Re: [PATCH] x86/rapl: Do not load in a guest

Jacob Pan
2015-12-04T18:40:57Z

On Fri, 4 Dec 2015 19:28:07 +0100
Borislav Petkov <bp@alien8.de> wrote:

> On Fri, Dec 04, 2015 at 10:16:10AM -0800, Jacob Pan wrote:
> > CPU model detection is the first level checking.
>
> And in the case of RAPL, the only checking you can do. This is why it
> should've had a CPUID bit.
>
I am 200% with you, all I can say is we are working on it. Look at the
pain in the driver for dealing with various quirks.

> > The error is about no valid domains (e.g. counters not working). So
> > the error on minnowboard board could be a real problem if you expect
> > to use RAPL.
>
> Right, and if you need to disable it there, you would need to add a
> quirk table looking at DMI strings or so. A CPUID bit might've been a
> bit better if BIOS update would clear it on those boards. Then, sw
> won't even try to load there.
who is gonna collect all the DMI strings? I don't think this is
scalable.