hv: instr_emul: fix movzx return memory opsize wrong

There're some instructions which not support bit 0(w bit) flag but which
memory opcode size is fixed and the memory opcode size is not equal to the
register opcode size. In our code, there is movzx (which opcode is 0F B7)
which memory opcode size is fixed to 16 bits. So add a flag VIE_OP_F_WORD_OP
to indicate a instruction which memory opcode size is fixed to 16 bits.

Tracked-On: #1337
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>

Author: lifeix

hypervisor/arch/x86/guest/instr_emul.c

@@ -96,6 +96,7 @@
  * FOR NON-64-BIT MODES, Vol 2, Intel SDM.
  */
 #define VIE_OP_F_BYTE_OP	(1U << 5U)  /* 8-bit operands. */
+#define VIE_OP_F_WORD_OP	(1U << 6U)  /* 16-bit operands. */
 
 static const struct instr_emul_vie_op two_byte_opcodes[256] = {
 	[0xB6] = {
@@ -104,6 +105,7 @@ static const struct instr_emul_vie_op two_byte_opcodes[256] = {
 	},
 	[0xB7] = {
 		.op_type = VIE_OP_TYPE_MOVZX,
+		.op_flags = VIE_OP_F_WORD_OP,
 	},
 	[0xBA] = {
 		.op_type = VIE_OP_TYPE_BITTEST,
@@ -2398,8 +2400,13 @@ int32_t decode_instruction(struct acrn_vcpu *vcpu)
 
 			if (retval >= 0) {
 				/* return the Memory Operand byte size */
-				retval = ((emul_ctxt->vie.op.op_flags & VIE_OP_F_BYTE_OP) != 0U) ?
-						1 : (int32_t)emul_ctxt->vie.opsize;
+				if ((emul_ctxt->vie.op.op_flags & VIE_OP_F_BYTE_OP) != 0U) {
+					retval = 1;
+				} else if ((emul_ctxt->vie.op.op_flags & VIE_OP_F_WORD_OP) != 0U) {
+					retval = 2;
+				} else {
+					retval = (int32_t)emul_ctxt->vie.opsize;
+				}
 			}
 		}
 	}