This series adds the generic firmware layer for talking to the Realm
Management Monitor (RMM), as specified by the RMM v2.0-bet2
specification[1]. It is the first part of the Arm CCA host support that
was previously posted as part of the larger KVM series.
The split allows this RMM support to be used as a base for other work,
including Aneesh's changes, without depending on the KVM Realm support
that follows in the second series.
The series adds:
* The RMI SMC definitions and direct-call wrappers.
* RMM discovery and version checks during firmware init.
* RMM host configuration, including the host page size.
* Stateful RMI Operation (SRO) infrastructure for commands which the RMM
can complete across multiple SMC calls while requesting or returning
memory to the host.
* GPT setup so that the RMM has entries for host memory.
The RMM v2.0 spec introduces Stateful RMI Operations (SROs), which allow
the RMM to complete an operation over several SMC calls while requesting
or returning memory to the host. This allows interrupts to be handled in
the middle of an operation and lets the RMM dynamically allocate memory
for internal tracking purposes. For example, RMI_REC_CREATE no longer
needs auxiliary granules to be provided up front, and can instead
request memory during the operation.
This series is based on v7.2-rc1 and Ackerley's guest_memfd in-place
series[2]. It is also available as a git repository along with the KVM
host support:
https://gitlab.arm.com/linux-arm/linux-cca cca-host/v15
The TF-RMM has now merged most of the RMM v2.0 support needed by this
series. The remaining PSCI changes have not yet merged; for testing those
changes are available in the following TF-RMM branch:
https://git.trustedfirmware.org/TF-RMM/tf-rmm.git topics/rmm-v2.0-poc_3
[1] https://developer.arm.com/documentation/den0137/2-0bet2/
Note that one bet2 change, which moves metadata out of the individual
address range descriptors, has intentionally not been implemented
because that part of the spec is expected to be reverted.
[2] https://lore.kernel.org/r/20260618-gmem-inplace-conversion-v8-0-9d2959357853@google.com
with Suzuki's fix on top:
https://lore.kernel.org/all/114e2488-97ed-4740-a8e8-1edd991f26c5@arm.com/
Steven Price (6):
firmware: arm_rmm: Add SMC definitions for calling the RMM
firmware: arm_rmm: Add wrappers for direct RMI calls
firmware: arm_rmm: Check for RMI support at init
firmware: arm_rmm: Configure the RMM with the host's page size
firmware: arm_rmm: Add support for SRO
firmware: arm_rmm: Ensure the RMM has GPT entries for memory
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/rmi_cmds.h | 459 +++++++++++++++++++
arch/arm64/kernel/cpufeature.c | 1 +
drivers/firmware/Kconfig | 1 +
drivers/firmware/Makefile | 1 +
drivers/firmware/arm_rmm/Kconfig | 22 +
drivers/firmware/arm_rmm/Makefile | 2 +
drivers/firmware/arm_rmm/rmi.c | 724 ++++++++++++++++++++++++++++++
include/linux/arm-rmi-cmds.h | 205 +++++++++
include/linux/arm-smccc-rmi.h | 499 ++++++++++++++++++++
10 files changed, 1915 insertions(+)
create mode 100644 arch/arm64/include/asm/rmi_cmds.h
create mode 100644 drivers/firmware/arm_rmm/Kconfig
create mode 100644 drivers/firmware/arm_rmm/Makefile
create mode 100644 drivers/firmware/arm_rmm/rmi.c
create mode 100644 include/linux/arm-rmi-cmds.h
create mode 100644 include/linux/arm-smccc-rmi.h
--
2.43.0