linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v9 0/7] KVM PCIe/MSI passthrough on ARM/ARM64: kernel part 3/3: vfio changes
@ 2016-05-04 11:54 Eric Auger
  2016-05-04 11:54 ` [PATCH v9 1/7] vfio: introduce a vfio_dma type field Eric Auger
                   ` (7 more replies)
  0 siblings, 8 replies; 38+ messages in thread
From: Eric Auger @ 2016-05-04 11:54 UTC (permalink / raw)
  To: eric.auger, eric.auger, robin.murphy, alex.williamson,
	will.deacon, joro, tglx, jason, marc.zyngier, christoffer.dall,
	linux-arm-kernel
  Cc: patches, linux-kernel, Bharat.Bhushan, pranav.sawargaonkar,
	p.fedin, iommu, Jean-Philippe.Brucker, julien.grall, yehuday

This series allows the user-space to register a reserved IOVA domain.
This completes the kernel integration of the whole functionality on top
of part 1 (v9) & 2 (v8).

It also depends on [PATCH 1/3] iommu: Add MMIO mapping type series,
http://comments.gmane.org/gmane.linux.kernel.iommu/12869

We reuse the VFIO DMA MAP ioctl with a new flag to bridge to the
msi-iommu API. The need for provisioning such MSI IOVA range is reported
through capability chain, using VFIO_IOMMU_TYPE1_INFO_CAP_MSI_GEOMETRY.

vfio_iommu_type1 checks if the MSI mapping is safe when attaching the
vfio group to the container (allow_unsafe_interrupts modality).

On ARM/ARM64, the IOMMU does not astract IRQ remapping. the modality is
abstracted on MSI controller side. The GICv3 ITS is the first controller
advertising the modality.

More details & context can be found at:
http://www.linaro.org/blog/core-dump/kvm-pciemsi-passthrough-armarm64/

Best Regards

Eric

Testing:
- functional on ARM64 AMD Overdrive HW (single GICv2m frame) with
  Intel X540-T2 (SR-IOV capable)
- also tested on Armada-7040 using an intel IXGBE (82599ES) by
  Yehuda Yitschak (v8)
- Not tested: ARM GICv3 ITS

References:
[1] [RFC 0/2] VFIO: Add virtual MSI doorbell support
    (https://lkml.org/lkml/2015/7/24/135)
[2] [RFC PATCH 0/6] vfio: Add interface to map MSI pages
    (https://lists.cs.columbia.edu/pipermail/kvmarm/2015-September/016607.html)
[3] [PATCH v2 0/3] Introduce MSI hardware mapping for VFIO
    (http://permalink.gmane.org/gmane.comp.emulators.kvm.arm.devel/3858)

Git: complete series available at
https://git.linaro.org/people/eric.auger/linux.git/shortlog/refs/heads/v4.6-rc6-pcie-passthrough-v9

previous version at
https://git.linaro.org/people/eric.auger/linux.git/shortlog/refs/heads/v4.6-rc5-pcie-passthrough-v8

History:
v8 -> v9:
- report MSI geometry through capability chain (last patch only);
  with the current limitation that an arbitrary number of 16 page
  requirement is reported. To be improved later on.


v7 -> v8:
- use renamed msi-iommu API
- VFIO only responsible for setting the IOVA aperture
- use new DOMAIN_ATTR_MSI_GEOMETRY iommu domain attribute

v6 -> v7:
- vfio_find_dma now accepts a dma_type argument.
- should have recovered the capability to unmap the whole user IOVA range
- remove computation of nb IOVA pages -> will post a separate RFC for that
  while respinning the QEMU part

RFC v5 -> patch v6:
- split to ease the review process

RFC v4 -> RFC v5:
- take into account Thomas' comments on MSI related patches
  - split "msi: IOMMU map the doorbell address when needed"
  - increase readability and add comments
  - fix style issues
 - split "iommu: Add DOMAIN_ATTR_MSI_MAPPING attribute"
 - platform ITS now advertises IOMMU_CAP_INTR_REMAP
 - fix compilation issue with CONFIG_IOMMU API unset
 - arm-smmu-v3 now advertises DOMAIN_ATTR_MSI_MAPPING

RFC v3 -> v4:
- Move doorbell mapping/unmapping in msi.c
- fix ref count issue on set_affinity: in case of a change in the address
  the previous address is decremented
- doorbell map/unmap now is done on msi composition. Should allow the use
  case for platform MSI controllers
- create dma-reserved-iommu.h/c exposing/implementing a new API dedicated
  to reserved IOVA management (looking like dma-iommu glue)
- series reordering to ease the review:
  - first part is related to IOMMU
  - second related to MSI sub-system
  - third related to VFIO (except arm-smmu IOMMU_CAP_INTR_REMAP removal)
- expose the number of requested IOVA pages through VFIO_IOMMU_GET_INFO
  [this partially addresses Marc's comments on iommu_get/put_single_reserved
   size/alignment problematic - which I did not ignore - but I don't know
   how much I can do at the moment]

RFC v2 -> RFC v3:
- should fix wrong handling of some CONFIG combinations:
  CONFIG_IOVA, CONFIG_IOMMU_API, CONFIG_PCI_MSI_IRQ_DOMAIN
- fix MSI_FLAG_IRQ_REMAPPING setting in GICv3 ITS (although not tested)

