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Howlett" , Mike Rapoport , Peter Xu , Suren Baghdasaryan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka , Muchun Song , Hugh Dickins , Andrew Morton , James Houghton , Michal Hocko , Andrea Arcangeli , Oscar Salvador , Axel Rasmussen , Ujwal Kundur References: <289eede1-d47d-49a2-b9b6-ff8050d84893@redhat.com> <930d8830-3d5d-496d-80d8-b716ea6446bb@amazon.com> <4czztpp7emy7gnigoa7aap2expmlnrpvhugko7q4ycfj2ikuck@v6aq7tzr6yeq> <7cccbceb-b833-4a21-bdc4-1ff9d1d6c14f@lucifer.local> 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <7cccbceb-b833-4a21-bdc4-1ff9d1d6c14f@lucifer.local> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Vy7ewHeJjxOiJm8VA88HtI-24hMFSftdm17x7a0vdDc_1758218029 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: utyonxb9aiaukoa3fjib5gj8tenhctpf X-Rspam-User: X-Rspamd-Queue-Id: A7210C000A X-Rspamd-Server: rspam04 X-HE-Tag: 1758218032-461113 X-HE-Meta: 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 dtpF7R7e 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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 18.09.25 19:45, Lorenzo Stoakes wrote: > On Thu, Sep 18, 2025 at 06:15:41PM +0100, Nikita Kalyazin wrote: >> The other patches it I was building on top were mmap support in guest_memfd >> [4], which is currently merged in kvm/next, and also part of [3]. >> >> [3] https://git.kernel.org/pub/scm/linux/kernel/git/david/linux.git/tree/virt/kvm/guest_memfd.c?id=911634bac3107b237dcd8fdcb6ac91a22741cbe7#n347 >> [4] https://lore.kernel.org/kvm/20250729225455.670324-1-seanjc@google.com > > Note that the mmap implementation is changing to mmap_prepare. It's the > case in point example of where we exposed an internal mm object (VMA) and > experienced significant issues including embargoed critical zero-day > security reports as a result. > > I took a quick look at [3] and it seems you're using it in a totally normal > way which is completely fine, however, and it'll be very easily convertible > to mmap_prepare. Yes, we'll take care of that once it's (finally :D ) upstream! Re Nikita: If we could just reuse fault() for userfaultfd purposes, that might actually be pretty nice. -- Cheers David / dhildenb