On 8/5/2025 9:54 AM, Fabiano Rosas wrote:
Steve Sistare <steven.sist...@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?
Good observation, thanks!. I may need patches 1-2 to completely close
the dropped interrupt race. I will do more testing to verify that.
- Steve
