Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933143AbcK3N5g (ORCPT ); Wed, 30 Nov 2016 08:57:36 -0500 Received: from foss.arm.com ([217.140.101.70]:47242 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752845AbcK3N52 (ORCPT ); Wed, 30 Nov 2016 08:57:28 -0500 Subject: Re: [RFC v3 00/10] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions To: Ganapatrao Kulkarni , Auger Eric References: <1479215363-2898-1-git-send-email-eric.auger@redhat.com> <6c9012fd-070b-6218-48e7-69b37f2559dd@redhat.com> <3d0ddb50-6e63-3fe2-55c0-ce49579905c9@redhat.com> Cc: eric.auger.pro@gmail.com, christoffer.dall@linaro.org, Marc Zyngier , alex.williamson@redhat.com, Will Deacon , joro@8bytes.org, "tglx@linutronix.de" , Jason Cooper , "linux-arm-kernel@lists.infradead.org" , drjones@redhat.com, kvm@vger.kernel.org, punit.agrawal@arm.com, "linux-kernel@vger.kernel.org" , diana.craciun@nxp.com, iommu@lists.linux-foundation.org, pranav.sawargaonkar@gmail.com, "ganapatrao.kulkarni@cavium.com" From: Robin Murphy Message-ID: <9e83990c-8f09-e21b-c86b-500e5e5c0f75@arm.com> Date: Wed, 30 Nov 2016 13:57:22 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4588 Lines: 125 On 30/11/16 10:52, Ganapatrao Kulkarni wrote: > On Wed, Nov 30, 2016 at 3:44 PM, Auger Eric wrote: >> Hi Ganapat, >> >> On 30/11/2016 11:04, Ganapatrao Kulkarni wrote: >>> Hi Eric, >>> >>> in you repo "https://github.com/eauger/linux/tree/v4.9-rc5-reserved-rfc-v3" >>> there is 11th patch "pci: Enable overrides for missing ACS capabilities" >>> is this patch part of some other series? >> >> Actually this is a very old patch from Alex aimed at working around lack >> of PCIe ACS support: https://lkml.org/lkml/2013/5/30/513 >> > > i have tried this patchset on thunderx-83xx for vfio and it works for me! > i was wondering is this patch required? i guess not. If your system and devices actually support and properly advertise ACS then there's nothing to override. Conversely, if you're happy assigning everything behind a single RC to the same guest then ACS doesn't really matter. It's only the in-between case - when the host still wants to keep control of one or more devices, but they all get grouped together due to lack of ACS - that warrants working around. Robin. > > please cc me when you respin this patchset. > > thanks > Ganapat > >> Thanks >> >> Eric >>> >>> thanks >>> Ganapat >>> >>> On Wed, Nov 30, 2016 at 3:19 PM, Auger Eric wrote: >>>> Hi, >>>> >>>> On 15/11/2016 14:09, Eric Auger wrote: >>>>> Following LPC discussions, we now report reserved regions through >>>>> iommu-group sysfs reserved_regions attribute file. >>>>> >>>>> Reserved regions are populated through the IOMMU get_resv_region callback >>>>> (former get_dm_regions), now implemented by amd-iommu, intel-iommu and >>>>> arm-smmu. >>>>> >>>>> The intel-iommu reports the [FEE0_0000h - FEF0_000h] MSI window as an >>>>> IOMMU_RESV_NOMAP reserved region. >>>>> >>>>> arm-smmu reports the MSI window (arbitrarily located at 0x8000000 and >>>>> 1MB large) and the PCI host bridge windows. >>>>> >>>>> The series integrates a not officially posted patch from Robin: >>>>> "iommu/dma: Allow MSI-only cookies". >>>>> >>>>> This series currently does not address IRQ safety assessment. >>>> >>>> I will respin this series taking into account Joerg's comment. Does >>>> anyone have additional comments or want to put forward some conceptual >>>> issues with the current direction and with this implementation? >>>> >>>> As for the IRQ safety assessment, in a first step I would propose to >>>> remove the IOMMU_CAP_INTR_REMAP from arm-smmus and consider the >>>> assignment as unsafe. Any objection? >>>> >>>> Thanks >>>> >>>> Eric >>>> >>>> >>>>> Best Regards >>>>> >>>>> Eric >>>>> >>>>> Git: complete series available at >>>>> https://github.com/eauger/linux/tree/v4.9-rc5-reserved-rfc-v3 >>>>> >>>>> History: >>>>> RFC v2 -> v3: >>>>> - switch to an iommu-group sysfs API >>>>> - use new dummy allocator provided by Robin >>>>> - dummy allocator initialized by vfio-iommu-type1 after enumerating >>>>> the reserved regions >>>>> - at the moment ARM MSI base address/size is left unchanged compared >>>>> to v2 >>>>> - we currently report reserved regions and not usable IOVA regions as >>>>> requested by Alex >>>>> >>>>> RFC v1 -> v2: >>>>> - fix intel_add_reserved_regions >>>>> - add mutex lock/unlock in vfio_iommu_type1 >>>>> >>>>> >>>>> Eric Auger (10): >>>>> iommu/dma: Allow MSI-only cookies >>>>> iommu: Rename iommu_dm_regions into iommu_resv_regions >>>>> iommu: Add new reserved IOMMU attributes >>>>> iommu: iommu_alloc_resv_region >>>>> iommu: Do not map reserved regions >>>>> iommu: iommu_get_group_resv_regions >>>>> iommu: Implement reserved_regions iommu-group sysfs file >>>>> iommu/vt-d: Implement reserved region get/put callbacks >>>>> iommu/arm-smmu: Implement reserved region get/put callbacks >>>>> vfio/type1: Get MSI cookie >>>>> >>>>> drivers/iommu/amd_iommu.c | 20 +++--- >>>>> drivers/iommu/arm-smmu.c | 52 +++++++++++++++ >>>>> drivers/iommu/dma-iommu.c | 116 ++++++++++++++++++++++++++------- >>>>> drivers/iommu/intel-iommu.c | 50 ++++++++++---- >>>>> drivers/iommu/iommu.c | 141 ++++++++++++++++++++++++++++++++++++---- >>>>> drivers/vfio/vfio_iommu_type1.c | 26 ++++++++ >>>>> include/linux/dma-iommu.h | 7 ++ >>>>> include/linux/iommu.h | 49 ++++++++++---- >>>>> 8 files changed, 391 insertions(+), 70 deletions(-) >>>>> >>>> >>>> _______________________________________________ >>>> linux-arm-kernel mailing list >>>> linux-arm-kernel@lists.infradead.org >>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel