qemu_cpu.cfg: introduce rhel_major_version variant name

This way we can make filters that include/exclude all RHEL-6 versions.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
qemu_cpu.cfg: host_cpu_vendor variants

This will allow us to filter/document cases that require a specific host
CPU vendor. Enable only host_cpu_vendor=unknown by default.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
qemu_cpu.cfg: run full_dump test case only on kvm mode

We don't have any dumps for nokvm mode, so there's no point in enabling
all those variants that won't run because of missing dump files.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
dump-cpus-from-qemu: additional special cases

Dump some additional models using "-abm,-sse4a".

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
cpuid_dumps: additional CPUID dumps

Add dumps with "+apic" flags for some models, and with "-abm,-sse4a" for
some other models.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
qemu_cpu.cfg: rules to set cpu_model_flags on specific cases

Add some new variants/rules that will run some tests using
additional cpu_model_flags values. Especially:

 * CPU models that require "+apic" to be run on RHEL-6 hosts on Intel
   CPUs
 * CPU models that require "-abm,-sse4a" on Intel CPUs
 * CPU models that require using "-svm" because we don't enable nesting
   by default

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>