From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2056.outbound.protection.outlook.com [40.107.244.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17F5C24A7E1 for ; Wed, 15 Jan 2025 14:30:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.244.56 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736951460; cv=fail; b=t8DEaHxRUsV9XlOnq8FKC1/3xVq85SsbKoY40FSrJRg9b/iHCsTJnT40KaY896VYUCPwJWOfhzr98KWbLOqwbJMd7NEufk6X+/U3ZL2uav3e4P/RiCRuEZDVn6nT1o5i2BO2ajO1+bxdg1NIELNDowxIVbxSMyP56NEBdRs4ooQ= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736951460; c=relaxed/simple; bh=pARxoIkwDzoF2ienjcfSSH2JIlkRuwk6x7JreriCAO4=; h=Message-ID:Date:Subject:From:To:Cc:References:In-Reply-To: Content-Type:MIME-Version; b=tuj2WhbRWFSlqXMqoEu2dEFT0zqDwewvA2vqaX1R9VMPJBgEgVCpa3P53BI3Ea/H1PdGm63UR+KV3jpP4nYHgsrYOgsIUv/uSaGf35letrQXuFpIVVGd5f2awpc/eOBZtRHEiNlmp5wxAF9hGTm/r9iNm6162K+pi85/vi4+3W0= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=h3ma+mUM; arc=fail smtp.client-ip=40.107.244.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="h3ma+mUM" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=oNJifmNSJdVMSKd4EuvtlFmXgw90TRYpkaFW3kUHVqLDZgmMPpqFSuwVkjPZRVf0R/FVYL5uw/viifKbM4cF2QWWwGEjRSNmD1NZW2auL8mlODIEBPcEqPvTovgRwMhfMGfXTNJ5bnouNUHsB2rviYfQfED/tfN3ycYyfrWOhz5c37LAZ4OZJxYFfDtB/868jZytXdtKv+lns2Xm3l1de3wHbFQe3N3X36czWImLsLybiu7LPr95dKYmVU8B6a83i4Vj7J4SdzDTZQmu/wdYP/2GiU2lkNxJIK69TF7oBy6Um80GFY3hw3cqBx6g7gquzr8Ge6z9q4Kn0vb5VDfrjw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=xFDZ93yw204WtMr/f/nRhR/6GEJux3aRL1LL0rkj1Bs=; b=Cqz3DTb/Tot8E1gz3a1i4gGTErRPS+FqruBK5B7JwM4wDXcMTAi+6Z1HtJbwvVKM5PPvcBl5mIBzGlHlDzzhXWSSfDUy7ZlfNziaSP0m5defrYxxh0ni/YQcancTc7fDYw67QUQqaGjbec6lc1nPa+9V8JtTdRocu+a6CNvMPpzo+la7PN9o4ml4LLbEAXIll9e0LN3SmONIq7j/iuk+pi4uYLx5mfzuNIr/VMcjjY2HdX7njmIHNl1u4Lm5S8WherumBx4rIlFweWlNnUA/T+kzN+7w2G6GItf5hKRhrnvwHr16DW1598SStroiWTdGeXB+bRT+taKEtn8VaLU0EA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=xFDZ93yw204WtMr/f/nRhR/6GEJux3aRL1LL0rkj1Bs=; b=h3ma+mUMurEu/oTKab/GJjYShRPGi/X9Y2DGcsAzmy4IgLMa4FS9Ct2iDFe6bIBWOvhqYrCaTX2GQYQHLtmUI7BwJK3+FwLkgy3zTLSS3hXlaCjloOMQ0qLFWmaqBjcPygN6AEKrBIeY1xb7tz27YGzlFfp+l8qJQO+rogIcePQ= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) by CH3PR12MB9453.namprd12.prod.outlook.com (2603:10b6:610:1c9::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8356.13; Wed, 15 Jan 2025 14:30:55 +0000 Received: from PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5]) by PH7PR12MB5685.namprd12.prod.outlook.com ([fe80::46fb:96f2:7667:7ca5%5]) with mapi id 15.20.8356.010; Wed, 15 Jan 2025 14:30:55 +0000 Message-ID: <86afb69a-79bd-4719-898e-c6c2e62103f7@amd.com> Date: Wed, 15 Jan 2025 15:30:47 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 01/12] dma-buf: Introduce dma_buf_get_pfn_unlocked() kAPI From: =?UTF-8?Q?Christian_K=C3=B6nig?