arch/x86/cpuinfo.rst

1 .. SPDX-License-Identifier: GPL-2.0
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42 displayed accordingly in /proc/cpuinfo. For example, the flag "avx2"
45 b: Flags can be from scattered CPUID-based features.
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48 software-defined values. Still, CPUID needs to be queried to determine
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89 X86_FEATURE_<name> in cpufeatures.h. For example, the flag "avx2" is from
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95 double-quote character (""), the string inside the double-quote characters
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125 c: The kernel disabled support for it at compile-time.
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127 For example, if 5-level-paging is not enabled when building (i.e.,
132 d: The feature is disabled at boot-time.
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134 A feature can be disabled either using a command-line parameter or because
135 it failed to be enabled. The command-line parameter clearcpuid= can be used
136 to disable features using the feature number as defined in
141 In addition, there exists a variety of custom command-line parameters that
142 disable specific features. The list of parameters includes, but is not limited
143 to, nofsgsbase, nosgx, noxsave, etc. 5-level paging can also be disabled using
146 e: The feature was known to be non-functional.
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148 The feature was known to be non-functional because a dependency was
154 .. [#f1] 5-level paging uses linear address of 57 bits.