Hi, I've been using my core i5 6500 (skylake-client) for some time now to test oVirt on my machine. However this is no longer the case. I am using Fedora 32 as my base system with nested-kvm enabled, when I try to install oVirt 4.4 as HCI single node, I get an error in the last phase which consists of copying the VM-Manager to the engine volume and boot it. It is the boot that causes the problem, I get an error about the CPU : *the CPU is incompatible with host CPU: Host CPU does not provide required features: mpx* *This is the CPU part from virsh domcapabilities on my physical machine* <cpu> <mode name='host-passthrough' supported='yes'/> <mode name='host-model' supported='yes'> *<model fallback='forbid'>Skylake-Client-IBRS</model> * <vendor>Intel</vendor> <feature policy='require' name='ss'/> <feature policy='require' name='vmx'/> <feature policy='require' name='pdcm'/> <feature policy='require' name='hypervisor'/> <feature policy='require' name='tsc_adjust'/> <feature policy='require' name='clflushopt'/> <feature policy='require' name='umip'/> <feature policy='require' name='md-clear'/> <feature policy='require' name='stibp'/> <feature policy='require' name='arch-capabilities'/> <feature policy='require' name='ssbd'/> <feature policy='require' name='xsaves'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='invtsc'/> <feature policy='require' name='ibpb'/> <feature policy='require' name='amd-ssbd'/> <feature policy='require' name='skip-l1dfl-vmentry'/> </mode> <mode name='custom' supported='yes'> <model usable='yes'>qemu64</model> <model usable='yes'>qemu32</model> <model usable='no'>phenom</model> <model usable='yes'>pentium3</model> <model usable='yes'>pentium2</model> <model usable='yes'>pentium</model> <model usable='yes'>n270</model> <model usable='yes'>kvm64</model> <model usable='yes'>kvm32</model> <model usable='yes'>coreduo</model> <model usable='yes'>core2duo</model> <model usable='no'>athlon</model> <model usable='yes'>Westmere-IBRS</model> <model usable='yes'>Westmere</model> <model usable='no'>Skylake-Server-IBRS</model> <model usable='no'>Skylake-Server</model> <model usable='yes'>Skylake-Client-IBRS</model> <model usable='yes'>Skylake-Client</model> <model usable='yes'>SandyBridge-IBRS</model> <model usable='yes'>SandyBridge</model> <model usable='yes'>Penryn</model> <model usable='no'>Opteron_G5</model> <model usable='no'>Opteron_G4</model> <model usable='no'>Opteron_G3</model> <model usable='yes'>Opteron_G2</model> <model usable='yes'>Opteron_G1</model> <model usable='yes'>Nehalem-IBRS</model> <model usable='yes'>Nehalem</model> <model usable='yes'>IvyBridge-IBRS</model> <model usable='yes'>IvyBridge</model> <model usable='no'>Icelake-Server</model> <model usable='no'>Icelake-Client</model> <model usable='yes'>Haswell-noTSX-IBRS</model> <model usable='yes'>Haswell-noTSX</model> <model usable='yes'>Haswell-IBRS</model> <model usable='yes'>Haswell</model> <model usable='no'>EPYC-IBPB</model> <model usable='no'>EPYC</model> <model usable='no'>Dhyana</model> <model usable='yes'>Conroe</model> <model usable='no'>Cascadelake-Server</model> <model usable='yes'>Broadwell-noTSX-IBRS</model> <model usable='yes'>Broadwell-noTSX</model> <model usable='yes'>Broadwell-IBRS</model> <model usable='yes'>Broadwell</model> <model usable='yes'>486</model> </mode> </cpu> *Here is the lscpu of my physical machine* # lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 94 Model name: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz Stepping: 3 CPU MHz: 954.588 CPU max MHz: 3600.0000 CPU min MHz: 800.0000 BogoMIPS: 6399.96 Virtualization: VT-x L1d cache: 128 KiB L1i cache: 128 KiB L2 cache: 1 MiB L3 cache: 6 MiB NUMA node0 CPU(s): 0-3 Vulnerability Itlb multihit: KVM: Mitigation: Split huge pages Vulnerability L1tf: Mitigation; PTE Inversion; VMX conditional cache flushes, SMT disabled Vulnerability Mds: Mitigation; Clear CPU buffers; SMT disabled Vulnerability Meltdown: Mitigation; PTI Vulnerability Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl and seccomp Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Vulnerability Spectre v2: Mitigation; Full generic retpoline, IBPB conditional, IBRS_FW, STIBP disabled, RSB filling Vulnerability Srbds: Vulnerable: No microcode Vulnerability Tsx async abort: Mitigation; Clear CPU buffers; SMT disabled 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 constan t_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm *mpx* rdseed adx smap clflushopt in tel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp md_clear flush_l1d *Here is the CPU part from virsh dumpxml of my ovirt hypervisor* <cpu mode='custom' match='exact' check='full'> <model fallback='forbid'>Skylake-Client-IBRS</model> <vendor>Intel</vendor> <feature policy='require' name='ss'/> <feature policy='require' name='vmx'/> <feature policy='require' name='pdcm'/> <feature policy='require' name='hypervisor'/> <feature policy='require' name='tsc_adjust'/> <feature policy='require' name='clflushopt'/> <feature policy='require' name='umip'/> <feature policy='require' name='md-clear'/> <feature policy='require' name='stibp'/> <feature policy='require' name='arch-capabilities'/> <feature policy='require' name='ssbd'/> <feature policy='require' name='xsaves'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='ibpb'/> <feature policy='require' name='amd-ssbd'/> <feature policy='require' name='skip-l1dfl-vmentry'/> <feature policy='disable' name='mpx'/> </cpu> *Here is the lcpu of my ovirt hypervisor* [root@node1 ~]# lscpu Architecture : x86_64 Mode(s) opératoire(s) des processeurs : 32-bit, 64-bit Boutisme : Little Endian Processeur(s) : 4 Liste de processeur(s) en ligne : 0-3 Thread(s) par cœur : 1 Cœur(s) par socket : 1 Socket(s) : 4 Nœud(s) NUMA : 1 Identifiant constructeur : GenuineIntel Famille de processeur : 6 Modèle : 94 Nom de modèle : Intel Core Processor (Skylake, IBRS) Révision : 3 Vitesse du processeur en MHz : 3191.998 BogoMIPS : 6383.99 Virtualisation : VT-x Constructeur d'hyperviseur : KVM Type de virtualisation : complet Cache L1d : 32K Cache L1i : 32K Cache L2 : 4096K Cache L3 : 16384K Nœud NUMA 0 de processeur(s) : 0-3 Drapaux : 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 rdtscp lm constant_tsc rep_go od nopl xtopology cpuid tsc_known_freq pni pclmulqdq vmx ssse3 fma cx16 pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnow prefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm rdseed adx smap clflushopt xs aveopt xsavec xgetbv1 xsaves arat umip md_clear arch_capabilities it seems not all the flags are presented to the hypervisor especially the mpx which causes the error Is there a workaround for this? Regards.