migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sist

migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-12-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.si

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/1710179338-294359-3-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sist

migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-12-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.si

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/1710179338-294359-3-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sist

migration: purge MigrationState from public interface

Move remaining MigrationState references from the public file
misc.h to the private file migration.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-12-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com

migration: export migration_is_running

Delete the MigrationState parameter from migration_is_running and move
it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/r/1710179338-294359-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.si

migration: export migration_is_setup_or_active

Delete the MigrationState parameter from migration_is_setup_or_active
and move it to the public API in misc.h.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/1710179338-294359-3-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: stop vm for cpr

When migration for cpr is initiated, stop the vm and set state
RUN_STATE_FINISH_MIGRATE before ram is saved. This eliminates the
possibility of ram and device state being

migration: stop vm for cpr

When migration for cpr is initiated, stop the vm and set state
RUN_STATE_FINISH_MIGRATE before ram is saved. This eliminates the
possibility of ram and device state being out of sync, and guarantees
that a guest in the suspended state remains suspended, because qmp_cont
rejects a cont command in the RUN_STATE_FINISH_MIGRATE state.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1708622920-68779-11-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: remove postcopy_after_devices

postcopy_after_devices and migration_in_postcopy_after_devices are no
longer used, so delete them.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>

migration: remove postcopy_after_devices

postcopy_after_devices and migration_in_postcopy_after_devices are no
longer used, so delete them.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1708622920-68779-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Centralize BH creation and dispatch

Now that the migration state reference counting is correct, further
wrap the bottom half dispatch process to avoid future issues.

Move BH creation and

migration: Centralize BH creation and dispatch

Now that the migration state reference counting is correct, further
wrap the bottom half dispatch process to avoid future issues.

Move BH creation and scheduling together and wrap the dispatch with an
intermediary function that will ensure we always keep the ref/unref
balanced.

Also move the responsibility of deleting the BH into the wrapper and
remove the now unnecessary pointers.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240119233922.32588-6-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Make threshold_size an uint64_t

It's always used to compare against another uint64_t. Make it always clear
that it's never a negative.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro

migration: Make threshold_size an uint64_t

It's always used to compare against another uint64_t. Make it always clear
that it's never a negative.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240117075848.139045-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Centralize BH creation and dispatch

Now that the migration state reference counting is correct, further
wrap the bottom half dispatch process to avoid future issues.

Move BH creation and

migration: Centralize BH creation and dispatch

Now that the migration state reference counting is correct, further
wrap the bottom half dispatch process to avoid future issues.

Move BH creation and scheduling together and wrap the dispatch with an
intermediary function that will ensure we always keep the ref/unref
balanced.

Also move the responsibility of deleting the BH into the wrapper and
remove the now unnecessary pointers.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240119233922.32588-6-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Make threshold_size an uint64_t

It's always used to compare against another uint64_t. Make it always clear
that it's never a negative.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro

migration: Make threshold_size an uint64_t

It's always used to compare against another uint64_t. Make it always clear
that it's never a negative.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240117075848.139045-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Remove errp parameter in migration_fd_process_incoming()

Errp parameter in migration_fd_process_incoming() is unused.
Remove it.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed

migration: Remove errp parameter in migration_fd_process_incoming()

Errp parameter in migration_fd_process_incoming() is unused.
Remove it.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20231231093016.14204-5-avihaih@nvidia.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Remove migrate_max_downtime() declaration

migrate_max_downtime() has been removed long ago, but its declaration
was mistakenly left. Remove it.

Signed-off-by: Avihai Horon <avihaih@nvidi

migration: Remove migrate_max_downtime() declaration

migrate_max_downtime() has been removed long ago, but its declaration
was mistakenly left. Remove it.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20231231093016.14204-2-avihaih@nvidia.com
Signed-off-by: Peter Xu <peterx@redhat.com>

show more ...

migration: Implement MigrateChannelList to hmp migration flow.

Integrate MigrateChannelList with all transport backends
(socket, exec and rdma) for both src and dest migration
endpoints for hmp migr

migration: Implement MigrateChannelList to hmp migration flow.

Integrate MigrateChannelList with all transport backends
(socket, exec and rdma) for both src and dest migration
endpoints for hmp migration.

Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
Signed-off-by: Het Gala <het.gala@nutanix.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Message-ID: <20231023182053.8711-14-farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

migration: Allow network to fail even during recovery

Normally the postcopy recover phase should only exist for a super short
period, that's the duration when QEMU is trying to recover from an
inter

migration: Allow network to fail even during recovery

Normally the postcopy recover phase should only exist for a super short
period, that's the duration when QEMU is trying to recover from an
interrupted postcopy migration, during which handshake will be carried out
for continuing the procedure with state changes from PAUSED -> RECOVER ->
POSTCOPY_ACTIVE again.

Here RECOVER phase should be super small, that happens right after the
admin specified a new but working network link for QEMU to reconnect to
dest QEMU.

However there can still be case where the channel is broken in this small
RECOVER window.

If it happens, with current code there's no way the src QEMU can got kicked
out of RECOVER stage. No way either to retry the recover in another channel
when established.

This patch allows the RECOVER phase to fail itself too - we're mostly
ready, just some small things missing, e.g. properly kick the main
migration thread out when sleeping on rp_sem when we found that we're at
RECOVER stage. When this happens, it fails the RECOVER itself, and
rollback to PAUSED stage. Then the user can retry another round of
recovery.

To make it even stronger, teach QMP command migrate-pause to explicitly
kick src/dst QEMU out when needed, so even if for some reason the migration
thread didn't got kicked out already by a failing rethrn-path thread, the
admin can also kick it out.

This will be an super, super corner case, but still try to cover that.

One can try to test this with two proxy channels for migration:

(a) socat unix-listen:/tmp/src.sock,reuseaddr,fork tcp:localhost:10000
(b) socat tcp-listen:10000,reuseaddr,fork unix:/tmp/dst.sock

So the migration channel will be:

(a) (b)
src -> /tmp/src.sock -> tcp:10000 -> /tmp/dst.sock -> dst

Then to make QEMU hang at RECOVER stage, one can do below:

(1) stop the postcopy using QMP command postcopy-pause
(2) kill the 2nd proxy (b)
(3) try to recover the postcopy using /tmp/src.sock on src
(4) src QEMU will go into RECOVER stage but won't be able to continue
from there, because the channel is actually broken at (b)

Before this patch, step (4) will make src QEMU stuck in RECOVER stage,
without a way to kick the QEMU out or continue the postcopy again. After
this patch, (4) will quickly fail qemu and bounce back to PAUSED stage.

Admin can also kick QEMU from (4) into PAUSED when needed using
migrate-pause when needed.

After bouncing back to PAUSED stage, one can recover again.

Reported-by: Xiaohui Li <xiaohli@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2111332
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231017202633.296756-3-peterx@redhat.com>

show more ...

migration: Refactor error handling in source return path

rp_state.error was a boolean used to show error happened in return path
thread. That's not only duplicating error reporting (migrate_set_err

migration: Refactor error handling in source return path

rp_state.error was a boolean used to show error happened in return path
thread. That's not only duplicating error reporting (migrate_set_error),
but also not good enough in that we only do error_report() and set it to
true, we never can keep a history of the exact error and show it in
query-migrate.

To make this better, a few things done:

- Use error_setg() rather than error_report() across the whole lifecycle
of return path thread, keeping the error in an Error*.

- With above, no need to have mark_source_rp_bad(), remove it, alongside
with rp_state.error itself.

- Use migrate_set_error() to apply that captured error to the global
migration object when error occured in this thread.

- Do the same when detected qemufile error in source return path

We need to re-export qemu_file_get_error_obj() to do the last one.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231017202633.296756-2-peterx@redhat.com>

show more ...

migration: migration_stop_vm() helper

Provide a helper for non-COLO use case of migration to stop a VM. This
prepares for adding some downtime relevant tracepoints to migration, where
they may or m

migration: migration_stop_vm() helper

Provide a helper for non-COLO use case of migration to stop a VM. This
prepares for adding some downtime relevant tracepoints to migration, where
they may or may not apply to COLO.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231030163346.765724-5-peterx@redhat.com>

show more ...

migration: Implement MigrateChannelList to hmp migration flow.

Integrate MigrateChannelList with all transport backends
(socket, exec and rdma) for both src and dest migration
endpoints for hmp migr

migration: Implement MigrateChannelList to hmp migration flow.

