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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH v6 4/5] xen/arm: scmi: introduce SCI SCMI SMC multi-agent driver
Hi @Stefano,
Below, I have provided my answers (marked as [OM]) to your questions
regarding the node implementation.
If you have no further comments, I will proceed with the implementation.
Best regards,
Oleksii
On 01/11/2025 14:00, Oleksii Moisieiev wrote:
> Hi all,
> Following up uncovered comments from v5. Questions are marked as Q:
> and answers as A:
> please see below:
>
> On 01/11/2025 13:56, Oleksii Moisieiev wrote:
>> This patch introduces SCI driver to support for ARM EL3 Trusted
>> Firmware-A
>> (TF-A) which provides SCMI interface with multi-agent support, as shown
>> below.
>>
>> +-----------------------------------------+
>> | |
>> | EL3 TF-A SCMI |
>> +-------+--+-------+--+-------+--+-------++
>> |shmem1 | |shmem0 | |shmem2 | |shmemX |
>> +-----+-+ +---+---+ +--+----+ +---+---+
>> smc-id1 | | | |
>> agent1 | | | |
>> +-----v--------+---------+-----------+----+
>> | | | | |
>> | | | | |
>> +--------------+---------+-----------+----+
>> smc-id0 | smc-id2| smc-idX|
>> agent0 | agent2 | agentX |
>> | | |
>> +----v---+ +--v-----+ +--v-----+
>> | | | | | |
>> | Dom0 | | Dom1 | | DomX |
>> | | | | | |
>> | | | | | |
>> +--------+ +--------+ +--------+
>>
>> The EL3 SCMI multi-agent firmware is expected to provide SCMI SMC shared
>> memory transport for every Agent in the system.
>>
>> The SCMI Agent transport channel defined by pair:
>> - smc-id: SMC id used for Doorbell
>> - shmem: shared memory for messages transfer, Xen page
>> aligned. Shared memort is mapped with the following flags:
>> MT_DEVICE_nGnRE.
>>
>> The follwoing SCMI Agents are expected to be defined by SCMI FW to
>> enable SCMI
>> multi-agent functionality under Xen:
>> - Xen management agent: trusted agents that accesses to the Base
>> Protocol
>> commands to configure agent specific permissions
>> - OSPM VM agents: non-trusted agent, one for each Guest domain which is
>> allowed direct HW access. At least one OSPM VM agent has to be
>> provided
>> by FW if HW is handled only by Dom0 or Driver Domain.
>>
>> The EL3 SCMI FW is expected to implement following Base protocol
>> messages:
>> - BASE_DISCOVER_AGENT (optional if agent_id was provided)
>> - BASE_RESET_AGENT_CONFIGURATION (optional)
>> - BASE_SET_DEVICE_PERMISSIONS (optional)
>>
>> The SCI SCMI SMC multi-agent driver implements following
>> functionality:
>> - The driver is initialized based on the ``xen,config`` node under
>> ``chosen``
>> (only one SCMI interface is supported), which describes the Xen
>> management
>> agent SCMI interface.
>>
>> scmi_shm_1: sram@47ff1000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff1000 0x0 0x1000>;
>> };
>> scmi_xen: scmi {
>> compatible = "arm,scmi-smc";
>> arm,smc-id = <0x82000003>; <--- Xen management agent smc-id
>> #address-cells = < 1>;
>> #size-cells = < 0>;
>> #access-controller-cells = < 1>;
>> shmem = <&scmi_shm_1>; <--- Xen management agent shmem
>> };
>>
>> - The driver obtains Xen specific SCMI Agent's configuration from the
>> Host DT, probes Agents and
>> builds SCMI Agents list. The Agents configuration is taken from
>> "scmi-secondary-agents"
>> property where first item is "arm,smc-id", second -
>> "arm,scmi-shmem" phandle and third is
>> optional "agent_id":
>>
>> chosen {
>> ranges;
>> xen,config {
> Q: [Stefano] The node name could be xen-config, but it doesn't matter
> because we
> should check for the compatible string instead (no check on node name).
>
> We need to add a compatible string here, I would use "xen,scmi":
>
> compatible = "xen,scmi";
>
>
> A: [OM] this is a great finding. After looking into hyperlauch code I
> see the following implementation:
>
>
> config {
> compatible = "xen,config";
> ...
> };
>
> I was thinking about changing current approach to have the following
> format:
>
> config {
> compatible = "xen,config";
> ...
> scmi_config {
> compatible = "xen,sci"; <-- more generic compatible string
> than "xen,scmi"
> scmi-secondary-agents = <
> 0x82000003 &scmi_shm_0 0
> 0x82000004 &scmi_shm_2 2
> ...>;
> #scmi-secondary-agents-cells = <3>; <--- optional,
> default 3
> scmi_shm_0 : sram@47ff0000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff0000 0x0 0x1000>;
> };
>
> scmi_shm_2: sram@47ff2000 {
> compatible = "arm,scmi-shmem";
> reg = <0x0 0x47ff2000 0x0 0x1000>;
> };
> scmi_xen: scmi {
> compatible = "arm,scmi-smc";
> arm,smc-id = <0x82000002>; <--- Xen manegement agent
> smc-id
> #address-cells = < 1>;
> #size-cells = < 0>;
> #access-controller-cells = < 1>;
> shmem = <&scmi_shm_1>; <--- Xen manegement agent shmem
> };
> };
> ...
> };
>
> and update scmi-multiagent driver to match "xen,sci" compatible and
> process all subnodes during probe.
> What do you think about this approach?
>
>> ranges;
>> scmi-secondary-agents = <
>> 0x82000003 &scmi_shm_0 0
>> 0x82000004 &scmi_shm_2 2
>> 0x82000005 &scmi_shm_3 3
>> 0x82000006 &scmi_shm_4 4>;
>> #scmi-secondary-agents-cells = <3>; <--- optional, default 3
>>
>> scmi_shm_0 : sram@47ff0000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff0000 0x0 0x1000>;
>> };
>>
>> scmi_shm_2: sram@47ff2000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff2000 0x0 0x1000>;
>> };
>> scmi_shm_3: sram@47ff3000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff3000 0x0 0x1000>;
>> };
>> scmi_shm_4: sram@47ff4000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff4000 0x0 0x1000>;
>> };
>>
>> // Xen SCMI management channel
>> scmi_shm_1: sram@47ff1000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff1000 0x0 0x1000>;
>> };
>>
>> scmi_xen: scmi {
>> compatible = "arm,scmi-smc";
>> arm,smc-id = <0x82000002>; <--- Xen management agent smc-id
>> #address-cells = < 1>;
>> #size-cells = < 0>;
>> #access-controller-cells = < 1>;
>> shmem = <&scmi_shm_1>; <--- Xen management agent shmem
>> };
>> };
>> };
>>
>> /{
>> // Host SCMI OSPM channel - provided to the Dom0 as is if SCMI
>> enabled for it
>> scmi_shm: sram@47ff0000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x47ff0000 0x0 0x1000>;
>> };
>>
>> firmware {
>> scmi: scmi {
>> compatible = "arm,scmi-smc";
>> arm,smc-id = <0x82000002>; <--- Host OSPM agent smc-id
>> #address-cells = < 1>;
>> #size-cells = < 0>;
>> shmem = <&scmi_shm>; <--- Host OSPM agent shmem
>>
>> protocol@X{
>> };
>> };
>> };
>> };
>>
>> This approach allows defining multiple SCMI Agents by adding
>> Xen-specific properties under
>> the ``/chosen`` node to the Host Device Tree, leaving the main part
>> unchanged. The Host DT
>> SCMI channel will be passed to Dom0.
>>
>> The Xen management agent is described as a ``scmi_xen`` node under
>> the ``/chosen`` node, which
>> is used by Xen to control other SCMI Agents in the system.
>>
>> All secondary agents' configurations are provided in the
>> ``scmi-secondary-agents`` property with
>> an optional ``agent_id`` field.
>>
>> The ``agent_id`` from the ``scmi-secondary-agents`` property is used
>> to identify the agent in the
>> system and can be omitted by setting ``#scmi-secondary-agents-cells =
>> <2>``, so the Secondary
>> Agents configuration will look like this:
>>
>> chosen {
>> xen,config {
>> scmi-secondary-agents = <
>> 0x82000003 &scmi_shm_0
>> 0x82000004 &scmi_shm_2
>> 0x82000005 &scmi_shm_3
>> 0x82000006 &scmi_shm_4>;
>> #scmi-secondary-agents-cells = <2>;
>> };
>> }
>>
>> In this case, Xen will use the ``SCMI_BASE_DISCOVER_AGENT`` call to
>> discover the ``agent_id``
>> for each secondary agent. Providing the ``agent_id`` in the
>> ``scmi-secondary-agents`` property
>> allows skipping the discovery call, which is useful when the
>> secondary agent's shared memory is
>> not accessible by Xen or when boot time is important because it
>> allows skipping the agent
>> discovery procedure.
>>
>> Note that Xen is the only one entry in the system which need to know
>> about SCMI multi-agent support.
>>
>> - It implements the SCI subsystem interface required for configuring and
>> enabling SCMI functionality for Dom0/hwdom and Guest domains. To enable
>> SCMI functionality for domain it has to be configured with unique
>> supported
>> SCMI Agent_id and use corresponding SCMI SMC shared memory transport
>> [smc-id, shmem] defined for this SCMI Agent_id.
>> - Once Xen domain is configured it can communicate with EL3 SCMI FW:
>> -- zero-copy, the guest domain puts SCMI message in shmem;
>> -- the guest triggers SMC exception with smc-id (doorbell);
>> -- the Xen driver catches exception, do checks and synchronously
>> forwards
>> it to EL3 FW.
