[PATCH v7 0/5] VIRTIO-IOMMU probe request support and MSI bypass on ARM

[Eric Auger]

By default the virtio-iommu translates MSI transactions. This
behavior is inherited from ARM SMMU. However the virt machine
code knows where the MSI doorbells are, so we can easily
declare those regions as VIRTIO_IOMMU_RESV_MEM_T_MSI. With that
setting the guest iommu subsystem will not need to map MSIs.
This setup will simplify the VFIO integration.

In this series, the ITS or GICV2M doorbells are declared as
HW MSI regions to be bypassed by the VIRTIO-IOMMU.

This also paves the way to the x86 integration where the MSI
region, [0xFEE00000,0xFEEFFFFF], will be exposed by the q35
machine.  However this will be handled in a separate series
when not-DT support gets resolved.

Best Regards

Eric

This series can be found at:
https://github.com/eauger/qemu/tree/v5.0.0-virtio-iommu-msi-bypass-v7

History:

v6 -> v7:
- fix the hint message
- put the assert again on probe request

v5 -> v6:
- do not hardcode start/end addresses of doorbells
- check reserved region type on realize()

v4 -> v5:
- Take into account some additional comments from Markus:
  - reserved region type becomes an unsigned + some comment/desc
    rewording
  - assert if the type is not RESERVED or MSI

v3 -> v4:
- collected Jean and markus's R-bs
- tool into account all Markus' comments in [1/5] (except removal of
  goto)
- use ':' as delimitor instead of commas
- add example in 4/5 commit message as suggested by Markus

v2 -> v3:
- Introduce VIRT_MSI_CTRL_NONE in VirtMSIControllerType
- do not fill the remainder of the probe buffer

v1 -> v2:
- check which MSI controller is in use and advertise the
  corresponding MSI doorbell
- managed for both ITS and GICv2M
- various fixes spotted by Peter and Jean-Philippe, see
  individual logs

v1: Most of those patches were respinned from
  [PATCH for-5.0 v11 00/20] VIRTIO-IOMMU device
  except the last one which is new


Eric Auger (5):
  qdev: Introduce DEFINE_PROP_RESERVED_REGION
  virtio-iommu: Implement RESV_MEM probe request
  virtio-iommu: Handle reserved regions in the translation process
  virtio-iommu-pci: Add array of Interval properties
  hw/arm/virt: Let the virtio-iommu bypass MSIs

 include/exec/memory.h            |   6 ++
 include/hw/arm/virt.h            |   7 ++
 include/hw/qdev-properties.h     |   3 +
 include/hw/virtio/virtio-iommu.h |   2 +
 include/qemu/typedefs.h          |   1 +
 hw/arm/virt.c                    |  30 ++++++++
 hw/core/qdev-properties.c        |  89 ++++++++++++++++++++++++
 hw/virtio/virtio-iommu-pci.c     |  11 +++
 hw/virtio/virtio-iommu.c         | 114 +++++++++++++++++++++++++++++--
 hw/virtio/trace-events           |   1 +
 10 files changed, 260 insertions(+), 4 deletions(-)

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2.20.1