[PATCH v6 1/2] dt-bindings: vcpu_stall_detector: Add qemu,vcpu-stall-detector compatible

From: Sebastian Ene
Date: Thu Jun 16 2022 - 05:28:11 EST


The VCPU stall detection mechanism allows to configure the expiration
duration and the internal counter clock frequency measured in Hz.
Add these properties in the schema.

While this is a memory mapped virtual device, it is expected to be loaded
when the DT contains the compatible: "qemu,vcpu-stall-detector" node.
In a protected VM we trust the generated DT nodes and we don't rely on
the host to present the hardware peripherals.

Signed-off-by: Sebastian Ene <sebastianene@xxxxxxxxxx>
---
.../bindings/misc/vcpu_stall_detector.yaml | 49 +++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/vcpu_stall_detector.yaml

diff --git a/Documentation/devicetree/bindings/misc/vcpu_stall_detector.yaml b/Documentation/devicetree/bindings/misc/vcpu_stall_detector.yaml
new file mode 100644
index 000000000000..55323676194b
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/vcpu_stall_detector.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/vcpu_stall_detector.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: VCPU stall detector
+
+description: |
+ This binding describes a CPU stall detector mechanism for virtual cpus
+ which is accessed through MMIO.
+
+maintainers:
+ - Sebastian Ene <sebastianene@xxxxxxxxxx>
+
+properties:
+ compatible:
+ enum:
+ - qemu,vcpu-stall-detector
+
+ clock-frequency:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ The internal clock of the stall detector peripheral measure in Hz used
+ to decrement its internal counter register on each tick.
+ Defaults to 10 if unset.
+
+ timeout-sec:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ The stall detector expiration timeout measured in seconds.
+ Defaults to 8 if unset. Please note that it also takes into account the
+ time spent while the VCPU is not running.
+
+required:
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ vmwdt@9030000 {
+ compatible = "qemu,vcpu-stall-detector";
+ clock-frequency = <10>;
+ timeout-sec = <8>;
+ reg = <0x0 0x9030000 0x0 0x10000>;
+ };
+
+...
--
2.36.1.476.g0c4daa206d-goog