>> - the Xen driver sends BASE_RESET_AGENT_CONFIGURATION message to Xen
>> management agent channel on domain destroy event. This allows to
>> reset
>> resources used by domain and so implement use-case like domain
>> reboot.
>>
>> Dom0 Enable SCMI SMC:
>> - pass dom0_scmi_agent_id=<agent_id> in Xen command line. if not
>> provided
>> SCMI will be disabled for Dom0 and all SCMI nodes removed from
>> Dom0 DT.
>> The driver updates Dom0 DT SCMI node "arm,smc-id" value and fix
>> up shmem
>> node according to assigned agent_id.
>>
>> Guest domains enable SCMI SMC:
>> - xl.cfg: add configuration option as below
>>
>> arm_sci = "type=scmi_smc_multiagent,agent_id=2"
>>
>> - xl.cfg: enable access to the "arm,scmi-shmem" which should
>> correspond assigned agent_id for
>> the domain, for example:
>>
>> iomem = [
>> "47ff2,1@22001",
>> ]
>>
>> - DT: add SCMI nodes to the Driver domain partial device tree as in
>> the
>> below example. The "arm,smc-id" should correspond assigned agent_id
>> for the domain:
>>
>> passthrough {
>> scmi_shm_0: sram@22001000 {
>> compatible = "arm,scmi-shmem";
>> reg = <0x0 0x22001000 0x0 0x1000>;
>> };
>>
>> firmware {
>> compatible = "simple-bus";
>> scmi: scmi {
>> compatible = "arm,scmi-smc";
>> arm,smc-id = <0x82000004>;
>> shmem = <&scmi_shm_0>;
>> ...
>> }
>> }
>> }
>>
>> SCMI "4.2.1.1 Device specific access control"
>>
>> The XEN SCI SCMI SMC multi-agent driver performs "access-controller"
>> provider function
>> in case EL3 SCMI FW implements SCMI "4.2.1.1 Device specific access
>> control" and provides the
>> BASE_SET_DEVICE_PERMISSIONS command to configure the devices that an
>> agents have access to.
>> The DT SCMI node should "#access-controller-cells=<1>" property and
>> DT devices should be bound
>> to the Xen SCMI.
>>
>> &i2c1 {
>> access-controllers = <&scmi 0>;
>> };
>>
>> The Dom0 and dom0less domains DT devices will be processed
>> automatically through
>> sci_assign_dt_device() call, but to assign SCMI devices from
>> toolstack the xl.cfg:"dtdev" property
>> shall be used:
>>
>> dtdev = [
>> "/soc/i2c@e6508000",
>> ]
>>
>> xl.cfg:dtdev will contain all nodes which are under SCMI management
>> (not only those which are behind IOMMU).
>>
>> [1]
>> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
>> [2]
>> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/access-controllers/access-controllers.yaml
>>
>> Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
>> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
>> ---
>>
>> Changes in v6:
>> - updated scmi-shmem to use io.h from generic location
>> - update scmi_agent_id parameter to be provided inside dom0= parameter
>> list and have the following format "dom0=sci-agent-id=0"
>> This change was done as a response for Stefano comment and
>> requires a lot of code changes, but produces much cleaner solution
>> that's why I've added it to the code.
>> - fix file comments and return codes
>> - fix lenght checks in shmem_{get,put}_message to use offsetof
>> - remove len member from scmi_channel structure as it is not used
>> - set scmi-secondary-agents property to be mandatory since if no
>> secondary agents were provided then there is no sence to enable scmi
>> when no secondary agents are populated to the Domains
>> - update documentation in booting.txt, added xen_scmi node to the
>> example
>> - adjust d->arch.sci_enabled value in scmi_domain_destroy
>> - fix lock management in smc_create_channel call
>> - avoid extra map_channel_memory command for Xen management channel
>> because collect_agent_id call unmaps memory if DOMID_XEN is not
>> set. So for Xen management channel we can init domain_id ad DOMID_XEN
>> before calling collect_agent_id so memory shouldn't be unmapped.
>>
>> Changes in v5:
>> - 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
>>
>> Changes in v4:
>> - toolstack comments from Anthony PERARD
>> - added dom0less support
>> - added doc for "xen,scmi-secondary-agents"
>>
>> MAINTAINERS | 4 +
>> SUPPORT.md | 11 +
>> docs/man/xl.cfg.5.pod.in | 13 +
>> docs/misc/arm/device-tree/booting.txt | 103 +++
>> docs/misc/xen-command-line.pandoc | 19 +-
>> tools/libs/light/libxl_arm.c | 4 +
>> tools/libs/light/libxl_types.idl | 4 +-
>> tools/xl/xl_parse.c | 12 +
>> xen/arch/arm/dom0less-build.c | 11 +
>> xen/arch/arm/domain_build.c | 26 +-
>> xen/arch/arm/firmware/Kconfig | 12 +
>> xen/arch/arm/firmware/Makefile | 1 +
>> xen/arch/arm/firmware/scmi-proto.h | 164 ++++
>> xen/arch/arm/firmware/scmi-shmem.c | 115 +++
>> xen/arch/arm/firmware/scmi-shmem.h | 45 ++
>> xen/arch/arm/firmware/scmi-smc-multiagent.c | 794 ++++++++++++++++++++
>> xen/include/public/arch-arm.h | 3 +
>> 17 files changed, 1338 insertions(+), 3 deletions(-)
>> 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
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ecd3f40df8..4ad1d818a6 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -532,6 +532,10 @@ R: Oleksii Moisieiev
>> <oleksii_moisieiev@xxxxxxxx>
>> S: Supported
>> F: xen/arch/arm/firmware/sci.c
>> F: xen/arch/arm/include/asm/firmware/sci.h
>> +F: xen/arch/arm/firmware/scmi-smc-multiagent.c
>> +F: xen/arch/arm/firmware/scmi-shmem.c
>> +F: xen/arch/arm/firmware/scmi-shmem.h
>> +F: xen/arch/arm/firmware/scmi-proto.h
>> SEABIOS UPSTREAM
>> M: Wei Liu <wl@xxxxxxx>
>> diff --git a/SUPPORT.md b/SUPPORT.md
>> index 491f9ecd1b..7c8951d67b 100644
>> --- a/SUPPORT.md
>> +++ b/SUPPORT.md
>> @@ -956,6 +956,17 @@ by hwdom. Some platforms use SCMI for access to
>> system-level resources.
>> Status: Supported
>> +### Arm: SCMI SMC multi-agent support
>> +
>> +Enable support for the multi-agent configuration of the EL3
>> Firmware, which
>> +allows Xen to provide an SCMI interface to the Domains.
>> +Xen manages access permissions to the HW resources and provides an
>> SCMI interface
>> +to the Domains. Each Domain is represented as a separate Agent,
>> which can
>> +communicate with EL3 Firmware using a dedicated shared memory
>> region, and
>> +notifications are passed through by Xen.
>> +
>> + Status, ARM64: Tech Preview
>> +
>> ### ARM: Guest PSCI support
>> Emulated PSCI interface exposed to guests. We support all mandatory
>> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
>> index ad1553c5e9..4fc3e12939 100644
>> --- a/docs/man/xl.cfg.5.pod.in
>> +++ b/docs/man/xl.cfg.5.pod.in
>> @@ -3156,8 +3156,21 @@ single SCMI OSPM agent support.
>> Should be used together with B<scmi-smc-passthrough> Xen command line
>> option.
>> +=item B<scmi_smc_multiagent>
>> +
>> +Enables ARM SCMI SMC multi-agent support for the guest by enabling
>> SCMI over
>> +SMC calls forwarding from domain to the EL3 firmware (like Trusted
>> Firmware-A)
>> +with a multi SCMI OSPM agent support. The SCMI B<agent_id> should be
>> +specified for the guest.
>> +
>> =back
>> +=item B<agent_id=NUMBER>
>> +
>> +Specifies a non-zero ARM SCI agent id for the guest. This option is
>> mandatory
>> +if the SCMI SMC support is enabled for the guest. The agent ids of
>> domains
>> +existing on a single host must be unique and in the range [1..255].
>> +
>> =back
> Q: [Stefano] Why is the option mandatory if the commit description
> explains that the
> agent_id can be probed by Xen? In the commit message, the mandatory
> field is smc-id instead?
>
> I guess it is because we expect Xen to have already the agent_id->smc-id
> mapping and we expect the agent_id to be easier to remember and to write
> in the config file?
>
> A: [OM] correct. during first iterations we did automatic agent_is
> assignment. But switched to setting agent_id because it simpifies
> logic and covers more cases for example when Xen doesn't have an
> access to the agent discover or when mailboxes are uses.
>
> Also, smc-id is related to SMC call, not SCMI itself. Agent_id is SCMI
> term which seems to be more generic and will be suitable for all
> implementation, such as mailboxes or other mechanism. This is because
> we can be sure that each SCMI server will follow SCMI specification
> therefore agent_id entity will be present.
>
>> =back
>> diff --git a/docs/misc/arm/device-tree/booting.txt
>> b/docs/misc/arm/device-tree/booting.txt
>> index 977b428608..6fd7e4a16b 100644
>> --- a/docs/misc/arm/device-tree/booting.txt
>> +++ b/docs/misc/arm/device-tree/booting.txt
>> @@ -322,6 +322,20 @@ with the following properties:
>> Should be used together with scmi-smc-passthrough Xen command line
>> option.
>> + - "scmi_smc_multiagent"
>> +
>> + Enables ARM SCMI SMC multi-agent support for the guest by
>> enabling SCMI over
>> + SMC calls forwarding from domain to the EL3 firmware (like ARM
>> + Trusted Firmware-A) with a multi SCMI OSPM agent support.
>> + The SCMI agent_id should be specified for the guest with
>> "xen,sci-agent-id"
>> + property.
