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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8cd8d4cad48sm148711185a.33.2026.03.09.07.29.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2026 07:29:55 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vzbcI-0000000GTxY-2R0b; Mon, 09 Mar 2026 11:29:54 -0300 Date: Mon, 9 Mar 2026 11:29:54 -0300 From: Jason Gunthorpe To: "David Hildenbrand (Arm)" Cc: linux-kernel@vger.kernel.org, "linux-mm @ kvack . org" , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , David Rientjes , Shakeel Butt , "Matthew Wilcox (Oracle)" , Alice Ryhl , Madhavan Srinivasan , Michael Ellerman , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Jarkko Sakkinen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Greg Kroah-Hartman , Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , Todd Kjos , Christian Brauner , Carlos Llamas , Ian Abbott , H Hartley Sweeten , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Simona Vetter , Leon Romanovsky , Dimitri Sivanich , Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Andy Lutomirski , Vincenzo Frascino , Eric Dumazet , Neal Cardwell , "David S. Miller" , David Ahern , Jakub Kicinski , Paolo Abeni , Miguel Ojeda , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-sgx@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, rust-for-linux@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v1 16/16] mm/memory: support VM_MIXEDMAP in zap_special_vma_range() Message-ID: <20260309142954.GM1687929@ziepe.ca> References: <20260227200848.114019-1-david@kernel.org> <20260227200848.114019-17-david@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260227200848.114019-17-david@kernel.org> X-Stat-Signature: dts6esfp7hxszm115cq5h639uhra1iq8 X-Rspamd-Server: rspam09 X-Rspam-User: X-Rspamd-Queue-Id: 180D2120014 X-HE-Tag: 1773066596-833721 X-HE-Meta: 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 30m2PnDF hYa6xuSmN4GoPDaYQe/p9MeQwf8i48AYBHWa2YHIu8phnKosw2o1Jh6gk3y8lz17gmyi0Pbwrxkrv5mNmdbAo/KS8OAM/jK17da4d3h2jEY/cM8rox5JJ4NWFtQ8Qy/qjyKqVE2gTKePKArdMcb8QAAEJXQZzUCNfL1Z38dIkgLnVhYlPAnMxQXTnpJNkpPwHj7avAC6lvFJmiERbP6hMxZKumAtgiEKSn3+r64ij8w90ICDXVPkRooocOWzWfS+OOMuMSDOBJcKcwLLOIAQXoAKr8+YVGOUJ31Ze1iEBdU7oaQ9e7tJSl1wESvhurIauQfuUXM2GKhMkX5FKutZOBRWvHatJ0hML7panA4S6aS6VZFnGrRRKPk7jkw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Feb 27, 2026 at 09:08:47PM +0100, David Hildenbrand (Arm) wrote: > There is demand for also zapping page table entries by drivers in > VM_MIXEDMAP VMAs[1]. > > Nothing really speaks against supporting VM_MIXEDMAP for driver use. We > just don't want arbitrary drivers to zap in ordinary (non-special) VMAs. > > [1] https://lore.kernel.org/r/aYSKyr7StGpGKNqW@google.com Are we sure about this? This whole function seems like a hack to support drivers that are not using an address_space. I say that as one of the five driver authors who have made this mistake. The locking to safely use this function is really hard to do properly, IDK if binder can shift to use address_space ?? Jason