qemu/docs/rdma.txt

2 RDMA Live Migration Specification, Version # 1
18 * RDMA Migration Protocol Description
21 * Migration of VM's ram
28 RDMA helps make your migration more deterministic under heavy load because
32 migration, under certain types of memory-bound workloads, may take a more
33 unpredictable amount of time to complete the migration if the amount of
34 memory tracked during each live migration iteration round cannot keep pace
39 migration using RDMA is capable of using both technologies because of
47 for a working build of QEMU to run successfully using RDMA Migration.
52 Use of RDMA during migration requires pinning and registering memory
56 of RDMA migration may in fact be harmful to co-located VMs or other
59 use of RDMA is discouraged and it is recommended to use standard TCP migration.
65 bulk-phase round of the migration and can be enabled for extremely
75 of the migration, which can greatly reduce the "total" time of your migration.
82 and thus extending the total migration time. However, this will not
83 affect the determinism or predictability of your migration you will
89 First, set the migration speed to match your hardware's capabilities:
98 Finally, perform the actual migration on the source machine:
106 Here is a brief summary of total migration time and downtime using RDMA:
114 1. Migration throughput: 26 gigabits/second.
130 migration *downtime*. This is because, without this feature, all of the
138 Migration with RDMA is separated into two parts:
166 (Memory is not released from pinning until the migration
173 a control transport for migration of device state.
175 To begin the migration, the initial connection setup is
176 as follows (migration-rdma.c):
267    this protocol before the actual migration begins. This information includes
278    its own protocol information during the migration process.
358 Migration of VM's ram:
361 At the beginning of the migration, (migration-rdma.c),
397 we use for RDMA migration.
400 the decision is to abort the migration entirely and
406 socket is broken during a non-RDMA based migration.
412    an aborted migration (but with the source VM left unaffected).