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Peter Anvin" , Sean Christopherson , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Bjorn Helgaas , Marek Szyprowski , Andrew Morton , Catalin Marinas , Michael Ellerman , Mike Rapoport , Tom Lendacky , Ard Biesheuvel , Neeraj Upadhyay , Ashish Kalra , Stefano Garzarella , Melody Wang , Seongman Lee , Joerg Roedel , Nikunj A Dadhania , Michael Roth , Suravee Suthikulpanit , Andi Kleen , Kuppuswamy Sathyanarayanan , Tony Luck , David Woodhouse , Greg Kroah-Hartman , Denis Efremov , Geliang Tang , Piotr Gregor , "Michael S. Tsirkin" , Alex Williamson , Arnd Bergmann , Jesse Barnes , Jacob Pan , Yinghai Lu , Kevin Brodsky , Jonathan Cameron , "Aneesh Kumar K.V (Arm)" , Xu Yilun , Herbert Xu , Kim Phillips , Konrad Rzeszutek Wilk , Stefano Stabellini , Claire Chang , linux-coco@lists.linux.dev, iommu@lists.linux.dev References: <20260225053806.3311234-1-aik@amd.com> <20260225053806.3311234-7-aik@amd.com> <699f6b1ad77cd_1cc51005d@dwillia2-mobl4.notmuch> From: Alexey Kardashevskiy Content-Language: en-US In-Reply-To: <699f6b1ad77cd_1cc51005d@dwillia2-mobl4.notmuch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SY5P300CA0084.AUSP300.PROD.OUTLOOK.COM (2603:10c6:10:247::22) To CH3PR12MB9194.namprd12.prod.outlook.com (2603:10b6:610:19f::7) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB9194:EE_|PH7PR12MB8795:EE_ X-MS-Office365-Filtering-Correlation-Id: c7643c06-448b-4903-9eb9-08de74ff70f5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014|7053199007; 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In CCA we should be in the same boat, wherein a >> trusted device can access memory at a DMA address based on its "normal" >> (private) GPA, rather than having to be redirected to the shared alias >> (it's really not an "SME mask" in that sense at all). > > Not quite, no, CCA *is* in the same boat as TDX, not SEV-SNP. Only > SEV-SNP has this concept that the DMA handle for private memory is the > dma_addr_unencrypted() conversion (C-bit masked) of the CPU physical > address. For CCA and TDX the typical expectation of dma_addr_encrypted() > for accepted devices holds. It just so happens that dma_addr_encrypted() > does not munge the address on is a nop conversion for CCA and TDX. OTOH TDX and SNP do not leak SME mask to DMA handles, and ARM does. Sounds like what, we need sme_dma_me_mask in addition to sme_me_mask? Scary. -- Alexey