Inroducing V4 RFC patch series on top of the Xen version 4.20-rc2
which includes implementation of the SCI SCMI SMC multi-agent support.
Patch 1 "xen/arm: add generic SCI subsystem"
- rebased and refactored
- introduced DEVICE_ARM_SCI DT device class and used for SCI drivers probing
instead of custom,
linker sections based implementation.
- added SCI API for Dom0 DT handling, instead of manipulating with ARM arch
dom0 code directly.
- RFC changes in XEN_DOMCTL_assign_device OP processing
- Introduce arch_handle_passthrough_prop call to handle arm specific
nodes
Patch 2 "xen/arm: scmi-smc: update to be used under sci subsystem"
- update driver introduced by commit 3e322bef8bc0 ("xen/arm: firmware: Add SCMI
over SMC calls
handling layer") be used under sci subsystem.
- no functional changes in general
Patch 3 "xen/arm: scmi-smc: passthrough SCMI SMC to guest domain
This is new change which allows passthrough SCMI SMC, single agent interface to
guest domain
cover use case "thin Dom0 with guest domain, which serves as Driver domain".
See patch commit message for full description.
Patch 4 - docs: arm: add docs for SCMI over SMC calls forwarding
driver
- add documentation section for Simple Arm SCMI over SMC/HVC calls
forwarding driver.
Patch 6 - xen/domctl: extend XEN_DOMCTL_assign_device to handle not
only iommu
- add chainged handling of assigned DT devices to support
access-controller functionality through SCI framework.
Change was done in two parts:
- update iommu_do_dt_domctl() to check for dt_device_is_protected()
and not fail if DT device is not protected by IOMMU
-add chained call to sci_do_domctl() to do_domctl()
Patch 9 - xen/arm: scmi: introduce SCI SCMI SMC multi-agent driver
- added "scmi-secondary-agents" and "#scmi-secondary-agent-cells"
property to "xen,config" node in "chosen" to inform SCI SCMI
multi-agent driver about available agents and their
configuration. It defines <agent_id> to <smc-id,scmi_shm> map.
This option is Xen specific as Xen is the only one entry in the
system which need to know about SCMI multi-agent support and configuration.
- each guest using SCMI should be configured with SCMI agent_id, so SCMI
FW can implement Agent-specific permission policy.
-- dom0: dom0_scmi_agent_id=<agent_id> in Xen command line option
-- toolstack: arm_sci = "type=scmi_smc_multiagent,agent_id=<agent_id>"
-- dom0less: "xen,sci_type", "xen,sci_agent_id" properties in
"xen,domain" nodes.
- factored out SCMI generic definitions (re-usable)
- factored out SCMI shmem code (re-usable)
- the SCMI passthrough configuration for guest domains is similar to any other
HW passthrough cfg.
Patch 10 - docs: arm: add SCI SCMI SMC multi-agent driver docs
- add SCI SCMI SMC multi-agent driver documentation.
Add separate SCMI DT node for Xen management agent under "xen,config"
node under chosen.
All Xen-specific configuration provided under "/chosen" node. This
approach allows to isolate modifications to Host DT only under
"/chosen" node.
This approach provides the following device tree (DT)
parameters (placed under xen,config node):
- "scmi-secondary-agents": A Xen-specific parameter under the
"/chosen" node, which describes the SCMI agent configuration for
the domains.
- the SCMI configuration for Xen (privileged agent) and the shared
memory configuration for all agents are provided under the "/chosen"
node and are used strictly by Xen for its initial configuration.
- the scmi_shm and SCMI configuration for Dom0 are placed in the
"/firmware/scmi" node so that they can be moved to Dom0 without
any changes.
This configuration allows the use of Xen-specific nodes to provide
information strictly needed by Xen while using the default SCMI
configuration for Dom0 and other domains. As a result, no additional
bindings need to be introduced to the device tree.
This simplifies the Xen SCMI multi-agent configuration and utilizes
generic device tree bindings for the domains.
