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

Auger Eric
2021-03-19T10:59:11Z

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?

Thanks

Eric
>
> Jean-Philippe Brucker (3):
> ACPICA: iASL: Add definitions for the VIOT table
> ACPI: Add driver for the VIOT table
> iommu/virtio: Enable x86 support
>
> drivers/acpi/Kconfig | 3 +
> drivers/iommu/Kconfig | 4 +-
> drivers/acpi/Makefile | 2 +
> include/acpi/actbl3.h | 67 ++++++
> include/linux/acpi_viot.h | 26 +++
> drivers/acpi/bus.c | 2 +
> drivers/acpi/scan.c | 6 +
> drivers/acpi/viot.c | 406 +++++++++++++++++++++++++++++++++++
> drivers/iommu/virtio-iommu.c | 3 +
> MAINTAINERS | 8 +
> 10 files changed, 526 insertions(+), 1 deletion(-)
> create mode 100644 include/linux/acpi_viot.h
> create mode 100644 drivers/acpi/viot.c