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

Ingo Molnar
2015-12-04T07:42:12Z

* Borislav Petkov <bp@alien8.de> wrote:

> From: Borislav Petkov <bp@suse.de>
>
> qemu/kvm doesn't support RAPL and RAPL doesn't have a CPUID feature bit
> so check whether we're in a guest instead.

So when a hypervisor starts supporting RAPL we'll disable the driver erroneously?

Isn't there any better method to detect RAPL support?

So in particular in drivers/powercap/intel_rapl.c there's an enumerated list of
CPU models, which is used via a x86_match_cpu() call. That's still not ideal (it
does not work on hypervisors for example), but even better would be to detect RAPL
support in some other fashion, that does not rely on us statically enumerating CPU
models that support it.

Thanks,

Ingo