Re: [PATCH 0/3] Add support for ACPI VIOT

Jean-Philippe Brucker
2021-03-19T11:17:22Z

Hi Eric,

On Fri, Mar 19, 2021 at 11:58:49AM +0100, Auger Eric wrote:
> Hi Jean,
>
> On 3/16/21 8:16 PM, Jean-Philippe Brucker wrote:
> > Add a driver for the ACPI VIOT table, which enables virtio-iommu on
> > non-devicetree platforms, including x86. This series depends on the
> > ACPICA changes of patch 1, which will be included in next release [1]
> > and pulled into Linux.
> >
> > The Virtual I/O Translation table (VIOT) describes the topology of
> > para-virtual I/O translation devices and the endpoints they manage.
> > It was recently approved for inclusion into the ACPI standard [2].
> > A provisional version of the specification can be found at [3].
> >
> > After discussing non-devicetree support for virtio-iommu at length
> > [4][5][6] we concluded that it should use this new ACPI table. And for
> > platforms that don't implement either devicetree or ACPI, a structure
> > that uses roughly the same format [6] can be built into the device.
> >
> > [1] https://github.com/acpica/acpica/pull/666
> > [2] https://lore.kernel.org/linux-iommu/20210218233943.GH702808@redhat.com/
> > [3] https://jpbrucker.net/virtio-iommu/viot/viot-v9.pdf
> > [4] https://lore.kernel.org/linux-iommu/20191122105000.800410-1-jean-philippe@linaro.org/
> > [5] https://lore.kernel.org/linux-iommu/20200228172537.377327-1-jean-philippe@linaro.org/
> > [6] https://lore.kernel.org/linux-iommu/20200821131540.2801801-1-jean-philippe@linaro.org/
>
> Do you have a qemu branch to share for us to start exercising different
> kinds of topology?

Yes: https://jpbrucker.net/git/qemu/log/?h=virtio-iommu/acpi
Thanks for the reviews, I'll rework this in a week or so

Jean