1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 =============== 3 ===============
4 ACRN CPUID bits 4 ACRN CPUID bits
5 =============== 5 ===============
6 6
7 A guest VM running on an ACRN hypervisor can c 7 A guest VM running on an ACRN hypervisor can check some of its features using
8 CPUID. 8 CPUID.
9 9
10 ACRN cpuid functions are: 10 ACRN cpuid functions are:
11 11
12 function: 0x40000000 12 function: 0x40000000
13 13
14 returns:: 14 returns::
15 15
16 eax = 0x40000010 16 eax = 0x40000010
17 ebx = 0x4e524341 17 ebx = 0x4e524341
18 ecx = 0x4e524341 18 ecx = 0x4e524341
19 edx = 0x4e524341 19 edx = 0x4e524341
20 20
21 Note that this value in ebx, ecx and edx corre 21 Note that this value in ebx, ecx and edx corresponds to the string
22 "ACRNACRNACRN". The value in eax corresponds t 22 "ACRNACRNACRN". The value in eax corresponds to the maximum cpuid function
23 present in this leaf, and will be updated if m 23 present in this leaf, and will be updated if more functions are added in the
24 future. 24 future.
25 25
26 function: define ACRN_CPUID_FEATURES (0x400000 26 function: define ACRN_CPUID_FEATURES (0x40000001)
27 27
28 returns:: 28 returns::
29 29
30 ebx, ecx, edx 30 ebx, ecx, edx
31 eax = an OR'ed group of (1 << flag) 31 eax = an OR'ed group of (1 << flag)
32 32
33 where ``flag`` is defined as below: 33 where ``flag`` is defined as below:
34 34
35 ================================= =========== 35 ================================= =========== ================================
36 flag value 36 flag value meaning
37 ================================= =========== 37 ================================= =========== ================================
38 ACRN_FEATURE_PRIVILEGED_VM 0 38 ACRN_FEATURE_PRIVILEGED_VM 0 guest VM is a privileged VM
39 ================================= =========== 39 ================================= =========== ================================
40 40
41 function: 0x40000010 41 function: 0x40000010
42 42
43 returns:: 43 returns::
44 44
45 ebx, ecx, edx 45 ebx, ecx, edx
46 eax = (Virtual) TSC frequency in kHz 46 eax = (Virtual) TSC frequency in kHz.
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