On QEMU's default i440FX machine type, rdmsr on unsupported MSRs
(0x19c IA32_THERM_STATUS, 0x1a2 IA32_TEMPERATURE_TARGET) causes a
kernel #GP that kills the process. Same pattern as cpufreqd: spawn a
child with --probe-msr to test readability before the main loop. If
probe fails, disable all MSR reads and report all CPUs as Unknown.
vasilito
ad74e920ae