From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] qemu: fix ATAPI read drive structure command Date: Sun, 25 May 2008 12:11:04 +0300 Message-ID: <48392D28.3020103@qumranet.com> References: <1211511513.21166.135.camel@bling> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Alex Williamson Return-path: Received: from bzq-179-150-194.static.bezeqint.net ([212.179.150.194]:32885 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753847AbYEYJLG (ORCPT ); Sun, 25 May 2008 05:11:06 -0400 In-Reply-To: <1211511513.21166.135.camel@bling> Sender: kvm-owner@vger.kernel.org List-ID: Alex Williamson wrote: > I believe this fixes bug 1967368. Windows Vista hangs if you try to run > diskpart.exe with a DVD image loaded. This does not occur on Xen > because their version of Qemu doesn't try to emulate the > GPCMD_READ_DVD_STRUCTURE command. If I comment out the version in KVM, > diskpart.exe works. Digging through the versions of the MMC-6 spec I > can find online, I believe the problem is that we're ignoring the > allocation length field. This specifies the maximum number of bytes > that may be returned by the drive. Instead we're returning the maximum > possible table size each time. I also found that we seem to be using > the wrong field for the format request. Byte 2 is MSB of the address > field, we want byte 7. I also added a few missing comments for the > fields as we fill them in. I've only tested this with Vista since it's > the only thing that I know using this command. Thanks, > This seems to fix a bug in upstream qemu, so the preferred path for this is to post the patch on qemu-devel, and kvm will get it on the next merge. -- error compiling committee.c: too many arguments to function