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 447AE7F9 for ; Wed, 4 Sep 2024 18:35:37 +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=1725474939; cv=none; b=iRwoVyovMVkB0bJYFvHpSJr0MiW6bFys9UYpdmtIl9rv1di+XFOn1HetGpZKB9hMzjfjFX5u9Cv/ba8TXdbpOh9QrGwpfL/0SrBPjkI2ba8LJdyyA4/WJkWfMuq5UTci82rg7Q1eyOCxe/35x8XudYf+f0XofpVdgWL5qlEns8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725474939; c=relaxed/simple; bh=ZgbBY7c+lpTPhuSXTLpXjno6LF3GWHdMMdsIDM6e8a8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fRAK3LYQtbQ25Pt6i00mDNYVTDTA+wloXeQhwyQFOJSKR81aHxFDTiesi66FZ1AD2VkyPParBb3Vy5KYir2ky6uY4F4XDO44iWGwyAPygSX3Jd66JCVs1EIgia8NMaZtgGYiZs5A1GxrU7PaV5aOeVf/ZVhukZZ84llnXhhUemM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=El5uH9pb; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="El5uH9pb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1725474936; 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=3HVsVF2xOn1FP/Bvg+Qsg7hEnzPUS8l4u7+VV8N40dk=; b=El5uH9pbwyljdnspCBXkIvKS+vBDQzaHcaWQcBpDi1f8kzldxB2SXt/yUOaQraZ8AV0s6o igmRgJXeyRKzeEx8s9ewmKXwAi7NcxgLBatjBmi4kI7CQD7iz1CDwkdWYAPnfWGmNLtabM wnxT4MWz1ukFKxJ85TOVFkngUKHdkWY= 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-265-DnPw2zVwN2e1pGk-VJMa7Q-1; Wed, 04 Sep 2024 14:35:35 -0400 X-MC-Unique: DnPw2zVwN2e1pGk-VJMa7Q-1 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-42bb5950d1aso76054825e9.2 for ; Wed, 04 Sep 2024 11:35:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725474934; x=1726079734; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language: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=3HVsVF2xOn1FP/Bvg+Qsg7hEnzPUS8l4u7+VV8N40dk=; b=o0W39J5PmHP7lhcR0AR2RKUEY+kV0gCNqomwRSq67V8tCbzvYnky/7GuXiAfENj37l EvAoViT9D+MfL5ezbDL9Yo4XKpG+z6a+fCSpLceCfFxjNEWO9MA4bao9Bz3hu70O/DBg BRZB3BP5YZkgl2PH8qu+rzk5SpETaoGHLli6RMaOhBJg4rCuOQ+8zILVfEh1Q+xjZZRz A/xv4kJYTxytXy00ACdZXLbqz77Y82ORoyEZAfiQM9kk842rnx9w50zjpnn24fO8djFz 3L1TXEtQsd3AJUvHbxflvLpg2tql2Mke0RcO1SaKlWEk+SYHvAnQ01qWQcKZluH1tEeO ypOw== X-Forwarded-Encrypted: i=1; AJvYcCUAqTK/QVHopcj9uOAuB61neTqkrgDtY9CGFg3W/9Czp9SFXA/yUkZ5b/jqhJwFwIxBMj2qxJ0VmWckTWE=@vger.kernel.org X-Gm-Message-State: AOJu0YyA/nA4Jdfg/jm9l3224pW0GWGSQa5Q2YA7LbkSfj1l5BCZUxnM lfEru77Yj48hxTvH01wmqq3S+4/RU0/oKWYsa0tCaHixuzPaSAxDXg8+M9g2KhXJkH7fNlS+bua OCqDqdkfTVlgRiQz93kj10cVi3rfFt7ESkIHP69vfZOw2dq21vRXLJVlRycuofQ== X-Received: by 2002:a05:600c:3b9a:b0:428:29e:8c42 with SMTP id 5b1f17b1804b1-42c9a364c50mr483505e9.9.1725474933796; Wed, 04 Sep 2024 11:35:33 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHjQ5W9UCQ2BAAdVNt5vuAXutYNCdvk03IQ6oU8BYEaSI83b+Vz6kIEQ5gshvUwmJyrypkS4Q== X-Received: by 2002:a05:600c:3b9a:b0:428:29e:8c42 with SMTP id 5b1f17b1804b1-42c9a364c50mr483225e9.9.1725474932856; Wed, 04 Sep 2024 11:35:32 -0700 (PDT) Received: from ?IPV6:2003:cb:c715:d00:e9a5:ae4b:9bdb:d992? (p200300cbc7150d00e9a5ae4b9bdbd992.dip0.t-ipconnect.de. [2003:cb:c715:d00:e9a5:ae4b:9bdb:d992]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42bbf00e095sm171582735e9.13.2024.09.04.11.35.