From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56120) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dMevj-00077S-Mw for qemu-devel@nongnu.org; Sun, 18 Jun 2017 14:28:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dMevg-0004nR-Gv for qemu-devel@nongnu.org; Sun, 18 Jun 2017 14:28:11 -0400 Received: from mx.treblig.org ([80.68.94.177]:46041) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dMevg-0004lO-5i for qemu-devel@nongnu.org; Sun, 18 Jun 2017 14:28:08 -0400 Date: Sun, 18 Jun 2017 19:27:56 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170618182756.GB5215@gallifrey> References: <5d090b82-dae7-ac67-a032-92c2e776b70f@univention.de> <2e7e9fe3-e603-d75f-84c6-d0fb048266da@redhat.com> <58d3a273-e857-fe9e-0b1e-a4aca4aa54ef@univention.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58d3a273-e857-fe9e-0b1e-a4aca4aa54ef@univention.de> Subject: Re: [Qemu-devel] [RFH] qemu-2.6 memory corruption with OVMF and linux-4.9 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philipp Hahn Cc: Laszlo Ersek , qemu-devel@nongnu.org, "linux-kernel@vger.kernel.org" , Peter Jones , linux-fbdev@vger.kernel.org * Philipp Hahn (hahn@univention.de) wrote: > Hello, > > Am 17.06.2017 um 18:51 schrieb Laszlo Ersek: > > (I also recommend using the "vbindiff" tool for such problems, it is > > great for picking out patterns.) > > > > ** ** ** ** ** ** ** ** 8 9 ** ** ** 13 14 15 > > -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 00000000 01 e8 00 00 00 00 00 00 8c 5e 00 00 00 10 ff f1 > > 00000010 5b 78 8a 3e 00 00 00 00 00 00 00 00 00 00 00 00 > > 00000020 8c 77 00 00 00 12 00 02 18 f0 00 00 00 00 00 00 > > 00000030 00 1e 00 00 00 00 00 00 8c 8c 00 00 00 12 00 02 > > 00000040 07 70 00 00 00 00 00 00 00 14 00 00 00 00 00 00 > > 00000050 8c 9c 00 00 00 12 00 02 22 00 00 00 00 00 00 00 > > 00000060 00 40 00 00 00 00 00 00 8c ac 00 00 00 10 ff f1 > > > > 00000000 01 e8 00 00 00 00 00 00 00 3c 00 00 00 17 00 00 > > 00000010 5b 78 8a 3e 00 00 00 00 00 3c 00 00 00 07 00 00 > > 00000020 8c 77 00 00 00 12 00 02 00 3c 00 00 00 07 00 00 > > 00000030 00 1e 00 00 00 00 00 00 00 3c 00 00 00 17 00 00 > > 00000040 07 70 00 00 00 00 00 00 00 3c 00 00 00 07 00 00 > > 00000050 8c 9c 00 00 00 12 00 02 00 3c 00 00 00 07 00 00 > > 00000060 00 40 00 00 00 00 00 00 00 3c 00 00 00 17 00 00 > > -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > ** ** ** ** ** ** ** ** 8 9 ** ** ** 13 14 15 > > > > The columns that I marked with "**" are identical between "good" and > > "bad". (These are columns 0-7, 10-12.) > > > > Column 8 is overwritten by zeros (every 16th byte). > > > > Column 9 is overwritten by 0x3c (every 16th byte). > > > > Column 13 is super interesting. The most significant nibble in that > > column is not disturbed. And, in the least significant nibble, the least > > significant three bits are turned on. Basically, the corruption could be > > described, for this column (i.e., every 16th byte), as > > > > bad = good | 0x7 > > > > Column 14 is overwritten by zeros (every 16th byte). > > > > Column 15 is overwritten by zeros (every 16th byte). > > > > My take is that your host machine has faulty RAM. Please run memtest86+ > > or something similar. > > I will do so, but for me very unlikely: > - it never happens with BIOS, only with OVMF > - for each test I start q new QEMU process, which should use a different > memory region > - it repeatedly hits e1000 or libata.ko > > After updating from OVMF to 0~20161202.7bbe0b3e-1 from > (0~20160813.de74668f-2 it has not yet happened again. > > Anyway, thank you for your help. What host CPU are you using? Dave > > Philipp -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/