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Mercier" References: <97c30fce-9bda-4c61-b1b9-10297b89c8d9@amd.com> <20260918153642.GD11599@ziepe.ca> <20260918165315.GF11599@ziepe.ca> <6115eaf7-21bc-49ce-8a74-08fd37a1e2c9@amd.com> <20260921115141.GJ11599@ziepe.ca> <45dd7a2f-8474-4388-b383-2dee3ee62206@amd.com> <20260921121739.GM11599@ziepe.ca> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: <20260921121739.GM11599@ziepe.ca> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MN2PR16CA0061.namprd16.prod.outlook.com (2603:10b6:208:234::30) To SJ0PR12MB5673.namprd12.prod.outlook.com (2603:10b6:a03:42b::13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR12MB5673:EE_|CY8PR12MB7098:EE_ X-MS-Office365-Filtering-Correlation-Id: 1747a5d3-1703-4331-08f2-08df17db476b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|23010399003|366016|376014|7416014|56012099006|11063799006|4143699003|10067099003|18002099003|22082099003; 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We discussed this with the heap maintainers and we >>> all agreed this was a kind of heap just like any of the other kinds of >>> heaps that userspace can request. >>> >>> It is *exactly* the "special allocation requirements" you are talking >>> about above. >> >> I only see a fraction of the patch set (because no DMA-buf >> maintainer was CCed) and to me it looked like the cc_shared flag was >> added as an additional parameter to the allocation and not a >> separate heap created. > > ? > > It was merged months ago, and you were CC'd: > > https://lore.kernel.org/all/20260325192352.437608-1-jiri@resnulli.us/ Ah! I though the flag was added in this patch set. > > It follows the design the dma heaps maintiners guided to create a new > named heap: > > + exp_info.name = "system_cc_shared"; > + exp_info.priv = &system_heap_cc_shared_priv; > > Along side the normal heap: > > exp_info.name = "system"; > > It is identical to "system" except the pages are "CC shared" meaning > the hypervisor and every DMA device can access them. > > This series is just adjusting the rules around how > set_memory_decrypted() works. It isn't changing any uAPI or adding > anything new to dmabuf heaps. Yeah that was absolutely not clear to me since I only got added to this single patch. I also don't see where mem_cc_shared_granule_size is added? > Yes, it ends up as a flag in the internal code flow, that is just how > it got coded.. In that case this is probably ok as it is. Christian. > > Jason