Re: [PATCH] x86 emulator: Add in/out instructions, opcodes (0xe4-0xe7, 0xec-0xef)

[Avi Kivity <avi@qumranet.com>]

Mohammed Gamal wrote:
> This patch adds instructions 'in' and 'out' to the x86 emulator.
> 

> +	SrcNone | ByteOp | ImplicitOps, SrcNone |ImplicitOps,

Missing blank.



>  	case 0xe8: /* call (near) */ {
>  		long int rel;
>  		switch (c->op_bytes) {
> @@ -1732,6 +1744,26 @@ special_insn:
>  		jmp_rel(c, c->src.val);
>  		c->dst.type = OP_NONE; /* Disable writeback. */
>  		break;
> +	case 0xec: /* in al,dx */
> +	case 0xed: /* in (e/r)ax,dx */
> +		port = c->regs[VCPU_REGS_RDX];
> +	in:	if(kvm_emulate_pio(ctxt->vcpu, NULL, 1,

missing blank.

> +				   (c->d & ByteOp) ? 1 : c->op_bytes,
> +				   port) != 0) { 
> +			c->eip = saved_eip;
> +			return -1;
> +		}
> +		return 0;
> +	case 0xee: /* out al,dx */
> +	case 0xef: /* out (e/r)ax,dx */
> +		port = c->regs[VCPU_REGS_RDX];
> +	out:	if(kvm_emulate_pio(ctxt->vcpu, NULL, 0,
> +				   (c->d & ByteOp) ? 1 : c->op_bytes,
> +				   port) != 0) { 
> +			c->eip = saved_eip;
> +			return -1;


goto cannot_emulate?

> +		}
> +		return 0;

It would be simpler to fold the in and out implementations together (and 
extract the direction flag from the instruction byte).