From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52085) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XyPJe-0006qx-Jv for qemu-devel@nongnu.org; Tue, 09 Dec 2014 13:15:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XyPJY-00070L-GY for qemu-devel@nongnu.org; Tue, 09 Dec 2014 13:15:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42646) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XyPJY-00070F-8m for qemu-devel@nongnu.org; Tue, 09 Dec 2014 13:15:12 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sB9IFB4I030471 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 9 Dec 2014 13:15:11 -0500 From: "Dr. David Alan Gilbert (git)" Date: Tue, 9 Dec 2014 18:15:07 +0000 Message-Id: <1418148909-19870-1-git-send-email-dgilbert@redhat.com> Subject: [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, jsnow@redhat.com From: "Dr. David Alan Gilbert" This pair of patches fixes a problem where IDE/ATAPI cdrom reads get lost/corrupted over migration. The first of the patches (restore atapi_dma flag) is a simple fix that I think is safe; it no longer causes corruption in the case we saw, but does still trigger a long timeout. The second is a hack; it throws a medium error causing the guest to retry the command in the case where migration happens just between the IDE/ATAPI command being submitted and the bmdma being finished. This recovers a lot faster than the timeout. Only tried on Linux guests so far; I think it might be possible to replace both of these by reparsing the command buffer for ATAPI; I'm just not confident I know when that's safe to do, and I wanted to see how disgusted people were by the 2nd hack. Dave Dr. David Alan Gilbert (2): Restore atapi_dma flag across migration atapi migration: Throw recoverable error to avoid recovery hw/ide/atapi.c | 17 +++++++++++++++++ hw/ide/core.c | 1 + hw/ide/internal.h | 2 ++ hw/ide/pci.c | 11 +++++++++++ 4 files changed, 31 insertions(+) -- 2.1.0