diff options
author | Liam Ni <zhiguangni01@gmail.com> | 2022-09-08 17:12:10 +0300 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-09-26 19:02:34 +0300 |
commit | e390f4d69da026149c8c80a7a2218e166d5643fc (patch) | |
tree | f2ddbf327ce12e43410d6061c9ee58295a244f36 | |
parent | 02dfc44f205772f0edc0d8e58420205c1cf2f83b (diff) | |
download | linux-e390f4d69da026149c8c80a7a2218e166d5643fc.tar.xz |
KVM:x86: Clean up ModR/M "reg" initialization in reg op decoding
Refactor decode_register_operand() to get the ModR/M register if and
only if the instruction uses a ModR/M encoding to make it more obvious
how the register operand is retrieved.
Signed-off-by: Liam Ni <zhiguangni01@gmail.com>
Link: https://lore.kernel.org/r/20220908141210.1375828-1-zhiguangni01@zhaoxin.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | arch/x86/kvm/emulate.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 08dbcff4045a..9367aaaacdf9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1137,9 +1137,11 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt) static void decode_register_operand(struct x86_emulate_ctxt *ctxt, struct operand *op) { - unsigned reg = ctxt->modrm_reg; + unsigned int reg; - if (!(ctxt->d & ModRM)) + if (ctxt->d & ModRM) + reg = ctxt->modrm_reg; + else reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); if (ctxt->d & Sse) { |