From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abnAk-0007HW-EE for qemu-devel@nongnu.org; Fri, 04 Mar 2016 05:41:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1abnAh-0003NS-32 for qemu-devel@nongnu.org; Fri, 04 Mar 2016 05:41:26 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60604) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1abnAg-0003NO-TS for qemu-devel@nongnu.org; Fri, 04 Mar 2016 05:41:23 -0500 References: <1456983051-14707-1-git-send-email-rth@twiddle.net> <1456983051-14707-5-git-send-email-rth@twiddle.net> <56D7E054.2040703@reactos.org> <56D80D2C.3060706@redhat.com> <56D88B42.7060208@twiddle.net> From: Paolo Bonzini Message-ID: <56D9664E.8070303@redhat.com> Date: Fri, 4 Mar 2016 11:41:18 +0100 MIME-Version: 1.0 In-Reply-To: <56D88B42.7060208@twiddle.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 4/7] target-i386: Dump illegal opcodes with -d unimp List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Richard Henderson , =?UTF-8?Q?Herv=c3=a9_Poussineau?= , qemu-devel@nongnu.org On 03/03/2016 20:06, Richard Henderson wrote: > On 03/03/2016 02:08 AM, Paolo Bonzini wrote: >>> Do you want LOG_UNIMP or LOG_GUEST_ERROR? >> >> I would actually use LOG_IN_ASM. As you noticed, guests sometimes use >> illegal opcodes; another example is Xen's hypercall interface. >> >> On 03/03/2016 07:57, Herv=E9 Poussineau wrote: >>> This patch is not quiet on some operating systems: >>> OS/2: >>> ILLOPC: 000172e1: 0f a6 >>> >>> Windows XP: >>> ILLOPC: 00020d1a: c4 c4 >>> >>> And very verbose in Windows 3.11, Windows 9x: >>> ILLOPC: 000ffb17: 63 >>> ILLOPC: 000ffb17: 63 >>> >>> Is it normal? >> >> Yes, it is. As usual, Raymond Chen explains what's going on: >> >> https://blogs.msdn.microsoft.com/oldnewthing/20041215-00/?p=3D37003 >=20 > Wow. That's... interesting. >=20 > I think maybe I'll re-do the patch to distinguish between those opcodes > that are completely unrecognized (which is what I was expecting to find= ) > and those that raise #UD due to cpu state (e.g. this arpl in vm86 mode)= . Good idea. UD2 should not warn too, and also VEX prefixes outside 64-bit mode. Any thoughts about patch 7? Paolo