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* [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack
@ 2014-12-09 18:15 Dr. David Alan Gilbert (git)
  2014-12-09 18:15 ` [Qemu-devel] [PATCH 1/2] Restore atapi_dma flag across migration Dr. David Alan Gilbert (git)
                   ` (2 more replies)
  0 siblings, 3 replies; 15+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2014-12-09 18:15 UTC (permalink / raw)
  To: qemu-devel; +Cc: pbonzini, jsnow

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

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

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2015-02-02 12:12 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-12-09 18:15 [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack Dr. David Alan Gilbert (git)
2014-12-09 18:15 ` [Qemu-devel] [PATCH 1/2] Restore atapi_dma flag across migration Dr. David Alan Gilbert (git)
2014-12-10  5:04   ` John Snow
2014-12-09 18:15 ` [Qemu-devel] [PATCH 2/2] atapi migration: Throw recoverable error to avoid recovery Dr. David Alan Gilbert (git)
2014-12-10  6:14   ` John Snow
2014-12-10 12:05     ` Dr. David Alan Gilbert
2014-12-10 20:09     ` Dr. David Alan Gilbert
2014-12-10 22:04   ` Paolo Bonzini
2014-12-11 19:45     ` Dr. David Alan Gilbert
2014-12-18 19:39       ` Dr. David Alan Gilbert
2014-12-18 23:42         ` John Snow
2015-01-16 17:28   ` John Snow
2015-02-02 12:11     ` Kevin Wolf
2015-01-07 16:26 ` [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack Dr. David Alan Gilbert
2015-01-30 16:07   ` Dr. David Alan Gilbert

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