Following up on my previous work to make virtio-mem consume multiple
memslots dynamically [1] that requires precise accounting between used vs.
reserved memslots, I realized that vhost makes this extra hard by
filtering out some memory region sections (so they don't consume a
memslot) in the vhost-user case, which messes up the whole memslot
accounting.
This series fixes what I found to be broken and prepares for more work on
[1]. Further, it cleanes up the merge checks that I consider unnecessary.
[1] https://lkml.kernel.org/r/20211027124531.57561-8-david@redhat.com
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: "Philippe Mathieu-Daudé" <philmd@linaro.org>