This is v10 patchset of modified 'migrate' and 'migrate-incoming'
QAPI design
for upstream review.
Would like to thank all the maintainers that actively participated in
the v9
patchset discussion and gave insightful suggestions to improve the
patches.
Link to previous upstream community patchset links:
v1: https://lists.gnu.org/archive/html/qemu-devel/2022-12/msg04339.html
v2: https://lists.gnu.org/archive/html/qemu-devel/2023-02/msg02106.html
v3: https://lists.gnu.org/archive/html/qemu-devel/2023-02/msg02473.html
v4: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg03064.html
v5: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg04845.html
v6: https://lists.gnu.org/archive/html/qemu-devel/2023-06/msg01251.html
v7: https://lists.gnu.org/archive/html/qemu-devel/2023-07/msg02027.html
v8: https://lists.gnu.org/archive/html/qemu-devel/2023-07/msg02770.html
v9: https://lists.gnu.org/archive/html/qemu-devel/2023-07/msg04216.html
v9 -> v10 changelog:
-------------------
- Patch6 : Added extra checks for migration arguments.
- Patch8 : Added checks for 'uri' and 'channels' both not present.
- Patch9 : Missed adding hmp_handle_error call to print error messages.
Abstract:
---------
Current QAPI 'migrate' command design (for initiating a migration
stream) contains information regarding different migrate transport
mechanism
(tcp / unix / exec), dest-host IP address, and binding port number in
form of
a string. Thus the design does seem to have some design issues. Some
of the
issues, stated below are:
1. Use of string URIs is a data encoding scheme within a data
encoding scheme.
QEMU code should directly be able to work with the results from
QAPI,
without resorting to do a second level of parsing (eg.
socket_parse()).
2. For features / parameters related to migration, the migration
tunables needs
to be defined and updated upfront. For example,
'migrate-set-capability'
and 'migrate-set-parameter' is required to enable multifd
capability and
multifd-number of channels respectively. Instead,
'Multifd-channels' can
directly be represented as a single additional parameter to
'migrate'
QAPI. 'migrate-set-capability' and 'migrate-set-parameter'
commands could
be used for runtime tunables that need setting after migration
has already
started.
The current patchset focuses on solving the first problem of multi-level
encoding of URIs. The patch defines 'migrate' command as a QAPI
discriminated
union for the various transport backends (like socket, exec and
rdma), and on
basis of transport backends, different migration parameters are defined.
(uri) string --> (channel) Channel-type
Transport-type
Migration parameters based on transport
type
------------------------------------------------------------------------------
Het Gala (10):
migration: New QAPI type 'MigrateAddress'
migration: convert migration 'uri' into 'MigrateAddress'
migration: convert socket backend to accept MigrateAddress
migration: convert rdma backend to accept MigrateAddress
migration: convert exec backend to accept MigrateAddress.
migration: New migrate and migrate-incoming argument 'channels'
migration: modify migration_channels_and_uri_compatible() for new
QAPI
syntax
migration: Implement MigrateChannelList to qmp migration flow.
migration: Implement MigrateChannelList to hmp migration flow.
migration: modify test_multifd_tcp_none() to use new QAPI syntax.
migration/exec.c | 72 +++++++++----
migration/exec.h | 8 +-
migration/migration-hmp-cmds.c | 17 ++-
migration/migration.c | 190 ++++++++++++++++++++++++++-------
migration/migration.h | 3 +-
migration/rdma.c | 34 +++---
migration/rdma.h | 6 +-
migration/socket.c | 39 ++-----
migration/socket.h | 7 +-
qapi/migration.json | 150 +++++++++++++++++++++++++-
softmmu/vl.c | 2 +-
tests/qtest/migration-test.c | 7 +-
12 files changed, 409 insertions(+), 126 deletions(-)