From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40875) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WBE3Y-0006pB-7e for qemu-devel@nongnu.org; Wed, 05 Feb 2014 20:47:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WBE3S-0004fN-8c for qemu-devel@nongnu.org; Wed, 05 Feb 2014 20:47:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45296) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WBE3S-0004f2-13 for qemu-devel@nongnu.org; Wed, 05 Feb 2014 20:47:02 -0500 Message-ID: <52F2E990.7040605@redhat.com> Date: Thu, 06 Feb 2014 02:46:56 +0100 From: Laszlo Ersek MIME-Version: 1.0 References: <20140206011459.1483.59437.malonedeb@wampee.canonical.com> <20140206011459.1483.59437.malonedeb@wampee.canonical.com> In-Reply-To: <20140206011459.1483.59437.malonedeb@wampee.canonical.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Bug 1276879] [NEW] lots of dma command 10, 14 not supported List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bug 1276879 <1276879@bugs.launchpad.net> Cc: qemu-devel@nongnu.org On 02/06/14 02:14, tyler knosis wrote: > Public bug reported: > > Trying to install NeXTSTEP 3.3 onto a 2GB file with QEMU 1.7.0. > In the terminal that started QEMU, there are a lot of > dma: command 10 not supported > and > dma: command 14 not supported > messages. These correspond to CMD_CYCLIC_PRIORITY and CMD_CYCLIC_PRIORITY | CMD_BLOCK_CONTROLLER in write_cont() [hw/dma/i8257.c]. They are not supported (see CMD_NOT_SUPPORTED in the same file). > When the installation of NeXTSTEP gets to > 'preparing disk for nextstep installation', there are a lot > of messages that ATA command c5 failed and other info. > The result is a failed installation. 0xC5 is WIN_MULTWRITE ("write sectors using multiple mode"), and it seems to hook into DMA. > Is this a bug in QEMU? Probably not, it's more likely "incomplete" DMA emulation ("lack of support"). > Is there a workaround, e.g. by > disabling DMA altogether? It's worth a try I guess, if you can figure out a way how to do that. FWIW, ide_identify() appears to report unconditional support for: - single word dma0-2 - mdma0-2 - udma5 (I have no clue about IDE or DMA btw.) Laszlo