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Wed, 05 Aug 2026 10:53:09 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wrfng-00000000ITS-3vYK; Wed, 05 Aug 2026 14:53:08 -0300 Date: Wed, 5 Aug 2026 14:53:08 -0300 From: Jason Gunthorpe To: "Deucher, Alexander" Cc: "Hegde, Vasant" , "Limonciello, Mario" , "Kuehling, Felix" , "iommu@lists.linux.dev" , "joro@8bytes.org" , "linux-pci@vger.kernel.org" , "will@kernel.org" , "robin.murphy@arm.com" , "Suthikulpanit, Suravee" , "bhelgaas@google.com" , "Longia, Amandeep Kaur" Subject: Re: [PATCH 2/2] iommu/amd: Force identity mode for selected GPUs only Message-ID: <20260805175308.GD28508@ziepe.ca> References: <838281e9-8ee7-433a-b06c-68675e9b285f@amd.com> <2f400c7f-eada-45e3-9079-7b5727ecb5c3@amd.com> <08f2e48e-6e98-4fde-af71-cb8cde666bdf@amd.com> <20260805010706.GC28508@ziepe.ca> <39ce2a2f-3bb8-43e7-9446-a67551cce104@amd.com> 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, Aug 05, 2026 at 05:22:22PM +0000, Deucher, Alexander wrote: > IIRC, they supported SME, but it wasn't usable due to other > limitations (e.g., the requirement for identity mappings due to the > display hw bug and the latency impact of encryption for displays in > system memory). Do you could effectively pick either SME or > displays. IMHO the GPU driver should fail if it cannot work because it can't reach the IOVA space requried for SME ... I don't think this should be a iommu problem to deal with Jason