On 30/05/2022 23:00, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx> Thank you for your patch. There is something to discuss/improve. > diff --git a/Documentation/devicetree/bindings/iommu/xen,grant-dma.yaml b/Documentation/devicetree/bindings/iommu/xen,grant-dma.yaml > new file mode 100644 > index 00000000..ab5765c > --- /dev/null > +++ b/Documentation/devicetree/bindings/iommu/xen,grant-dma.yaml > @@ -0,0 +1,49 @@ > +# 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@xxxxxxxxxx> > + > +description: > + 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 binding is required to restrict memory access using Xen grant mappings. > + > +properties: > + compatible: > + const: xen,grant-dma > + > + '#iommu-cells': > + const: 1 > + description: > + Xen specific IOMMU is multiple-master IOMMU device. > + The single cell describes the domid (domain ID) of the domain where > + the backend is running. > + > +required: > + - compatible > + - "#iommu-cells" > + > +additionalProperties: false > + > +examples: > + - | > + xen_iommu { No underscores in node names, generic node names, so this looks like "iommu". > + compatible = "xen,grant-dma"; > + #iommu-cells = <1>; > + }; > + > + virtio@3000 { > + compatible = "virtio,mmio"; > + reg = <0x3000 0x100>; > + interrupts = <41>; > + > + /* The backend is located in Xen domain with ID 1 */ > + iommus = <&xen_iommu 1>; There is no need usually to give consumer examples in provider binding. If there is nothing specific here (looks exactly like every IOMMU consumer in Linux kernel), drop the consumer. > + }; Best regards, Krzysztof