>> +
>> +- "xen,sci-agent-id"
>> +
>> + Specifies ARM SCMI agent id for the guest. This option is
>> mandatory if the
>> + SCMI SMC "scmi_smc_multiagent" support is enabled for the guest.
>> The agent ids
>> + of guest must be unique and in the range [0..255].
>> +
>> Under the "xen,domain" compatible node, one or more sub-nodes are
>> present
>> for the DomU kernel and ramdisk.
>> @@ -824,3 +838,92 @@ The automatically allocated static shared
>> memory will get mapped at
>> 0x80000000 in DomU1 guest physical address space, and at 0x90000000
>> in DomU2
>> guest physical address space. DomU1 is explicitly defined as the
>> owner domain,
>> and DomU2 is the borrower domain.
>> +
>> +SCMI SMC multi-agent support
>> +============================
>> +
>> +For enabling the ARM SCMI SMC multi-agent support (enabled by
>> CONFIG_SCMI_SMC_MA)
>> +the Xen specific SCMI Agent's configuration shall be provided in the
>> Host DT
>> +according to the SCMI compliant EL3 Firmware specification with
>> +ARM SMC/HVC transport using property "scmi-secondary-agents" placed
>> in "xen,config"
>> +node under "chosen" node:
>> +
>> +- scmi-secondary-agents
>> +
>> + Defines a set of SCMI agents configuration supported by SCMI EL3
>> FW and
>> + available for Xen. Each Agent defined as triple consisting of:
>> + SMC/HVC function_id assigned for the agent transport
>> ("arm,smc-id"),
>> + phandle to SCMI SHM assigned for the agent transport
>> ("arm,scmi-shmem"),
>> + SCMI agent_id (optional) if not set - Xen will determine Agent
>> ID for
>> + each provided channel using BASE_DISCOVER_AGENT message.
>> +
>> +As an example:
>> +
>> +/{
>> +chosen {
>> + xen,config {
>> + scmi_shm_0 : sram@47ff0000 {
>> + compatible = "arm,scmi-shmem";
>> + reg = <0x0 0x47ff0000 0x0 0x1000>;
>> + };
>> + // Xen SCMI management channel
>> + scmi_shm_1: sram@47ff1000 {
>> + compatible = "arm,scmi-shmem";
>> + reg = <0x0 0x47ff1000 0x0 0x1000>;
>> + };
>> + scmi_shm_2: sram@47ff2000 {
>> + compatible = "arm,scmi-shmem";
>> + reg = <0x0 0x47ff2000 0x0 0x1000>;
>> + };
>> + scmi_shm_3: sram@47ff3000 {
>> + compatible = "arm,scmi-shmem";
>> + reg = <0x0 0x47ff3000 0x0 0x1000>;
>> + };
>> + scmi_shm_3: sram@47ff4000 {
>> + compatible = "arm,scmi-shmem";
>> + reg = <0x0 0x47ff4000 0x0 0x1000>;
>> + };
>> + scmi-secondary-agents = <
>> + 0x82000002 &scmi_shm_0 0
>> + 0x82000004 &scmi_shm_2 2
>> + 0x82000005 &scmi_shm_3 3
>> + 0x82000006 &scmi_shm_4 4>;
>> + #scmi-secondary-agents-cells = <3>;
>> + };
>> +
>> + scmi_xen: scmi {
>> + compatible = "arm,scmi-smc";
>> + arm,smc-id = <0x82000002>; <--- Xen management agent smc-id
>> + #address-cells = < 1>;
>> + #size-cells = < 0>;
>> + #access-controller-cells = < 1>;
>> + shmem = <&scmi_shm_1>; <--- Xen management agent shmem
>> + };
>> +
>> + };
>> +};
>> +
>> +- #scmi-secondary-agents-cells
>> +
>> + Defines whether Agent_id is set in the "scmi-secondary-agents"
>> property.
>> + Possible values are: 2, 3.
>> + When set to 3 (the default), expect agent_id to be present in
>> the secondary
>> + agents list.
>> + When set to 2, agent_id will be discovered for each channel using
>> + BASE_DISCOVER_AGENT message.
>> +
>> +
>> +Example:
>> +
>> +/{
>> +chosen {
>> + xen,config {
>> + scmi-secondary-agents = <
>> + 0x82000003 &scmi_shm_1
>> + 0x82000004 &scmi_shm_2
>> + 0x82000005 &scmi_shm_3
>> + 0x82000006 &scmi_shm_4>;
>> + #scmi-secondary-agents-cells = <2>;
>> + };
>> + };
>> +};
>> diff --git a/docs/misc/xen-command-line.pandoc
>> b/docs/misc/xen-command-line.pandoc
>> index 34004ce282..5541c4a4ed 100644
>> --- a/docs/misc/xen-command-line.pandoc
>> +++ b/docs/misc/xen-command-line.pandoc
>> @@ -835,7 +835,7 @@ Specify the bit width of the DMA heap.
>> cpuid-faulting=<bool>, msr-relaxed=<bool>,
>> pf-fixup=<bool> ] (x86)
>> - = List of [ sve=<integer> ] (Arm64)
>> + = List of [ sve=<integer>, sci-agent-id=<integer> ] (Arm)
>> Controls for how dom0 is constructed on x86 systems.
>> @@ -923,6 +923,14 @@ Enables features on dom0 on Arm systems.
>> option is provided with a positive non zero value, but the
>> platform doesn't
>> support SVE.
>> +* The `sci-agent-id` integer parameter enables ARM SCMI (System
>> Control and
>> + Management Interface) functionality for Dom0 when
>> `CONFIG_SCMI_SMC_MA` is
>> + compiled in. This parameter specifies the SCMI agent ID for Dom0.
>> + A value equal to 0xFF (or omitted) disables SCMI for Dom0, which
>> is useful
>> + for thin Dom0 or dom0less use-cases. Values from 0 to 254
>> specify the SCMI
>> + agent ID. The agent IDs of domains existing on a single host
>> must be unique.
>> + Example: `dom0=sci-agent-id=0` to enable SCMI with agent ID 0
>> for Dom0.
>> +
>> ### dom0-cpuid
>> = List of comma separated booleans
>> @@ -1107,6 +1115,15 @@ affinities to prefer but be not limited to
>> the specified node(s).
>> Pin dom0 vcpus to their respective pcpus
>> +### scmi-smc-passthrough (ARM)
>> +> `= <boolean>`
>> +
>> +The option is available when `CONFIG_SCMI_SMC` is compiled in, and
>> allows to
>> +enable SCMI SMC single agent interface for any, but only one guest
>> domain,
>> +which serves as Driver domain. The SCMI will be disabled for
>> Dom0/hwdom and
>> +SCMI nodes removed from Dom0/hwdom device tree.
>> +(for example, thin Dom0 with Driver domain use-case).
>> +
>> ### dtuart (ARM)
>> > `= path [:options]`
>> diff --git a/tools/libs/light/libxl_arm.c
>> b/tools/libs/light/libxl_arm.c
>> index e4407d6e3f..be0e6263ae 100644
>> --- a/tools/libs/light/libxl_arm.c
>> +++ b/tools/libs/light/libxl_arm.c
>> @@ -240,6 +240,10 @@ int libxl__arch_domain_prepare_config(libxl__gc
>> *gc,
>> case LIBXL_ARM_SCI_TYPE_SCMI_SMC:
>> config->arch.arm_sci_type =
>> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC;
>> break;
>> + case LIBXL_ARM_SCI_TYPE_SCMI_SMC_MULTIAGENT:
>> + config->arch.arm_sci_type =
>> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA;
>> + config->arch.arm_sci_agent_id =
>> d_config->b_info.arch_arm.arm_sci.agent_id;
>> + break;
>> default:
>> LOG(ERROR, "Unknown ARM_SCI type %d",
>> d_config->b_info.arch_arm.arm_sci.type);
>> diff --git a/tools/libs/light/libxl_types.idl
>> b/tools/libs/light/libxl_types.idl
>> index 4a958f69f4..9bfbf09145 100644
>> --- a/tools/libs/light/libxl_types.idl
>> +++ b/tools/libs/light/libxl_types.idl
>> @@ -554,11 +554,13 @@ libxl_sve_type = Enumeration("sve_type", [
>> libxl_arm_sci_type = Enumeration("arm_sci_type", [
>> (0, "none"),
>> - (1, "scmi_smc")
>> + (1, "scmi_smc"),
>> + (2, "scmi_smc_multiagent")
>> ], init_val = "LIBXL_ARM_SCI_TYPE_NONE")
>> libxl_arm_sci = Struct("arm_sci", [
>> ("type", libxl_arm_sci_type),
>> + ("agent_id", uint8)
>> ])
>> libxl_rdm_reserve = Struct("rdm_reserve", [
>> diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
>> index 1cc41f1bff..0c389d25f9 100644
>> --- a/tools/xl/xl_parse.c
>> +++ b/tools/xl/xl_parse.c
>> @@ -1306,6 +1306,18 @@ static int parse_arm_sci_config(XLU_Config
>> *cfg, libxl_arm_sci *arm_sci,
>> }
>> }
>> + if (MATCH_OPTION("agent_id", ptr, oparg)) {
>> + unsigned long val = parse_ulong(oparg);
>> +
>> + if (!val || val > 255) {
>> + fprintf(stderr, "An invalid ARM_SCI agent_id
