Re: [PATCH V3 5/8] dt-bindings: Add xen,grant-dma IOMMU description for xen-grant DMA ops
From: Krzysztof Kozlowski <hidden>
Date: 2022-05-31 11:52:22
Also in:
linux-devicetree, linux-iommu, lkml, xen-devel
On 30/05/2022 23:00, Oleksandr Tyshchenko wrote:
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Thank you for your patch. There is something to discuss/improve.
quoted hunk ↗ jump to hunk
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@kernel.org> + +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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel