RE: [PATCH v2 5/8] cxl/mem: Add a "RAW" send command

Ariel.Sibley
2021-02-10T15:26:48Z

> diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
> index c4ba3aa0a05d..08eaa8e52083 100644
> --- a/drivers/cxl/Kconfig
> +++ b/drivers/cxl/Kconfig
> @@ -33,6 +33,24 @@ config CXL_MEM
>
> If unsure say 'm'.
>
> +config CXL_MEM_RAW_COMMANDS
> + bool "RAW Command Interface for Memory Devices"
> + depends on CXL_MEM
> + help
> + Enable CXL RAW command interface.
> +
> + The CXL driver ioctl interface may assign a kernel ioctl command
> + number for each specification defined opcode. At any given point in
> + time the number of opcodes that the specification defines and a device
> + may implement may exceed the kernel's set of associated ioctl function
> + numbers. The mismatch is either by omission, specification is too new,
> + or by design. When prototyping new hardware, or developing /
> debugging
> + the driver it is useful to be able to submit any possible command to
> + the hardware, even commands that may crash the kernel due to their
> + potential impact to memory currently in use by the kernel.
> +
> + If developing CXL hardware or the driver say Y, otherwise say N.

Blocking RAW commands by default will prevent vendors from developing user space tools that utilize vendor specific commands. Vendors of CXL.mem devices should take ownership of ensuring any vendor defined commands that could cause user data to be exposed or corrupted are disabled at the device level for shipping configurations.