From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53499) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XhLKU-0001Y5-Mw for qemu-devel@nongnu.org; Thu, 23 Oct 2014 12:33:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XhLKO-0007Lg-O3 for qemu-devel@nongnu.org; Thu, 23 Oct 2014 12:33:38 -0400 Received: from mail-yh0-x230.google.com ([2607:f8b0:4002:c01::230]:61002) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XhLKO-0007Lc-JZ for qemu-devel@nongnu.org; Thu, 23 Oct 2014 12:33:32 -0400 Received: by mail-yh0-f48.google.com with SMTP id v1so1365873yhn.21 for ; Thu, 23 Oct 2014 09:33:32 -0700 (PDT) Sender: Richard Henderson Message-ID: <54492DD7.90805@twiddle.net> Date: Thu, 23 Oct 2014 09:33:27 -0700 From: Richard Henderson MIME-Version: 1.0 References: <20141021121453.7268.529.stgit@PASHA-ISP> <5449299B.9070902@twiddle.net> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] arm: fix TB alignment check List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: =?UTF-8?B?QWxleCBCZW5uw6ll?= , QEMU Developers , Kirill Batuzov , maria.klimushenkova@ispras.ru, Pavel Dovgalyuk , Paolo Bonzini , =?UTF-8?B?0JTQtdC90LjRgSDQlNC80LjRgtGA0LjQtdCy?= , Leon Alrae On 10/23/2014 09:25 AM, Peter Maydell wrote: > On 23 October 2014 17:15, Richard Henderson wrote: >> [1] Why 32 when the maximum insn size is more like 15 bytes, I don't know. But >> it likely doesn't matter since I'd expect such large TB's to fill up the opcode >> buffer first. There would have to be a lot of nops on that page. > > Do we actually correctly GPF if the guest hands us an instruction > with a huge long set of prefix bytes? I can't see anything obviously > in the code that catches this case... No, I don't think we check for that at all. r~