Addresses issue #336: when running inside a VM (KVM, VMware, ESXi,
Hyper-V, VirtualBox), the hypervisor can present a fake CPUID and
microcode version to the guest, making the microcode up-to-date check
meaningless or misleading.
Changes:
- Add is_running_as_guest() to 370_hw_vmm.sh: detects VM guest status
by checking for the 'hypervisor' CPUID flag in /proc/cpuinfo, which
is exposed by KVM, VMware, Hyper-V, VirtualBox and most other
hypervisors. Result is cached in g_is_guest_vm / g_is_guest_vm_reason.
- Add "Running as VM guest: YES/NO" line to the CPU details block in
check_cpu() (400_hw_check.sh), shown for both x86 and ARM guests.
- Add a pr_warn block after the microcode-is-latest check in check_cpu()
advising the user to verify microcode information on the hypervisor
host when a VM guest is detected.
- Add minimal ARM CPU details block in check_cpu(): vendor, model name,
implementer(s), part(s), architecture(s), and VM guest status. ARM CPUs
previously got no output from check_cpu() due to the x86-only early
return guard.
- Expose guest VM status in JSON output (250_output_emitters.sh):
- system section: guest_vm (bool) and guest_vm_reason (string)
- cpu_microcode section: unreliable_in_vm (bool)
Stéphane Lesimple