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 E715BC6FD1D for ; Sat, 1 Apr 2023 13:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229970AbjDANlW (ORCPT ); Sat, 1 Apr 2023 09:41:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229461AbjDANlV (ORCPT ); Sat, 1 Apr 2023 09:41:21 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C89EA1BF5D; Sat, 1 Apr 2023 06:41:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680356480; x=1711892480; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=oo7ZKkfMW2SRqFUeLHxvdNWhSGFJwlIB/+Xmjgc78Gw=; b=gStNySngv6hBlCCLjn05CcNI4CPhDHKCOdP6jvNLSkCNVvD2CFbegrXm lQKqLxDlZTRRJjdq2RXRU4Qlc2CypWeqFh60TVq3WfXY0EIAyOxxyfKVE 4V4tk14pIInSDs3vErDhphlizyDLgVlDsfGfzU+zyDwxaAkh5TVJKW1dt 31HWg30M0b9mzavxdls7iVlGMKSl/SGyQqGwoumGq845eu9ELvs3nrXiS Cp5Ffu3cbzLjOos3noMoqmAtxj/9K2VocmIysWN3OBjWjCSuD4NQozP1h yU6OQwW9kiso+KlutjNqMaEaM/y3aAPSMKe9XuheRmQ+AlO4bjXCaPuB9 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10667"; a="406690580" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="406690580" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2023 06:41:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10667"; a="931516604" X-IronPort-AV: E=Sophos;i="5.98,310,1673942400"; d="scan'208";a="931516604" Received: from blu2-mobl.ccr.corp.intel.com (HELO [10.254.211.241]) ([10.254.211.241]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2023 06:41:16 -0700 Message-ID: <2a5d6d53-f86a-43b4-b3cd-4c78951bc6ff@linux.intel.com> Date: Sat, 1 Apr 2023 21:41:13 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Cc: baolu.lu@linux.intel.com, Will Deacon , David Woodhouse , Raj Ashok , "Tian, Kevin" , Yi Liu , "Yu, Fenghua" , Dave Jiang , Tony Luck , "Zanussi, Tom" Subject: Re: [PATCH v3 1/7] iommu/vt-d: Use non-privileged mode for all PASIDs Content-Language: en-US To: Jacob Pan , LKML , iommu@lists.linux.dev, Robin Murphy , Jason Gunthorpe , Joerg Roedel , dmaengine@vger.kernel.org, vkoul@kernel.org References: <20230331231137.1947675-1-jacob.jun.pan@linux.intel.com> <20230331231137.1947675-2-jacob.jun.pan@linux.intel.com> From: Baolu Lu In-Reply-To: <20230331231137.1947675-2-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 2023/4/1 7:11, Jacob Pan wrote: > Supervisor Request Enable (SRE) bit in a PASID entry is for permission > checking on DMA requests. When SRE = 0, DMA with supervisor privilege > will be blocked. However, for in-kernel DMA this is not necessary in that > we are targeting kernel memory anyway. There's no need to differentiate > user and kernel for in-kernel DMA. > > Let's use non-privileged (user) permission for all PASIDs used in kernel, > it will be consistent with DMA without PASID (RID_PASID) as well. > > Signed-off-by: Jacob Pan Reviewed-by: Lu Baolu Best regards, baolu