From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49922) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YOPLT-0004kQ-Kn for qemu-devel@nongnu.org; Thu, 19 Feb 2015 06:32:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YOPLQ-0000IU-FQ for qemu-devel@nongnu.org; Thu, 19 Feb 2015 06:32:39 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:58319) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YOPLQ-0000IG-7P for qemu-devel@nongnu.org; Thu, 19 Feb 2015 06:32:36 -0500 Message-ID: <54E5C9D0.6010700@imgtec.com> Date: Thu, 19 Feb 2015 11:32:32 +0000 From: Leon Alrae MIME-Version: 1.0 References: <1422288626-6595-1-git-send-email-leon.alrae@imgtec.com> In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] target-mips: fix CP0.BadVAddr by stopping translation on Address error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Maciej W. Rozycki" Cc: qemu-devel@nongnu.org, aurelien@aurel32.net On 28/01/2015 00:39, Maciej W. Rozycki wrote: > On Mon, 26 Jan 2015, Leon Alrae wrote: >=20 >> BadVAddr is supposed to capture the most recent address that caused >> the exception. Currently this is not happening as translation is not s= topped >> and BadVAddr is updated with subsequent addresses. >> >> Signed-off-by: Leon Alrae >> --- >=20 > I think this deserves a better description as it is about the specific= =20 > case of an unaligned standard MIPS instruction fetch. Address Error=20 > exceptions can also happen for other reasons: unaligned data accesses o= r=20 > any accesses outside memory segments the current execution mode is allo= wed=20 > to reach. I believe that the one line change in the patch makes that clear. I agree however that the description itself could be more precise. > While at it I think it may be worth double-checking if the other place= s=20 > that trigger this exception get it right. Other places seem to look fine. Even decode_micromips_opc handles it correctly whereas decode_opc -=96 which obviously was implemented before microMIPS -- never got fixed. Regards, Leon