Re: [PATCH v2 1/1] Documentation/x86: Add the AMX enabling example

From: Chang S. Bae
Date: Thu Jun 30 2022 - 12:19:48 EST


On 6/30/2022 9:07 AM, Luck, Tony wrote:
But these state components are architectural. While this can help
userspace anyway, saying "XSTATE component" here and on the man-page is
probably it as they are already defined in the x86 spec.

An application writer can't use:

# include {x86 spec}"

to get these values ... if applications need them to find out if AMX is present,
and to enable it, then they need an API.

Yeah, you're right.


Maybe your example code should just be a library routine? So application writers
can just do:

if (!intel_amx_enable()) {
error message, or fall back to non-AMX implementation
}

without having to worry about those #defines.

I guess we cannot assume this. Given the arch_prctl() options, they can do this by themselves.

Let me include those defines on the next version.

Thanks,
Chang