>> specified (%lu). Valid range [1..255]\n",
>> + val);
>> + ret = ERROR_INVAL;
>> + goto out;
>> + }
>> + arm_sci->agent_id = val;
>> + }
>> +
>> ptr = strtok(NULL, ",");
>> }
>> diff --git a/xen/arch/arm/dom0less-build.c
>> b/xen/arch/arm/dom0less-build.c
>> index 4181c10538..ddadc89148 100644
>> --- a/xen/arch/arm/dom0less-build.c
>> +++ b/xen/arch/arm/dom0less-build.c
>> @@ -299,6 +299,17 @@ static int __init domu_dt_sci_parse(struct
>> dt_device_node *node,
>> d_cfg->arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_NONE;
>> else if ( !strcmp(sci_type, "scmi_smc") )
>> d_cfg->arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC;
>> + else if ( !strcmp(sci_type, "scmi_smc_multiagent") )
>> + {
>> + uint32_t agent_id = 0;
>> +
>> + if ( !dt_property_read_u32(node, "xen,sci-agent-id",
>> &agent_id) ||
>> + agent_id > UINT8_MAX )
>> + return -EINVAL;
>> +
>> + d_cfg->arch.arm_sci_type =
>> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA;
>> + d_cfg->arch.arm_sci_agent_id = agent_id;
>> + }
>> else
>> {
>> printk(XENLOG_ERR "xen,sci_type in not valid (%s) for
>> domain %s\n",
>> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
>> index fb8fbb1650..794ea1aa42 100644
>> --- a/xen/arch/arm/domain_build.c
>> +++ b/xen/arch/arm/domain_build.c
>> @@ -55,6 +55,10 @@ boolean_param("ext_regions", opt_ext_regions);
>> static u64 __initdata dom0_mem;
>> static bool __initdata dom0_mem_set;
>> +/* SCMI agent ID for dom0, parsed from dom0=sci-agent-id=<value> */
>> +#define SCMI_AGENT_ID_INVALID 0xFF
>> +static uint8_t __initdata opt_dom0_scmi_agent_id =
>> SCMI_AGENT_ID_INVALID;
>> +
>> static int __init parse_dom0_mem(const char *s)
>> {
>> dom0_mem_set = true;
>> @@ -83,6 +87,16 @@ int __init parse_arch_dom0_param(const char *s,
>> const char *e)
>> #endif
>> }
>> + if ( !parse_signed_integer("sci-agent-id", s, e, &val) )
>> + {
>> + if ( (val >= 0) && (val <= UINT8_MAX) )
>> + opt_dom0_scmi_agent_id = val;
>> + else
>> + printk(XENLOG_INFO "'sci-agent-id=%lld' value out of
>> range!\n", val);
>> +
>> + return 0;
>> + }
>> +
>> return -EINVAL;
>> }
>> @@ -509,7 +523,8 @@ static int __init write_properties(struct
>> domain *d, struct kernel_info *kinfo,
>> dt_property_name_is_equal(prop,
>> "linux,uefi-mmap-start") ||
>> dt_property_name_is_equal(prop,
>> "linux,uefi-mmap-size") ||
>> dt_property_name_is_equal(prop,
>> "linux,uefi-mmap-desc-size") ||
>> - dt_property_name_is_equal(prop,
>> "linux,uefi-mmap-desc-ver"))
>> + dt_property_name_is_equal(prop,
>> "linux,uefi-mmap-desc-ver") ||
>> + dt_property_name_is_equal(prop, "xen,config") )
>> continue;
>> if ( dt_property_name_is_equal(prop,
>> "xen,dom0-bootargs") )
>> @@ -2067,6 +2082,15 @@ void __init create_dom0(void)
>> dom0_cfg.arch.tee_type = tee_get_type();
>> dom0_cfg.max_vcpus = dom0_max_vcpus();
>> + /* Set up SCMI agent ID if specified in dom0= command line */
>> + if ( opt_dom0_scmi_agent_id != SCMI_AGENT_ID_INVALID )
>> + {
>> + dom0_cfg.arch.arm_sci_type =
>> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA;
>> + dom0_cfg.arch.arm_sci_agent_id = opt_dom0_scmi_agent_id;
>> + }
>> + else
>> + dom0_cfg.arch.arm_sci_type = XEN_DOMCTL_CONFIG_ARM_SCI_NONE;
>> +
>> if ( iommu_enabled )
>> dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
>> diff --git a/xen/arch/arm/firmware/Kconfig
>> b/xen/arch/arm/firmware/Kconfig
>> index 5c5f0880c4..972cd9b173 100644
>> --- a/xen/arch/arm/firmware/Kconfig
>> +++ b/xen/arch/arm/firmware/Kconfig
>> @@ -29,6 +29,18 @@ config SCMI_SMC
>> driver domain.
>> Use with EL3 firmware which supports only single SCMI OSPM
>> agent.
>> +config SCMI_SMC_MA
>> + bool "Enable ARM SCMI SMC multi-agent driver"
>> + depends on ARM_64
>> + select ARM_SCI
>> + help
>> + Enables SCMI SMC/HVC multi-agent in XEN to pass SCMI requests
>> from Domains
>> + to EL3 firmware (TF-A) which supports multi-agent feature.
>> + This feature allows to enable SCMI per Domain using unique
>> SCMI agent_id,
>> + so Domain is identified by EL3 firmware as an SCMI Agent and
>> can access
>> + allowed platform resources through dedicated SMC/HVC Shared
>> memory based
>> + transport.
>> +
>> endchoice
>> endmenu
>> diff --git a/xen/arch/arm/firmware/Makefile
>> b/xen/arch/arm/firmware/Makefile
>> index 71bdefc24a..37927e690e 100644
>> --- a/xen/arch/arm/firmware/Makefile
>> +++ b/xen/arch/arm/firmware/Makefile
>> @@ -1,2 +1,3 @@
>> obj-$(CONFIG_ARM_SCI) += sci.o
>> obj-$(CONFIG_SCMI_SMC) += scmi-smc.o
>> +obj-$(CONFIG_SCMI_SMC_MA) += scmi-shmem.o scmi-smc-multiagent.o
>> diff --git a/xen/arch/arm/firmware/scmi-proto.h
>> b/xen/arch/arm/firmware/scmi-proto.h
>> new file mode 100644
>> index 0000000000..49f63cfc0a
>> --- /dev/null
>> +++ b/xen/arch/arm/firmware/scmi-proto.h
>> @@ -0,0 +1,164 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Arm System Control and Management Interface definitions
>> + * Version 3.0 (DEN0056C)
>> + *
>> + * Copyright (c) 2025 EPAM Systems
>> + */
>> +
>> +#ifndef ARM_FIRMWARE_SCMI_PROTO_H_
>> +#define ARM_FIRMWARE_SCMI_PROTO_H_
>> +
>> +#include <xen/stdint.h>
>> +
>> +#define SCMI_SHORT_NAME_MAX_SIZE 16
>> +
>> +/* SCMI status codes. See section 4.1.4 */
>> +#define SCMI_SUCCESS 0
>> +#define SCMI_NOT_SUPPORTED (-1)
>> +#define SCMI_INVALID_PARAMETERS (-2)
>> +#define SCMI_DENIED (-3)
>> +#define SCMI_NOT_FOUND (-4)
>> +#define SCMI_OUT_OF_RANGE (-5)
>> +#define SCMI_BUSY (-6)
>> +#define SCMI_COMMS_ERROR (-7)
>> +#define SCMI_GENERIC_ERROR (-8)
>> +#define SCMI_HARDWARE_ERROR (-9)
>> +#define SCMI_PROTOCOL_ERROR (-10)
>> +
>> +/* Protocol IDs */
>> +#define SCMI_BASE_PROTOCOL 0x10
>> +
>> +/* Base protocol message IDs */
>> +#define SCMI_BASE_PROTOCOL_VERSION 0x0
>> +#define SCMI_BASE_PROTOCOL_ATTIBUTES 0x1
>> +#define SCMI_BASE_PROTOCOL_MESSAGE_ATTRIBUTES 0x2
>> +#define SCMI_BASE_DISCOVER_AGENT 0x7
>> +#define SCMI_BASE_SET_DEVICE_PERMISSIONS 0x9
>> +#define SCMI_BASE_RESET_AGENT_CONFIGURATION 0xB
>> +
>> +typedef struct scmi_msg_header {
>> + uint8_t id;
>> + uint8_t type;
>> + uint8_t protocol;
>> + uint32_t status;
>> +} scmi_msg_header_t;
>> +
>> +/* Table 2 Message header format */
>> +#define SCMI_HDR_ID GENMASK(7, 0)
>> +#define SCMI_HDR_TYPE GENMASK(9, 8)
>> +#define SCMI_HDR_PROTO GENMASK(17, 10)
>> +
>> +#define SCMI_FIELD_GET(_mask,
>> _reg) \
>> + ((typeof(_mask))(((_reg) & (_mask)) >> (ffs64(_mask) - 1)))
>> +#define SCMI_FIELD_PREP(_mask,
>> _val) \
>> + (((typeof(_mask))(_val) << (ffs64(_mask) - 1)) & (_mask))
>> +
>> +static inline uint32_t pack_scmi_header(scmi_msg_header_t *hdr)
>> +{
>> + return SCMI_FIELD_PREP(SCMI_HDR_ID, hdr->id) |
>> + SCMI_FIELD_PREP(SCMI_HDR_TYPE, hdr->type) |
>> + SCMI_FIELD_PREP(SCMI_HDR_PROTO, hdr->protocol);
>> +}
>> +
>> +static inline void unpack_scmi_header(uint32_t msg_hdr,
>> scmi_msg_header_t *hdr)
>> +{
>> + hdr->id = SCMI_FIELD_GET(SCMI_HDR_ID, msg_hdr);
>> + hdr->type = SCMI_FIELD_GET(SCMI_HDR_TYPE, msg_hdr);
>> + hdr->protocol = SCMI_FIELD_GET(SCMI_HDR_PROTO, msg_hdr);
>> +}
>> +
>> +static inline int scmi_to_xen_errno(int scmi_status)
>> +{
>> + if ( scmi_status == SCMI_SUCCESS )
>> + return 0;
>> +
>> + switch ( scmi_status )
>> + {
>> + case SCMI_NOT_SUPPORTED:
>> + return -EOPNOTSUPP;
>> + case SCMI_INVALID_PARAMETERS:
>> + return -EINVAL;
>> + case SCMI_DENIED:
>> + return -EACCES;
>> + case SCMI_NOT_FOUND:
>> + return -ENOENT;
>> + case SCMI_OUT_OF_RANGE:
>> + return -ERANGE;
>> + case SCMI_BUSY:
>> + return -EBUSY;
>> + case SCMI_COMMS_ERROR:
>> + return -ENOTCONN;
>> + case SCMI_GENERIC_ERROR:
>> + return -EIO;
>> + case SCMI_HARDWARE_ERROR:
>> + return -ENXIO;
>> + case SCMI_PROTOCOL_ERROR:
>> + return -EBADMSG;
>> + default:
>> + return -EINVAL;
>> + }
>> +}
>> +
>> +/* PROTOCOL_VERSION */
>> +#define SCMI_VERSION_MINOR GENMASK(15, 0)
>> +#define SCMI_VERSION_MAJOR GENMASK(31, 16)
>> +
>> +struct scmi_msg_prot_version_p2a {
>> + uint32_t version;
>> +} __packed;
>> +
>> +/* BASE PROTOCOL_ATTRIBUTES */
>> +#define SCMI_BASE_ATTR_NUM_PROTO GENMASK(7, 0)
>> +#define SCMI_BASE_ATTR_NUM_AGENT GENMASK(15, 8)
>> +
>> +struct scmi_msg_base_attributes_p2a {
>> + uint32_t attributes;
>> +} __packed;
>> +
>> +/*
>> + * BASE_DISCOVER_AGENT
>> + */
>> +#define SCMI_BASE_AGENT_ID_OWN 0xFFFFFFFF
>> +
>> +struct scmi_msg_base_discover_agent_a2p {
>> + uint32_t agent_id;
>> +} __packed;
>> +
>> +struct scmi_msg_base_discover_agent_p2a {
>> + uint32_t agent_id;
>> + char name[SCMI_SHORT_NAME_MAX_SIZE];
>> +} __packed;
>> +
>> +/*
>> + * BASE_SET_DEVICE_PERMISSIONS
>> + */
>> +#define SCMI_BASE_DEVICE_ACCESS_ALLOW BIT(0, UL)
>> +
>> +struct scmi_msg_base_set_device_permissions_a2p {
>> + uint32_t agent_id;
>> + uint32_t device_id;
>> + uint32_t flags;
>> +} __packed;
>> +
>> +/*
>> + * BASE_RESET_AGENT_CONFIGURATION
>> + */
>> +#define SCMI_BASE_AGENT_PERMISSIONS_RESET BIT(0, UL)
>> +
>> +struct scmi_msg_base_reset_agent_cfg_a2p {
>> + uint32_t agent_id;
>> + uint32_t flags;
>> +} __packed;
>> +
>> +#endif /* ARM_FIRMWARE_SCMI_PROTO_H_ */
>> +
>> +/*
>> + * Local variables:
>> + * mode: C
>> + * c-file-style: "BSD"
>> + * c-basic-offset: 4
>> + * tab-width: 4
>> + * indent-tabs-mode: nil
>> + * End:
>> + */
>> diff --git a/xen/arch/arm/firmware/scmi-shmem.c
>> b/xen/arch/arm/firmware/scmi-shmem.c
>> new file mode 100644
>> index 0000000000..c681e3c476
>> --- /dev/null
>> +++ b/xen/arch/arm/firmware/scmi-shmem.c
>> @@ -0,0 +1,115 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * SMC/HVC shmem transport implementation used by
>> + * SCI SCMI multi-agent driver.
>> + *
>> + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
>> + * Copyright (c) 2025 EPAM Systems
>> + */
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +
>> +#include <xen/err.h>
>> +#include <xen/lib/io.h>
>> +#include <asm/io.h>
>> +
>> +#include "scmi-proto.h"
>> +#include "scmi-shmem.h"
>> +
>> +static inline int
>> +shmem_channel_is_free(const volatile struct scmi_shared_mem __iomem
>> *shmem)
>> +{
>> + return (readl(&shmem->channel_status) &
>> + SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE) ? 0 : -EBUSY;
>> +}
>> +
>> +int shmem_put_message(volatile struct scmi_shared_mem __iomem *shmem,
>> + scmi_msg_header_t *hdr, void *data, int len)
>> +{
>> + int ret;
>> +
>> + if ( (len + offsetof(struct scmi_shared_mem, msg_payload)) >
>> + SCMI_SHMEM_MAPPED_SIZE )
>> + {
>> + printk(XENLOG_ERR "scmi: Wrong size of smc message. Data is
>> invalid\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = shmem_channel_is_free(shmem);
>> + if ( ret )
>> + return ret;
>> +
>> + writel_relaxed(0x0, &shmem->channel_status);
>> + /* Writing 0x0 right now, but "shmem"_FLAG_INTR_ENABLED can be
>> set */
>> + writel_relaxed(0x0, &shmem->flags);
>> + writel_relaxed(sizeof(shmem->msg_header) + len, &shmem->length);
>> + writel(pack_scmi_header(hdr), &shmem->msg_header);
>> +
>> + if ( len > 0 && data )
>> + __memcpy_toio(shmem->msg_payload, data, len);
>> +
>> + return 0;
>> +}
>> +
>> +int shmem_get_response(const volatile struct scmi_shared_mem __iomem
>> *shmem,
>> + scmi_msg_header_t *hdr, void *data, int len)
>> +{
>> + int recv_len;
>> + int ret;
>> + int pad = sizeof(hdr->status);
>> +
>> + if ( len >= SCMI_SHMEM_MAPPED_SIZE -
>> + offsetof(struct scmi_shared_mem, msg_payload) )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Wrong size of input smc message. Data may be
>> invalid\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = shmem_channel_is_free(shmem);
>> + if ( ret )
>> + return ret;
>> +
>> + recv_len = readl(&shmem->length) - sizeof(shmem->msg_header);
>> +
>> + if ( recv_len < 0 )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Wrong size of smc message. Data may be
>> invalid\n");
>> + return -EINVAL;
>> + }
>> +
>> + unpack_scmi_header(readl(&shmem->msg_header), hdr);
>> +
>> + hdr->status = readl(&shmem->msg_payload);
>> + recv_len = recv_len > pad ? recv_len - pad : 0;
>> +
>> + ret = scmi_to_xen_errno(hdr->status);
>> + if ( ret )
>> + {
>> + printk(XENLOG_DEBUG "scmi: Error received: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + if ( recv_len > len )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Not enough buffer for message %d, expecting
>> %d\n",
>> + recv_len, len);
>> + return -EINVAL;
>> + }
>> +
>> + if ( recv_len > 0 )
>> + __memcpy_fromio(data, shmem->msg_payload + pad, recv_len);
>> +
>> + return 0;
>> +}
>> +
>> +/*
>> + * Local variables:
>> + * mode: C
>> + * c-file-style: "BSD"
>> + * c-basic-offset: 4
>> + * tab-width: 4
>> + * indent-tabs-mode: nil
>> + * End:
>> + */
>> diff --git a/xen/arch/arm/firmware/scmi-shmem.h
>> b/xen/arch/arm/firmware/scmi-shmem.h
>> new file mode 100644
>> index 0000000000..7313cb6b26
>> --- /dev/null
>> +++ b/xen/arch/arm/firmware/scmi-shmem.h
>> @@ -0,0 +1,45 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Arm System Control and Management Interface definitions
>> + * Version 3.0 (DEN0056C)
>> + * Shared Memory based Transport
>> + *
>> + * Copyright (c) 2024 EPAM Systems
>> + */
>> +
>> +#ifndef ARM_FIRMWARE_SCMI_SHMEM_H_
>> +#define ARM_FIRMWARE_SCMI_SHMEM_H_
>> +
>> +#include <xen/stdint.h>
>> +
>> +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0, UL)
>> +#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1, UL)
>> +
>> +struct scmi_shared_mem {
>> + uint32_t reserved;
>> + uint32_t channel_status;
>> + uint32_t reserved1[2];
>> + uint32_t flags;
>> + uint32_t length;
>> + uint32_t msg_header;
>> + uint8_t msg_payload[];
>> +};
>> +
>> +#define SCMI_SHMEM_MAPPED_SIZE PAGE_SIZE
>> +
>> +int shmem_put_message(volatile struct scmi_shared_mem __iomem *shmem,
>> + scmi_msg_header_t *hdr, void *data, int len);
>> +
>> +int shmem_get_response(const volatile struct scmi_shared_mem __iomem
>> *shmem,
>> + scmi_msg_header_t *hdr, void *data, int len);
>> +#endif /* ARM_FIRMWARE_SCMI_SHMEM_H_ */
>> +
>> +/*
>> + * Local variables:
>> + * mode: C
>> + * c-file-style: "BSD"
>> + * c-basic-offset: 4
>> + * tab-width: 4
>> + * indent-tabs-mode: nil
>> + * End:
>> + */
>> diff --git a/xen/arch/arm/firmware/scmi-smc-multiagent.c
>> b/xen/arch/arm/firmware/scmi-smc-multiagent.c
>> new file mode 100644
>> index 0000000000..8e532798a6
>> --- /dev/null
>> +++ b/xen/arch/arm/firmware/scmi-smc-multiagent.c
>> @@ -0,0 +1,794 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * SCI SCMI multi-agent driver, using SMC/HVC shmem as transport.