NOTE: Haven't added RB tags for patch 1 and 2 because rebase and some
minor changes were done.
Code can be found at:
https://github.com/oleksiimoisieiev/xen/tree/scmi_upstrv5
[1] RFC v2:
http://patchwork.kernel.org/project/xen-devel/cover/cover.1644341635.git.oleksii_moisie...@epam.com/
[2] RFC v3:
https://patchwork.kernel.org/project/xen-devel/patch/20250311111618.1850927-1-grygorii_stras...@epam.com
SCMI spec:
https://developer.arm.com/documentation/den0056/e/?lang=en
SCMI bindings:
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
Reference EL3 FW:
RPI5: https://github.com/xen-troops/arm-trusted-firmware/commits/rpi5_dev/
Renesas v4h:
https://github.com/GrygiriiS/arm-trusted-firmware/commits/rcar_gen4_v2.7_v4x-scmi_upd/
base-commit: dbe60f244c (Update Xen to 4.21, 2025-02-21)
Changes in v5:
- update Maintainers file. Set role as a Reviewer
- rebased on the latest master branch
- Introduce arch_handle_passthrough_prop call to handle arm specific nodes
- rename dom0_scmi_smc_passthrough to scmi_smc_passthrough
- rename dom0_scmi_smc_passthrough in documentation
- set error code to -ENXIO when iommu is disabled
- return -EINVAL if mediator without assign_dt_device was provided
- invert return code check for iommu_do_domctl in
XEN_DOMCTL_assign_device domctl processing to make cleaner code
- change -ENOTSUPP error code to -ENXIO in sci_do_domctl
- handle -ENXIO return comde of iommu_do_domctl
- leave !dt_device_is_protected check in iommu_do_dt_domctl to make
code work the same way it's done in "handle_device" call while
creating hwdom(dom0) and "handle_passthrough_prop" call for dom0less
creation
- drop return check from sci_assign_dt_device call as not needed
- do not return EINVAL when addign_dt_device is not set. That is
because this callback is optional and not implemented in single-agent driver
- move memcpy_toio/fromio to the generic place
- fix device-tree example format in booting.txt, added ";" after "}".
- update define in scmi-proto.h
- update define in scmi-shmem.h file
- scmi_assign_device - do not ignore -EOPNOTSUPP return
code of the do_smc_xfer
- remove overwriting agent_channel->agent_id after
SCMI_BASE_DISCOVER_AGENT call
- add multi-agent files to the MAINTAINERS
- add SCMI multi-agent description to the SUPPORT.md
- handle ARM_SMCCC_INVALID_PARAMETER return code and return -EINVAL
for smc call
- updated collect_agents function. Set agent_id parameter as optional
in scmi-secondary-agents device-tree property
- introduce "#scmi-secondary-agents-cells" parameter to set if
agent_id was provided
- reanme xen,scmi-secondary-agents property to scmi-secondary-agents
- move memcpu_toio/fromio for the generic place
- update Xen to get management channel from /chosen/xen,config node
- get hypervisor channnel from node instead of using hardcoded
- update handling scmi and shmem nodes for the domain
- Set multi-agent driver to support only Arm64
- rework multi-agent driver to leave Host Device-tree unmodified
Changes in v4:
- fix SPDX-License
- rename DEVICE_ARM_SCI DT device class to FIRMWARE_DEVICE
- move XEN_DOMCTL_assign_device code in separate patch
- Add documentation for SCI SCMI drivers