= To: Jason Gunthorpe Cc: Xu Yilun , Christoph Hellwig , Leon Romanovsky , kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, sumit.semwal@linaro.org, pbonzini@redhat.com, seanjc@google.com, alex.williamson@redhat.com, vivek.kasireddy@intel.com, dan.j.williams@intel.com, aik@amd.com, yilun.xu@intel.com, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, lukas@wunner.de, yan.y.zhao@intel.com, leon@kernel.org, baolu.lu@linux.intel.com, zhenzhong.duan@intel.com, tao1.su@intel.com References: <20250108162227.GT5556@nvidia.com> <58e97916-e6fd-41ef-84b4-bbf53ed0e8e4@amd.com> <20250110205454.GM5556@nvidia.com> <20250115133821.GO5556@nvidia.com> <1afd5049-d1d4-4fd6-8259-e7a5454e6a1d@amd.com> <20250115141458.GP5556@nvidia.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: FR2P281CA0065.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:93::11) To PH7PR12MB5685.namprd12.prod.outlook.com (2603:10b6:510:13c::22) 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: PH7PR12MB5685:EE_|CH3PR12MB9453:EE_ X-MS-Office365-Filtering-Correlation-Id: 6e8df7ac-99d2-45a9-c300-08dd35713854 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?T3VsTXNWbG9IbU92bHhjbzY2TVNma2t3OXRRMGZsdFFRN3JCNnMzRXRjN0FD?= =?utf-8?B?Tml5T3NVUjlKR2tuRStEVHd4TWJhYVkxOEpNV2dQZGthT3ZxZ0t5b2ZsL0Y2?= =?utf-8?B?blBpRGNmNXN3WmhiQVRMZ25JcS9aRU9jbVNJWnM0NTA4Z0hRZjRNSFhpUkhJ?= =?utf-8?B?NDdXRldzbDRZdEpMbjZKTkNxR0NzM29iandkcUJ4bnd5aGlTUjRKUXlRU283?= =?utf-8?B?dlRPdm5iOExGY2FKSVU4T2FncUZHZWIwaDJ5Y2MzSThyenBiL1ExQ0MvL3pz?= =?utf-8?B?SDNyTitXV0xHQ1VNQ2NWMmg1NThVaGR3eHN2YnNpQXdvQm1xZTUzZEdkR0wy?= =?utf-8?B?NWIrcWEvSER6OTdPTC9TaXZwRjNRVFF4UzRsaTVsN0l1ZExSank4NlNhWTFW?= =?utf-8?B?aUpvcTJjalgwVXgxeHV3RWVOYkZidDYzWDA2MS9CdzVhY1hXU29yYnVLcXgx?= =?utf-8?B?eGU5c3p4OHpGZVZBd0tVTU1sYVpCOXZhWXAwcldPRzhGRHJETDZGVDArNWNm?= =?utf-8?B?b3lvT01ITXkxVzRZVDljaXZ3dWk4cjJvWGV6RjNlOHd0c0tha2FuN2VnbzVD?= =?utf-8?B?V1pjenM3dmhBVU1tckpKMGswUTJsKytMKzhJRkF4ZlVHMjhwTUZsVU9wRTM4?= =?utf-8?B?c0ZQclVsc1g4NzNubGc5TDJtZi9TYzM4eTNzeTVGY2hyeHVJN1pKeE1rZndP?= =?utf-8?B?ZGVxVS80WkNwRDdOZ21QUDIydGp3UzJ6UWI4dWdyY1huVzQ3WTBwUzlPQ3FK?= =?utf-8?B?SU9lZTBlaHovSERrNW9XaklCUHFmcFRVbzhwRld4VUIwR0huL3JPazBON2lD?= =?utf-8?B?aHUrYm9NRWNucDJqZ1VQaW5XRkFFL2cvVlMrUVVISUtJbXUxZU9oYlJxNjJW?= =?utf-8?B?Sm9OdjF6TDhNbWZOKzJoektzUUpCV1VvR1cydHk5SGFHVjNBZ01KVDhrY0Z4?= =?utf-8?B?eGkyQzJhUExQdjBrejJMUklJQVIyc1RyY2VDT3AvRWJXT3BmTlI2YWt4WE5v?