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Re: [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH 0/2] ATAPI migration fix/hack |
Date: |
Fri, 30 Jan 2015 16:07:54 +0000 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
* Dr. David Alan Gilbert (address@hidden) wrote:
>
> Oops, forgot to include Kevin and Stefan on cc for this.
Ping;
John R-b'd the two patches:
https://lists.gnu.org/archive/html/qemu-devel/2014-12/msg01133.html
http://lists.gnu.org/archive/html/qemu-devel/2015-01/msg01956.html
although hmm, possibly before I added both of you on
the cc.
Dave
>
> Dave
>
> * Dr. David Alan Gilbert (git) (address@hidden) wrote:
> > From: "Dr. David Alan Gilbert" <address@hidden>
> >
> > 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
> >
> >
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK