Re: [PATCH] x86: add hintable NOPs emulation

[Marcos Del Sol Vives]

El 20/08/2025 a las 11:43, Borislav Petkov escribió:
> On Wed, Aug 20, 2025 at 11:33:05AM +0200, Marcos Del Sol Vives wrote:
>> But I think the kernel should let the user know the binaries they're
>> running are having some performance penalty due to this emulation, in case
>> they want to recompile without the offending flags.
> 
> Sure, once perhaps.
> 
> Do you want to let the user know for each binary?
> 
> And how many users do you really think will look at dmesg and recompile their
> binaries?

I mean, they should know what they need to recompile if they want to, not
just that their machine is having a bug triggered by some binary.

A global flag would mean they'd need to reboot to see if there is any other
binary triggering it too.

Whether they look or not at the dmesg I cannot tell, but if IOPL emulation
does logging this way, I assumed this should too. Otherwise, would that
mean IOPL emulation logging is also too verbose?