[libvirt] [PATCH 1/2] Add new elements source, access and allocation

This change introduces support for preallocated shared file descriptor based memory backing. It  allows vhost-user to be used without hugepages. This is achieved by introducing 3 new sub elements to the memoryBacking element: source, access & allocation which will configure qemu commandline during VM startup accordingly. First patch adds parsing of elements and storing the values in mem structure. Second patch configures the qemu commandline on the base of values in mem structure. -------------------------------------------------------------- Intel Research and Development Ireland Limited Registered in Ireland Registered Office: Collinstown Industrial Park, Leixlip, County Kildare Registered Number: 308263 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.