When prefixing with string (optional) or optional in the description
of arguments to libvirt C APIs, in python, these arguments will be
set as optional arugments, for example:

 * virDomainSaveFlags:
 * @domain: a domain object
 * @to: path for the output file
 * @dxml: (optional) XML config for adjusting guest xml used on restore
 * @flags: bitwise-OR of virDomainSaveRestoreFlags

 the corresponding python APIs is
 restoreFlags(self, frm, dxml=None, flags=0)

The following python APIs are changed to:
 blockCommit(self, disk, base, top, bandwidth=0, flags=0)
 blockPull(self, disk, bandwidth=0, flags=0)
 blockRebase(self, disk, base, bandwidth=0, flags=0)
 migrate(self, dconn, flags=0, dname=None, uri=None, bandwidth=0)
 migrate2(self, dconn, dxml=None, flags=0, dname=None, uri=None, bandwidth=0)
 migrateToURI(self, duri, flags=0, dname=None, bandwidth=0)
 migrateToURI2(self, dconnuri=None, miguri=None, dxml=None, flags=0, \
               dname=None, bandwidth=0)
 saveFlags(self, to, dxml=None, flags=0)
 migrate(self, domain, flags=0, dname=None, uri=None, bandwidth=0)
 migrate2(self, domain, dxml=None, flags=0, dname=None, uri=None, bandwidth=0)
 restoreFlags(self, frm, dxml=None, flags=0)

This breaked "make syntax-check" testing

Pushed under trivial rule

The following four functions have not changed because default arguments
have to come after positional arguments. Changing them will break the
the binding APIs.

migrate(self, dconn, flags, dname, uri, bandwidth):
migrate2(self, dconn, dxml, flags, dname, uri, bandwidth):
migrateToURI(self, duri, flags, dname, bandwidth):
migrateToURI2(self, dconnuri, miguri, dxml, flags, dname, bandwidth):

The addition of emulator pinning APIs didn't think of doing the right
job with python APIs for them. The default generator produced unusable
code for this.

This patch switches to proper code as in the case of domain Vcpu pining.
This change can be classified as a python API-breaker but in the state
the code was before I doubt anyone was able to use it successfully.

For example:
 >>> dom.memoryStats()
 libvir: QEMU Driver error : Requested operation is not valid:\
         domain is not running

There are six such python API functions like so.
The root reason is that generator.py script checks the type of return
value of a python stub function defined in libvirt-api.xml or
libvirt-override-api.xml to see whether to add the raise clause or not
in python wrapper code in libvirt.py.

The type of return value is supposed to be C types.
For those stub functions which return python non-integer data type like
string, list, tuple, dictionary, the existing type in functions varies
from each other which leads problem like this.

Currently, in generator.py, it maintains a buggy whitelist for stub functions
returning a list type. I think it is easy to forget adding new function name
in the whitelist.

This patch makes the value of type consistent with C type "char *"
in libvirt-override-api.xml. For python, any of types could be printed
as string, so I choose "char *" in this case. And the comment in xml
could explain it when adding new function definition.

      <function name='virNodeGetCPUStats' file='python'>
        ...
 -      <return type='virNodeCPUStats' info='...'/>
 +      <return type='char *' info='...'/>
        ...
      </function>

Add a new virDomainLxcEnterSecurityLabel() function as a
counterpart to virDomainLxcEnterNamespaces(), which can
change the current calling process to have a new security
context. This call runs client side, not in libvirtd
so we can't use the security driver infrastructure.

When entering a namespace, the process spawned from virsh
will default to running with the security label of virsh.
The actual desired behaviour is to run with the security
label of the container most of the time. So this changes
virsh lxc-enter-namespace command to invoke the
virDomainLxcEnterSecurityLabel method.

The current behaviour is:

LABEL                             PID TTY          TIME CMD
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 29 ? 00:00:00 dhclient
staff_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 47 ? 00:00:00 ps

Note the ps command is running as unconfined_t,  After this patch,

The new behaviour is this:

virsh -c lxc:/// lxc-enter-namespace dan -- /bin/ps -eZ
LABEL                             PID TTY          TIME CMD
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 1 pts/0 00:00:00 systemd
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 3 pts/1 00:00:00 sh
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 24 ? 00:00:00 systemd-journal
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 32 ? 00:00:00 dhclient
system_u:system_r:svirt_lxc_net_t:s0:c0.c1023 38 ? 00:00:00 ps

The '--noseclabel' flag can be used to skip security labelling.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Introduce virDomainMigrateGetCompressionCache and
virDomainMigrateSetCompressionCache APIs.

This is an extensible version of virDomainGetJobInfo.