Re: [Qemu-devel] [PATCH v3 0/5] virtio-9p: hotplug and migration support

[Michael S. Tsirkin]

On Tue, Oct 20, 2015 at 11:16:40AM +0200, Greg Kurz wrote:
> We already have a blocker to prevent migration of an active virtio-9p device.
> But in fact, there is no migration support at all for 9p, even if the device
> is considered to be quiescent (when the VirtFS share is not mounted): 
> migration
> succeeds but the device is lost in the restarted guest.
> Hotunplug of a virtio-9p device is not supported either (no unrealize handler)
> and leads to a QEMU crash on the source node, if one unplugs and migrates.
> 
> This series tries to fix that and brings hotplug and migration support of
> *quiescent* virtio-9p devices.
> 
> v2->v3:
>  - renamed QDEV handler @unpluggable to @unplug_is_blocked (patches 2/5
>    and 3/5)
> 
> v1->v2:
>  - introduced unplug blocker (patches 2/5 and 3/5)
>  - moved fixes to separate patches (see individual changelogs)

I have some doubts about how hotunplug is handled, but migration
looks ok.
Is there a dependency, or can I just pick savevm things meanwhile?

> ---
> 
> Greg Kurz (5):
>       virtio-9p-coth: fix init function
>       qdev: add the @unplug_is_blocked handler
>       virtio-9p: block hot-unplug when device is active
>       virtio-9p: add unrealize handler
>       virtio-9p: add savem handlers
> 
> 
>  hw/9pfs/virtio-9p-coth.c   |   22 ++++++++++++++++++----
>  hw/9pfs/virtio-9p-coth.h   |    2 ++
>  hw/9pfs/virtio-9p-device.c |   24 ++++++++++++++++++++++++
>  hw/9pfs/virtio-9p.c        |   14 ++++++++++++++
>  hw/9pfs/virtio-9p.h        |    2 ++
>  hw/core/qdev.c             |    4 ++++
>  hw/s390x/virtio-ccw.c      |    8 ++++++++
>  hw/virtio/virtio-pci.c     |    8 ++++++++
>  include/hw/qdev-core.h     |    4 ++++
>  9 files changed, 84 insertions(+), 4 deletions(-)