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Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyKzX-0000000BcoG-1EAX; Tue, 16 Sep 2025 02:00:23 +0000 Date: Tue, 16 Sep 2025 03:00:23 +0100 From: Matthew Wilcox To: "Kalyazin, Nikita" Cc: "akpm@linux-foundation.org" , "david@redhat.com" , "pbonzini@redhat.com" , "seanjc@google.com" , "viro@zeniv.linux.org.uk" , "brauner@kernel.org" , "peterx@redhat.com" , "lorenzo.stoakes@oracle.com" , "Liam.Howlett@oracle.com" , "vbabka@suse.cz" , "rppt@kernel.org" , "surenb@google.com" , "mhocko@suse.com" , "jack@suse.cz" , "linux-mm@kvack.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "jthoughton@google.com" , "tabba@google.com" , "vannapurve@google.com" , "Roy, Patrick" , "Thomson, Jack" , "Manwaring, Derek" , "Cali, Marco" Subject: Re: [RFC PATCH v6 1/2] mm: guestmem: introduce guestmem library Message-ID: References: <20250915161815.40729-1-kalyazin@amazon.com> <20250915161815.40729-2-kalyazin@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250915161815.40729-2-kalyazin@amazon.com> X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 0B9C94000E X-Stat-Signature: jdyj7idanhii35fyrop3wef9cgnxm6up X-Rspam-User: X-HE-Tag: 1757988031-309971 X-HE-Meta: U2FsdGVkX1/U/do07Wl1e4J3iD9y62GwOiVGoIuA8ubZuxtf+HyO38OCR+kMyiV4gzHQNF3NzxoOqUiZ2YOcHIzRrOV2e4NmnEgnBxo90HqeYBIkG48OtZ4o6DJFD8G+TAGbJwPVTMr3ofKvS8qMSHdn8jr2/tJ8e9ajeK5XG8CTkjBN8SAwanQA4ImhluZRyMhRubJwfpMFj+Kh01grPvcSlApOSDSOca2i6RgqMQw9F4dAaITO2q2j/dm9R9gibvV3aU9JsInN0voQ9Vs1t7YLcXjsL7r54SCcjWawRMlZVjiTPbvZ/svIiaVVav/lrBTq4eH8G4ryw3vckGqg3os8LjcXpF6sUUp0jiHZhzEKKQXKnekhXw6o0W/6UuKJZ+hSnojEzob9iJ2WnwIy08K8+MdI332QiSMDpwfsYyhxufcdzSI0HGMA7xfkYO9/W123QmJQqjPYvYvZ0PKfPUQrrxxAgMeNQ8++ubhnkCkq1406D4I8P57HeWq5GcoSmXJ3F1UHcVsP7Yk9UjkAo7Sf6EhEVtK1nX4v8w80JMO82PqzIZAHmP7mwxPAfYglW5/l+1d7rr6tXmK5zSBSmhJ3CNJE01HPbmPloOQGRjfArAPNvFfAtRRHQz/ImKwffLfBPZ6SA/u8eO6VoPtMpGyEoqoUAgbMHyw78HmfmcLO/Ar0xYKOhMM/LoGsLHIYOdJaP7V2lo7XkghxXLEuus+uqGHMThoQsl1tvTDnp9uXkz5W1ZYnIKpZxi60eioPujkehRE8ISn6ntXAunpzSTd+s4xPQWuKEqVFktRgE8zyfOrYwgUHdf5UWv8pML/OlWBw1Qpk0OsL118MGabT6yh56wj76cswa1Hcj7c5iosdsfPdyIm/+/S68rbajQ4+rxQOT2bg5AIxw+O7J1nflTkpFm3iHY+HgVwYu4HeXo7Ok12JMNb9+qhR5Ah1l57xQKaa9keeTUybZKkdvWK mig682i5 cR300DQ7hYbw3Bq2HruYT1tqpQ6tIxgyjlWeme7+9KGoyyeKCBS/8ItfMhjfo4JvGLauEw4R0Noj5yQ0d2YkpfkB3itDGi59PQstI/RAopa+OUn06oDXtuSBvzaaO/7jt3OI1ydvjhnoAS9kx6cyjUy7EMCRtfrzge3YudL0iGWXFl2jn5XOs/WkNm/OtaMQoQ89VSfCVjSdBgxlUNhubzCKns5vL8ztPQXuwSWwDK1/XfDK1QCeTEtDipFmuu8iiDqk9QFm8QQMtxvOpspKvnAmeb3MNfGXqJOY7MAniwx6Us82f3Zpl07JDmsZcQIPvtk/n 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 Mon, Sep 15, 2025 at 04:18:27PM +0000, Kalyazin, Nikita wrote: > From: Nikita Kalyazin > > Move MM-generic parts of guest_memfd from KVM to MM. This allows other > hypervisors to use guestmem code and enables UserfaultFD implementation > for guest_memfd [1]. Previously it was not possible because KVM (and > guest_memfd code) might be built as a module. https://lore.kernel.org/kvm/Z0DOdTRAaK3whZKW@casper.infradead.org/ remains un-addressed. ie this entire approach is garbage. throw it away and start again.