While we do cache the hosts's capabilities in self._caps in the
libvirt Host object, if we happen to fist call get_capabilities() with
some of our dedicated CPUs offline, libvirt erroneously reports them
as being on socket 0 regardless of their real socket. We would then
cache that topology, thus breaking pretty much all of our NUMA
accounting.

To fix this, this patch makes sure to call get_capabilities()
immediately upon host init, and to power up all our dedicated CPUs
before doing so. That way, we cache their real socket ID.

For testing, because we don't really want to implement a libvirt bug
in our Python libvirt fixture, we make due with a simple unit tests
that asserts that init_host() has powered on the correct CPUs.

Closes-bug: 2077228
Change-Id: I9a2a7614313297f11a55d99fb94916d3583a9504
(cherry picked from commit 79d1f06)
(cherry picked from commit 294444b)
(cherry picked from commit 6448e38)

Since the commit the remove AMI snapshot format special casing
has merged, we're now running the libvirt snapshot tests as expected.
However, for those tests qemu-img binary needs to be installed.
Because these tests have been silently and incorrectly skipped for so long,
they didn't receive the same maintenance as other tests as the failures went unnoticed.

Change-Id: Ia90eedbe35f4ab2b200bdc90e0e35e5a86cc2110
Closes-bug: #2075178
Signed-off-by: Julien Le Jeune <[email protected]>
(cherry picked from commit 0809f75)
(cherry picked from commit cd4e581)
(cherry picked from commit f58e8df)

…able/2023.1