From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 2/2] x86 emulator: Add into, int, and int3 instructions
 (opcodes 0xcc-0xce)
Date: Wed, 04 Aug 2010 09:21:43 +0300
Message-ID: <4C5906F7.6020009@redhat.com>
References: <1280889892-25751-1-git-send-email-m.gamal005@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: mtosatti@redhat.com, kvm@vger.kernel.org
To: Mohammed Gamal <m.gamal005@gmail.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from mx1.redhat.com ([209.132.183.28]:53998 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1758284Ab0HDGVs (ORCPT <rfc822;kvm@vger.kernel.org>);
	Wed, 4 Aug 2010 02:21:48 -0400
In-Reply-To: <1280889892-25751-1-git-send-email-m.gamal005@gmail.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

  On 08/04/2010 05:44 AM, Mohammed Gamal wrote:
> This adds support for int instructions to the emulator
>
> @@ -2963,6 +3025,21 @@ special_insn:
>   		if (rc != X86EMUL_CONTINUE)
>   			goto done;
>   		break;
> +	case 0xcc:		/* int3 */
> +		irq = 3;
> +		goto do_interrupt;
> +	case 0xcd:		/* int n */
> +		irq = c->src.val;
> +	do_interrupt:
> +		rc = emulate_int(ctxt, ops, irq);
> +		if (rc != X86EMUL_CONTINUE)
> +			goto done;
> +		break;
> +	case 0xce:		/* into */
> +		if (ctxt->eflags&  EFLG_OF) {
> +			irq = 4;
> +			goto do_interrupt;
> +		}

If OF is clear, you fall through and emulate an IRET.

>   	case 0xcf:		/* iret */
>   		rc = emulate_iret(ctxt, ops);
>


-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.