CPU features which change their value from disabled to enabled between
two calls to query-cpu-model-expansion (the first with no extra
properties set and the second with 'migratable' property set to false)
can be marked as enabled and non-migratable in qemuMonitorCPUModelInfo.
Since the code consuming qemuMonitorCPUModelInfo currently ignores the
migratable flag, this change is effectively changing the CPU model
advertised in domain capabilities to contain all features (even those
which block migration). And this matches what we do for QEMU older than
2.9.0, when we detect all CPUID bits ourselves without asking QEMU.
As a result of this change
<cpu mode='host-model'>
<feature name='invtsc' policy='require'/>
</cpu>
will work with all QEMU versions. Such CPU definition would be forbidden
with QEMU >= 2.9.0 without this patch.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
The static CPU model expansion is designed to return only canonical
names of all CPU properties. To maintain backwards compatibility libvirt
is stuck with different spelling of some of the features, but we need to
use the full expansion to get the additional spellings. In addition to
returning all spelling variants for all properties the full expansion
will contain properties which are not guaranteed to be migration
compatible. Thus, we need to combine both expansions. First we need to
call the static expansion to limit the result to migratable properties.
Then we can use the result of the static expansion as an input to the
full expansion to get both canonical names and their aliases.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
