From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:60099)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1ZtXMx-00046H-69
	for qemu-devel@nongnu.org; Tue, 03 Nov 2015 03:55:11 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1ZtXMu-0005VX-00
	for qemu-devel@nongnu.org; Tue, 03 Nov 2015 03:55:07 -0500
Received: from mail-lf0-x22b.google.com ([2a00:1450:4010:c07::22b]:33230)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1ZtXMt-0005VS-PY
	for qemu-devel@nongnu.org; Tue, 03 Nov 2015 03:55:03 -0500
Received: by lfbf136 with SMTP id f136so9816559lfb.0
	for <qemu-devel@nongnu.org>; Tue, 03 Nov 2015 00:55:03 -0800 (PST)
References: <1446488173-2621-1-git-send-email-serge.fdrv@gmail.com>
	<CAFEAcA8k7Kp-UOy0FsupqvxtEOCpS+aqOc5-ObUXC9wYzkTv_w@mail.gmail.com>
From: Sergey Fedorov <serge.fdrv@gmail.com>
Message-ID: <56387665.8010904@gmail.com>
Date: Tue, 3 Nov 2015 11:55:01 +0300
MIME-Version: 1.0
In-Reply-To: <CAFEAcA8k7Kp-UOy0FsupqvxtEOCpS+aqOc5-ObUXC9wYzkTv_w@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH] target-arm: Clean up DISAS_UPDATE usage in
 AArch32 translation code
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>

On 02.11.2015 21:29, Peter Maydell wrote:
> On 2 November 2015 at 18:16, Sergey Fedorov <serge.fdrv@gmail.com> wrote:
>> AArch32 translation code does not distinguish between DISAS_UPDATE and
>> DISAS_JUMP. Thus, we cannot use any of them without first updating PC in
>> CPU state. Furthermore, it is too complicated to update PC in CPU state
>> before PC gets updated in disas context. So it is hardly possible to
>> correctly end TB early if is is not likely to be executed before calling
>> disas_*_insn(), e.g. just after calling breakpoint check helper.
>>
>> Modify DISAS_UPDATE and DISAS_JUMP usage in AArch32 translation and
>> apply to them the same semantic as AArch64 translation does:
>>  - DISAS_UPDATE: update PC in CPU state when finishing translation
>>  - DISAS_JUMP:   preserve current PC value in CPU state when finishing
>>                  translation
> Is this fixing the breakpoint related bug? If so the commit message
> should say so. Otherwise it just looks like cleanup...
>
> (I'll review the patch tomorrow.)

Yes it's fixing a bug in breakpoint handling. I'll update the commit
message.

Best,
Sergey