knowing hosts type and understanding flags

knowing hosts type and understanding flags

For sure, learning from internet, but trying to make it over here, so my search will be less sometime :)

Links:

https://en.wikipedia.org/wiki/CPUID#EAX.3D1:_Processor_Info_and_Feature_Bits

To know if the OS is running on VM or Bare Metal:

# grep for "hypervisor" in /proc/cpuinfo

# grep hypervisor /proc/cpuinfo
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq ssse3 cx16 sse4_1 sse4_2 popcnt aes xsave avx hypervisor lahf_lm ida arat epb pln pts dtherm

https://unix.stackexchange.com/questions/43539/what-do-the-flags-in-proc-cpuinfo-mean

• 64-bit (x86_64/AMD64/Intel64)? lm
• Hardware virtualization (VMX/AMD-V)? vmx (Intel), svm (AMD)
• Accelerated AES (AES-NI)? aes
• TXT (TPM)? smx
• a hypervisor (announced as such)? hypervisor

Most of the other features are only of interest to compiler or kernel authors.

The full listing is in the kernel source, in the file arch/x86/include/asm/cpufeatures.h.

Intel-defined CPU features, CPUID level 0x00000001 (edx)