>> + *
>> + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
>> + * Copyright (c) 2025 EPAM Systems
>> + */
>> +
>> +#include <xen/acpi.h>
>> +
>> +#include <xen/device_tree.h>
>> +#include <xen/init.h>
>> +#include <xen/iocap.h>
>> +#include <xen/err.h>
>> +#include <xen/libfdt/libfdt.h>
>> +#include <xen/param.h>
>> +#include <xen/sched.h>
>> +#include <xen/vmap.h>
>> +
>> +#include <asm/firmware/sci.h>
>> +#include <asm/smccc.h>
>> +
>> +#include "scmi-proto.h"
>> +#include "scmi-shmem.h"
>> +
>> +#define SCMI_AGENT_ID_INVALID 0xFF
>> +
>> +#define SCMI_SECONDARY_AGENTS "scmi-secondary-agents"
>> +
>> +struct scmi_channel {
>> + uint32_t agent_id;
>> + uint32_t func_id;
>> + domid_t domain_id;
>> + uint64_t paddr;
>> + struct scmi_shared_mem __iomem *shmem;
>> + spinlock_t lock;
>> + struct list_head list;
>> +};
>> +
>> +struct scmi_data {
>> + struct list_head channel_list;
>> + spinlock_t channel_list_lock;
>> + uint32_t func_id;
>> + bool initialized;
>> + uint32_t shmem_phandle;
>> + uint32_t hyp_channel_agent_id;
>> + struct dt_device_node *dt_dev;
>> +};
>> +
>> +static struct scmi_data scmi_data;
>> +
>> +static int send_smc_message(struct scmi_channel *chan_info,
>> + scmi_msg_header_t *hdr, void *data, int
>> len)
>> +{
>> + struct arm_smccc_res resp;
>> + int ret;
>> +
>> + ret = shmem_put_message(chan_info->shmem, hdr, data, len);
>> + if ( ret )
>> + return ret;
>> +
>> + arm_smccc_1_1_smc(chan_info->func_id, 0, 0, 0, 0, 0, 0, 0, &resp);
>> +
>> + if ( resp.a0 == ARM_SMCCC_INVALID_PARAMETER )
>> + return -EINVAL;
>> +
>> + if ( resp.a0 )
>> + return -EOPNOTSUPP;
>> +
>> + return 0;
>> +}
>> +
>> +static int do_smc_xfer(struct scmi_channel *chan_info,
>> scmi_msg_header_t *hdr,
>> + void *tx_data, int tx_size, void *rx_data,
>> int rx_size)
>> +{
>> + int ret = 0;
>> +
>> + ASSERT(chan_info && chan_info->shmem);
>> +
>> + if ( !hdr )
>> + return -EINVAL;
>> +
>> + spin_lock(&chan_info->lock);
>> +
>> + printk(XENLOG_DEBUG
>> + "scmi: agent_id = %d msg_id = %x type = %d, proto = %x\n",
>> + chan_info->agent_id, hdr->id, hdr->type, hdr->protocol);
>> +
>> + ret = send_smc_message(chan_info, hdr, tx_data, tx_size);
>> + if ( ret )
>> + goto clean;
>> +
>> + ret = shmem_get_response(chan_info->shmem, hdr, rx_data, rx_size);
>> +
>> +clean:
>> + printk(XENLOG_DEBUG
>> + "scmi: get smc response agent_id = %d msg_id = %x proto =
>> %x res=%d\n",
>> + chan_info->agent_id, hdr->id, hdr->protocol, ret);
>> +
>> + spin_unlock(&chan_info->lock);
>> +
>> + return ret;
>> +}
>> +
>> +static struct scmi_channel *get_channel_by_id(uint32_t agent_id)
>> +{
>> + struct scmi_channel *curr;
>> + bool found = false;
>> +
>> + spin_lock(&scmi_data.channel_list_lock);
>> + list_for_each_entry(curr, &scmi_data.channel_list, list)
>> + {
>> + if ( curr->agent_id == agent_id )
>> + {
>> + found = true;
>> + break;
>> + }
>> + }
>> +
>> + spin_unlock(&scmi_data.channel_list_lock);
>> + if ( found )
>> + return curr;
>> +
>> + return NULL;
>> +}
>> +
>> +static struct scmi_channel *acquire_scmi_channel(struct domain *d,
>> + uint32_t agent_id)
>> +{
>> + struct scmi_channel *curr;
>> + struct scmi_channel *ret = ERR_PTR(-ENOENT);
>> +
>> + spin_lock(&scmi_data.channel_list_lock);
>> + list_for_each_entry(curr, &scmi_data.channel_list, list)
>> + {
>> + if ( curr->agent_id == agent_id )
>> + {
>> + if ( curr->domain_id != DOMID_INVALID )
>> + {
>> + ret = ERR_PTR(-EEXIST);
>> + break;
>> + }
>> +
>> + curr->domain_id = d->domain_id;
>> + ret = curr;
>> + break;
>> + }
>> + }
>> +
>> + spin_unlock(&scmi_data.channel_list_lock);
>> +
>> + return ret;
>> +}
>> +
>> +static void relinquish_scmi_channel(struct scmi_channel *channel)
>> +{
>> + ASSERT(channel != NULL);
>> +
>> + spin_lock(&scmi_data.channel_list_lock);
>> + channel->domain_id = DOMID_INVALID;
>> + spin_unlock(&scmi_data.channel_list_lock);
>> +}
>> +
>> +static int map_channel_memory(struct scmi_channel *channel)
>> +{
>> + ASSERT(channel && channel->paddr);
>> + channel->shmem = ioremap_nocache(channel->paddr,
>> SCMI_SHMEM_MAPPED_SIZE);
>> + if ( !channel->shmem )
>> + return -ENOMEM;
>> +
>> + channel->shmem->channel_status = SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
>> + printk(XENLOG_DEBUG "scmi: Got shmem %lx after vmap %p\n",
>> channel->paddr,
>> + channel->shmem);
>> +
>> + return 0;
>> +}
>> +
>> +static void unmap_channel_memory(struct scmi_channel *channel)
>> +{
>> + ASSERT(channel && channel->shmem);
>> + iounmap(channel->shmem);
>> + channel->shmem = NULL;
>> +}
>> +
>> +static struct scmi_channel *smc_create_channel(uint32_t agent_id,
>> + uint32_t func_id,
>> uint64_t addr)
>> +{
>> + struct scmi_channel *channel, *curr;
>> +
>> + spin_lock(&scmi_data.channel_list_lock);
>> +
>> + /* Check if channel already exists while holding the lock */
>> + list_for_each_entry(curr, &scmi_data.channel_list, list)
>> + {
>> + if ( curr->agent_id == agent_id )
>> + {
>> + spin_unlock(&scmi_data.channel_list_lock);
>> + return ERR_PTR(-EEXIST);
>> + }
>> + }
>> +
>> + channel = xmalloc(struct scmi_channel);
>> + if ( !channel )
>> + {
>> + spin_unlock(&scmi_data.channel_list_lock);
>> + return ERR_PTR(-ENOMEM);
>> + }
>> +
>> + spin_lock_init(&channel->lock);
>> + channel->agent_id = agent_id;
>> + channel->func_id = func_id;
>> + channel->domain_id = DOMID_INVALID;
>> + channel->shmem = NULL;
>> + channel->paddr = addr;
>> + list_add_tail(&channel->list, &scmi_data.channel_list);
>> +
>> + spin_unlock(&scmi_data.channel_list_lock);
>> + return channel;
>> +}
>> +
>> +static void free_channel_list(void)
>> +{
>> + struct scmi_channel *curr, *_curr;
>> +
>> + list_for_each_entry_safe(curr, _curr, &scmi_data.channel_list,
>> list)
>> + {
>> + list_del(&curr->list);
>> + xfree(curr);
>> + }
>> +}
>> +
>> +static int __init
>> +scmi_dt_read_hyp_channel_addr(struct dt_device_node *scmi_node, u64
>> *addr,
>> + u64 *size)
>> +{
>> + struct dt_device_node *shmem_node;
>> + const __be32 *prop;
>> +
>> + prop = dt_get_property(scmi_node, "shmem", NULL);
>> + if ( !prop )
>> + return -EINVAL;
>> +
>> + shmem_node = dt_find_node_by_phandle(be32_to_cpu(*prop));
>> + if ( IS_ERR_OR_NULL(shmem_node) )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Device tree error, can't parse reserved memory
>> %ld\n",
>> + PTR_ERR(shmem_node));
>> + return PTR_ERR(shmem_node);
>> + }
>> +
>> + return dt_device_get_address(shmem_node, 0, addr, size);
>> +}
>> +
>> +/*
>> + * Handle Dom0 SCMI specific DT nodes
>> + *
>> + * Make a decision on copying SCMI specific nodes into Dom0 device
>> tree.
