From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50259) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPbFT-0005a3-Jy for qemu-devel@nongnu.org; Thu, 04 Sep 2014 13:55:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPbFN-0007cD-F4 for qemu-devel@nongnu.org; Thu, 04 Sep 2014 13:55:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59923) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPbFN-0007bv-70 for qemu-devel@nongnu.org; Thu, 04 Sep 2014 13:55:01 -0400 Message-ID: <5408A76E.1080501@redhat.com> Date: Thu, 04 Sep 2014 13:54:54 -0400 From: John Snow MIME-Version: 1.0 References: <1408050186-27800-1-git-send-email-jsnow@redhat.com> <20140818131229.GB1273@stefanha-thinkpad.redhat.com> <53F3A366.1010307@redhat.com> <20140820142716.GA3673@stefanha-thinkpad.redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3] ide: Add resize callback to ide/core List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Kevin Wolf , qemu-devel , Markus Armbruster On 09/04/2014 12:13 PM, Stefan Hajnoczi wrote: > This patch seems to break tests/bios-tables-test.c: > ERROR:tests/bios-tables-test.c:744:test_acpi_one: assertion failed > (signature == SIGNATURE): (0x00000000 == 0x0000dead) > GTester: last random seed: R02S3d881198f35228a485b4c3d116dff3b1 > > I have run it many times to make sure the failure is deterministic and > I used git-bisect(1) to find this commit as the cause. > > Not sure why but it seems to break the test. Please take a look. > > Dropped from the block branch. > > Stefan > I've fixed it in a v4, but before I submit and while I'm at it, you didn't like the comments I left in the identify functions because they were "prone to bitrot." would you prefer I excised them entirely? I found them helpful because it makes sense to read these functions alongside the identify data specs, and excising any references to those word indices in their natural order obfuscates the code needlessly. My inclination is to leave them in. Meanwhile, the bios-tables-test problem is such: We serve the identify request out of the io_buffer, not the identify_data cache, thus for 2nd and subsequent requests for identify_data, we get correct size information, but for the 1st request to ide_identify, we get zeroes. I corrected this by making ide_identify and ide_atapi_identify mimic the flow of ide_cfata_identify, which is more clear about the nature of the two buffers. Why this causes a failure here and for only the Q35 machine type I am not certain, but this is the causative bug. --j