[libvirt] [PATCH v3] qemu: call drive_unplug in DetachPciDiskDevice

[Daniel P. Berrange]

On Tue, Nov 02, 2010 at 04:43:06PM -0600, Eric Blake wrote:
> On 10/25/2010 09:28 AM, Daniel P. Berrange wrote:
> > On Fri, Oct 22, 2010 at 09:14:22AM -0500, Ryan Harper wrote:
> >> Currently libvirt doesn't confirm whether the guest has responded to the
> >> disk removal request.  In some cases this can leave the guest with
> >> continued access to the device while the mgmt layer believes that it has
> >> been removed.  With a recent qemu monitor command[1] we can
> >> deterministically revoke a guests access to the disk (on the QEMU side)
> >> to ensure no futher access is permitted.
> >>
> >> This patch adds support for the drive_unplug() command and introduces it
> >> in the disk removal paths.  There is some discussion to be had about how
> >> to handle the case where the guest is running in a QEMU without this
> >> command (and the fact that we currently don't have a way of detecting
> >> what monitor commands are available).
> >>
> >> Changes since v2:
> >>  - use VIR_ERROR to report when unplug command not found
> >> Changes since v1:
> >>  - return > 0 when command isn't present, < 0 on command failure
> >>  - detect when drive_unplug command isn't present and log error
> >>    instead of failing entire command
> > 
> > This looks good to me now, ACK, pending my testing with old QEMU
> > versions under the TCK
> 
> Is there any further TCK testing needed for this before we push, or
> should I go ahead and push it now?

I'm not clear that they have accepted the drive_unplug command into QEMU
GIT yet, since there is still a huge ongoing discussion about it on the
qemu mailing list, and the QEMU git server has been unavailable for days
now :-(  Until I can confirm and test this, we'll have to wait.

Daniel
-- 
|: Red Hat, Engineering, London    -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :|
|: http://autobuild.org        -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|