From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA561C433EF for ; Tue, 22 Mar 2022 00:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234554AbiCVAzh (ORCPT ); Mon, 21 Mar 2022 20:55:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234502AbiCVAzf (ORCPT ); Mon, 21 Mar 2022 20:55:35 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89D4A36E3B for ; Mon, 21 Mar 2022 17:54:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647910449; x=1679446449; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=25WEx/VI04GLdRJN6w8aNF3alk3XvOfUYr/ih2ArDWI=; b=CWXHbuSiOhAf3tF9IVykXa7tN4czZ3mRdmliqNyavfEADjgsSUkZREOf k6OynFLWUVhQ49ZnXdRiG6rzClaQtFLLqNsMVrBsbByrTIU0ySbX0mgMF IAjjE25V8m2OcEL4Di88qcymIXz6HAspr/m8p2BY93FYWIrlJuGhlykCx BjyoUgvA6F1/+Kb5/7CNl3V7txqDYrZsBB9RNlL59/q9Hsthg2avu0NXO efhXWJzsVhuW8D6NuieHmL5t9tLVXX5LkvOpdV2Z+GCpIQLW5yodD3xwE OBv2JoZzMhpXadY6M4vVFIfojiIWUwsQBVvsO/KGNF1F9s8Y1uoJV1bOf g==; X-IronPort-AV: E=McAfee;i="6200,9189,10293"; a="320889122" X-IronPort-AV: E=Sophos;i="5.90,200,1643702400"; d="scan'208";a="320889122" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Mar 2022 17:54:09 -0700 X-IronPort-AV: E=Sophos;i="5.90,200,1643702400"; d="scan'208";a="560121532" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.208.85]) ([10.254.208.85]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Mar 2022 17:54:05 -0700 Message-ID: <355235cb-1fe9-cdd5-45a5-3105aead417d@linux.intel.com> Date: Tue, 22 Mar 2022 08:54:03 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Cc: baolu.lu@linux.intel.com, Joerg Roedel , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Eric Auger , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 02/11] iommu: Add iommu_domain type for SVA Content-Language: en-US To: Jason Gunthorpe References: <20220320064030.2936936-1-baolu.lu@linux.intel.com> <20220320064030.2936936-3-baolu.lu@linux.intel.com> <20220321114745.GI11336@nvidia.com> From: Lu Baolu In-Reply-To: <20220321114745.GI11336@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/3/21 19:47, Jason Gunthorpe wrote: > On Sun, Mar 20, 2022 at 02:40:21PM +0800, Lu Baolu wrote: >> Add a new iommu domain type IOMMU_DOMAIN_SVA to represent an I/O page >> table which is shared from CPU host VA. Add a sva_cookie field in the >> iommu_domain structure to save the mm_struct which represent the CPU >> memory page table. >> >> Signed-off-by: Lu Baolu >> include/linux/iommu.h | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index 36f43af0af53..3e179b853380 100644 >> +++ b/include/linux/iommu.h >> @@ -64,6 +64,9 @@ struct iommu_domain_geometry { >> #define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */ >> #define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */ >> >> +#define __IOMMU_DOMAIN_SHARED (1U << 4) /* Page table shared from CPU */ >> +#define __IOMMU_DOMAIN_HOST_VA (1U << 5) /* Host CPU virtual address */ >> + >> /* >> * This are the possible domain-types >> * >> @@ -86,6 +89,8 @@ struct iommu_domain_geometry { >> #define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \ >> __IOMMU_DOMAIN_DMA_API | \ >> __IOMMU_DOMAIN_DMA_FQ) >> +#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SHARED | \ >> + __IOMMU_DOMAIN_HOST_VA) > > Is there any use for this in the core code? I feel like flags should > only be created if the core code needs to test them in some way. flags are some attributes of the domain and the combination of multiple flags forms a domain type. > >> @@ -95,6 +100,7 @@ struct iommu_domain { >> void *handler_token; >> struct iommu_domain_geometry geometry; >> struct iommu_dma_cookie *iova_cookie; >> + struct mm_struct *sva_cookie; > > Don't call a mm_struct a cookie please Sure. > > And why do we need this in core code? Need to connect an SVA domain with mm. Best regards, baolu