Re: [Qemu-devel] Re: [PATCH 0/2] v8 Decouple block device removal from device removal

[Ryan Harper <ryanh@us.ibm.com>]

* Kevin Wolf <kwolf@redhat.com> [2010-11-16 08:05]:
> Am 16.11.2010 14:51, schrieb Luiz Capitulino:
> > On Fri, 12 Nov 2010 18:38:57 +0100
> > Kevin Wolf <kwolf@redhat.com> wrote:
> > 
> >> Am 12.11.2010 18:07, schrieb Ryan Harper:
> >>> details, details, v8
> >>>
> >>> This patch series decouples the detachment of a block device from the
> >>> removal of the backing pci-device.  Removal of a hotplugged pci device
> >>> requires the guest to respond before qemu tears down the block device.
> >>> In some cases, the guest may not respond leaving the guest with
> >>> continued access to the block device.  Mgmt layer doesn't have a
> >>> reliable method to force a disconnect.  
> >>>
> >>> The new monitor command, drive_del, will revoke a guests access to the
> >>> block device independently of the removal of the pci device.
> >>>
> >>> The first patch implements drive_del, the second patch implements the
> >>> qmp version of the monitor command.
> >>>
> >>> Changes since v7:
> >>> - Fixed up doc strings (delete -> drive_del)
> >>> Changes since v6:
> >>> - Updated patch description
> >>> - Dropped bdrv_unplug and inlined in drive_del
> >>> - Explicitly invoke drive_uninit()
> >>> Changes since v5:
> >>> - Removed dangling pointers in guest and host state.  This ensures things like 
> >>>   info block no longer displays the deleted drive; though info pci will
> >>>   continue to display the pci device until the guest responds to the removal
> >>>   request.
> >>> - Renamed drive_unplug -> drive_del
> >>> Changes since v4:
> >>> - Droppped drive_get_by_id patch and use bdrv_find() instead
> >>> - Added additional details about drive_unplug to hmp/qmp interface
> >>>
> >>> Changes since v3:
> >>> - Moved QMP command for drive_unplug() to separate patch
> >>>
> >>> Changes since v2:
> >>> - Added QMP command for drive_unplug()
> >>>
> >>> Changes since v1:
> >>> - CodingStyle fixes
> >>> - Added qemu_aio_flush() to bdrv_unplug()
> >>>
> >>> Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
> >>
> >> Thanks, applied both to the block branch.
> > 
> > I guess the conclusion was that we don't want the new command
> > in QMP?
> > 
> >   http://lists.gnu.org/archive/html/qemu-devel/2010-11/msg01084.html
> 
> If you compare the time of these mails, Markus sent his mail only a few
> minutes after I had applied the patches and posted this.
> 
> Ryan split the patch in two parts only to allow dropping the QMP part if
> we decided so, so I think he'll agree. I'm going to drop the second

Indeed.

> patch from my queue again before I send a pull request.
> 
> Kevin

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com