On 04.02.2015 22:32, Dennis Jacobfeuerborn wrote: > Hi, > today I tried to configure a guest using Virt-Manager and used the "copy > host cpu configuration" option which resultet in a "Sandy Bridge" model. > What I noticed is that for example the "aes" extension is not available > in the guest even though it is available on the host cpu. > > This is what the host cpu looks like: > > model name : Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz > 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 fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 > x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm > abm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority > ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid > > And this is what I get in the guest: > > model name : Intel Xeon E312xx (Sandy Bridge) > 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 pdpe1gb lm > constant_tsc pni ssse3 cx16 sse4_1 sse4_2 popcnt lahf_lm abm > > Is there a way to get closer to the hardware and get as many of the host > features in the guest as possible? I never intend to do anything like > live-migration with this guest so compatibility for that case is not a > concern. > I think this is XML snippet you're aiming for: <cpu mode='host-model'> <model fallback='allow'/> </cpu>