- xl.cfg doc
- fix comments from Stefano Stabellini
- fix toolstack code as sugested by Anthony PERARD
- use MATCH_OPTION()
- move arm_sci struct and cfg params in "arch_arm"
- add SCMI passthrough for dom0less case
- toolstack comments from Anthony PERARD
- added dom0less support
- added doc for "xen,scmi-secondary-agents"
Grygorii Strashko (5):
xen/arm: scmi-smc: update to be used under sci subsystem
xen/arm: scmi-smc: passthrough SCMI SMC to domain, single agent
docs: arm: add docs for SCMI over SMC calls forwarding driver
xen/domctl: extend XEN_DOMCTL_assign_device to handle not only iommu
docs: arm: add SCI SCMI SMC multi-agent driver docs
Oleksii Moisieiev (5):
xen/arm: add generic SCI subsystem
drivers: iommu: change error code when iommu is disabled
xen: arm: smccc: add INVALID_PARAMETER error code
lib/arm: Add I/O memory copy helpers
xen/arm: scmi: introduce SCI SCMI SMC multi-agent driver
MAINTAINERS | 10 +
SUPPORT.md | 11 +
.../arm/firmware/arm-scmi.rst | 516 +++++++++++
docs/hypervisor-guide/arm/index.rst | 9 +
docs/hypervisor-guide/index.rst | 1 +
docs/man/xl.cfg.5.pod.in | 47 +
docs/misc/arm/device-tree/booting.txt | 103 +++
docs/misc/xen-command-line.pandoc | 18 +
tools/include/libxl.h | 5 +
tools/libs/light/libxl_arm.c | 18 +
tools/libs/light/libxl_types.idl | 12 +
tools/xl/xl_parse.c | 48 ++
xen/arch/arm/device.c | 5 +
xen/arch/arm/dom0less-build.c | 51 ++
xen/arch/arm/domain.c | 12 +-
xen/arch/arm/domain_build.c | 11 +-
xen/arch/arm/firmware/Kconfig | 37 +-
xen/arch/arm/firmware/Makefile | 2 +
xen/arch/arm/firmware/sci.c | 189 +++++
xen/arch/arm/firmware/scmi-proto.h | 164 ++++
xen/arch/arm/firmware/scmi-shmem.c | 112 +++
xen/arch/arm/firmware/scmi-shmem.h | 45 +
xen/arch/arm/firmware/scmi-smc-multiagent.c | 803 ++++++++++++++++++
xen/arch/arm/firmware/scmi-smc.c | 191 ++++-
xen/arch/arm/include/asm/domain.h | 5 +
xen/arch/arm/include/asm/firmware/sci.h | 214 +++++
xen/arch/arm/include/asm/firmware/scmi-smc.h | 41 -
xen/arch/arm/include/asm/smccc.h | 1 +
xen/arch/arm/vsmc.c | 4 +-
xen/common/device-tree/dom0less-build.c | 4 +
xen/common/domctl.c | 19 +
xen/drivers/passthrough/device_tree.c | 6 +
xen/drivers/passthrough/iommu.c | 2 +-
xen/include/asm-generic/device.h | 1 +
xen/include/asm-generic/dom0less-build.h | 9 +
xen/include/public/arch-arm.h | 8 +
xen/include/xen/lib/arm/io.h | 15 +
xen/lib/Makefile | 1 +
xen/lib/arm/Makefile | 1 +
xen/lib/arm/io.c | 80 ++
40 files changed, 2744 insertions(+), 87 deletions(-)
create mode 100644 docs/hypervisor-guide/arm/firmware/arm-scmi.rst
create mode 100644 docs/hypervisor-guide/arm/index.rst
create mode 100644 xen/arch/arm/firmware/sci.c
create mode 100644 xen/arch/arm/firmware/scmi-proto.h
create mode 100644 xen/arch/arm/firmware/scmi-shmem.c
create mode 100644 xen/arch/arm/firmware/scmi-shmem.h
create mode 100644 xen/arch/arm/firmware/scmi-smc-multiagent.c
create mode 100644 xen/arch/arm/include/asm/firmware/sci.h
delete mode 100644 xen/arch/arm/include/asm/firmware/scmi-smc.h
create mode 100644 xen/include/xen/lib/arm/io.h
create mode 100644 xen/lib/arm/Makefile
create mode 100644 xen/lib/arm/io.c
--
2.34.1
