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.
While I am respinning this series into v4, here is a tentative summary
of technical topics for which no consensus was reached at this point.
1) Shall we report the usable IOVA range instead of reserved IOVA
ranges. Not discussed at/after LPC.
x I currently report reserved regions. Alex expressed the need to
report the full usable IOVA range instead (x86 min-max range
minus MSI APIC window). I think this is meaningful for ARM
too where arm-smmu might not support the full 64b range.
x Any objection we report the usable IOVA regions instead?
2) Shall the kernel check collision with MSI window* when userspace
calls VFIO_IOMMU_MAP_DMA?
Joerg/Will No; Alex yes
*for IOVA regions consumed downstream to the IOMMU: everyone says NO
3) RMRR reporting in the iommu group sysfs? Joerg: yes; Don: no
My current series does not expose them in iommu group sysfs.
I understand we can expose the RMRR regions in the iomm group sysfs
without necessarily supporting RMRR requiring device assignment.
We can also add this support later.
Thanks
Eric
>
> 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.
>
> 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(-)
>
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