RE: [PATCH v8 00/18] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions

[Bharat Bhushan]

> -----Original Message-----
> From: Eric Auger [mailto:eric.auger@xxxxxxxxxx]
> Sent: Wednesday, January 11, 2017 3:12 PM
> To: eric.auger@xxxxxxxxxx; eric.auger.pro@xxxxxxxxx;
> christoffer.dall@xxxxxxxxxx; marc.zyngier@xxxxxxx;
> robin.murphy@xxxxxxx; alex.williamson@xxxxxxxxxx;
> will.deacon@xxxxxxx; joro@xxxxxxxxxx; tglx@xxxxxxxxxxxxx;
> jason@xxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: kvm@xxxxxxxxxxxxxxx; drjones@xxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; pranav.sawargaonkar@xxxxxxxxx;
> iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; punit.agrawal@xxxxxxx; Diana Madalina
> Craciun <diana.craciun@xxxxxxx>; gpkulkarni@xxxxxxxxx;
> shankerd@xxxxxxxxxxxxxx; Bharat Bhushan <bharat.bhushan@xxxxxxx>;
> geethasowjanya.akula@xxxxxxxxx
> Subject: [PATCH v8 00/18] KVM PCIe/MSI passthrough on ARM/ARM64 and
> IOVA reserved regions
> 
> Following LPC discussions, we now report reserved regions through the
> 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 [0xfee00000 - 0xfeefffff] MSI window
>   as a reserved region and RMRR regions as direct-mapped regions.
> - the amd-iommu reports device direct mapped regions, the MSI region
>   and HT regions.
> - the arm-smmu reports the MSI window (arbitrarily located at
>   0x8000000 and 1MB large).
> 
> Unsafe interrupt assignment is tested by enumerating all MSI irq domains
> and checking MSI remapping is supported in the above hierarchy.
> This check is done in case we detect the iommu translates MSI (an
> IOMMU_RESV_MSI window exists). Otherwise the IRQ remapping capability
> is checked at IOMMU level. Obviously this is a defensive IRQ safety
> assessment: Assuming there are several MSI controllers in the system and at
> least one does not implement IRQ remapping, the assignment will be
> considered as unsafe (even if this controller is not acessible from the
> assigned devices).
> 
> The series first patch stems from Robin's branch:
> http://linux-arm.org/git?p=linux-
> rm.git;a=shortlog;h=refs/heads/iommu/misc
> 
> Best Regards
> 
> Eric
> 
> Git: complete series available at
> https://github.com/eauger/linux/tree/v4.10-rc3-reserved-v8

This series is tested on NXP platform, if you want you can add my tested by
Tested-by: Bharat Bhushan <bharat.bhushan@xxxxxxx>

Thanks
-Bharat

> 
> istory:
> 
> PATCHv7 -> PATCHv8
> - take into account Marc's comments and apply his R-b
> - remove iommu_group_remove_file call in iommu_group_release
> - add Will's A-b
> - removed [PATCH v7 01/19] iommu/dma: Implement PCI allocation
>   optimisation and updated iommu/dma: Allow MSI-only cookies
>   as per Robin's indications
> 
> PATCHv6 -> PATCHv7:
> - iommu/dma: Implement PCI allocation optimisation was added to apply
>   iommu/dma: Allow MSI-only cookies
> - report Intel RMRR as direct-mapped regions
> - report the type in the iommu group sysfs reserved_regions file
> - do not merge regions of different types when building the list
>   of reserved regions
> - intgeration Robin's "iommu/dma: Allow MSI-only cookies" last
>   version
> - update Documentation/ABI/testing/sysfs-kernel-iommu_groups
> - rename IOMMU_RESV_NOMAP into IOMMU_RESV_RESERVED
> 
> PATCHv5 -> PATCHv6
> - Introduce IRQ_DOMAIN_FLAG_MSI as suggested by Marc
> - irq_domain_is_msi, irq_domain_is_msi_remap,
>   irq_domain_hierarchical_is_msi_remap,
> - set IRQ_DOMAIN_FLAG_MSI in msi_create_irq_domain
> - fix compil issue on i386
> - rework test at VFIO level
> 
> RFCv4 -> PATCHv5
> - fix IRQ security assessment by looking at irq domain parents
> - check DOMAIN_BUS_FSL_MC_MSI irq domains
> - AMD MSI and HT regions are exposed in iommu group sysfs
> 
> RFCv3 -> RFCv4:
> - arm-smmu driver does not register PCI host bridge windows as
>   reserved regions anymore
> - Implement reserved region get/put callbacks also in arm-smmuv3
> - take the iommu_group lock on iommu_get_group_resv_regions
> - add a type field in iommu_resv_region instead of using prot
> - init the region list_head in iommu_alloc_resv_region, also
>   add type parameter
> - iommu_insert_resv_region manage overlaps and sort reserved
>   windows
> - address IRQ safety assessment by enumerating all the MSI irq
>   domains and checking the MSI_REMAP flag
> - update Documentation/ABI/testing/sysfs-kernel-iommu_groups
> 
> 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 (17):
>   iommu: Rename iommu_dm_regions into iommu_resv_regions
>   iommu: Add a new type field in iommu_resv_region
>   iommu: iommu_alloc_resv_region
>   iommu: Only map direct mapped 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/amd: Declare MSI and HT regions as reserved IOVA regions
>   iommu/arm-smmu: Implement reserved region get/put callbacks
>   iommu/arm-smmu-v3: Implement reserved region get/put callbacks
>   irqdomain: Add irq domain MSI and MSI_REMAP flags
>   genirq/msi: Set IRQ_DOMAIN_FLAG_MSI on MSI domain creation
>   irqdomain: irq_domain_check_msi_remap
>   irqchip/gicv3-its: Sets IRQ_DOMAIN_FLAG_MSI_REMAP
>   vfio/type1: Allow transparent MSI IOVA allocation
>   vfio/type1: Check MSI remapping at irq domain level
>   iommu/arm-smmu: Do not advertise IOMMU_CAP_INTR_REMAP anymore
> 
> Robin Murphy (1):
>   iommu/dma: Allow MSI-only cookies
> 
>  .../ABI/testing/sysfs-kernel-iommu_groups          |  12 ++
>  drivers/iommu/amd_iommu.c                          |  54 ++++---
>  drivers/iommu/arm-smmu-v3.c                        |  30 +++-
>  drivers/iommu/arm-smmu.c                           |  30 +++-
>  drivers/iommu/dma-iommu.c                          | 119 +++++++++++---
>  drivers/iommu/intel-iommu.c                        |  92 ++++++++---
>  drivers/iommu/iommu.c                              | 177 +++++++++++++++++++--
>  drivers/irqchip/irq-gic-v3-its.c                   |   1 +
>  drivers/vfio/vfio_iommu_type1.c                    |  37 ++++-
>  include/linux/dma-iommu.h                          |   6 +
>  include/linux/iommu.h                              |  46 ++++--
>  include/linux/irqdomain.h                          |  36 +++++
>  kernel/irq/irqdomain.c                             |  36 +++++
>  kernel/irq/msi.c                                   |   4 +-
>  14 files changed, 587 insertions(+), 93 deletions(-)
> 
> --
> 1.9.1