commit f0736cf0550b349a5d5a374d65ca0488cc2eee40
author Alex Williamson <alex.williamson@redhat.com> Mon Dec 10 10:32:45 2012 -0700
committer Marcelo Tosatti <mtosatti@redhat.com> Thu Dec 13 23:21:50 2012 -0200
tree d72fbc1acd03c5047961bcfb5d4063137a392384
parent f3200d00ea42e485772ff92d6d649aa8eeb640c0

KVM: Restrict non-existing slot state transitions

The API documentation states:

	When changing an existing slot, it may be moved in the guest
	physical memory space, or its flags may be modified.

An "existing slot" requires a non-zero npages (memory_size).  The only
transition we should therefore allow for a non-existing slot should be
to create the slot, which includes setting a non-zero memory_size.  We
currently allow calls to modify non-existing slots, which is pointless,
confusing, and possibly wrong.

With this we know that the invalidation path of __kvm_set_memory_region
is always for a delete or move and never for adding a zero size slot.

Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>