Re: [PATCH 0/5] FlexRM support in VFIO platform

From	Anup Patel <anup.patel@broadcom.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/5] FlexRM support in VFIO platform
Date	2017-07-19 13:20 +0200
Message-ID	<u4Vbk-7Nz-13@gated-at.bofh.it> (permalink)
References	<u4TCy-6D1-9@gated-at.bofh.it> <u4URX-7qy-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Jul 19, 2017 at 4:27 PM, Robin Murphy <robin.murphy@arm.com> wrote:
> On 19/07/17 10:33, Anup Patel wrote:
>> This patchset primarily adds Broadcom FlexRM reset module for
>> VFIO platform driver. We also have minor improvments in IOMMU
>> and VFIO driver to allow VFIO no-IOMMU mode access to FlexRM.
>
> I'm struggling to understand the IOMMU changes here - what's the
> FlexRM's hardware relationship with the IOMMU, and how is it different
> from any other device? Furthermore, if there *is* a relevant IOMMU
> present, why would no-IOMMU mode need to be involved at all?

We want to have FlexRM device accessible from user-space
using VFIO platform with and without IOMMU.

Currently, if IOMMU ops are available for platform bus then
I cannot access FlexRM device using VFIO no-IOMMU mode.

Since, SMMU can bypass transactions which do not match
any SMRs, we should allow no-IOMMU mode for devices
when IOMMU group is not available.

Regards,
Anup

Thread

[PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
  [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
    Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
      Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:20 +0200
        Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:30 +0200
        Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Will Deacon <will.deacon@arm.com> - 2017-07-19 13:30 +0200
          Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:30 +0200
            Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:40 +0200
            Re: [PATCH 1/5] iommu: Add capability IOMMU_CAP_BYPASS Will Deacon <will.deacon@arm.com> - 2017-07-19 13:40 +0200
  [PATCH 2/5] iommu/arm-smmu: add IOMMU_CAP_BYPASS to the ARM SMMU driver Anup Patel <anup.patel@broadcom.com> - 2017-07-19 11:40 +0200
    Re: [PATCH 2/5] iommu/arm-smmu: add IOMMU_CAP_BYPASS to the ARM SMMU  driver Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
  Re: [PATCH 0/5] FlexRM support in VFIO platform Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:00 +0200
    Re: [PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:20 +0200
      Re: [PATCH 0/5] FlexRM support in VFIO platform Robin Murphy <robin.murphy@arm.com> - 2017-07-19 13:30 +0200
        Re: [PATCH 0/5] FlexRM support in VFIO platform Anup Patel <anup.patel@broadcom.com> - 2017-07-19 13:30 +0200

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