On 23/01/2026 03:51, Stefano Stabellini wrote:
> Not a full review, but I found three issues plus some spurious changes
>
>
> On Wed, 21 Jan 2026, Oleksii Moisieiev wrote:
>> diff --git a/docs/misc/xen-command-line.pandoc
>> b/docs/misc/xen-command-line.pandoc
>> index 15f7a315a4..268df3010b 100644
>> --- a/docs/misc/xen-command-line.pandoc
>> +++ b/docs/misc/xen-command-line.pandoc
>> @@ -789,7 +789,7 @@ 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> ] (Arm)
>>
>> Controls for how dom0 is constructed on x86 systems.
> Spurious change
>
>
>> 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 986a456f17..0796561306 100644
>> --- a/xen/arch/arm/domain_build.c
>> +++ b/xen/arch/arm/domain_build.c
>> @@ -86,6 +86,37 @@ int __init parse_arch_dom0_param(const char *s, const
>> char *e)
>> return -EINVAL;
>> }
>>
>> +/* SCMI agent ID for dom0 obtained from xen,sci container */
>> +#define SCMI_AGENT_ID_INVALID UINT8_MAX
>> +
>> +static uint8_t __init get_dom0_scmi_agent_id(void)
>> +{
>> + const struct dt_device_node *config_node;
>> + u32 val;
>> + const struct dt_property *prop;
>> +
>> + config_node = dt_find_compatible_node(NULL, NULL, "xen,sci");
>> + if ( !config_node )
>> + return SCMI_AGENT_ID_INVALID;
>> +
>> + prop = dt_find_property(config_node, "xen,dom0-sci-agent-id", NULL);
>> + if ( !prop )
>> + return SCMI_AGENT_ID_INVALID;
>> +
>> + if ( !dt_property_read_u32(config_node, "xen,dom0-sci-agent-id", &val) )
>> + return SCMI_AGENT_ID_INVALID;
>> +
>> + if ( val >= SCMI_AGENT_ID_INVALID )
>> + {
>> + printk(XENLOG_WARNING
>> + "Invalid xen,dom0-sci-agent-id=%u, SCMI disabled for Dom0\n",
>> + val);
>> + return SCMI_AGENT_ID_INVALID;
>> + }
>> +
>> + return val;
>> +}
>> +
>> /* Override macros from asm/page.h to make them work with mfn_t */
>> #undef virt_to_mfn
>> #define virt_to_mfn(va) _mfn(__virt_to_mfn(va))
>> @@ -509,7 +540,7 @@ 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") )
>> continue;
> Spurious change
>
>
>> +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;
> This comparison can erroneously fail when the pointers point to
> different copies of the same data
>
>
>> + 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_compatible_node(NULL, NULL, "xen,sci");
>> + if ( !config_node )
>> + {
>> + printk(XENLOG_WARNING "scmi: xen,sci 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: xen,dom0-sci-agent-id property under the xen,sci
>> container
>> + * - For dom0less: xen,sci-agent-id in the domain node
>> + * 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;
> is this correct?
>
>
>> + 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);
>> +
>> + /*
>> + * Only bind to the SCMI node provided by Xen under the xen,sci
>> container
>> + * (e.g. /chosen/xen/xen_scmi_config/scmi). This avoids binding to
>> firmware
>> + * SCMI nodes that belong to the host OSPM and keeps the mediator
>> scoped to
>> + * Xen-provided configuration only.
>> + */
>> + if ( !scmi_is_under_xen_sci(scmi_node) )
>> + return -ENODEV;
>> +
>> + 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);
> This might cause the ASSERT at the beginning of unmap_channel_memory to
> trigger
>
>
Great finding... First `goto error` could be called after
`collect_agent_id`.
So in case if we receive -ENOMEM from `ioremap_nocache` inside
`map_channel_memory`
ASSERT will fire.
I'm planning to refactor this as follows:
static void unmap_channel_memory(struct scmi_channel *channel)
{
ASSERT(channel);
if ( !channel->shmem )
return;
...
}
This will cause function to skip iounmap if shmem is NULL;
What do you think?
>> + free_channel_list();
>> +out:
>> + return ret;
>> +}
>> +
>> +static const struct dt_device_match scmi_smc_match[] __initconst = {
>> + DT_MATCH_COMPATIBLE("arm,scmi-smc"),
>> + { /* 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 d30a288592..8f0f68544e 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__ */
>>
>> --
>> 2.34.1
>>
