[PATCH v3 0/7] Add virtio-iommu driver

[Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org>]

Implement the virtio-iommu driver, following specification v0.8 [1].
Changes since v2 [2]:

* Patches 2-4 allow virtio-iommu to use the PCI transport, since QEMU
  would like to phase out the MMIO transport. This produces a complex
  topology where the programming interface of the IOMMU could appear
  lower than the endpoints that it translates. It's not unheard of (e.g.
  AMD IOMMU), and the guest easily copes with this.
  
  The "Firmware description" section of the specification has been
  updated with all combinations of PCI, MMIO and DT, ACPI.

* Fix structures layout, they don't need the "packed" attribute anymore.

* While we're at it, add domain parameter to DETACH request, and leave
  some padding. This way the next version, that adds PASID support,
  won't have to introduce a "DETACH2" request to stay backward
  compatible.

* Require virtio device 1.0+. Remove legacy transport notes from the
  specification.

* Request timeout is now only enabled with DEBUG.

* The patch for VFIO Kconfig (previously patch 5/5) is in next.

You can find Linux driver and kvmtool device on branches
virtio-iommu/v0.8 [3] (currently based on 4.19-rc7 but rebasing onto
next only produced a trivial conflict). Branch virtio-iommu/devel
contains a few patches that I'd like to send once the base is upstream:

* virtio-iommu as a module. It got *much* nicer after Rob's probe
  deferral rework, but I still have a bug to fix when re-loading the
  virtio-iommu module.

* ACPI support requires a minor IORT spec update (reservation of node
  ID). I think it should be easier to obtain once the device and drivers
  are upstream.

[1] Virtio-iommu specification v0.8, diff from v0.7, and sources
    git://linux-arm.org/virtio-iommu.git virtio-iommu/v0.8
    http://jpbrucker.net/virtio-iommu/spec/v0.8/virtio-iommu-v0.8.pdf
    http://jpbrucker.net/virtio-iommu/spec/diffs/virtio-iommu-pdf-diff-v0.7-v0.8.pdf

[2] [PATCH v2 0/5] Add virtio-iommu driver
    https://www.spinics.net/lists/kvm/msg170655.html

[3] git://linux-arm.org/linux-jpb.git virtio-iommu/v0.8
    git://linux-arm.org/kvmtool-jpb.git virtio-iommu/v0.8

Jean-Philippe Brucker (7):
  dt-bindings: virtio-mmio: Add IOMMU description
  dt-bindings: virtio: Add virtio-pci-iommu node
  PCI: OF: allow endpoints to bypass the iommu
  PCI: OF: Initialize dev->fwnode appropriately
  iommu: Add virtio-iommu driver
  iommu/virtio: Add probe request
  iommu/virtio: Add event queue

 .../devicetree/bindings/virtio/iommu.txt      |   66 +
 .../devicetree/bindings/virtio/mmio.txt       |   30 +
 MAINTAINERS                                   |    7 +
 drivers/iommu/Kconfig                         |   11 +
 drivers/iommu/Makefile                        |    1 +
 drivers/iommu/virtio-iommu.c                  | 1171 +++++++++++++++++
 drivers/pci/of.c                              |   14 +-
 include/uapi/linux/virtio_ids.h               |    1 +
 include/uapi/linux/virtio_iommu.h             |  159 +++
 9 files changed, 1457 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/virtio/iommu.txt
 create mode 100644 drivers/iommu/virtio-iommu.c
 create mode 100644 include/uapi/linux/virtio_iommu.h

-- 
2.19.1