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 D5243C77B7C for ; Sun, 21 May 2023 06:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229938AbjEUGWm (ORCPT ); Sun, 21 May 2023 02:22:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230004AbjEUGWi (ORCPT ); Sun, 21 May 2023 02:22:38 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75DEFE43; Sat, 20 May 2023 23:22:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684650155; x=1716186155; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=ekzYqo7EzgZT0OkwVWM3WQ4Ormn8rtrKMWfR7boXeYc=; b=ZuWDNHQb0MoaIRsXJ4OkGdk1l1hnLSlbR1lmV0iIrBOewNo3VYzJHGi8 YuTOxtO0vQFpp0zJ0TAP1dMc8i2Czm4Sp+fpSiqFs1hfAWsZqS4XrN591 3LKoO7Jb4NKeVJuUzaRIMemNi44IUzJrmPcC3sTd2jgaPUeIBp25/EXxf 0YBm90rSlXu3ropXNPo+cJfQ728HH4BBP7ssKB4UsP5OqSztgoJi9sBPX bgWTwrfnL0J56ksSs5UiTFs55/LyrSG6gWnzJrqeMqqRpZLTY97GIEY9s P46Nqv4q0XxiBefDxN5zlchzdr9Ng47NYiFiBtsRbFLOGEXxowY52rRGn w==; X-IronPort-AV: E=McAfee;i="6600,9927,10716"; a="332282579" X-IronPort-AV: E=Sophos;i="6.00,181,1681196400"; d="scan'208";a="332282579" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2023 23:22:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10716"; a="1033113548" X-IronPort-AV: E=Sophos;i="6.00,181,1681196400"; d="scan'208";a="1033113548" Received: from allen-box.sh.intel.com (HELO [10.239.159.127]) ([10.239.159.127]) by fmsmga005.fm.intel.com with ESMTP; 20 May 2023 23:22:30 -0700 Message-ID: Date: Sun, 21 May 2023 14:21:48 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Cc: baolu.lu@linux.intel.com, Robin Murphy , Will Deacon , David Woodhouse , Raj Ashok , "Tian, Kevin" , Yi Liu , "Yu, Fenghua" , Dave Jiang , Tony Luck , "Zanussi, Tom" , narayan.ranganathan@intel.com Subject: Re: [PATCH v6 1/4] iommu: Generalize default PCIe requester ID PASID Content-Language: en-US To: Jacob Pan , LKML , iommu@lists.linux.dev, Jason Gunthorpe , Joerg Roedel , dmaengine@vger.kernel.org, vkoul@kernel.org References: <20230519203223.2777255-1-jacob.jun.pan@linux.intel.com> <20230519203223.2777255-2-jacob.jun.pan@linux.intel.com> From: Baolu Lu In-Reply-To: <20230519203223.2777255-2-jacob.jun.pan@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 5/20/23 4:32 AM, Jacob Pan wrote: > PCIe Process address space ID (PASID) is used to tag DMA traffic, it > provides finer grained isolation than requester ID (RID). > > For each RID, 0 is as a special PASID for the legacy DMA (without > PASID), thus RID_PASID. This is universal across all architectures, > therefore warranted to be declared in the common header. > Noting that VT-d could support none-zero RID_PASID, but currently not > used. > > By having a common RID_PASID, we can avoid conflicts between different > use cases in the generic code. e.g. SVA and DMA API with PASIDs. > > Signed-off-by: Jacob Pan Reviewed-by: Lu Baolu Best regards, baolu