= =?utf-8?B?VzhoanZaM2lkSTZtWGxFUElXMEpUejMwbXNBTkZuTE9mR0ZMKzFMV1l1REVk?= =?utf-8?B?eUZlRlVqckpDbUFjS09YSzk3a0g3azBnbnpyS0lwQ2hwaFpSV3h6bHVXQnVS?= =?utf-8?B?bUlCOG0rNDJNOXN5WEVJZ0syenVhZnBULzdqbGU0UEtBcDRwNEhCUko4TzQ2?= =?utf-8?B?Z2R3Nzl4RUtZQ1lJNnBsYk92ZDlMclhEakYvVDZOa1ZPRWxLMU4yUW5CY2lS?= =?utf-8?B?ekVXWUhtVFowSUdpc2lKeklla3VNTXVWeTNNNzBWOUdHU0NaSmF1U3N1amht?= =?utf-8?B?YWtyZ2NMRmpTT0VmbENhVEtWY0ZkSVBmbkdsMktEVDYwNnpOaUhBelJnbEU1?= =?utf-8?B?bGR5WHBoMERPa3RWWVZhS3hTOEVlbHNBTEVKclk5U1RVcUhjZzNvOWNjdWFT?= =?utf-8?B?VXJOMCs3cEdLVjluMEZKK1lRRHp2ZWFtc1RVQkxPeHdwUm42WTYyMUZybytp?= =?utf-8?B?aDBJd3NHc0ZtNlEvUXYxM0FXN0ZUakp2WXFMTk90SVF3T25MOGtiZEsxUTlM?= =?utf-8?B?QmVyWFpMQmRGT3dvbk9icW5CNllxZ0orN1U0ay9VQmlia3hrcHRFMlRuTmp6?= =?utf-8?B?TEtUekNtZmV0VFU0QTVJSzl6L1RCYTNINjNOVzRkRXJIRkE5RkVxaFk3ZWRU?= =?utf-8?B?V25hTStKZTg2ZWNvWkpuaUhsKzd2Ym1kUndOaUplaUlzLzNiWWRwR3B6aXQx?= =?utf-8?B?b0I5MEpCb0loZzhIMGxWNHhieVplSzBFKzFHa1YwcG9XY1NOMDZvbFFxVXJ2?= =?utf-8?B?bTVSTThtNlM2T3poNys3UDFhdlZualluOEdpUUlJQnQvTFV2NWdsUzk2d2hQ?= =?utf-8?Q?m7VOrIi3G2JhL?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR12MB5685.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TDgwVDlPM09UOEFXdWphU2QxS0hGMnhsNTViMTA0Wlllb1lLZmNNRTdDaVBh?= =?utf-8?B?WWtGb0pLUVRvcGxUOGR6UEtBVEp0N28zTjVNaEhvTFd5MDJ4UWdEVHEzNHZw?= =?utf-8?B?ZUdLZ3c1WnpCYTVudUpqWXhKVHRyb1JQa01KWjRJNGFHc1g4MXB5VDlQR3JT?= =?utf-8?B?QjJybUkzSDZKeHNTc3JTUXJCc2JCZ0k4ZDA2UDdLQnpxZVVJcERCNVJJYXZj?= =?utf-8?B?SERoQ2h5TVJ1RFFpbmxyVkg3TjlteDNEQ2hSSmJXTlNVZmNlT1d1YXlUY280?= =?utf-8?B?VVJyK1BBajBqd01HOGtjQ2NVODNUZWNWOU4xWWhqRXBFNWxHa1lTV0J6QzF6?= =?utf-8?B?cGsyYzFSUFFJVWd6ZUh0ZnI2S0FzQW50ampjT29UcWNtaENPY3BhWVpZWjAw?= =?utf-8?B?eWJHemNsZXlYRTJuc3I4WlV0K0JsNFdxbVJWeHRMMDBqaEU3K2diQTA4VVBh?= =?utf-8?B?b29CdFBrTDJiZFdrUlQ1QStFSDA3YWNQd1o1V240d2FoTlZyZFlEMSt2NjZh?= =?utf-8?B?R1JJWG9WMXYwYTJEWnlidGR3UmFHTDRIeENVaDFha0c4VlpKWDBFcTVlcDlS?= =?utf-8?B?cXFSRDRodkhac0prOWhiQytIRmxuRkV1UVhKWGJNMlBNNnhYUDVJVlJBUjZS?= =?utf-8?B?bmRPc25Zd2xLRzlIWFd1RGZ2bXp6M1lxUkpWeERmT2Q0QTd2NXVSZG90bkpr?= =?utf-8?B?cDYxZVBNelNzaFBpU05NQndXbTNvalVIYW43VHJYeTdtTXpxcmk5T1NXRllp?= =?utf-8?B?aCtaQkFIM3YvbXJHaCtaQ1VSUFBzZndIY2tWZUFUaXU5WFYxQWxQNzZ5NWcv?= =?utf-8?B?VE9taXhhY3pRYVFuandoQ3hRK1ViOHh2eG1PYjM5MW1LTU9ERitTZDJMdG93?= =?utf-8?B?N1drUHRraXVBZXFqdHkxYXYyR1NSQi9ldlJwc09ZNHRMZ1pCcDNnOG04R3dE?= =?utf-8?B?MjVycWZnNkplZE5PeTBhMzBRemQxOVVJQXRSckRZankvSUVJTzVEay92SmxK?= =?utf-8?B?ODlaYWRtWmx2dWxOTWt4UXUvdGFxMzNwa3pnN0JDWndTTnVuYkRvY0s1UDY1?= =?utf-8?B?bUdwTEZMWHJjRFFFZ3hQWDV3YmxPZ1lKalkwM0tNbmRZRU1LWW0rc01pK2Vw?= =?utf-8?B?OGhvRWpYY21VUlFhZlJrMS9Sa203WmZZTm9lN01xeHhSWlROU21rR3JGNy9U?= =?utf-8?B?NmtBUmsxM1hjRjdVNk1qTjJBeDB0WjlTdmt3dkhtRTVyVVZUTmdzMXgyOXBC?= =?utf-8?B?YkFYWCtWOVhmdHZRbWVZV3BIc08rekFUTmcvM3VnWEVnT3QxSUpaUXh2R0pJ?= =?utf-8?B?aEJEZkVEUjg0bjZZZW8xdk5CWGd0WitVTERCS0xqY25rSEFhT3JRWWFjanUv?= =?utf-8?B?THRVeHByOWFSU1hCeE5kY0ovTG1xbUFJS2ZPanBwSUtmZmE3ZXc1b0NTR1ND?= =?utf-8?B?UkFJaUp3SG9oZUJFVTVkVTlJVTNaNm0wYXB1L2ZWRlpMYmFDZnJkVHJmRkhi?= =?utf-8?B?M0wzRlZNRDI2RDlLb1l5ZG9uM3A2UGdPUkR1TGE3d3JZeUIzazFLOURlTVNF?= =?utf-8?B?bldGU29WTWEvMVVkM1hPQ0tVYy9UQWg3OGRsSGMyVFZueFloSStWL2NuU2xw?= =?utf-8?B?Um4zekg0emMyMlFMa1l6M21SZ2hVU0JiMlMvY1ZlNllReEUrZFhUeGQ1UW9w?= =?utf-8?B?OUZhak12anNTYVJheW5vN2JTWlhiT2FaWXBucWlYNUJtNmhDTU5zcFk4RjFy?= =?utf-8?B?SCtuOVQreklDWnFrUHgzTEJ2WWUwVXArVUlNRjh3WXU4akdWYkZrVGxSR0No?= =?utf-8?B?cFIxNnZjckxaaWNJSHNROWgvUmlyNFNsSW0zWnlVYXFrd1BtR3FMdmpPeE9v?= =?utf-8?B?SFFEQjVPZHlUZUdHbWVHelJVSW90UDJQc1dFdFZNZjByOFg1VVhHZngzeU9h?= =?utf-8?B?enVSY1lNZHFieU5LMjFmMWVuMm5QVlhlbW8zT3dXNUtZZXBHNkVGYUljbzlV?= =?utf-8?B?bzhBU2dzY0hUYm1iaTJyYmo2alNtNDlFaG4rOWszVTRTVS8xU1JueGdxSEVJ?= =?utf-8?B?aDBoYUpQeXdRSExiNkRJOFIvVkVER1RTZUJxTVdhdDdGR0VYMXh6bUlWS1Bh?= =?utf-8?Q?s327N1ntljNb9r73+FPbv7J0f?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6e8df7ac-99d2-45a9-c300-08dd35713854 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5685.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Jan 2025 14:30:55.0892 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: F0YunvMpA0j/Vxcgu6DLXcVg+seTyaORNu/wyLhf38239wlkrmzDW2KAi/XlERKX X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB9453 Sending it as text mail to the mailing lists once more :( Christian. Am 15.01.25 um 15:29 schrieb Christian König: > Am 15.01.25 um 15:14 schrieb Jason Gunthorpe: >> On Wed, Jan 15, 2025 at 02:46:56PM +0100, Christian König wrote: >> [SNIP] >>>> Yeah, but it's private to the exporter. And a very fundamental rule of >>>> DMA-buf is that the exporter is the one in control of things. >> I've said a few times now, I don't think we can build the kind of >> buffer sharing framework we need to solve all the problems with this >> philosophy. It is also inefficient with the new DMA API. >> >> I think it is backwards looking and we need to move forwards with >> fixing the fundamental API issues which motivated that design. > > And that's what I clearly see completely different. > > Those rules are not something we cam up with because of some > limitation of the DMA-API, but rather from experience working with > different device driver and especially their developers. > > Applying and enforcing those restrictions is absolutely mandatory must > have for extending DMA-buf. > >>>> So for example it is