Read and write "toolstack" information using the new
EMULATOR_XENSTORE_DATA record, and have the conversion script take care
of the old format.
The entire libxc and libxl migration v2 streams are now bitness-neutral
in their records.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Previously, in the case of an error causing a call to
libxl__conversion_helper_abort() on a stream without legacy conversion,
libxl would fall over a NULL pointer because chs->ao was not set up.
Arrange for all ->ao's to be set up at _init() time, by having each
_init() function assert that their caller has done the right thing.
While doing so, introduce a previously-missing save_helper_init() in
stream_read_init().
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Part of the callback contract with check_all_finished() is that each
running parallel task shall call it exactly once.
Previously, it was possible for stream_continue() or
write_toolstack_record() to fail and call into check_all_finished(). As
the save helpers callback has fired, it no longer counts as in use,
which causes check_all_finished() to fire the stream callback. Then,
unwinding the stack back and calling check_all_finished() a second time
results in the same conditions being observed, and the stream callback
being fired a second time.
To avoid this, check_all_finished() is called before any other actions
which continue the stream functionality, and the stream is only
continued if it has not been torn down. This guarantees not to continue
stream operations if the stream does not owe a callback to
check_all_finished().
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Avoid stacking of check_all_finished() via synchronous teardown of
tasks. If the _abort() functions call back synchronously,
stream->completion_callback() ends up getting called twice, as first
and last check_all_finished() frames observe each task being finished.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Only ever set stream->rc in check_all_finished(). The first version of
the migration v2 series had separate rc and joined_rc parameters, where
this logic worked. However when combining the two, the teardown path
fails to trigger if stream_complete() records stream->rc itself. A side
effect of this is that stream_done() needs to take an rc parameter.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
All of these are UNUSED_VALUE defects where a default value is
unconditionally overwritten. They are not particularly interesting,
bug wise, but keeping these defects at bay helps prevent real bugs
going unnoticed in the volume.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Applying the series out of order led to d72befc35f "tools/libxl:
Identify copywhat in stream v2 datacopiers" unintentionally reverting
part of 21d9b079e5 "tools/libxl: Initialise the fd of the unused
half of a datacopier".
Put this back.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
This is the final bit of untangling for Remus.
When libxc issues a checkpoint callback, start reading and buffering
all libxl records from the stream. Once a CHECKPOINT_END record is
encountered, start processing all records.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
v4: Adjustments in line with review for earlier patches in the series
v3: Simplify, use named constants for API
This is a complicated set of changes which must be done together for
bisectability.
* libxl-save-helper is updated to unconditionally use libxc migration
v2.
* libxl compatibility workarounds in libxc are disabled for restore
operations.
* libxl__stream_read_start() is logically spliced into the event
location where libxl__xc_domain_restore() used to reside.
* Ownership of the save_helper_state moves to stream_read_state.
The parameters 'hvm', 'pae', and 'superpages' were previously
superfluous, and are completely unused in migration
v2. callbacks->toolstack_restore is handled via a migration v2 record
now, rather than via a callback from libxc.
NB: this change breaks Remus. Further untangling needs to happen
before Remus will function.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
v4:
* Don't use _init() needlessly
v3:
* Simplify from v2.
* Alter the ownership of save_helper_state
v2:
* Drop "legacy_width" from the IDL
* Gain a LIBXL_HAVE_ to signify support of migration v2 streams
For backwards compatibility, a legacy stream needs converting before
it can be read by the v2 stream logic.
This causes the v2 stream logic to need to juggle two parallel tasks.
check_all_finished() is introduced for the purpose of joining the
tasks in both success and error cases.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
v4: Alter logic layout in check_all_finished()
v3: Simplified greatly from v2. No practical change.
This contains the event machinery and state machines to read an act on
a non-checkpointed migration v2 stream (with the exception of the
xc_domain_restore() handling which is spliced later in a bisectable
way).
It also contains some boilerplate to help support checkpointed
streams, which shall be introduced in a later patch.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
---
v4:
* Don't make _init() mandatory
* Don't unilaterally clobber rc from datacopier callback
* Comment adjustments
* More assertions
v3: More descriptions of the internal state, shuffle function order, add
an _init() call, condense error handling
Roger Pau Monne
Andrew Cooper
Ian Campbell
Ross Lagerwall