In qemu there are 2 cpu models (cpu64-rhel5 and cpu64-rhel6) not
supported by libvirt. This patch adds the support with the flags
specifications from /usr/share/qemu-kvm/cpu-model/cpu-x86_64.conf
The only difference is that AMD-specific features are removed so
the processor type is not vendor-specific. Those features are either
emulated or ignored by qemu if host CPU doesn't support them.

Recently (or not so recently) QEMU added the kvm32 and kvm64
architectures, representing a least common denominator of all
hosts that can run KVM.  Add them to the machine map.

Also, some features that TCG supports were added to qemu64.
Add them to the cpu_map.xml whenever KVM is guaranteed to support
those.  We still have to leave some out, because they would not
be available to guests running on older hosts.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add support for newly supported Intel cpu features. Newly supported
flags are: pclmuldq, dtes64, smx, fma, pdcm, movbe, xsave, osxsave and
avx. This adds support for Intel's Sandy Bridge platform.

Recent CPU models were specified using invalid vendor element
<vendor>NAME</vendor>, which was silently ignored due to a bug in the
code which was parsing it.

Some features provided by the recently added CPU models were mentioned
twice for each model. This was a result of automatic generation of the
XML from qemu's CPU configuration file without noticing this redundancy.

By specifying <vendor> element in CPU requirements a guest can be
restricted to run only on CPUs by a given vendor. Host CPU vendor is
also specified in capabilities XML.

The vendor is checked when migrating a guest but it's not forced, i.e.,
guests configured without <vendor> element can be freely migrated.

* src/cpu/cpu_map.xml: newdescription file
* src/Makefile.am: include it in dist