The intend of failover is to allow to migrate a VM with a VFIO
networking card without disrupting the network operation by switching
to a virtio-net device during the migration.
This simple change allows to test failover with a simulated device
like e1000e rather than a vfio device, even if it's useless in real
life it can help to debug failover.
This is interesting to developers that want to test failover on
a system with no vfio device. Moreover it simplifies host networking
configuration as we can use the same bridge for virtio-net and
the other failover networking device.
Without this change the migration of a system configured with failover
fails with:
...
-device virtio-net-pci,id=virtionet0,failover=on,... \
-device e1000,failover_pair_id=virtionet0,... \
...
(qemu) migrate ...
Unknown ramblock "0000:00:01.1:00.0/e1000e.rom", cannot accept migration
error while loading state for instance 0x0 of device 'ram'
load of migration failed: Invalid argument
This happens because QEMU correctly unregisters the interface vmstate but
not the ROM one. This patch fixes that.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
Notes:
v3:
remove useless space before comma
v2:
reset has_rom to false
update commit log message
hw/net/virtio-net.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 16d20cdee52a..c0c2ec1ebb98 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3256,6 +3256,10 @@ static void virtio_net_handle_migration_primary(VirtIONet *n, MigrationState *s)
if (migration_in_setup(s) && !should_be_hidden) {
if (failover_unplug_primary(n, dev)) {
vmstate_unregister(VMSTATE_IF(dev), qdev_get_vmsd(dev), dev);
+ if (PCI_DEVICE(dev)->has_rom) {
+ PCI_DEVICE(dev)->has_rom = false;
+ vmstate_unregister_ram(&PCI_DEVICE(dev)->rom, dev);
+ }
qapi_event_send_unplug_primary(dev->id);
qatomic_set(&n->failover_primary_hidden, true);
} else {
--
2.31.1