Add a new file checkpoint_conf.c that performs the translation to and
from new XML describing a checkpoint. The code shares a common base
class with snapshots, since a checkpoint similarly represents the
domain state at a moment in time. Add some basic testing of round trip
XML handling through the new code.
Of note - this code intentionally differs from snapshots in that XML
schema validation is unconditional, rather than based on a public API
flag. We have many existing interfaces that still need to add a flag
for opt-in schema validation, but those interfaces have existing
clients that may not have been producing strictly-compliant XML, or we
may still uncover bugs where our RNG grammar is inconsistent with our
code (where omitting the opt-in flag allows existing apps to keep
working while waiting for an RNG patch). But since checkpoints are
brand-new, it's easier to ensure the code matches the schema by always
using the schema. If needed, a later patch could extend the API and
add a flag to turn on to request schema validation, rather than having
it forced (possibly just the validation of the <domain> sub-element
during REDEFINE) - but if a user encounters XML that looks like it
should be good but fails to validate with our RNG schema, they would
either have to upgrade to a new libvirt that adds the new flag, or
upgrade to a new libvirt that fixes the RNG schema, which implies
adding such a flag won't help much.
Also, the redefine flag requires the <domain> sub-element to be
present, rather than catering to historical back-compat to older
versions.
Signed-off-by: Eric Blake <eblake@redhat.com>
Prepare for new checkpoint APIs by describing the XML that will
represent a checkpoint. The checkpoint XML is modeled heavily after
virDomainSnapshotPtr. See the docs for more details.
Add testsuite coverage for some minimal uses of the XML (bare minimum,
the sample from html, and a full dumpxml, and some counter-examples
that should fail schema validation). Although use of the REDEFINE flag
will require the <domain> subelement to be present, it is easier for
most of the tests to provide counterpart output produced with the
NO_DOMAIN flag (particularly since synthesizing a valid <domain>
during testing is not trivial).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
