From 840cfb7cf570b681f5d20e19f7c2675a9d991732 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 27 Feb 2025 20:26:33 -0400 Subject: fwctl: FWCTL_RPC to execute a Remote Procedure Call to device firmware Add the FWCTL_RPC ioctl which allows a request/response RPC call to device firmware. Drivers implementing this call must follow the security guidelines under Documentation/userspace-api/fwctl.rst The core code provides some memory management helpers to get the messages copied from and back to userspace. The driver is responsible for allocating the output message memory and delivering the message to the device. Link: https://patch.msgid.link/r/5-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Reviewed-by: Shannon Nelson Tested-by: Dave Jiang Tested-by: Shannon Nelson Signed-off-by: Jason Gunthorpe --- include/uapi/fwctl/fwctl.h | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/fwctl/fwctl.h b/include/uapi/fwctl/fwctl.h index 4052df63f66d..0bec798790a6 100644 --- a/include/uapi/fwctl/fwctl.h +++ b/include/uapi/fwctl/fwctl.h @@ -37,6 +37,7 @@ enum { FWCTL_CMD_BASE = 0, FWCTL_CMD_INFO = 0, + FWCTL_CMD_RPC = 1, }; enum fwctl_device_type { @@ -66,4 +67,72 @@ struct fwctl_info { }; #define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO) +/** + * enum fwctl_rpc_scope - Scope of access for the RPC + * + * Refer to fwctl.rst for a more detailed discussion of these scopes. + */ +enum fwctl_rpc_scope { + /** + * @FWCTL_RPC_CONFIGURATION: Device configuration access scope + * + * Read/write access to device configuration. When configuration + * is written to the device it remains in a fully supported state. + */ + FWCTL_RPC_CONFIGURATION = 0, + /** + * @FWCTL_RPC_DEBUG_READ_ONLY: Read only access to debug information + * + * Readable debug information. Debug information is compatible with + * kernel lockdown, and does not disclose any sensitive information. For + * instance exposing any encryption secrets from this information is + * forbidden. + */ + FWCTL_RPC_DEBUG_READ_ONLY = 1, + /** + * @FWCTL_RPC_DEBUG_WRITE: Writable access to lockdown compatible debug information + * + * Allows write access to data in the device which may leave a fully + * supported state. This is intended to permit intensive and possibly + * invasive debugging. This scope will taint the kernel. + */ + FWCTL_RPC_DEBUG_WRITE = 2, + /** + * @FWCTL_RPC_DEBUG_WRITE_FULL: Write access to all debug information + * + * Allows read/write access to everything. Requires CAP_SYS_RAW_IO, so + * it is not required to follow lockdown principals. If in doubt + * debugging should be placed in this scope. This scope will taint the + * kernel. + */ + FWCTL_RPC_DEBUG_WRITE_FULL = 3, +}; + +/** + * struct fwctl_rpc - ioctl(FWCTL_RPC) + * @size: sizeof(struct fwctl_rpc) + * @scope: One of enum fwctl_rpc_scope, required scope for the RPC + * @in_len: Length of the in memory + * @out_len: Length of the out memory + * @in: Request message in device specific format + * @out: Response message in device specific format + * + * Deliver a Remote Procedure Call to the device FW and return the response. The + * call's parameters and return are marshaled into linear buffers of memory. Any + * errno indicates that delivery of the RPC to the device failed. Return status + * originating in the device during a successful delivery must be encoded into + * out. + * + * The format of the buffers matches the out_device_type from FWCTL_INFO. + */ +struct fwctl_rpc { + __u32 size; + __u32 scope; + __u32 in_len; + __u32 out_len; + __aligned_u64 in; + __aligned_u64 out; +}; +#define FWCTL_RPC _IO(FWCTL_TYPE, FWCTL_CMD_RPC) + #endif -- cgit v1.2.3