add413a1d9
The main purpose of this binding is to communicate Xen specific information using generic IOMMU device tree bindings (which is a good fit here) rather than introducing a custom property. Introduce Xen specific IOMMU for the virtualized device (e.g. virtio) to be used by Xen grant DMA-mapping layer in the subsequent commit. The reference to Xen specific IOMMU node using "iommus" property indicates that Xen grant mappings need to be enabled for the device, and it specifies the ID of the domain where the corresponding backend resides. The domid (domain ID) is used as an argument to the Xen grant mapping APIs. This is needed for the option to restrict memory access using Xen grant mappings to work which primary goal is to enable using virtio devices in Xen guests. Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/1654197833-25362-6-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross <jgross@suse.com>
40 lines
993 B
YAML
40 lines
993 B
YAML
# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
|
|
%YAML 1.2
|
|
---
|
|
$id: http://devicetree.org/schemas/iommu/xen,grant-dma.yaml#
|
|
$schema: http://devicetree.org/meta-schemas/core.yaml#
|
|
|
|
title: Xen specific IOMMU for virtualized devices (e.g. virtio)
|
|
|
|
maintainers:
|
|
- Stefano Stabellini <sstabellini@kernel.org>
|
|
|
|
description:
|
|
The Xen IOMMU represents the Xen grant table interface. Grant mappings
|
|
are to be used with devices connected to the Xen IOMMU using the "iommus"
|
|
property, which also specifies the ID of the backend domain.
|
|
The binding is required to restrict memory access using Xen grant mappings.
|
|
|
|
properties:
|
|
compatible:
|
|
const: xen,grant-dma
|
|
|
|
'#iommu-cells':
|
|
const: 1
|
|
description:
|
|
The single cell is the domid (domain ID) of the domain where the backend
|
|
is running.
|
|
|
|
required:
|
|
- compatible
|
|
- "#iommu-cells"
|
|
|
|
additionalProperties: false
|
|
|
|
examples:
|
|
- |
|
|
iommu {
|
|
compatible = "xen,grant-dma";
|
|
#iommu-cells = <1>;
|
|
};
|