Messages in this thread | | | Date | Thu, 27 Oct 2022 09:17:13 -0700 | Subject | Re: [PATCH v5 02/13] dt-bindings: Add binding for gunyah hypervisor | From | Elliot Berman <> |
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Hi Rob,
On 10/26/2022 2:16 PM, Rob Herring wrote: > On Thu, Oct 13, 2022 at 6:59 PM Elliot Berman <quic_eberman@quicinc.com> wrote: >> >> >> On 10/12/2022 8:56 AM, Rob Herring wrote: >>> On Mon, Oct 10, 2022 at 05:08:29PM -0700, Elliot Berman wrote: >>>> When Linux is booted as a guest under the Gunyah hypervisor, the Gunyah >>>> Resource Manager 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. This >>>> information is not otherwise discoverable by a VM: the Gunyah hypervisor >>>> core does not provide a direct interface to discover capability IDs nor >>>> a way to communicate with RM without having already known the >>>> corresponding message queue capability ID. Add the DT bindings that >>>> Gunyah adheres for the hypervisor node and message queues. >>>> >>>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> >>>> --- >>>> .../bindings/firmware/gunyah-hypervisor.yaml | 87 +++++++++++++++++++ >>>> MAINTAINERS | 1 + >>>> 2 files changed, 88 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..f0a14101e2fd >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml >>>> @@ -0,0 +1,87 @@ >>>> +# 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 >>> >>> How you end up with the node (applying an overlay) is not relavent to >>> the binding. >>> >>>> + describes the basic configuration of the hypervisor. Virtual machines use this information to determine >>>> + the capability IDs of the message queues used to communicate with the Gunyah Resource Manager. >>> >>> Wrap at 80. That is the coding standard still though 100 is deemed >>> allowed. And yamllint only complains at 110 because I didn't care to fix >>> everyones lines over 100. >>> >>>> + See also: https://github.com/quic/gunyah-resource-manager/blob/develop/src/vm_creation/dto_construct.c >>>> + >>>> +properties: >>>> + compatible: >>>> + items: >>>> + - const: gunyah-hypervisor-1.0 >>>> + - const: gunyah-hypervisor >>> >>> 2 compatibles implies a difference between the 2. What's the difference? >>> Where does '1.0' come from? >>> >> >> There's no difference. I thought the convention was to have >> device-specific compatible and the generic compatible. "device-specific" >> here would be specific to version of Gunyah since it's software. > > No, that's just what people do because "vendor,new-soc", > "vendor,old-soc" seems to bother them for some reason. At the end of > the day, it's just a string identifier that means something. If > there's no difference in that 'something', then there is no point in > having more than one string. > > You only need something specific enough to discover the rest from the > firmware. When that changes, then you add a new compatible. Of course, > if you want existing OSs to work, then better not change the > compatible. >
Thanks for the info, I'll drop the "-1.0" suffix.
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