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| author | Chang S. Bae <chang.seok.bae@intel.com> | 2025-11-13 19:36:31 -0500 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-11-19 14:36:38 -0800 |
| commit | 825f0aece084ecde02805083d44d08ab189a9249 (patch) | |
| tree | cb836c92619da4ccf7bbd6f9eb781bd24f669e8c /tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c | |
| parent | 4cb21be4c3b0cb6248da1dcc4f19f05d3443a235 (diff) | |
KVM: x86: Refactor REX prefix handling in instruction emulation
Restructure how to represent and interpret REX fields, preparing
for handling of both REX2 and VEX.
REX uses the upper four bits of a single byte as a fixed identifier,
and the lower four bits containing the data. VEX and REX2 extends this so
that the first byte identifies the prefix and the rest encode additional
bits; and while VEX only has the same four data bits as REX, eight zero
bits are a valid value for the data bits of REX2. So, stop storing the
REX byte as-is. Instead, store only the low bits of the REX prefix and
track separately whether a REX-like prefix was used.
No functional changes intended.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Message-ID: <20251110180131.28264-11-chang.seok.bae@intel.com>
[Extracted from APX series; removed bitfields and REX2-specific default. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://patch.msgid.link/20251114003633.60689-9-pbonzini@redhat.com
[sean: name REX_{BXRW} enum "rex_bits"]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/stacktrace_ips.c')
0 files changed, 0 insertions, 0 deletions