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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 29640C64EC4 for ; Fri, 10 Mar 2023 15:45:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mBA7Q+chYt95UAmJKEyiSVyBk5nF+ftD6d3OsryiDVk=; b=VjOT14+KMjYI3C SbkFKIn4s5QnrzkvMTiSZhP6kvzPdlkoeS/T1ZQ+cVLNTVJMqSdjcHZH8H7oLNt3SEkh/olggs5lC FMlBEc5JIYtQbAm14u+TIFuT2R+TjWTd4lAbd+RqffyyY6LYflgqjZ6NKFlIHkILBjv56JosFUcwr 9YmnCam1zMlBDoMSkqJXvQgU81iThMJYDIwKwayLINKOuwri+P9+GYQO3BlpVHQ94ooulaLcxAzmV Oa1KmJ704TNQDN9vFW50sPBZrcfXkaJ0wdx5leyHM3SrWVfF5p4eBHVtTlEuNQs/nbQxttVsRd96m u03XTmVin3HLyQqP5RTQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1paeur-00F3SX-9m; Fri, 10 Mar 2023 15:44:21 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1paeuo-00F3Q6-57 for linux-arm-kernel@lists.infradead.org; Fri, 10 Mar 2023 15:44:20 +0000 Received: from lhrpeml100003.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PY9Lh6fFLz6J6rP; Fri, 10 Mar 2023 23:43:24 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (7.191.163.240) by lhrpeml100003.china.huawei.com (7.191.160.210) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Fri, 10 Mar 2023 15:44:03 +0000 Received: from lhrpeml500005.china.huawei.com ([7.191.163.240]) by lhrpeml500005.china.huawei.com ([7.191.163.240]) with mapi id 15.01.2507.021; Fri, 10 Mar 2023 15:44:03 +0000 From: Shameerali Kolothum Thodi To: Jason Gunthorpe , Eric Auger CC: Nicolin Chen , "robin.murphy@arm.com" , "will@kernel.org" , "kevin.tian@intel.com" , "baolu.lu@linux.intel.com" , "joro@8bytes.org" , "jean-philippe@linaro.org" , "linux-arm-kernel@lists.infradead.org" , "iommu@lists.linux.dev" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper Thread-Topic: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain helper Thread-Index: AQHZUnWRmBwtrmleCk69JH8tQLhaPq7zzWuAgABY2gCAAAIMsA== Date: Fri, 10 Mar 2023 15:44:02 +0000 Message-ID: References: <9b1077601cace998533129327f5e7ad946752d29.1678348754.git.nicolinc@nvidia.com> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.202.227.178] MIME-Version: 1.0 X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230310_074418_363138_B8624B39 X-CRM114-Status: GOOD ( 18.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org > -----Original Message----- > From: Jason Gunthorpe [mailto:jgg@nvidia.com] > Sent: 10 March 2023 15:33 > To: Eric Auger > Cc: Nicolin Chen ; robin.murphy@arm.com; > will@kernel.org; kevin.tian@intel.com; baolu.lu@linux.intel.com; > joro@8bytes.org; Shameerali Kolothum Thodi > ; jean-philippe@linaro.org; > linux-arm-kernel@lists.infradead.org; iommu@lists.linux.dev; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH v1 01/14] iommu: Add iommu_get_unmanaged_domain > helper > > On Fri, Mar 10, 2023 at 11:14:59AM +0100, Eric Auger wrote: > > Hi Nicolin, > > > > On 3/9/23 11:53, Nicolin Chen wrote: > > > The nature of ITS virtualization on ARM is done via hypercalls, so > > > kernel handles all IOVA mappings for the MSI doorbell in > > > iommu_dma_prepare_msi() and iommu_dma_compose_msi_msg(). The > current > > > virtualization solution with a 2-stage nested translation setup is > > > to do 1:1 IOVA mappings at stage-1 > > Note that if we still intend to use that trick there is a known issue > > at kernel side that needs to be fixed. > > > > ARM DEN 0049E.b IORT specification mandates that when RMRs are > > present, the OS must preserve PCIe configuration performed by the boot > > FW. > > This limitation doesn't seem necessary for this MSI stuff? > > What is it for? That is to make sure the Stream Ids specified in RMR are still valid and is not being reassigned by OS. The kernel checks for this(iort_rmr_has_dev()), https://lore.kernel.org/linux-arm-kernel/20220420164836.1181-5-shameerali.kolothum.thodi@huawei.com/ Thanks, Shameer _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel