On 01/08/2022 23:12, Elliot Berman wrote:
When Linux is booted as a guest under the Gunyah hypervisor, Gunyah
applies a devicetree overlay describing the virtual platform
configuration of the guest VM, such as the message queue capability IDs
for communicating with the Resource Manager. Add the DT bindings that
Gunyah adheres for the hypervisor node and message queues.
Previously you explained that this cannot be discoverable, because EL2
hypervisor follows micro-kernel architecture and it is small. Size of
your code is not a reason to push things to DT... This is a kind of
explanation like: we did not add auto-discoverability, because we don't
want to add more code.
quoted hunk ↗ jump to hunk
Signed-off-by: Elliot Berman <redacted>
---
.../bindings/firmware/gunyah-hypervisor.yaml | 84 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 85 insertions(+)
create mode 100644 Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
diff --git a/Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml b/Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
new file mode 100644
index 000000000000..e50d932e768c
--- /dev/null
+++ b/Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/gunyah-hypervisor.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Gunyah Hypervisor
+
+maintainers:
+ - Murali Nalajala <quic_mnalajal@quicinc.com>
+ - Elliot Berman <quic_eberman@quicinc.com>
+
+description: |+
+ On systems which support devicetree, Gunyah generates and overlays a deviceetree overlay which
+ describes the basic configuration of the hypervisor. Virtual machines use this information for
+ initial discovery that they are running as a Gunyah guest VM.
+ See also: https://github.com/quic/gunyah-resource-manager/blob/develop/src/vm_creation/dto_construct.c
+
+properties:
+ compatible:
+ oneOf:
+ - items:
+ - const: gunyah-hypervisor-1.0
+ - const: gunyah-hypervisor
+
+ "#address-cells":
+ description: Number of cells needed to represent 64-bit capability IDs.
+ const: 2
Blank line between definition of each property.
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+ "#size-cells":
+ description: must be 0, because capability IDs are not memory address
+ ranges and do not have a size.
+ const: 0
+
+patternProperties:
+ "^gunyah-resource-mgr(@.*)?":
+ type: object
+ description:
+ Resource Manager node which is required to communicate to Resource
+ Manager VM using Gunyah Message Queues.
+
+ properties:
+ compatible:
+ oneOf:
+ - items:
+ - const: gunyah-resource-manager-1-0
+ - const: gunyah-resource-manager
Blank line.
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+ reg:
+ items:
+ - description: Gunyah capability ID of the TX message queue
+ - description: Gunyah capability ID of the RX message queue
Blank line.
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+ interrupts:
+ items:
+ - description: Interrupt for the TX message queue
+ - description: Interrupt for the RX message queue
Blank line.
+ additionalProperties: false
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+ required:
+ - compatible
+ - reg
+ - interrupts
+
+additionalProperties: false
+
+required:
+ - compatible
+ - "#address-cells"
+ - "#size-cells"
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+ hypervisor {
+ #address-cells = <2>;
+ #size-cells = <0>;
+ compatible = "gunyah-hypervisor-1.0", "gunyah-hypervisor";
+
+ gunyah-resource-mgr@1 {
+ compatible = "gunyah-resource-manager-1-0", "gunyah-resource-manager";
+ interrupts = <GIC_SPI 3 IRQ_TYPE_EDGE_RISING>, /* TX full IRQ */
+ <GIC_SPI 4 IRQ_TYPE_EDGE_RISING>; /* RX empty IRQ */
+ reg = <0x00000000 0x00000000>, <0x00000000 0x00000001>;
+ /* TX, RX cap ids */
+ };
+ };
Best regards,
Krzysztof