Back at the time I failed to pay attention to op_bytes still being zero
when reaching the respective case block: With the ext0f38_table[]
entries having simd_packed_int, the defaulting at the bottom of
x86emul_decode() won't set the field to non-zero for F3-prefixed insns.
Fixes: 37ccca740c26 ("x86emul: support AVX512CD insns")
Signed-off-by: Jan Beulich <[email protected]>
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -5929,6 +5929,7 @@ x86_emulate(
evex.w == ((b >> 4) & 1)),
X86_EXC_UD);
d |= TwoOp;
+ op_bytes = 1; /* fake */
/* fall through */
case X86EMUL_OPC_EVEX_66(0x0f38, 0xc4): /* vpconflict{d,q}
[xyz]mm/mem,[xyz]mm{k} */
fault_suppression = false;