Integrate MigrateChannelList with all transport backends
(socket, exec and rdma) for both src and dest migration
endpoints for hmp migration.

Suggested-by: Aravind Retnakaran <aravind.retnakaran@nutanix.com>
Signed-off-by: Het Gala <het.gala@nutanix.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Message-ID: <20231023182053.8711-14-farosas@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>

show more ...

migration: Allow network to fail even during recovery

Normally the postcopy recover phase should only exist for a super short
period, that's the duration when QEMU is trying to recover from an
inter

migration: Allow network to fail even during recovery

Normally the postcopy recover phase should only exist for a super short
period, that's the duration when QEMU is trying to recover from an
interrupted postcopy migration, during which handshake will be carried out
for continuing the procedure with state changes from PAUSED -> RECOVER ->
POSTCOPY_ACTIVE again.

Here RECOVER phase should be super small, that happens right after the
admin specified a new but working network link for QEMU to reconnect to
dest QEMU.

However there can still be case where the channel is broken in this small
RECOVER window.

If it happens, with current code there's no way the src QEMU can got kicked
out of RECOVER stage. No way either to retry the recover in another channel
when established.

This patch allows the RECOVER phase to fail itself too - we're mostly
ready, just some small things missing, e.g. properly kick the main
migration thread out when sleeping on rp_sem when we found that we're at
RECOVER stage. When this happens, it fails the RECOVER itself, and
rollback to PAUSED stage. Then the user can retry another round of
recovery.

To make it even stronger, teach QMP command migrate-pause to explicitly
kick src/dst QEMU out when needed, so even if for some reason the migration
thread didn't got kicked out already by a failing rethrn-path thread, the
admin can also kick it out.

This will be an super, super corner case, but still try to cover that.

One can try to test this with two proxy channels for migration:

(a) socat unix-listen:/tmp/src.sock,reuseaddr,fork tcp:localhost:10000
(b) socat tcp-listen:10000,reuseaddr,fork unix:/tmp/dst.sock

So the migration channel will be:

(a) (b)
src -> /tmp/src.sock -> tcp:10000 -> /tmp/dst.sock -> dst

Then to make QEMU hang at RECOVER stage, one can do below:

(1) stop the postcopy using QMP command postcopy-pause
(2) kill the 2nd proxy (b)
(3) try to recover the postcopy using /tmp/src.sock on src
(4) src QEMU will go into RECOVER stage but won't be able to continue
from there, because the channel is actually broken at (b)

Before this patch, step (4) will make src QEMU stuck in RECOVER stage,
without a way to kick the QEMU out or continue the postcopy again. After
this patch, (4) will quickly fail qemu and bounce back to PAUSED stage.

Admin can also kick QEMU from (4) into PAUSED when needed using
migrate-pause when needed.

After bouncing back to PAUSED stage, one can recover again.

Reported-by: Xiaohui Li <xiaohli@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2111332
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231017202633.296756-3-peterx@redhat.com>

show more ...

migration: Refactor error handling in source return path

rp_state.error was a boolean used to show error happened in return path
thread. That's not only duplicating error reporting (migrate_set_err

migration: Refactor error handling in source return path

rp_state.error was a boolean used to show error happened in return path
thread. That's not only duplicating error reporting (migrate_set_error),
but also not good enough in that we only do error_report() and set it to
true, we never can keep a history of the exact error and show it in
query-migrate.

To make this better, a few things done:

- Use error_setg() rather than error_report() across the whole lifecycle
of return path thread, keeping the error in an Error*.

- With above, no need to have mark_source_rp_bad(), remove it, alongside
with rp_state.error itself.

- Use migrate_set_error() to apply that captured error to the global
migration object when error occured in this thread.

- Do the same when detected qemufile error in source return path

We need to re-export qemu_file_get_error_obj() to do the last one.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231017202633.296756-2-peterx@redhat.com>

show more ...

migration: migration_stop_vm() helper

Provide a helper for non-COLO use case of migration to stop a VM. This
prepares for adding some downtime relevant tracepoints to migration, where
they may or m

migration: migration_stop_vm() helper

Provide a helper for non-COLO use case of migration to stop a VM. This
prepares for adding some downtime relevant tracepoints to migration, where
they may or may not apply to COLO.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231030163346.765724-5-peterx@redhat.com>

show more ...