[libvirt-users] libvirt does not show same CPU Model as /proc/cpuinfo for CPU Model info.

Hi , Created new thread . Environment: Bare Metal server + CentOs with qemu/KVM +libvirt for virtualization Guest Instantiated with virt-install with forced CPU model like below virt-install --virt-type kvm --name compute-0 --cpu Haswell,+fma,+movbe,+fsgsbase,+bmi1,+hle,+avx2,+smep,+bmi2,+erms,+invpcid,+rtm --ram=61440 --vcpus=20 --os-type=linux --os-variant=generic After guest installation /proc/cpuinfo show model name as Haswell . However Libvirt virsh capabilities show CPU configuration as "SandyBridge . " 1. Could I get explanation of the why inconsistency . 2. Is this expected behaviour 3. Why libvirt does not show same CPU Model as /proc/cpuinfo for CPU Model info. My Aim : Nested Virtualization and Nested Guest needs CPU model as Haswell strictly . 4. IS it possible alternative to succeed in my aim ? Thanks a lot for support. ! Guest CPU config: processor : 19 vendor_id : GenuineIntel cpu family : 6 model : 60 model name : Intel Core Processor (Haswell) stepping : 1 microcode : 0x1 cpu MHz : 1995.144 cache size : 4096 KB fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx rdtscp lm constant_tsc rep_good nopl eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx hypervisor lahf_lm xsaveopt bogomips : 4105.33 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: <capabilities> <host> <uuid>95c4e625-3383-4ec1-9ee4-c47a87d93b97</uuid> <cpu> <arch>x86_64</arch> <model>SandyBridge</model> <vendor>Intel</vendor> <topology sockets='20' cores='1' threads='1'/> <feature name='hypervisor'/> <feature name='osxsave'/> <feature name='pcid'/> <pages unit='KiB' size='4'/> <pages unit='KiB' size='2048'/> Host CPU config: processor : 23 vendor_id : GenuineIntel cpu family : 6 model : 45 model name : Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz stepping : 7 microcode : 0x710 cpu MHz : 1200.000 cache size : 15360 KB physical id : 1 siblings : 12 core id : 5 cpu cores : 6 apicid : 43 initial apicid : 43 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm ida arat epb pln pts dtherm tpr_shadow vnmi flexpriority ept vpid xsaveopt bogomips : 4004.01 clflush size : 64 cache_alignment : 64 address sizes : 46 bits physical, 48 bits virtual power management: Br Aki