enabling X86_FEATURE_ARCH_PERFMON in guest

How do I get X86_FEATURE_ARCH_PERFMON enabled for a guest?

I've tried "-cpu host,+perfmon" and "-cpu host,+arch_perfmon", but both get rejected with an error: CPU feature perfmon not found

Host processor:

model name : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
stepping : 5
...

flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida tpr_shadow vnmi flexpriority ept vpid

Guest side:
model name : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
stepping : 5
...
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ss syscall nx lm constant_tsc pni ssse3 cx16 sse4_1 sse4_2 popcnt lahf_lm

David

qemu doesn't know about the perfmon feature bits. Even if it did, kvm doesn't, so it wouldn't work.

Jes is working on this.

error compiling committee.c: too many arguments to function