Re: [RFC V2 0/8] Live update: tap and vhost

[Fabiano Rosas <farosas@suse.de>]

Steve Sistare <steven.sistare@oracle.com> writes:

> Tap and vhost devices can be preserved during cpr-transfer using
> traditional live migration methods, wherein the management layer
> creates new interfaces for the target and fiddles with 'ip link'
> to deactivate the old interface and activate the new.
>
> However, CPR can simply send the file descriptors to new QEMU,
> with no special management actions required.  The user enables
> this behavior by specifing '-netdev tap,cpr=on'.  The default
> is cpr=off.
>
> Steve Sistare (8):
>   migration: stop vm earlier for cpr
>   migration: cpr setup notifier
>   vhost: reset vhost devices for cpr
>   cpr: delete all fds
>   Revert "vhost-backend: remove vhost_kernel_reset_device()"
>   tap: common return label
>   tap: cpr support
>   tap: postload fix for cpr
>
>  qapi/net.json             |   5 +-
>  include/hw/virtio/vhost.h |   1 +
>  include/migration/cpr.h   |   3 +-
>  include/net/tap.h         |   1 +
>  hw/net/virtio-net.c       |  20 +++++++
>  hw/vfio/device.c          |   2 +-
>  hw/virtio/vhost-backend.c |   6 ++
>  hw/virtio/vhost.c         |  32 +++++++++++
>  migration/cpr.c           |  24 ++++++--
>  migration/migration.c     |  38 ++++++++-----
>  net/tap-win32.c           |   5 ++
>  net/tap.c                 | 141 +++++++++++++++++++++++++++++++++++-----------
>  12 files changed, 223 insertions(+), 55 deletions(-)

Hi Steve,

Patches 1-2 seem to potentially interact with your arm pending
interrupts fix. Do we want them together?