[Qemu-devel] [PATCH 0/5] Drop support for Xen 4.1 and older from qemu-xen

[Ian Campbell]

This is most easily explained by the commit log of the first patch:

    Xen 4.2 become unsupported upstream in 09/2105 (see
    http://wiki.xen.org/wiki/Xen_Release_Features). However as far as the
    interfaces provided by the toolstack libraries go 4.2 and 4.3 are
    indistinguishable.
    
    Therefore drop support for Xen 4.1 and earlier which removes a whole
    pile of compatibility code which makes future work (to use stable
    library interfaces provided by upstream) more difficult. In particular
    all supported versions now use a pointer as a libxc handle (4.1 and
    earlier used an integer, resulting in various shim layers).
    
    Also Xen 4.2 was the first version of Xen to formally support upstream
    QEMU (as a preview) so that makes sense as a cut-off now.

The rest of the patches are just further cleanups which become possible.