The pds_fwctl driver doesn't know what RPC operations are available
in the firmware, so also doesn't know what scope they might have. The
userland utility supplies the firmware "endpoint" and "operation" id values
and this driver queries the firmware for endpoints and their available
operations. The operation descriptions include the scope information
which the driver uses for scope testing.
Link: https://patch.msgid.link/r/20250320194412.67983-6-shannon.nelson@amd.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Initial files for adding a new fwctl driver for the AMD/Pensando PDS
devices. This sets up a simple auxiliary_bus driver that registers
with fwctl subsystem. It expects that a pds_core device has set up
the auxiliary_device pds_core.fwctl
Link: https://patch.msgid.link/r/20250320194412.67983-5-shannon.nelson@amd.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
mlx5 FW has a built in security context called UID. Each UID has a set of
permissions controlled by the kernel when it is created and every command
is tagged by the kernel with a particular UID. In general commands cannot
reach objects outside of their UID and commands cannot exceed their UID's
permissions. These restrictions are enforced by FW.
This mechanism has long been used in RDMA for the devx interface where
RDMA will sent commands directly to the FW and the UID limitations
restrict those commands to a ib_device/verbs security domain. For instance
commands that would effect other VFs, or global device resources. The
model is suitable for unprivileged userspace to operate the RDMA
functionality.
The UID has been extended with a "tools resources" permission which allows
additional commands and sub-commands that are intended to match with the
scope limitations set in FWCTL. This is an alternative design to the
"command intent log" where the FW does the enforcement rather than having
the FW report the enforcement the kernel should do.
Consistent with the fwctl definitions the "tools resources" security
context is limited to the FWCTL_RPC_CONFIGURATION,
FWCTL_RPC_DEBUG_READ_ONLY, FWCTL_RPC_DEBUG_WRITE, and
FWCTL_RPC_DEBUG_WRITE_FULL security scopes.
Like RDMA devx, each opened fwctl file descriptor will get a unique UID
associated with each file descriptor.
The fwctl driver is kept simple and we reject commands that can create
objects as the UID mechanism relies on the kernel to track and destroy
objects prior to detroying the UID. Filtering into fwctl sub scopes is
done inside the driver with a switch statement. This substantially limits
what is possible to primarily query functions ad a few limited set
operations.
mlx5 already has a robust infrastructure for delivering RPC messages to
fw. Trivially connect fwctl's RPC mechanism to mlx5_cmd_do(). Enforce the
User Context ID in every RPC header accepted from the FD so the FW knows
the security context of the issuing ID.
Link: https://patch.msgid.link/r/7-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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 <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Userspace will need to know some details about the fwctl interface being
used to locate the correct userspace code to communicate with the
kernel. Provide a simple device_type enum indicating what the kernel
driver is.
Allow the device to provide a device specific info struct that contains
any additional information that the driver may need to provide to
userspace.
Link: https://patch.msgid.link/r/3-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Each file descriptor gets a chunk of per-FD driver specific context that
allows the driver to attach a device specific struct to. The core code
takes care of the memory lifetime for this structure.
The ioctl dispatch and design is based on what was built for iommufd. The
ioctls have a struct which has a combined in/out behavior with a typical
'zero pad' scheme for future extension and backwards compatibility.
Like iommufd some shared logic does most of the ioctl marshaling and
compatibility work and table dispatches to some function pointers for
each unique ioctl.
This approach has proven to work quite well in the iommufd and rdma
subsystems.
Allocate an ioctl number space for the subsystem.
Link: https://patch.msgid.link/r/2-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Create the class, character device and functions for a fwctl driver to
un/register to the subsystem.
A typical fwctl driver has a sysfs presence like:
$ ls -l /dev/fwctl/fwctl0
crw------- 1 root root 250, 0 Apr 25 19:16 /dev/fwctl/fwctl0
$ ls /sys/class/fwctl/fwctl0
dev device power subsystem uevent
$ ls /sys/class/fwctl/fwctl0/device/infiniband/
ibp0s10f0
$ ls /sys/class/infiniband/ibp0s10f0/device/fwctl/
fwctl0/
$ ls /sys/devices/pci0000:00/0000:00:0a.0/fwctl/fwctl0
dev device power subsystem uevent
Which allows userspace to link all the multi-subsystem driver components
together and learn the subsystem specific names for the device's
components.
Link: https://patch.msgid.link/r/1-v5-642aa0c94070+4447f-fwctl_jgg@nvidia.com
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Tested-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
