scripts/cpu-x86-uarch-abi.py

   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
   9 from qemu.aqmp.legacy import QEMUMonitorProtocol
  10 import sys
  11
  12 if len(sys.argv) != 2:
  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
  20 levels = [
  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
  68 sock = sys.argv[1]
  69 shell = QEMUMonitorProtocol(sock)
  70 shell.connect()
  71
  72 models = shell.cmd("query-cpu-definitions")
  73
  74 # These QMP props don't correspond to CPUID fatures
  75 # so ignore them
  76 skip = [
  77     "family",
  78     "min-level",
  79     "min-xlevel",
  80     "vendor",
  81     "model",
  82     "model-id",
  83     "stepping",
  84 ]
  85
  86 names = []
  87
  88 for model in models["return"]:
  89     if "alias-of" in model:
  90         continue
  91     names.append(model["name"])
  92
  93 models = {}
  94
  95 for name in sorted(names):
  96     cpu = shell.cmd("query-cpu-model-expansion",
  97                      { "type": "static",
  98                        "model": { "name": name }})
  99
 100     got = {}
 101     for (feature, present) in cpu["return"]["model"]["props"].items():
 102         if present and feature not in skip:
 103             got[feature] = True
 104
 105     if name in ["host", "max", "base"]:
 106         continue
 107
 108     models[name] = {
 109         # Dict of all present features in this CPU model
 110         "features": got,
 111
 112         # Whether each x86-64 ABI level is satisfied
 113         "levels": [False, False, False, False],
 114
 115         # Number of extra CPUID features compared to the x86-64 ABI level
 116         "distance":[-1, -1, -1, -1],
 117
 118         # CPUID features present in model, but not in ABI level
 119         "delta":[[], [], [], []],
 120
 121         # CPUID features in ABI level but not present in model
 122         "missing": [[], [], [], []],
 123     }
 124
 125
 126 # Calculate whether the CPU models satisfy each ABI level
 127 for name in models.keys():
 128     for level in range(len(levels)):
 129         got = set(models[name]["features"])
 130         want = set(levels[level])
 131         missing = want - got
 132         match = True
 133         if len(missing) > 0:
 134             match = False
 135         models[name]["levels"][level] = match
 136         models[name]["missing"][level] = missing
 137
 138 # Cache list of CPU models satisfying each ABI level
 139 abi_models = [
 140     [],
 141     [],
 142     [],
 143     [],
 144 ]
 145
 146 for name in models.keys():
 147     for level in range(len(levels)):
 148         if models[name]["levels"][level]:
 149             abi_models[level].append(name)
 150
 151
 152 for level in range(len(abi_models)):
 153     # Find the union of features in all CPU models satisfying this ABI
 154     allfeatures = {}
 155     for name in abi_models[level]:
 156         for feat in models[name]["features"]:
 157             allfeatures[feat] = True
 158
 159     # Find the intersection of features in all CPU models satisfying this ABI
 160     commonfeatures = []
 161     for feat in allfeatures:
 162         present = True
 163         for name in models.keys():
 164             if not models[name]["levels"][level]:
 165                 continue
 166             if feat not in models[name]["features"]:
 167                 present = False
 168         if present:
 169             commonfeatures.append(feat)
 170
 171     # Determine how many extra features are present compared to the lowest
 172     # common denominator
 173     for name in models.keys():
 174         if not models[name]["levels"][level]:
 175             continue
 176
 177         delta = set(models[name]["features"].keys()) - set(commonfeatures)
 178         models[name]["distance"][level] = len(delta)
 179         models[name]["delta"][level] = delta
 180
 181 def print_uarch_abi_csv():
 182     print("# Automatically generated from '%s'" % __file__)
 183     print("Model,baseline,v2,v3,v4")
 184     for name in models.keys():
 185         print(name, end="")
 186         for level in range(len(levels)):
 187             if models[name]["levels"][level]:
 188                 print(",✅", end="")
 189             else:
 190                 print(",", end="")
 191         print()
 192
 193 print_uarch_abi_csv()