# msrprobe2 under KVM -cpu host (exact acpi_pst_intel_init dance + PERF_CTL write)
msrprobe2: cpu_vendor_id 32902 cpu_id 0x506e3 cpu_feature2 0xf7fab223 (CPUID2_EST clear)
msrprobe2: rdmsr(0x1a0) -> error 0 val 0x1
msrprobe2: wrmsr(0x1a0,|EST) -> error 0
msrprobe2: rdmsr(0x1a0) -> error 0 val 0x10001 -> EST bit STUCK (init would succeed)
msrprobe2: wrmsr_safe(0x199, 0x0e00) -> error 14 (raw wrmsr at pstate_machdep.c:533 would #GP panic)

# under TCG -cpu SandyBridge (md engageable, MSRs virtualized):
msrprobe2: cpu_vendor_id 32902 cpu_id 0x206a1 cpu_feature2 0x96982203 (CPUID2_EST clear)
msrprobe2: rdmsr(0x1a0) -> error 0 val 0x1
msrprobe2: wrmsr(0x1a0,|EST) -> error 0
msrprobe2: rdmsr(0x1a0) -> error 0 val 0x10001 -> EST bit STUCK (init would succeed)
msrprobe2: wrmsr_safe(0x199, 0x0e00) -> error 0 (raw wrmsr at pstate_machdep.c:533 would succeed)