xref: /openbmc/qemu/scripts/cpu-x86-uarch-abi.py (revision 65d1a2bd) 
1#!/usr/bin/python3
2#
3# SPDX-License-Identifier: GPL-2.0-or-later
4#
5# A script to generate a CSV file showing the x86_64 ABI
6# compatibility levels for each CPU model.
7#
8
9from qemu import qmp
10import sys
11
12if len(sys.argv) != 1:
13    print("syntax: %s QMP-SOCK\n\n" % __file__ +
14          "Where QMP-SOCK points to a QEMU process such as\n\n" +
15          " # qemu-system-x86_64 -qmp unix:/tmp/qmp,server,nowait " +
16          "-display none -accel kvm", file=sys.stderr)
17    sys.exit(1)
18
19# Mandatory CPUID features for each microarch ABI level
20levels = [
21    [ # x86-64 baseline
22        "cmov",
23        "cx8",
24        "fpu",
25        "fxsr",
26        "mmx",
27        "syscall",
28        "sse",
29        "sse2",
30    ],
31    [ # x86-64-v2
32        "cx16",
33        "lahf-lm",
34        "popcnt",
35        "pni",
36        "sse4.1",
37        "sse4.2",
38        "ssse3",
39    ],
40    [ # x86-64-v3
41        "avx",
42        "avx2",
43        "bmi1",
44        "bmi2",
45        "f16c",
46        "fma",
47        "abm",
48        "movbe",
49    ],
50    [ # x86-64-v4
51        "avx512f",
52        "avx512bw",
53        "avx512cd",
54        "avx512dq",
55        "avx512vl",
56    ],
57]
58
59# Assumes externally launched process such as
60#
61#   qemu-system-x86_64 -qmp unix:/tmp/qmp,server,nowait -display none -accel kvm
62#
63# Note different results will be obtained with TCG, as
64# TCG masks out certain features otherwise present in
65# the CPU model definitions, as does KVM.
66
67
68sock = sys.argv[1]
69cmd = sys.argv[2]
70shell = qmp.QEMUMonitorProtocol(sock)
71shell.connect()
72
73models = shell.cmd("query-cpu-definitions")
74
75# These QMP props don't correspond to CPUID fatures
76# so ignore them
77skip = [
78    "family",
79    "min-level",
80    "min-xlevel",
81    "vendor",
82    "model",
83    "model-id",
84    "stepping",
85]
86
87names = []
88
89for model in models["return"]:
90    if "alias-of" in model:
91        continue
92    names.append(model["name"])
93
94models = {}
95
96for name in sorted(names):
97    cpu = shell.cmd("query-cpu-model-expansion",
98                     { "type": "static",
99                       "model": { "name": name }})
100
101    got = {}
102    for (feature, present) in cpu["return"]["model"]["props"].items():
103        if present and feature not in skip:
104            got[feature] = True
105
106    if name in ["host", "max", "base"]:
107        continue
108
109    models[name] = {
110        # Dict of all present features in this CPU model
111        "features": got,
112
113        # Whether each x86-64 ABI level is satisfied
114        "levels": [False, False, False, False],
115
116        # Number of extra CPUID features compared to the x86-64 ABI level
117        "distance":[-1, -1, -1, -1],
118
119        # CPUID features present in model, but not in ABI level
120        "delta":[[], [], [], []],
121
122        # CPUID features in ABI level but not present in model
123        "missing": [[], [], [], []],
124    }
125
126
127# Calculate whether the CPU models satisfy each ABI level
128for name in models.keys():
129    for level in range(len(levels)):
130        got = set(models[name]["features"])
131        want = set(levels[level])
132        missing = want - got
133        match = True
134        if len(missing) > 0:
135            match = False
136        models[name]["levels"][level] = match
137        models[name]["missing"][level] = missing
138
139# Cache list of CPU models satisfying each ABI level
140abi_models = [
141    [],
142    [],
143    [],
144    [],
145]
146
147for name in models.keys():
148    for level in range(len(levels)):
149        if models[name]["levels"][level]:
150            abi_models[level].append(name)
151
152
153for level in range(len(abi_models)):
154    # Find the union of features in all CPU models satisfying this ABI
155    allfeatures = {}
156    for name in abi_models[level]:
157        for feat in models[name]["features"]:
158            allfeatures[feat] = True
159
160    # Find the intersection of features in all CPU models satisfying this ABI
161    commonfeatures = []
162    for feat in allfeatures:
163        present = True
164        for name in models.keys():
165            if not models[name]["levels"][level]:
166                continue
167            if feat not in models[name]["features"]:
168                present = False
169        if present:
170            commonfeatures.append(feat)
171
172    # Determine how many extra features are present compared to the lowest
173    # common denominator
174    for name in models.keys():
175        if not models[name]["levels"][level]:
176            continue
177
178        delta = set(models[name]["features"].keys()) - set(commonfeatures)
179        models[name]["distance"][level] = len(delta)
180        models[name]["delta"][level] = delta
181
182def print_uarch_abi_csv():
183    print("# Automatically generated from '%s'" % __file__)
184    print("Model,baseline,v2,v3,v4")
185    for name in models.keys():
186        print(name, end="")
187        for level in range(len(levels)):
188            if models[name]["levels"][level]:
189                print(",✅", end="")
190            else:
191                print(",", end="")
192        print()
193
194print_uarch_abi_csv()
195