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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8FFCFC4360F for ; Thu, 4 Apr 2019 06:54:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65BE5206DF for ; Thu, 4 Apr 2019 06:54:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727281AbfDDGyz (ORCPT ); Thu, 4 Apr 2019 02:54:55 -0400 Received: from mga03.intel.com ([134.134.136.65]:42021 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726031AbfDDGyy (ORCPT ); Thu, 4 Apr 2019 02:54:54 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Apr 2019 23:54:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,306,1549958400"; d="scan'208";a="128519166" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by orsmga007.jf.intel.com with ESMTP; 03 Apr 2019 23:54:52 -0700 Cc: baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org, Tom Murphy , Dmitry Safonov , Jacob Pan , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/7] iommu/vt-d: Expose ISA direct mapping region via iommu_get_resv_regions To: James Sewart References: <0F0C82BE-86E5-4BAC-938C-6F7629E18D27@arista.com> <83B82113-8AE5-4B0C-A079-F389520525BD@arista.com> <445F31EA-20F3-481C-B1DF-8B163791FF8C@arista.com> <6C211BF1-B5A0-4821-AB42-092B573DE667@arista.com> <8B1FC0C7-9BAC-498D-B1F0-0138EACF75C2@arista.com> From: Lu Baolu Message-ID: Date: Thu, 4 Apr 2019 14:49:05 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <8B1FC0C7-9BAC-498D-B1F0-0138EACF75C2@arista.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi James, I did a sanity test from my end. The test machine fails to boot. I haven't seen any valuable kernel log. It results in a purple screen. Best regards, Lu Baolu On 3/29/19 11:26 PM, James Sewart wrote: > Hey Lu, > > I’ve attached a preliminary v3, if you could take a look and run some tests > that would be great. > > Since v2 i’ve added your default domain type patches, the new device_group > handler, and incorporated Jacob’s feedback. > >> On 28 Mar 2019, at 18:37, James Sewart wrote: >> >> Hey Lu, >> >>> On 26 Mar 2019, at 01:24, Lu Baolu wrote: >>> >>> Hi James, >>> >>> On 3/25/19 8:57 PM, James Sewart wrote: >>>>>> Theres an issue that if we choose to alloc a new resv_region with type >>>>>> IOMMU_RESV_DIRECT, we will need to refactor intel_iommu_put_resv_regions >>>>>> to free this entry type which means refactoring the rmrr regions in >>>>>> get_resv_regions. Should this work be in this patchset? >>>>> Do you mean the rmrr regions are not allocated in get_resv_regions, but >>>>> are freed in put_resv_regions? I think we should fix this in this patch >>>>> set since this might impact the device passthrough if we don't do it. >>>> They’re not allocated and not freed currently, only type IOMMU_RESV_MSI is >>>> freed in put_resv_regions. If we allocate a new resv_region with type >>>> IOMMU_RESV_DIRECT for the isa region, then it won’t be freed. If we modify >>>> put_resv_regions to free type IOMMU_RESV_DIRECT, then we will try to free >>>> the static RMRR regions. >>>> Either the ISA region is static and not freed as with my implementation, >>>> or the RMRR regions are converted to be allocated on each call to >>>> get_resv_regions and freed in put_resv_regions. >>> >>> By the way, there's another way in my mind. Let's add a new region type >>> for LPC devices, e.x. IOMMU_RESV_LPC, and then handle it in the same way >>> as those MSI regions. Just FYI. >> >> This solution would require adding some extra code to >> iommu_group_create_direct_mappings as currently only type >> IOMMU_RESV_DIRECT is identity mapped, other types are only reserved. >> >> >>> >>> Best regards, >>> Lu Baolu >> >> Cheers, >> James. > > Cheers, > James. >