From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.24]) (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 45B51362 for ; Wed, 9 Aug 2023 00:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1691540304; x=1723076304; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=HJlcHiHuNgv/7TraiPpo1NPMzUrumGGz0oolwOb/Hvs=; b=GnbAb4/1jbgcwMBnL6Cw7CCnt6YhGsiK9zfWQ9q5xuOs2vs1QeTfvjki CSUsC8KoFzVTFyqkTQNJmsdHzi+Rzeq8xdAa+Vk8FrKeEob6fBSKL4JHF AHsNwH0pSx1QM0yJQVfgtonJYFxge8dEwAPxJv2IrFSCJBmM0Mx23pMWN IlrccYTv7Cu2eZc2pmC//KLclyZJr8Rmo7zQmWRrFiXU+GLWPjUHmMsyT vmq31sC2n/up13/gmEoHmJs+XHgVA/A+jmzege6Ep21sQampnScWhMFtV est58TgJ657IFp04FUd0p5RIayg1qL4Ts2MlvkUiCofhX+Xwp+DiB7Z4g w==; X-IronPort-AV: E=McAfee;i="6600,9927,10795"; a="373766059" X-IronPort-AV: E=Sophos;i="6.01,157,1684825200"; d="scan'208";a="373766059" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Aug 2023 17:18:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10795"; a="978163637" X-IronPort-AV: E=Sophos;i="6.01,157,1684825200"; d="scan'208";a="978163637" Received: from blu2-mobl.ccr.corp.intel.com (HELO [10.249.169.46]) ([10.249.169.46]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Aug 2023 17:18:21 -0700 Message-ID: <184044ad-880f-5452-727b-f7fd18330c22@linux.intel.com> Date: Wed, 9 Aug 2023 08:18:18 +0800 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.14.0 Cc: baolu.lu@linux.intel.com, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/5] Share sva domains with all devices bound to a mm Content-Language: en-US To: Tina Zhang , Jason Gunthorpe , Kevin Tian , Michael Shavit References: <20230808074944.7825-1-tina.zhang@intel.com> From: Baolu Lu In-Reply-To: <20230808074944.7825-1-tina.zhang@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2023/8/8 15:49, Tina Zhang wrote: > A sva domain's lifetime begins with binding a device to a mm and ends > by releasing all the bound devices from that sva domain. Technically, > there could be more than one sva domain identified by the mm PASID for > the use of bound devices issuing DMA transactions. > > To support mm PASID 1:n with sva domains, each mm needs to keep both a > reference list of allocated sva domains and the corresponding PASID. > However, currently, mm struct only has one pasid field for sva usage, > which is used to keep the info of an assigned PASID. That pasid field > cannot provide sufficient info to build up the 1:n mapping between PASID > and sva domains. Is it more appropriate to have the same life cycle for sva domain and mm pasid? I feel that they represent the same thing, that is, the address space shared by mm to a device. Best regards, baolu > > This patch-set fills the gap by adding an mm_iommu field[1], whose type is > mm_iommu_data struct, to replace the old pasid field. The introduced > mm_iommu_data struct keeps info of both a reference list of sva domains > and an assigned PASID. > > > [1]: https://lore.kernel.org/linux-iommu/ZIBxPd1%2FJCAle6yP@nvidia.com/ > > > The RFC version of this patch-set is here: > https://lore.kernel.org/linux-iommu/20230707013441.365583-1-tina.zhang@intel.com/ > > Tina Zhang (5): > iommu: Add mm_get_pasid() helper function > iommu: Call helper function to get assigned pasid value > mm: Add structure to keep sva information > iommu: Support mm PASID 1:n with sva domains > mm: Deprecate pasid field > > arch/x86/kernel/traps.c | 2 +- > .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 12 ++--- > drivers/iommu/intel/svm.c | 8 +-- > drivers/iommu/iommu-sva.c | 50 ++++++++++++------- > include/linux/iommu.h | 19 +++++-- > include/linux/mm_types.h | 3 +- > kernel/fork.c | 1 - > mm/init-mm.c | 3 -- > 8 files changed, 58 insertions(+), 40 deletions(-) >