| Message ID | 20240521043102.2786284-2-davidai@google.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Improve VM CPUfreq and task placement behavior | expand |
On Mon, 20 May 2024 21:30:51 -0700, David Dai wrote: > Adding bindings to represent a virtual cpufreq device. > > Virtual machines may expose MMIO regions for a virtual cpufreq device > for guests to read performance information or to request performance > selection. The virtual cpufreq device has an individual controller for > each performance domain. Performance points for a given domain can be > normalized across all domains for ease of allowing for virtual machines > to migrate between hosts. > > Co-developed-by: Saravana Kannan <saravanak@google.com> > Signed-off-by: Saravana Kannan <saravanak@google.com> > Signed-off-by: David Dai <davidai@google.com> > --- > .../cpufreq/qemu,virtual-cpufreq.yaml | 48 +++++++++++++++++++ > 1 file changed, 48 insertions(+) > create mode 100644 Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml b/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml new file mode 100644 index 000000000000..018d98bcdc82 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/qemu,virtual-cpufreq.yaml @@ -0,0 +1,48 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/cpufreq/qemu,virtual-cpufreq.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Virtual CPUFreq + +maintainers: + - David Dai <davidai@google.com> + - Saravana Kannan <saravanak@google.com> + +description: + Virtual CPUFreq is a virtualized driver in guest kernels that sends performance + selection of its vCPUs as a hint to the host through MMIO regions. Each vCPU + is associated with a performance domain which can be shared with other vCPUs. + Each performance domain has its own set of registers for performance controls. + +properties: + compatible: + const: qemu,virtual-cpufreq + + reg: + maxItems: 1 + description: + Address and size of region containing performance controls for each of the + performance domains. Regions for each performance domain is placed + contiguously and contain registers for controlling DVFS(Dynamic Frequency + and Voltage) characteristics. The size of the region is proportional to + total number of performance domains. + +required: + - compatible + - reg + +additionalProperties: false + +examples: + - | + soc { + #address-cells = <1>; + #size-cells = <1>; + + cpufreq@1040000 { + compatible = "qemu,virtual-cpufreq"; + reg = <0x1040000 0x2000>; + }; + };