Hmm,
<cpu mode='custom' match='minimum'><model>Nehalem</model><feature policy='optional' name='pcid'/><feature policy='optional' name='invpcid'/></cpu>
bringt jeweils das beste CPU-Modell und aktiviert *PCID, so vorhanden:
wusel@luggage:~$ grep "Model name" *.lscpu
colosses.lscpu:Model name: Westmere E56xx/L56xx/X56xx (Nehalem-C)
inflexible.lscpu:Model name: Intel Core i7 9xx (Nehalem Class Core i7)
nihil_cpu.lscpu:Model name: Intel Xeon E312xx (Sandy Bridge)
relentless.lscpu:Model name: Intel Xeon E312xx (Sandy Bridge)
Ohne cpu-Flag ist’s …
nihil_xcpu.lscpu:Model name: QEMU Virtual CPU version 2.5+