[Qemu-devel] [PULL 20/20] Add missing bit for SSE instr in VEX decoding

Paolo Bonzini posted 20 patches 7 years, 10 months ago
There is a newer version of this series
[Qemu-devel] [PULL 20/20] Add missing bit for SSE instr in VEX decoding
Posted by Paolo Bonzini 7 years, 10 months ago
From: Eugene Minibaev <mail@kitsu.me>

The 2-byte VEX prefix imples a leading 0Fh opcode byte.

Signed-off-by: Eugene Minibaev <mail@kitsu.me>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/translate.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/i386/translate.c b/target/i386/translate.c
index 3b7ce92..c9ed8dc 100644
--- a/target/i386/translate.c
+++ b/target/i386/translate.c
@@ -4563,9 +4563,11 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
 #endif
             rex_r = (~vex2 >> 4) & 8;
             if (b == 0xc5) {
+                /* 2-byte VEX prefix: RVVVVlpp, implied 0f leading opcode byte */
                 vex3 = vex2;
-                b = x86_ldub_code(env, s);
+                b = x86_ldub_code(env, s) | 0x100;
             } else {
+                /* 3-byte VEX prefix: RXBmmmmm wVVVVlpp */
 #ifdef TARGET_X86_64
                 s->rex_x = (~vex2 >> 3) & 8;
                 s->rex_b = (~vex2 >> 2) & 8;
-- 
1.8.3.1