PATCH v1 -> RFC v2:
- reverted to RFC since it looks more reasonable ;-) the code is split
  between VFIO, IOMMU, MSI controller and I am not sure I did the right
  choices. Also API need to be further discussed.
- iova API usage in arm-smmu.c.
- MSI controller natively programs the MSI addr with either the PA or IOVA.
  This is not done anymore in vfio-pci driver as suggested by Alex.
- check irq remapping capability of the group

RFC v1 [2] -> PATCH v1:
- use the existing dma map/unmap ioctl interface with a flag to register a
  reserved IOVA range. Use the legacy Rb to store this special vfio_dma.
- a single reserved IOVA contiguous region now is allowed
- use of an RB tree indexed by PA to store allocated reserved slots
- use of a vfio_domain iova_domain to manage iova allocation within the
  window provided by the userspace
- vfio alloc_map/unmap_free take a vfio_group handle
- vfio_group handle is cached in vfio_pci_device
- add ref counting to bindings
- user modality enabled at the end of the series


Eric Auger (7):
  vfio: introduce a vfio_dma type field
  vfio/type1: vfio_find_dma accepting a type argument
  vfio/type1: bypass unmap/unpin and replay for VFIO_IOVA_RESERVED slots
  vfio: allow reserved msi iova registration
  vfio/type1: also check IRQ remapping capability at msi domain
  iommu/arm-smmu: do not advertise IOMMU_CAP_INTR_REMAP
  vfio/type1: return MSI geometry through VFIO_IOMMU_GET_INFO capability
    chains

 drivers/iommu/arm-smmu-v3.c     |   3 +-
 drivers/iommu/arm-smmu.c        |   3 +-
 drivers/vfio/vfio_iommu_type1.c | 270 +++++++++++++++++++++++++++++++++++++---
 include/uapi/linux/vfio.h       |  40 +++++-
 4 files changed, 298 insertions(+), 18 deletions(-)

-- 
1.9.1

^ permalink raw reply	[flat|nested] 38+ messages in thread

end of thread, other threads:[~2016-06-20 15:47 UTC | newest]

Thread overview: 38+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-04 11:54 [PATCH v9 0/7] KVM PCIe/MSI passthrough on ARM/ARM64: kernel part 3/3: vfio changes Eric Auger
2016-05-04 11:54 ` [PATCH v9 1/7] vfio: introduce a vfio_dma type field Eric Auger
2016-05-04 11:54 ` [PATCH v9 2/7] vfio/type1: vfio_find_dma accepting a type argument Eric Auger
2016-05-09 22:49   ` Alex Williamson
2016-05-10 14:54     ` Eric Auger
2016-05-04 11:54 ` [PATCH v9 3/7] vfio/type1: bypass unmap/unpin and replay for VFIO_IOVA_RESERVED slots Eric Auger
2016-05-09 22:49   ` Alex Williamson
2016-05-11 12:58     ` Eric Auger
2016-05-04 11:54 ` [PATCH v9 4/7] vfio: allow reserved msi iova registration Eric Auger
2016-05-05 19:22   ` Chalamarla, Tirumalesh
2016-05-09  7:55     ` Eric Auger
2016-05-10 15:29   ` Alex Williamson
2016-05-10 15:34     ` Eric Auger
2016-05-04 11:54 ` [PATCH v9 5/7] vfio/type1: also check IRQ remapping capability at msi domain Eric Auger
2016-05-05 19:23   ` Chalamarla, Tirumalesh
2016-05-09  8:05     ` Eric Auger
2016-05-09 22:49   ` Alex Williamson
2016-05-10 16:10     ` Eric Auger
2016-05-10 17:24       ` Robin Murphy
2016-05-11  8:38         ` Eric Auger
2016-05-11  9:31           ` Robin Murphy
2016-05-11  9:44             ` Eric Auger
2016-05-11 13:48               ` Robin Murphy
2016-05-11 14:37                 ` Eric Auger
2016-05-04 11:54 ` [PATCH v9 6/7] iommu/arm-smmu: do not advertise IOMMU_CAP_INTR_REMAP Eric Auger
2016-05-04 11:54 ` [PATCH v9 7/7] vfio/type1: return MSI geometry through VFIO_IOMMU_GET_INFO capability chains Eric Auger
2016-05-04 12:06   ` Eric Auger
2016-05-09 23:03     ` Alex Williamson
2016-05-10 16:50       ` Eric Auger
2016-05-09 22:49   ` Alex Williamson
2016-05-10 16:36     ` Eric Auger
2016-05-20 16:01 ` [PATCH v9 0/7] KVM PCIe/MSI passthrough on ARM/ARM64: kernel part 3/3: vfio changes Eric Auger
2016-06-08  8:29   ` Auger Eric
2016-06-08 21:06     ` Alex Williamson
2016-06-09  7:55       ` Auger Eric
2016-06-09 19:44         ` Alex Williamson
2016-06-20 15:42         ` Pranav Sawargaonkar
2016-06-20 15:46           ` Pranav Sawargaonkar

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).