Re: [PATCH v4 09/11] tests/acpi: add test cases for VIOT

[Jean-Philippe Brucker]

On Tue, Oct 05, 2021 at 03:57:17PM +0530, Ani Sinha wrote:
> 
> 
> On Fri, 1 Oct 2021, Jean-Philippe Brucker wrote:
> 
> > Add two test cases for VIOT, one on the q35 machine and the other on
> > virt. To test complex topologies the q35 test has two PCIe buses that
> > bypass the IOMMU (and are therefore not described by VIOT), and two
> > buses that are translated by virtio-iommu.
> >
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> 
> This might be a stupid question but what about virtio-mmio and single mmio
> cases? I see none of your tables has nodes for those and here too you do
> not add test cases for it.

No it's a good question, there is no support for either at the moment.
virtio-mmio based virtio-iommu is relatively easy to implement, just
requires a little more machine support. QEMU doesn't support putting MMIO
endpoints behind an IOMMU at the moment, and implementing that is more
complicated.

To test the Linux VIOT driver I did both prototypes, but I don't have a
compelling reason or time to upstream them at the moment
https://jpbrucker.net/git/qemu/log/?h=virtio-iommu/acpi-2021-06-02

Thanks,
Jean