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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8942e6a9d97sm127467116d6.34.2026.01.21.07.50.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jan 2026 07:50:00 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1viaT2-00000006Emy-0KMB; Wed, 21 Jan 2026 11:50:00 -0400 Date: Wed, 21 Jan 2026 11:50:00 -0400 From: Jason Gunthorpe To: Pranjal Shrivastava Cc: Leon Romanovsky , Sumit Semwal , Christian =?utf-8?B?S8O2bmln?= , Alex Deucher , David Airlie , Simona Vetter , Gerd Hoffmann , Dmitry Osipenko , Gurchetan Singh , Chia-I Wu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Lucas De Marchi , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , Rodrigo Vivi , Kevin Tian , Joerg Roedel , Will Deacon , Robin Murphy , Felix Kuehling , Alex Williamson , Ankit Agrawal , Vivek Kasireddy , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, virtualization@lists.linux.dev, intel-xe@lists.freedesktop.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, kvm@vger.kernel.org Subject: Re: [PATCH v4 8/8] vfio: Validate dma-buf revocation semantics Message-ID: <20260121155000.GE961572@ziepe.ca> References: <20260121-dmabuf-revoke-v4-0-d311cbc8633d@nvidia.com> <20260121-dmabuf-revoke-v4-8-d311cbc8633d@nvidia.com> <20260121134712.GZ961572@ziepe.ca> <20260121142528.GC13201@unreal> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jan 21, 2026 at 02:47:29PM +0000, Pranjal Shrivastava wrote: > But at the same time, I'd like to discuss if we should think about > changing the dmabuf core, NULL op == success feels like relying on a bug Agree, IMHO, it is surprising and counter intuitive in the kernel that a NULL op means the feature is supported and default to success. Jason