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[142.162.112.119]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5033745c426sm56137391cf.7.2026.01.30.06.44.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Jan 2026 06:44:15 -0800 (PST) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1vlpjL-0000000B0t1-0Fhg; Fri, 30 Jan 2026 10:44:15 -0400 Date: Fri, 30 Jan 2026 10:44:15 -0400 From: Jason Gunthorpe To: Christian =?utf-8?B?S8O2bmln?= Cc: Leon Romanovsky , Sumit Semwal , 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 v5 4/8] vfio: Wait for dma-buf invalidation to complete Message-ID: <20260130144415.GE2328995@ziepe.ca> References: <20260124-dmabuf-revoke-v5-0-f98fca917e96@nvidia.com> <20260124-dmabuf-revoke-v5-4-f98fca917e96@nvidia.com> <31872c87-5cba-4081-8196-72cc839c6122@amd.com> <20260130130131.GO10992@unreal> <20260130135618.GC2328995@ziepe.ca> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jan 30, 2026 at 03:11:48PM +0100, Christian König wrote: > On 1/30/26 14:56, Jason Gunthorpe wrote: > > On Fri, Jan 30, 2026 at 02:21:08PM +0100, Christian König wrote: > > > >> That would work for me. > >> > >> Question is if you really want to do it this way? See usually > >> exporters try to avoid blocking such functions. > > > > Yes, it has to be this way, revoke is a synchronous user space > > triggered operation around things like FLR or device close. We can't > > defer it into some background operation like pm. > > Yeah, but you only need that in a couple of use cases and not all. Not all, that is why the dma_buf_attach_revocable() is there to distinguish this case from others. Jason