Ubuntu - KVM - Check Hardware Virtualization Support

KVM requires either Intel processor with VT-x (virtualization technology extension) or AMD processor with AMD-V (AMD4 Virtualization extension).

egrep '(vmx|svm)' /proc/cpuinfo

If it results in output like this:

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 art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx 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 epb invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp md_clear flush_l1d

NOTE: The CPU is able to run KVM virtual machines, as either svm or vmx is shown.

svm stands for Secure Virtual Machine.
- AMD virtualization extension support.

vmx stands for Virtual Machine Extensions.
- (Intel) Processor support for virtualization.

Check using count

egrep -c '(vmx|svm)' /proc/cpuinfo

returns:

NOTE: If this returns more than zero then Virtualization is supported.

If the output is zero it could be that Virtualization is not enabled in the BIOS.
In this case, restart the machine and go to the BIOS settings and enable Virtualization.