Re: [PATCH v5 0/7] Add virtio-iommu driver

["Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Thu, Nov 22, 2018 at 07:37:54PM +0000, Jean-Philippe Brucker wrote:
> Implement the virtio-iommu driver, following specification v0.9 [1].
> 
> Since v4 [2] I fixed the issues reported by Eric, and added Reviewed-by
> from Eric and Rob. Thanks!
> 
> I changed the specification to fix one inconsistency discussed in v4.
> That the device fills the probe buffer with zeroes is now a "SHOULD"
> instead of a "MAY", since it's the only way for the driver to know if
> the device wrote the status. Existing devices already do this. In
> addition the device now needs to fill the three padding bytes at the
> tail with zeroes.
> 
> You can find Linux driver and kvmtool device on branches
> virtio-iommu/v0.9 [3]. I also lightly tested with Eric's latest QEMU
> device [4].

I tried to get this to work on my x86 box but without
success. Any hints? Does this have to do with the IORT table?
I think we really should just reserve our own table ID
and avoid the pain of trying to add things to the IORT spec.
I'm reluctant to merge lots of code that I can't easily test.
Again, if we found a way to push more configuration into
virtio config space the problem space would be smaller.

> [1] Virtio-iommu specification v0.9, sources, pdf and diff from v0.8
>     git://linux-arm.org/virtio-iommu.git virtio-iommu/v0.9
>     http://jpbrucker.net/virtio-iommu/spec/v0.9/virtio-iommu-v0.9.pdf
>     http://jpbrucker.net/virtio-iommu/spec/diffs/virtio-iommu-pdf-diff-v0.8-v0.9.pdf
> 
> [2] [PATCH v4 0/7] Add virtio-iommu driver
>     https://lists.linuxfoundation.org/pipermail/iommu/2018-November/031074.html
> 
> [3] git://linux-arm.org/linux-jpb.git virtio-iommu/v0.9
>     git://linux-arm.org/kvmtool-jpb.git virtio-iommu/v0.9
> 
> [4] [RFC v9 00/17] VIRTIO-IOMMU device
>     https://www.mail-archive.com/qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org/msg575578.html
> 
> Jean-Philippe Brucker (7):
>   dt-bindings: virtio-mmio: Add IOMMU description
>   dt-bindings: virtio: Add virtio-pci-iommu node
>   of: Allow the iommu-map property to omit untranslated devices
>   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                  | 1157 +++++++++++++++++
>  drivers/of/base.c                             |   10 +-
>  drivers/pci/of.c                              |    7 +
>  include/uapi/linux/virtio_ids.h               |    1 +
>  include/uapi/linux/virtio_iommu.h             |  161 +++
>  10 files changed, 1448 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