This feature introduces the ability to dump hardware registered data upon demand. Data that is dumped is stored in a kernel buffer, and can be later manually copied to userspace using mlx5tool. It can be maintained until explicitly cleared.
mlx5tool is a simple program which utilizes the mlx5io interface and allows executing the following firmware dump commands:
MLX5_FWDUMP_FORCE - forces dump unless one was already stored in the kernel buffer
MLX5_FWDUMP_GET - copies the recorded dump from kernel into user mode
MLX5_FWDUMP_RESET - clears the kernel buffer, in preparation for storing another dump
Commands are communicated with the driver using ioctl interface over the devfs device /dev/mlx5ctl.
To build the mlx5tool, run the following command from the driver’s top-level directory:
cd usr.sbin/mlx5tool && make all install clean
mlx5tool -d pci0:<x>:0:0 -e - Force dump, storing it into the kernel buffer
mlx5tool -d pci0:<x>:0:0 -w [-o dump.file] - Store the recorded dump into file dump.file. If -o is omitted, the dump is streamed into standard output.
mlx5tool -d pci0:<x>:0:0 -r - Reset dump