From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34145) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eGlXH-0006mb-Ie for qemu-devel@nongnu.org; Mon, 20 Nov 2017 07:50:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eGlXF-0007EM-TI for qemu-devel@nongnu.org; Mon, 20 Nov 2017 07:50:51 -0500 Received: from mail-wr0-x244.google.com ([2a00:1450:400c:c0c::244]:45878) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eGlXF-0007E8-MS for qemu-devel@nongnu.org; Mon, 20 Nov 2017 07:50:49 -0500 Received: by mail-wr0-x244.google.com with SMTP id a63so7952706wrc.12 for ; Mon, 20 Nov 2017 04:50:49 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <20171116115926.16627-1-pbonzini@redhat.com> <20171116115926.16627-8-pbonzini@redhat.com> <001b01d361e9$d46ace40$7d406ac0$@ru> From: Peter Maydell Date: Mon, 20 Nov 2017 12:50:27 +0000 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [PULL 07/11] cpu-exec: don't overwrite exception_index List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk Cc: Paolo Bonzini , QEMU Developers , Pavel Dovgalyuk On 20 November 2017 at 11:06, Peter Maydell wrote: > On 20 November 2017 at 10:25, Pavel Dovgalyuk wrote: >>> From: Peter Maydell [mailto:peter.maydell@linaro.org] >>> On 17 November 2017 at 20:26, Paolo Bonzini wrote: >>> > On 17/11/2017 21:07, Peter Maydell wrote: >>> >> Hi. This commit breaks booting of Debian on aarch64 virt board. >>> >> (repro instructions for creating the image available at: >>> >> https://translatedcode.wordpress.com/2017/07/24/installing-debian-on-qemus-64-bit-arm-virt- >>> board/) >>> >> The guest kernel never prints anything to the serial port. >>> >> >>> >> Reverting this commit fixes master for me, so I plan to do >>> >> that on Monday. >>> > >>> > Maybe you can also test moving the atomic_set inside the "if". It does >>> > seem to be a genuine bugfix. >>> >>> No, that doesn't help: guest still sits there like a lemon. >> >> Maybe this is a more complex problem? >> I tried removing this if and aarch64 still does not work. > > Reverting the commit fixes it for me; I have that going through > build tests and will push the revert later today. Revert pushed to git master. More generally, this commit seems to assume that QEMU always does: * set exception_index to something * handle that * clear exception_index to -1 but it's not clear to me that it's actually always the case that it gets cleared back to -1. thanks -- PMM