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Sep 2024 11:35:32 -0700 (PDT) Message-ID: Date: Wed, 4 Sep 2024 20:35:31 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [v2 PATCH 1/2] hugetlb: arm64: add mte support To: Yang Shi , catalin.marinas@arm.com, will@kernel.org, muchun.song@linux.dev, akpm@linux-foundation.org Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20240821184752.3535276-1-yang@os.amperecomputing.com> <034f3269-7290-4599-8f12-72b63bf75195@redhat.com> <3ba2cc44-811b-44ff-b376-50c31b7717c3@os.amperecomputing.com> Content-Language: en-US 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: <3ba2cc44-811b-44ff-b376-50c31b7717c3@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 04.09.24 19:57, Yang Shi wrote: > > > On 9/3/24 2:35 PM, David Hildenbrand wrote: >> On 03.09.24 18:46, Yang Shi wrote: >>> >>> >>> On 9/2/24 7:33 AM, David Hildenbrand wrote: >>>> On 21.08.24 20:47, Yang Shi wrote: >>>>> Enable MTE support for hugetlb. >>>>> >>>>> The MTE page flags will be set on the head page only.  When copying >>>>> hugetlb folio, the tags for all tail pages will be copied when copying >>>>> head page. >>>>> >>>>> When freeing hugetlb folio, the MTE flags will be cleared. >>>>> >>>>> Signed-off-by: Yang Shi >>>>> --- >>>>>    arch/arm64/include/asm/hugetlb.h | 11 ++++++++++- >>>>>    arch/arm64/include/asm/mman.h    |  3 ++- >>>>>    arch/arm64/kernel/hibernate.c    |  7 +++++++ >>>>>    arch/arm64/kernel/mte.c          | 25 +++++++++++++++++++++++-- >>>>>    arch/arm64/kvm/guest.c           | 16 +++++++++++++--- >>>>>    arch/arm64/kvm/mmu.c             | 11 +++++++++++ >>>>>    arch/arm64/mm/copypage.c         | 25 +++++++++++++++++++++++-- >>>>>    fs/hugetlbfs/inode.c             |  2 +- >>>>>    8 files changed, 90 insertions(+), 10 deletions(-) >>>>> >>>>> v2: * Reimplemented the patch to fix the comments from Catalin. >>>>>       * Added test cases (patch #2) per Catalin. >>>>> >>>>> diff --git a/arch/arm64/include/asm/hugetlb.h >>>>> b/arch/arm64/include/asm/hugetlb.h >>>>> index 293f880865e8..00a1f75d40ee 100644 >>>>> --- a/arch/arm64/include/asm/hugetlb.h >>>>> +++ b/arch/arm64/include/asm/hugetlb.h >>>>> @@ -11,6 +11,7 @@ >>>>>    #define __ASM_HUGETLB_H >>>>>      #include >>>>> +#include >>>>>    #include >>>>>      #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION >>>>> @@ -20,7 +21,15 @@ extern bool >>>>> arch_hugetlb_migration_supported(struct hstate *h); >>>>>      static inline void arch_clear_hugetlb_flags(struct folio *folio) >>>>>    { >>>>> -    clear_bit(PG_dcache_clean, &folio->flags); >>>>> +    const unsigned long clear_flags = BIT(PG_dcache_clean) | >>>>> +        BIT(PG_mte_tagged) | BIT(PG_mte_lock); >>>>> + >>>>> +    if (!system_supports_mte()) { >>>>> +        clear_bit(PG_dcache_clean, &folio->flags); >>>>> +        return; >>>>> +    } >>>>> + >>>>> +    folio->flags &= ~clear_flags; >>>>>    } >>>>>    #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags >>>>>    diff --git a/arch/arm64/include/asm/mman.h >>>>> b/arch/arm64/include/asm/mman.h >>>>> index 5966ee4a6154..304dfc499e68 100644 >>>>> --- a/arch/arm64/include/asm/mman.h >>>>> +++ b/arch/arm64/include/asm/mman.h >>>>> @@ -28,7 +28,8 @@ static inline unsigned long >>>>> arch_calc_vm_flag_bits(unsigned long flags) >>>>>         * backed by tags-capable memory. The vm_flags may be >>>>> overridden by a >>>>>         * filesystem supporting MTE (RAM-based). >>>>>         */ >>>>> -    if (system_supports_mte() && (flags & MAP_ANONYMOUS)) >>>>> +    if (system_supports_mte() && >>>>> +        (flags & (MAP_ANONYMOUS | MAP_HUGETLB))) >>>>>            return VM_MTE_ALLOWED; >>>>>          return 0; >>>>> diff --git a/arch/arm64/kernel/hibernate.c >>>>> b/arch/arm64/kernel/hibernate.c >>>>> index 02870beb271e..722e76f29141 100644 >>>>> --- a/arch/arm64/kernel/hibernate.c >>>>> +++ b/arch/arm64/kernel/hibernate.c >>>>> @@ -266,10 +266,17 @@ static int swsusp_mte_save_tags(void) >>>>>            max_zone_pfn = zone_end_pfn(zone); >>>>>            for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; >>>>> pfn++) { >>>>>                struct page *page = pfn_to_online_page(pfn); >>>>> +            struct folio *folio; >>>>>                  if (!page) >>>>>                    continue; >>>>>    +            folio = page_folio(page); >>>>> + >>>>> +            if (folio_test_hugetlb(folio) && >>>>> +                !page_mte_tagged(&folio->page)) >>>>> +                continue; >>>> >>>> Can we have folio_test_mte_tagged() whereby you make sure that only >>>> folio_test_hugetlb() uses it for now (VM_WARN_ON_ONCE) and then make >>>> sure that nobody uses page_mte_tagged() on hugetlb folios >>>> (VM_WARN_ON_ONCE)? >>> >>> >>> IIUC, you mean something like the below? >>> >>> bool folio_test_mte_tagged(struct folio *folio) >>> { >>>       VM_WARN_ON_ONCE(!folio_test_hugetlb(folio)); >>> >>>       return test_bit(PG_mte_tagged, &folio->page->flags); >> >> folio->flags >> >>> } >>> >>> bool page_mte_tagged(struct page *page) >>> { >>>       struct folio *folio = page_folio(page); >>> >>>       VM_WARN_ON_ONCE(folio_test_hugetlb(folio)); >> >> Yes, but better as >> >> VM_WARN_ON_ONCE(folio_test_hugetlb(page_folio(page))); > > I see. But I think all the call sites for folio_test_mte_tagged() > actually need have folio_test_hugetlb() before it. So the warn seems not > very useful other than warning on some misuse. ... well, that's the whole reason for them :) > >> >>> >>>       return test_bit(PG_mte_tagged, &pge->flags); >>> } >>> >>>> >>>> Same for folio_set_mte_tagged() and other functions. We could slap a >>>> "hugetlb" into the function names, but maybe in the future we'll be >>>> able to use a single flag per folio (I know, it's complicated ...). >>> >>> A single flag per folio should be the future direction, but I haven't >>> done the research so can't tell how complicated it will be. >> >> There were some discussions on it, and it's tricky. So maybe we should >> really just have folio_test_hugetlb_mte_tagged() etc. for now > > Either w/ hugetlb or w/o hugetlb is fine, I don't have strong opinion on > the naming. Let's go with "hugetlb" for now, using it for other large folios is out of sight a bit ... at least right now :) -- Cheers, David / dhildenb