/rHYIS39Xvbj cpoTjCPJF3mQ4hj8gVFIrnwh8kHKgQeLbBCgCwaM5yi3pXJggasRq0h8WWT+CUP0LADpstmtyXi 8YYbdw2UdkxyMVe42/7gMCjUJFgY75tH5/G6jJ9Ia24APmOdIXh2IXX4qww== X-Gm-Gg: ASbGncsKRc1nwcnj8Gu5XWFO21CuCfE93l1Th0PehEjpyJsrefWc6a1M40ID53ta18N gkkHPSOmMOV2q3HhtYqlMOXeKGC3JKQtTrP2rQBk+COuNk6qcsYs0gY0jrDqGO+uZv3XDZehZwF XnCy18g/8NCVaq/Gq7UTvskzfPzPNOPW9oXLTvlNk/3T8ROuPKLjyUyOLOvqRdbT7iSOKvg+gro IO1N3F4tOaIR+trb6bFRoS+9E07HTSQlqw+BpGK8vxfIQcS1HdMulEi+lJhwFRU7aeLV35TBYTb rOVtIWHGSaamZAsmZdAfLItYldc8IVSGPnnZyWLp1CWLpNtETEHNJ0vG3HbPo49jqxcx1+d6nYQ jELT5alPIODIsPlDaSYNbRRsi37Az/mq4EHze8Fg/gv7HBvE= X-Received: by 2002:a05:6000:4202:b0:3a4:dfaa:df8d with SMTP id ffacd0b85a97d-3a572367c45mr11265707f8f.9.1750151977294; Tue, 17 Jun 2025 02:19:37 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHt8iXJvJT0W2e4sI8GT6VcpVG8jxrePAU09oM8r6xnq4XSbjmN3FC6k4gXR+D2djVSpIQQtw== X-Received: by 2002:a05:6000:4202:b0:3a4:dfaa:df8d with SMTP id ffacd0b85a97d-3a572367c45mr11265656f8f.9.1750151976687; Tue, 17 Jun 2025 02:19:36 -0700 (PDT) Received: from ?IPV6:2003:d8:2f31:700:3851:c66a:b6b9:3490? (p200300d82f3107003851c66ab6b93490.dip0.t-ipconnect.de. [2003:d8:2f31:700:3851:c66a:b6b9:3490]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a568b08e21sm13528866f8f.52.2025.06.17.02.19.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 17 Jun 2025 02:19:36 -0700 (PDT) Message-ID: Date: Tue, 17 Jun 2025 11:19:34 +0200 Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 01/14] mm: Convert pXd_devmap checks to vma_is_dax To: Alistair Popple , akpm@linux-foundation.org Cc: linux-mm@kvack.org, 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, m.szyprowski@samsung.com, Jason Gunthorpe References: <361009510f346090fad328c53ec228d99bb955ee.1750075065.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: <361009510f346090fad328c53ec228d99bb955ee.1750075065.git-series.apopple@nvidia.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 0IvDUCD4Iv2xpxjxbp7GsJrXXCG2FAC90IfrZZ2hs3Y_1750151977 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 16.06.25 13:58, 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 > Reviewed-by: Jason Gunthorpe > Reviewed-by: Dan Williams > > --- > > Changes from v1: > > - Remove vma_is_dax() check from mm/userfaultfd.c as > validate_move_areas() will already skip DAX VMA's on account of them > not being anonymous. This should be documented in the patch description above. > --- > fs/userfaultfd.c | 2 +- > mm/hmm.c | 2 +- > mm/userfaultfd.c | 6 ------ > 3 files changed, 2 insertions(+), 8 deletions(-) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index ef054b3..a886750 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; VMA checks should be done before doing any page table walk. > > if (pmd_trans_huge(_pmd)) { > diff --git a/mm/hmm.c b/mm/hmm.c > index feac861..5311753 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -441,7 +441,7 @@ 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; Dito. > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index 58b3ad6..8395db2 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -1818,12 +1818,6 @@ 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)) { > - spin_unlock(ptl); > - err = -ENOENT; > - break; > - } > - > /* Check if we can move the pmd without splitting it. */ > if (move_splits_huge_pmd(dst_addr, src_addr, src_start + len) || > !pmd_none(dst_pmdval)) { -- Cheers, David / dhildenb