.. SPDX-License-Identifier: GPL-2.0 =============== ACRN CPUID bits =============== A guest VM running on an ACRN hypervisor can check some of its features using CPUID. ACRN cpuid functions are: function: 0x40000000 returns:: eax = 0x40000010 ebx = 0x4e524341 ecx = 0x4e524341 edx = 0x4e524341 Note that this value in ebx, ecx and edx corresponds to the string "ACRNACRNACRN". The value in eax corresponds to the maximum cpuid function present in this leaf, and will be updated if more functions are added in the future. function: define ACRN_CPUID_FEATURES (0x40000001) returns:: ebx, ecx, edx eax = an OR'ed group of (1 << flag) where ``flag`` is defined as below: ================================= =========== ================================ flag value meaning ================================= =========== ================================ ACRN_FEATURE_PRIVILEGED_VM 0 guest VM is a privileged VM ================================= =========== ================================ function: 0x40000010 returns:: ebx, ecx, edx eax = (Virtual) TSC frequency in kHz.