>> + * For SCMI multi-agent case:
>> + * - shmem nodes will not be copied and generated instead if SCMI
>> + * is enabled for Dom0
>> + * - scmi node will be copied if SCMI is enabled for Dom0
>> + */
>> +static bool scmi_dt_handle_node(struct domain *d, struct
>> dt_device_node *node)
>> +{
>> + static const struct dt_device_match shmem_matches[] __initconst = {
>> + DT_MATCH_COMPATIBLE("arm,scmi-shmem"),
>> + { /* sentinel */ },
>> + };
>> + static const struct dt_device_match scmi_matches[] __initconst = {
>> + DT_MATCH_PATH("/firmware/scmi"),
>> + { /* sentinel */ },
>> + };
>> +
>> + if ( !scmi_data.initialized )
>> + return false;
>> +
>> + /* skip scmi shmem node for dom0 if scmi not enabled */
>> + if ( dt_match_node(shmem_matches, node) &&
>> !sci_domain_is_enabled(d) )
>> + {
>> + dt_dprintk(" Skip scmi shmem node\n");
>> + return true;
>> + }
>> +
>> + /* drop scmi if not enabled */
>> + if ( dt_match_node(scmi_matches, node) &&
>> !sci_domain_is_enabled(d) )
>> + {
>> + dt_dprintk(" Skip scmi node\n");
>> + return true;
>> + }
>> +
>> + return false;
>> +}
>> +
>> +static int scmi_assign_device(uint32_t agent_id, uint32_t device_id,
>> + uint32_t flags)
>> +{
>> + struct scmi_msg_base_set_device_permissions_a2p tx;
>> + struct scmi_channel *channel;
>> + scmi_msg_header_t hdr;
>> +
>> + channel = get_channel_by_id(scmi_data.hyp_channel_agent_id);
>> + if ( !channel )
>> + return -EINVAL;
>> +
>> + hdr.id = SCMI_BASE_SET_DEVICE_PERMISSIONS;
>> + hdr.type = 0;
>> + hdr.protocol = SCMI_BASE_PROTOCOL;
>> +
>> + tx.agent_id = agent_id;
>> + tx.device_id = device_id;
>> + tx.flags = flags;
>> +
>> + return do_smc_xfer(channel, &hdr, &tx, sizeof(tx), NULL, 0);
>> +}
>> +
>> +static int scmi_dt_assign_device(struct domain *d,
>> + struct dt_phandle_args *ac_spec)
>> +{
>> + struct scmi_channel *agent_channel;
>> + uint32_t scmi_device_id = ac_spec->args[0];
>> + int ret;
>> +
>> + if ( !d->arch.sci_data )
>> + return 0;
>> +
>> + /* The access-controllers is specified for DT dev, but it's not
>> a SCMI */
>> + if ( ac_spec->np != scmi_data.dt_dev )
>> + return 0;
>> +
>> + agent_channel = d->arch.sci_data;
>> +
>> + spin_lock(&agent_channel->lock);
>> +
>> + ret = scmi_assign_device(agent_channel->agent_id, scmi_device_id,
>> + SCMI_BASE_DEVICE_ACCESS_ALLOW);
>> + if ( ret )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: could not assign dev for %pd agent:%d
>> dev_id:%u (%d)",
>> + d, agent_channel->agent_id, scmi_device_id, ret);
>> + }
>> +
>> + spin_unlock(&agent_channel->lock);
>> + return ret;
>> +}
>> +
>> +static int collect_agent_id(struct scmi_channel *agent_channel)
>> +{
>> + int ret;
>> + scmi_msg_header_t hdr;
>> + struct scmi_msg_base_discover_agent_p2a da_rx;
>> + struct scmi_msg_base_discover_agent_a2p da_tx;
>> +
>> + ret = map_channel_memory(agent_channel);
>> + if ( ret )
>> + return ret;
>> +
>> + hdr.id = SCMI_BASE_DISCOVER_AGENT;
>> + hdr.type = 0;
>> + hdr.protocol = SCMI_BASE_PROTOCOL;
>> +
>> + da_tx.agent_id = agent_channel->agent_id;
>> +
>> + ret = do_smc_xfer(agent_channel, &hdr, &da_tx, sizeof(da_tx),
>> &da_rx,
>> + sizeof(da_rx));
>> + if ( agent_channel->domain_id != DOMID_XEN )
>> + unmap_channel_memory(agent_channel);
>> + if ( ret )
>> + return ret;
>> +
>> + printk(XENLOG_DEBUG "id=0x%x name=%s\n", da_rx.agent_id,
>> da_rx.name);
>> + agent_channel->agent_id = da_rx.agent_id;
>> + return 0;
>> +}
>> +
>> +static __init int collect_agents(struct dt_device_node *scmi_node)
>> +{
>> + const struct dt_device_node *config_node;
>> + const __be32 *prop;
>> + uint32_t len;
>> + const __be32 *end;
>> + uint32_t cells_per_entry = 3; /* Default to 3 cells if property
>> is absent. */
>> +
>> + config_node = dt_find_node_by_path("/chosen/xen,config");
>> + if ( !config_node )
>> + {
>> + printk(XENLOG_WARNING "scmi: /chosen/xen,config node not
>> found, no agents to collect.\n");
>> + return -ENOENT;
>> + }
>> +
>> + /* Check for the optional '#scmi-secondary-agents-cells'
>> property. */
>> + if ( dt_property_read_u32(config_node,
>> "#scmi-secondary-agents-cells",
>> + &cells_per_entry) )
>> + {
>> + if ( cells_per_entry != 2 && cells_per_entry != 3 )
>> + {
>> + printk(XENLOG_ERR "scmi: Invalid
>> #scmi-secondary-agents-cells value: %u\n",
>> + cells_per_entry);
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + prop = dt_get_property(config_node, SCMI_SECONDARY_AGENTS, &len);
>> + if ( !prop )
>> + {
>> + printk(XENLOG_ERR "scmi: No %s property found, no agents to
>> collect.\n",
>> + SCMI_SECONDARY_AGENTS);
>> + return -EINVAL;
>> + }
>> +
>> + /* Validate that the property length is a multiple of the cell
>> size. */
>> + if ( len == 0 || len % (cells_per_entry * sizeof(uint32_t)) != 0 )
>> + {
>> + printk(XENLOG_ERR "scmi: Invalid length of %s property: %u
>> for %u cells per entry\n",
>> + SCMI_SECONDARY_AGENTS, len, cells_per_entry);
>> + return -EINVAL;
>> + }
>> +
>> + end = (const __be32 *)((const u8 *)prop + len);
>> +
>> + for ( ; prop < end; )
>> + {
>> + uint32_t agent_id;
>> + uint32_t smc_id;
>> + uint32_t shmem_phandle;
>> + struct dt_device_node *node;
>> + u64 addr, size;
>> + int ret;
>> + struct scmi_channel *agent_channel;
>> +
>> + smc_id = be32_to_cpu(*prop++);
>> + shmem_phandle = be32_to_cpu(*prop++);
>> +
>> + if ( cells_per_entry == 3 )
>> + agent_id = be32_to_cpu(*prop++);
>> + else
>> + agent_id = SCMI_BASE_AGENT_ID_OWN;
>> +
>> + node = dt_find_node_by_phandle(shmem_phandle);
>> + if ( !node )
>> + {
>> + printk(XENLOG_ERR "scmi: Could not find shmem node for
>> agent %u\n",
>> + agent_id);
>> + return -EINVAL;
>> + }
>> +
>> + ret = dt_device_get_address(node, 0, &addr, &size);
>> + if ( ret )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Could not read shmem address for agent %u:
>> %d\n",
>> + agent_id, ret);
>> + return ret;
>> + }
>> +
>> + if ( !IS_ALIGNED(size, SCMI_SHMEM_MAPPED_SIZE) )
>> + {
>> + printk(XENLOG_ERR "scmi: shmem memory is not aligned\n");
>> + return -EINVAL;
>> + }
>> +
>> + agent_channel = smc_create_channel(agent_id, smc_id, addr);
>> + if ( IS_ERR(agent_channel) )
>> + {
>> + printk(XENLOG_ERR "scmi: Could not create channel for
>> agent %u: %ld\n",
>> + agent_id, PTR_ERR(agent_channel));
>> + return PTR_ERR(agent_channel);
>> + }
>> +
>> + if ( cells_per_entry == 2 )
>> + {
>> + ret = collect_agent_id(agent_channel);
>> + if ( ret )
>> + return ret;
>> + }
>> +
>> + printk(XENLOG_DEBUG "scmi: Agent %u SMC %X addr %lx\n",
>> agent_channel->agent_id,
>> + smc_id, (unsigned long)addr);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int scmi_domain_init(struct domain *d,
>> + struct xen_domctl_createdomain *config)
>> +{
>> + struct scmi_channel *channel;
>> + int ret;
>> +
>> + if ( !scmi_data.initialized )
>> + return 0;
>> +
>> + /*
>> + * SCMI support is configured via:
>> + * - For dom0: dom0=sci-agent-id=<value> in Xen command line
>> + * - For dom0less: xen,sci-agent-id in device tree
>> + * The config->arch.arm_sci_type and config->arch.arm_sci_agent_id
>> + * are already set by domain_build.c or dom0less-build.c
>> + */
>> +
>> + if ( config->arch.arm_sci_type == XEN_DOMCTL_CONFIG_ARM_SCI_NONE )
>> + return 0;
>> +
>> + channel = acquire_scmi_channel(d, config->arch.arm_sci_agent_id);
>> + if ( IS_ERR(channel) )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Failed to acquire SCMI channel for agent_id
>> %u: %ld\n",
>> + config->arch.arm_sci_agent_id, PTR_ERR(channel));
>> + return PTR_ERR(channel);
>> + }
>> +
>> + printk(XENLOG_INFO
>> + "scmi: Acquire channel id = 0x%x, domain_id = %d paddr =
>> 0x%lx\n",
>> + channel->agent_id, channel->domain_id, channel->paddr);
>> +
>> + /*
>> + * Dom0 (if present) needs to have an access to the guest memory
>> range
>> + * to satisfy iomem_access_permitted() check in
>> XEN_DOMCTL_iomem_permission
>> + * domctl.
