Hi all!
Here is a new migration parameter backend-transfer, which, being
assisted by new device property backend-transfer, allows to
enable local migration of TAP virtio-net backend, including its
properties and open fds.
With this new option, management software doesn't need to
initialize new TAP and do a switch to it. Nothing should be
done around virtio-net in local migration: it just migrates
and continues to use same TAP device. So we avoid extra logic
in management software, extra allocations in kernel (for new TAP),
and corresponding extra delay in migration downtime.
v8:
14: add a-b by Peter
16: rework to one boolean parameter
17: rework to use per-device property
19: update to use new API
Vladimir Sementsov-Ogievskiy (19):
net/tap: net_init_tap_one(): drop extra error propagation
net/tap: net_init_tap_one(): move parameter checking earlier
net/tap: rework net_tap_init()
net/tap: pass NULL to net_init_tap_one() in cases when scripts are
NULL
net/tap: rework scripts handling
net/tap: setup exit notifier only when needed
net/tap: split net_tap_fd_init()
net/tap: tap_set_sndbuf(): add return value
net/tap: rework tap_set_sndbuf()
net/tap: rework sndbuf handling
net/tap: introduce net_tap_setup()
net/tap: move vhost fd initialization to net_tap_new()
net/tap: finalize net_tap_set_fd() logic
migration: introduce .pre_incoming() vmsd handler
net/tap: postpone tap setup to pre-incoming
qapi: introduce backend-transfer migration parameter
virtio-net: support backend-transfer migration for virtio-net/tap
tests/functional: add skipWithoutSudo() decorator
tests/functional: add test_x86_64_tap_migration
hw/core/machine.c | 1 +
hw/net/virtio-net.c | 151 ++++++-
include/hw/virtio/virtio-net.h | 1 +
include/migration/vmstate.h | 1 +
include/net/tap.h | 5 +
migration/migration.c | 4 +
migration/options.c | 18 +
migration/options.h | 2 +
migration/savevm.c | 15 +
migration/savevm.h | 1 +
net/tap-bsd.c | 3 +-
net/tap-linux.c | 19 +-
net/tap-solaris.c | 3 +-
net/tap-stub.c | 3 +-
net/tap-win32.c | 11 +
net/tap.c | 425 +++++++++++++-----
net/tap_int.h | 3 +-
qapi/migration.json | 38 +-
tests/functional/qemu_test/decorators.py | 16 +
tests/functional/test_x86_64_tap_migration.py | 395 ++++++++++++++++
20 files changed, 984 insertions(+), 131 deletions(-)
create mode 100644 tests/functional/test_x86_64_tap_migration.py
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2.48.1
