6574232fff
Migration downtime estimation is calculated based on bandwidth and remaining migration data. This assumes that loading of migration data in the destination takes a negligible amount of time and that downtime depends only on network speed. While this may be true for RAM, it's not necessarily true for other migrated devices. For example, loading the data of a VFIO device in the destination might require from the device to allocate resources, prepare internal data structures and so on. These operations can take a significant amount of time which can increase migration downtime. This patch adds a new capability "switchover ack" that prevents the source from stopping the VM and completing the migration until an ACK is received from the destination that it's OK to do so. This can be used by migrated devices in various ways to reduce downtime. For example, a device can send initial precopy metadata to pre-allocate resources in the destination and use this capability to make sure that the pre-allocation is completed before the source VM is stopped, so it will have full effect. This new capability relies on the return path capability to communicate from the destination back to the source. The actual implementation of the capability will be added in the following patches. Signed-off-by: Avihai Horon <avihaih@nvidia.com> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: Markus Armbruster <armbru@redhat.com> Tested-by: YangHang Liu <yanghliu@redhat.com> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Cédric Le Goater <clg@redhat.com> |
||
|---|---|---|
| .. | ||
| acpi.json | ||
| audio.json | ||
| authz.json | ||
| block-core.json | ||
| block-export.json | ||
| block.json | ||
| char.json | ||
| common.json | ||
| compat.json | ||
| control.json | ||
| crypto.json | ||
| cryptodev.json | ||
| cxl.json | ||
| dump.json | ||
| error.json | ||
| introspect.json | ||
| job.json | ||
| machine-target.json | ||
| machine.json | ||
| meson.build | ||
| migration.json | ||
| misc-target.json | ||
| misc.json | ||
| net.json | ||
| opts-visitor.c | ||
| pci.json | ||
| pragma.json | ||
| qapi-clone-visitor.c | ||
| qapi-dealloc-visitor.c | ||
| qapi-forward-visitor.c | ||
| qapi-schema.json | ||
| qapi-type-helpers.c | ||
| qapi-util.c | ||
| qapi-visit-core.c | ||
| qdev.json | ||
| qmp-dispatch.c | ||
| qmp-event.c | ||
| qmp-registry.c | ||
| qobject-input-visitor.c | ||
| qobject-output-visitor.c | ||
| qom.json | ||
| rdma.json | ||
| replay.json | ||
| rocker.json | ||
| run-state.json | ||
| sockets.json | ||
| stats.json | ||
| string-input-visitor.c | ||
| string-output-visitor.c | ||
| tpm.json | ||
| trace-events | ||
| trace.h | ||
| trace.json | ||
| transaction.json | ||
| ui.json | ||
| virtio.json | ||
| yank.json | ||