On Wed, Sep 02, 2020 at 04:14:13PM -0600, Rob Herring wrote: > On Sat, Aug 29, 2020 at 06:09:15PM +0100, Sudeep Holla wrote: > > From: Will Deacon <will@xxxxxxxxxx> > > > > Add devicetree bindings for a FF-A-compliant hypervisor, its partitions > > and their memory regions. The naming is ludicrous but also not by fault. > > > > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > > (sudeep.holla: Dropped PSA from name and elsewhere as it seem to have > > disappeared mysteriously just before the final release) > > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> > > --- > > .../devicetree/bindings/arm/arm,ffa.yaml | 102 ++++++++++++++++++ > > .../reserved-memory/arm,ffa-memory.yaml | 71 ++++++++++++ > > 2 files changed, 173 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/arm/arm,ffa.yaml > > create mode 100644 Documentation/devicetree/bindings/reserved-memory/arm,ffa-memory.yaml > > > > diff --git a/Documentation/devicetree/bindings/arm/arm,ffa.yaml b/Documentation/devicetree/bindings/arm/arm,ffa.yaml > > new file mode 100644 > > index 000000000000..668a5995fcab > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/arm/arm,ffa.yaml > > @@ -0,0 +1,102 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > Dual license new bindings: > > (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/arm/arm,ffa.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Arm Firmware Framework for Arm v8-A > > + > > +maintainers: > > + - Will Deacon <will@xxxxxxxxxx> > > + > > +description: | > > + Firmware frameworks implementing partition setup according to the FF-A > > + specification defined by ARM document number ARM DEN 0077A ("Arm Firmware > > + Framework for Arm v8-A") [0] must provide a "manifest and image" for each > > + partition to the "partition manager" so that the partition execution contexts > > + can be initialised. > > + > > + In the case of a virtual FFA instance, the manifest and image details can be > > + passed to the hypervisor (e.g. Linux KVM) using this binding. > > + > > + [0] https://developer.arm.com/docs/den0077/latest > > There's efforts to define 'system DT' describing all the CPUs in a > system (such as both A and R cores) as well as physical partitioning. > I'm not sure that virtual partitioning would need a different binding. > Or at least there's probably some overlap. > > > + > > +properties: > > + $nodename: > > + const: ffa_hyp > > + > > + compatible: > > + oneOf: > > + - const: arm,ffa-1.0-hypervisor > > + > > + memory-region: > > + $ref: '/schemas/types.yaml#/definitions/phandle' > > + description: | > > + A phandle to the reserved memory region [1] to be used by the hypervisor. > > + The reserved memory region must be compatible with > > + "arm,ffa-1.0-hypervisor-memory-region". > > + > > + [1] Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt > > + > > +patternProperties: > > + "^ffa_partition[0-9]+$": > > s/_/-/ > > Probably should use 'reg' to number partitions. Is the numbering > significant? > Not really, the partitions will get IDs assigned by Hypervisor or Secure Partition Manager. > > + type: object > > + description: One or more child nodes, each describing an FFA partition. > > + properties: > > + $nodename: > > + const: ffa_partition > > + > > + compatible: > > + oneOf: > > + - const: arm,ffa-1.0-partition > > + > > + uuid: > > + $ref: '/schemas/types.yaml#definitions/string' > > json-schema can do better here: > > format: uuid > > Though 'format' will need to be allowed in our meta-schema. > OK I need to explore this. > > + description: | > > + The 128-bit UUID [2] of the service implemented by this partition. > > + > > + [2] https://tools.ietf.org/html/rfc4122 > > + > > + nr-exec-ctxs: > > + $ref: '/schemas/types.yaml#/definitions/uint32' > > + description: | > > + The number of virtual CPUs to instantiate for this partition. > > Just 'nr-cpus' would be clearer in my opinion. > The idea must be to use the names as is from the spec. > What happens on big.LITTLE? > AFAIU, we don't have notion of bL in KVM. > > + > > + exec-state: > > + description: The execution state in which to execute the partition. > > + oneOf: > > + - const: "AArch64" > > + - const: "AArch32" > > Why is this needed? We don't need anything like this for KVM today. > Again this is from the spec listed under manifests for the partitions. This will let the KVM know to start the partition in Aarch32/64. > > + > > + entry-point: > > + $ref: '/schemas/types.yaml#/definitions/uint32-matrix' > > + description: | > > + The entry address of the partition specified as an Intermediate > > + Physical Address (IPA) encoded according to the '#address-cells' > > + property. > > Is the address unique or you could have the same image for multiple > partitions? If unique, then you could use 'reg' here. > I don't have full knowledge on the details, will let Will comment on this. > You didn't document using '#address-cells'. Really, I'd just make this a > fixed uint64 (if not 'reg'). > I was wondering the same as the format from spec must be fixed, checked and unfortunately it is not 🙁. -- Regards, Sudeep
