Re: [PATCH v6 2/7] iwlwifi: mei: add the driver to allow cooperation with CSME

On Mon, Oct 18, 2021 at 1:58 PM Kalle Valo [off-list ref] wrote:

Emmanuel Grumbach [off-list ref] writes:

quoted

CSME in two words
-----------------
CSME stands for Converged Security and Management Engine. It is
a CPU on the chipset and runs a dedicated firmware.
AMT (Active Management Technology) is one of the applications
that run on that CPU. AMT allows to control the platform remotely.
Here is a partial list of the use cases:
* View the screen of the plaform, with keyboard and mouse (KVM)
* Attach a remote IDE device
* Have a serial console to the device
* Query the state of the platform
* Reset / shut down / boot the platform

[...]

quoted

--- a/drivers/net/wireless/intel/iwlwifi/Kconfig
+++ b/drivers/net/wireless/intel/iwlwifi/Kconfig

@@ -92,6 +92,23 @@ config IWLWIFI_BCAST_FILTERING
        If unsure, don't enable this option, as some programs might
        expect incoming broadcasts for their normal operations.

+config IWLMEI
+     tristate "Intel Management Engine communication over WLAN"
+     depends on INTEL_MEI
+     depends on PM
+     depends on IWLMVM
+     help
+       Enables the iwlmei kernel module. This allows to communicate with
+       the Intel Management Engine over Wifi. This is supported starting
+       from Tiger Lake platforms and has been tested on 9260 devices only.
+       Enabling this option on a platform that has a different device and
+       has Wireless enabled on AMT can prevent WiFi from working correctly.

I don't understand the last sentence, please elaborate. Are you saying
that enabling CONFIG_IWLMEI will break wi-fi in some cases?

Since we don't support all the devices (yet), and we haven't integrated it
with all our devices, then yes, it shouldn't be enabled unless you know
exactly what platform this kernel runs on. This is basically a warning for
distros not to enable this kernel option (just as many others that are specific
to a certain use case). The plan is to add support for more and more devices
so that we will be able to remove this comment and be confident that it can
be enabled on generic platforms as well.

quoted

+       For more information see
+       <https://software.intel.com/en-us/manageability/>
+
+       If unsure, say N.

IMHO the help text still contains too much Intel jargon to be really
understandable by everyone. I think the commit log pretty well
summarises what this is all about:

  "CSME stands for Converged Security and Management Engine. It is a CPU
   on the chipset and runs a dedicated firmware. AMT (Active Management
   Technology) is one of the applications that run on that CPU. AMT
   allows to control the platform remotely."

Somehow including that information to the Kconfig help text would be
very helpful to everyone.

I'll try.

Thanks!

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