question regarding intel_idle inside kvm

[Daniel Lezcano <daniel.lezcano@free.fr>]

Hi all,

I recently did some modification in the cpuidle core and the patches 
were merge to linux-next.
Someone reported a problem with the intel_idle cpuidle driver.

I tried to reproduce the problem with kvm but the kernel fails to 
intialize the driver because of intel_intel_init function fails in the 
processor probe.

After digging a bit, I found it fails at:

drivers/idle/intel_idle.c

static int intel_idle_probe(void)
{

...


         if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
                 return -ENODEV;

         ^^^^^

  ...

}

I assumed the virtualized processor does not support this, so I 
specified the "-cpu host" because the host was running the intel_idle 
driver. But the driver still fails in kvm.

I was wondering why that happens ? Does anyone have an idea of this 
problem ?

Thanks in advance
   -- Daniel