illegal for an importer to setup CPU mappings to a >>>> buffer. That's why we have dma_buf_mmap() which redirects mmap() >>>> requests from the importer to the exporter. >> Like this, in a future no-scatter list world I would want to make this >> safe. The importer will have enough information to know if CPU >> mappings exist and are safe to use under what conditions. >> >> There is no reason the importer should not be able to CPU access >> memory that is HW permitted to be CPU accessible. >> >> If the importer needs CPU access and the exporter cannot provide it >> then the attachment simply fails. >> >> Saying CPU access is banned 100% of the time is not a helpful position >> when we have use cases that need it. > > That approach is an absolutely no-go from my side. > > We have fully intentionally implemented the restriction that importers > can't CPU access DMA-buf for both kernel and userspace without going > through the exporter because of design requirements and a lot of > negative experience with exactly this approach. > > This is not something which is discuss-able in any way possible. > >>>> As far as I can see that is really not an use case which fits DMA-buf in >>>> any way. >> I really don't want to make a dmabuf2 - everyone would have to >> implement it, including all the GPU drivers if they want to work with >> RDMA. I don't think this makes any sense compared to incrementally >> evolving dmabuf with more optional capabilities. > > The point is that a dmabuf2 would most likely be rejected as well or > otherwise run into the same issues we have seen before. > >>>>>> That sounds more something for the TEE driver instead of anything DMA-buf >>>>>> should be dealing with. >>>>> Has nothing to do with TEE. >>>> Why? >> The Linux TEE framework is not used as part of confidential compute. >> >> CC already has guest memfd for holding it's private CPU memory. > > Where is that coming from and how it is used? > >> This is about confidential MMIO memory. > > Who is the exporter and who is the importer of the DMA-buf in this use > case? > >> This is also not just about the KVM side, the VM side also has issues >> with DMABUF and CC - only co-operating devices can interact with the >> VM side "encrypted" memory and there needs to be a negotiation as part >> of all buffer setup what the mutual capability is. :\ swiotlb hides >> some of this some times, but confidential P2P is currently unsolved. > > Yes and it is documented by now how that is supposed to happen with > DMA-buf. > > As far as I can see there is not much new approach here. > > Regards, > Christian. > >> Jason >