Accessing QEMU CLI on CentOS 7

By default, the QEMU CLI module is not “in-path” on CentOS 7.

This is because RedHat (by proxy) does not want you calling QEMU CLI directly, in favor of some abstraction layer (like libvirt).

That said, there are situations where you might want to call it directly. If so, it is located in /usr/libexec.

One quick example would be checking all supported processors and cpu flags for the specific version of qemu-kvm.

[jon@centos7 libexec]$ pwd
[jon@centos7 libexec]$ ./qemu-kvm -cpu help
x86 qemu64 QEMU Virtual CPU version 1.5.3
x86 phenom AMD Phenom(tm) 9550 Quad-Core Processor
x86 core2duo Intel(R) Core(TM)2 Duo CPU T7700 @ 2.40GHz
x86 kvm64 Common KVM processor
x86 qemu32 QEMU Virtual CPU version 1.5.3
x86 kvm32 Common 32-bit KVM processor
x86 coreduo Genuine Intel(R) CPU T2600 @ 2.16GHz
x86 486
x86 pentium
x86 pentium2
x86 pentium3
x86 athlon QEMU Virtual CPU version 1.5.3
x86 n270 Intel(R) Atom(TM) CPU N270 @ 1.60GHz
x86 cpu64-rhel6 QEMU Virtual CPU version (cpu64-rhel6)
x86 Conroe Intel Celeron_4x0 (Conroe/Merom Class Core 2)
x86 Penryn Intel Core 2 Duo P9xxx (Penryn Class Core 2)
x86 Nehalem Intel Core i7 9xx (Nehalem Class Core i7)
x86 Westmere Westmere E56xx/L56xx/X56xx (Nehalem-C)
x86 SandyBridge Intel Xeon E312xx (Sandy Bridge)
x86 Haswell Intel Core Processor (Haswell)
x86 Opteron_G1 AMD Opteron 240 (Gen 1 Class Opteron)
x86 Opteron_G2 AMD Opteron 22xx (Gen 2 Class Opteron)
x86 Opteron_G3 AMD Opteron 23xx (Gen 3 Class Opteron)
x86 Opteron_G4 AMD Opteron 62xx class CPU
x86 Opteron_G5 AMD Opteron 63xx class CPU
x86 host KVM processor with all supported host features (only available in KVM mode)

Recognized CPUID flags:
pbe ia64 tm ht ss sse2 sse fxsr mmx acpi ds clflush pn pse36 pat cmov mca pge mtrr sep apic cx8 mce pae msr tsc pse de vme fpu
hypervisor rdrand f16c avx osxsave xsave aes tsc-deadline popcnt movbe x2apic sse4.2|sse4_2 sse4.1|sse4_1 dca pcid pdcm xtpr cx16 fma cid ssse3 tm2 est smx vmx ds_cpl monitor dtes64 pclmulqdq|pclmuldq pni|sse3
smap adx rdseed rtm invpcid erms bmi2 smep avx2 hle bmi1 fsgsbase
3dnow 3dnowext lm|i64 rdtscp pdpe1gb fxsr_opt|ffxsr mmxext nx|xd syscall
perfctr_nb perfctr_core topoext tbm nodeid_msr tce fma4 lwp wdt skinit xop ibs osvw 3dnowprefetch misalignsse sse4a abm cr8legacy extapic svm cmp_legacy lahf_lm
pmm-en pmm phe-en phe ace2-en ace2 xcrypt-en xcrypt xstore-en xstore
kvm_pv_unhalt kvm_pv_eoi kvm_steal_time kvm_asyncpf kvmclock kvm_mmu kvm_nopiodelay kvmclock
pfthreshold pause_filter decodeassists flushbyasid vmcb_clean tsc_scale nrip_save svm_lock lbrv npt