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[2003:cb:c709:7f00:8a04:4c6f:a761:af60]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-374c7fa443esm7787522f8f.41.2024.09.03.14.35.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 03 Sep 2024 14:35:37 -0700 (PDT) Message-ID: Date: Tue, 3 Sep 2024 23:35:36 +0200 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> 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: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 41C99C0007 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: xfb9ouar1x3o13w8dtczz5ugwroqpjm1 X-HE-Tag: 1725399344-100099 X-HE-Meta: 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 bG1SrREi 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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))); > >     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 -- Cheers, David / dhildenb