>> + */
>> + if ( hardware_domain && !is_hardware_domain(d) )
>> + {
>> + ret = iomem_permit_access(hardware_domain,
>> paddr_to_pfn(channel->paddr),
>> + paddr_to_pfn(channel->paddr + PAGE_SIZE - 1));
>> + if ( ret )
>> + goto error;
>> + }
>> +
>> + d->arch.sci_data = channel;
>> + d->arch.sci_enabled = true;
>> +
>> + return 0;
>> +
>> +error:
>> + relinquish_scmi_channel(channel);
>> + return ret;
>> +}
>> +
>> +int scmi_domain_sanitise_config(struct xen_domctl_createdomain *config)
>> +{
>> + if ( config->arch.arm_sci_type != XEN_DOMCTL_CONFIG_ARM_SCI_NONE &&
>> + config->arch.arm_sci_type !=
>> XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA )
>> + {
>> + dprintk(XENLOG_INFO, "scmi: Unsupported ARM_SCI type\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int scmi_relinquish_resources(struct domain *d)
>> +{
>> + int ret;
>> + struct scmi_channel *channel, *agent_channel;
>> + scmi_msg_header_t hdr;
>> + struct scmi_msg_base_reset_agent_cfg_a2p tx;
>> +
>> + if ( !d->arch.sci_data )
>> + return 0;
>> +
>> + agent_channel = d->arch.sci_data;
>> +
>> + spin_lock(&agent_channel->lock);
>> + tx.agent_id = agent_channel->agent_id;
>> + spin_unlock(&agent_channel->lock);
>> +
>> + channel = get_channel_by_id(scmi_data.hyp_channel_agent_id);
>> + if ( !channel )
>> + {
>> + printk(XENLOG_ERR
>> + "scmi: Unable to get Hypervisor scmi channel for
>> domain %d\n",
>> + d->domain_id);
>> + return -EINVAL;
>> + }
>> +
>> + hdr.id = SCMI_BASE_RESET_AGENT_CONFIGURATION;
>> + hdr.type = 0;
>> + hdr.protocol = SCMI_BASE_PROTOCOL;
>> +
>> + tx.flags = 0;
>> +
>> + ret = do_smc_xfer(channel, &hdr, &tx, sizeof(tx), NULL, 0);
>> + if ( ret == -EOPNOTSUPP )
>> + return 0;
>> +
>> + return ret;
>> +}
>> +
>> +static void scmi_domain_destroy(struct domain *d)
>> +{
>> + struct scmi_channel *channel;
>> +
>> + if ( !d->arch.sci_data )
>> + return;
>> +
>> + channel = d->arch.sci_data;
>> + spin_lock(&channel->lock);
>> +
>> + relinquish_scmi_channel(channel);
>> + printk(XENLOG_DEBUG "scmi: Free domain %d\n", d->domain_id);
>> +
>> + d->arch.sci_data = NULL;
>> + d->arch.sci_enabled = false;
>> +
>> + spin_unlock(&channel->lock);
>> +}
>> +
>> +static bool scmi_handle_call(struct cpu_user_regs *regs)
>> +{
>> + uint32_t fid = (uint32_t)get_user_reg(regs, 0);
>> + struct scmi_channel *agent_channel;
>> + struct domain *d = current->domain;
>> + struct arm_smccc_res resp;
>> + bool res = false;
>> +
>> + if ( !sci_domain_is_enabled(d) )
>> + return false;
>> +
>> + agent_channel = d->arch.sci_data;
>> + spin_lock(&agent_channel->lock);
>> +
>> + if ( agent_channel->func_id != fid )
>> + {
>> + res = false;
>> + goto unlock;
>> + }
>> +
>> + arm_smccc_1_1_smc(fid,
>> + get_user_reg(regs, 1),
>> + get_user_reg(regs, 2),
>> + get_user_reg(regs, 3),
>> + get_user_reg(regs, 4),
>> + get_user_reg(regs, 5),
>> + get_user_reg(regs, 6),
>> + get_user_reg(regs, 7),
>> + &resp);
>> +
>> + set_user_reg(regs, 0, resp.a0);
>> + set_user_reg(regs, 1, resp.a1);
>> + set_user_reg(regs, 2, resp.a2);
>> + set_user_reg(regs, 3, resp.a3);
>> + res = true;
>> +unlock:
>> + spin_unlock(&agent_channel->lock);
>> +
>> + return res;
>> +}
>> +
>> +static const struct sci_mediator_ops scmi_ops = {
>> + .domain_init = scmi_domain_init,
>> + .domain_destroy = scmi_domain_destroy,
>> + .relinquish_resources = scmi_relinquish_resources,
>> + .handle_call = scmi_handle_call,
>> + .dom0_dt_handle_node = scmi_dt_handle_node,
>> + .domain_sanitise_config = scmi_domain_sanitise_config,
>> + .assign_dt_device = scmi_dt_assign_device,
>> +};
>> +
>> +static int __init scmi_check_smccc_ver(void)
>> +{
>> + if ( smccc_ver < ARM_SMCCC_VERSION_1_1 )
>> + {
>> + printk(XENLOG_WARNING
>> + "scmi: No SMCCC 1.1 support, SCMI calls forwarding
>> disabled\n");
>> + return -ENOSYS;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int __init scmi_dt_hyp_channel_read(struct dt_device_node
>> *scmi_node,
>> + struct scmi_data *scmi_data,
>> + u64 *addr)
>> +{
>> + int ret;
>> + u64 size;
>> +
>> + if ( !dt_property_read_u32(scmi_node, "arm,smc-id",
>> &scmi_data->func_id) )
>> + {
>> + printk(XENLOG_ERR "scmi: unable to read smc-id from DT\n");
>> + return -ENOENT;
>> + }
>> +
>> + ret = scmi_dt_read_hyp_channel_addr(scmi_node, addr, &size);
>> + if ( IS_ERR_VALUE(ret) )
>> + return -ENOENT;
>> +
>> + if ( !IS_ALIGNED(size, SCMI_SHMEM_MAPPED_SIZE) )
>> + {
>> + printk(XENLOG_ERR "scmi: shmem memory is not aligned\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static __init int scmi_probe(struct dt_device_node *scmi_node, const
>> void *data)
>> +{
>> + u64 addr;
>> + int ret;
>> + struct scmi_channel *channel;
>> + unsigned int n_agents;
>> + scmi_msg_header_t hdr;
>> + struct scmi_msg_base_attributes_p2a rx;
>> +
>> + ASSERT(scmi_node != NULL);
>> +
>> + INIT_LIST_HEAD(&scmi_data.channel_list);
>> + spin_lock_init(&scmi_data.channel_list_lock);
>> +
>> + if ( !acpi_disabled )
>> + {
>> + printk(XENLOG_WARNING "scmi: is not supported when using
>> ACPI\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = scmi_check_smccc_ver();
>> + if ( ret )
>> + return ret;
>> +
>> + ret = scmi_dt_hyp_channel_read(scmi_node, &scmi_data, &addr);
>> + if ( ret )
>> + return ret;
>> +
>> + scmi_data.dt_dev = scmi_node;
>> +
>> + channel = smc_create_channel(SCMI_BASE_AGENT_ID_OWN,
>> scmi_data.func_id, addr);
>> + if ( IS_ERR(channel) )
>> + goto out;
>> +
>> + /* Mark as Xen management channel before collecting agent ID */
>> + channel->domain_id = DOMID_XEN;
>> +
>> + /* Request agent id for Xen management channel */
>> + ret = collect_agent_id(channel);
>> + if ( ret )
>> + goto error;
>> +
>> + /* Save the agent id for Xen management channel */
>> + scmi_data.hyp_channel_agent_id = channel->agent_id;
>> +
>> + hdr.id = SCMI_BASE_PROTOCOL_ATTIBUTES;
>> + hdr.type = 0;
>> + hdr.protocol = SCMI_BASE_PROTOCOL;
>> +
>> + ret = do_smc_xfer(channel, &hdr, NULL, 0, &rx, sizeof(rx));
>> + if ( ret )
>> + goto error;
>> +
>> + n_agents = SCMI_FIELD_GET(SCMI_BASE_ATTR_NUM_AGENT, rx.attributes);
>> + printk(XENLOG_DEBUG "scmi: Got agent count %d\n", n_agents);
>> + ret = collect_agents(scmi_node);
>> + if ( ret )
>> + goto error;
>> +
>> + ret = sci_register(&scmi_ops);
>> + if ( ret )
>> + {
>> + printk(XENLOG_ERR "SCMI: mediator already registered (ret =
>> %d)\n",
>> + ret);
>> + return ret;
>> + }
>> +
>> + scmi_data.initialized = true;
>> + goto out;
>> +
>> +error:
>> + unmap_channel_memory(channel);
>> + free_channel_list();
>> +out:
>> + return ret;
>> +}
>> +
>> +static const struct dt_device_match scmi_smc_match[] __initconst = {
>> + DT_MATCH_PATH("/chosen/xen,config/scmi"),
>> + { /* sentinel */ },
>> +};
>> +
>> +DT_DEVICE_START(scmi_smc_ma, "SCMI SMC MEDIATOR", DEVICE_FIRMWARE)
>> + .dt_match = scmi_smc_match,
>> + .init = scmi_probe,
>> +DT_DEVICE_END
>> +
>> +/*
>> + * Local variables:
>> + * mode: C
>> + * c-file-style: "BSD"
>> + * c-basic-offset: 4
>> + * tab-width: 4
>> + * indent-tabs-mode: nil
>> + * End:
>> + */
>> diff --git a/xen/include/public/arch-arm.h
>> b/xen/include/public/arch-arm.h
>> index 095b1a23e3..30e46de6d7 100644
>> --- a/xen/include/public/arch-arm.h
>> +++ b/xen/include/public/arch-arm.h
>> @@ -329,6 +329,7 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_guest_context_t);
>> #define XEN_DOMCTL_CONFIG_ARM_SCI_NONE 0
>> #define XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC 1
>> +#define XEN_DOMCTL_CONFIG_ARM_SCI_SCMI_SMC_MA 2
>> struct xen_arch_domainconfig {
>> /* IN/OUT */
>> @@ -355,6 +356,8 @@ struct xen_arch_domainconfig {
>> uint32_t clock_frequency;
>> /* IN */
>> uint8_t arm_sci_type;
>> + /* IN */
>> + uint8_t arm_sci_agent_id;
>> };
>> #endif /* __XEN__ || __XEN_TOOLS__ */
>
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