qemuDomainAttachHostPciDevice: Fall back to mem balloon if there's no hard_limit
qemuDomainAttachHostPciDevice: Fall back to mem balloon if there's no hard_limit

If there's no hard_limit set and domain uses VFIO we still must lock
the guest memory (prerequisite from qemu). Hence, we should compute
the amount to be locked from max_balloon.

zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,zhlcindy/libvirt-1.1.4-maintain,crobinso/libvirt,andreabolognani/libvirt,libvirt/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,elmarco/libvirt,jardasgit/libvirt,datto/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,taget/libvirt,fabianfreyer/libvirt,elmarco/libvirt,nertpinx/libvirt,zippy2/libvirt,crobinso/libvirt,cbosdo/libvirt,agx/libvirt,taget/libvirt,cbosdo/libvirt,agx/libvirt,elmarco/libvirt,elmarco/libvirt,zippy2/libvirt,rlaager/libvirt,taget/libvirt,jardasgit/libvirt,libvirt/libvirt,zippy2/libvirt,rlaager/libvirt,cbosdo/libvirt,rlaager/libvirt,shugaoye/libvirt,andreabolognani/libvirt,nertpinx/libvirt,agx/libvirt,agx/libvirt,libvirt/libvirt,taget/libvirt,nertpinx/libvirt,elmarco/libvirt,datto/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,crobinso/libvirt,nertpinx/libvirt,zhlcindy/libvirt-1.1.4-maintain,jfehlig/libvirt,datto/libvirt,datto/libvirt,zippy2/libvirt,taget/libvirt,shugaoye/libvirt,rlaager/libvirt,agx/libvirt,eskultety/libvirt,zhlcindy/libvirt-1.1.4-maintain,datto/libvirt,andreabolognani/libvirt,crobinso/libvirt,eskultety/libvirt,eskultety/libvirt,shugaoye/libvirt,jfehlig/libvirt,cbosdo/libvirt,jfehlig/libvirt,andreabolognani/libvirt,olafhering/libvirt,olafhering/libvirt,shugaoye/libvirt,rlaager/libvirt,fabianfreyer/libvirt,libvirt/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,olafhering/libvirt,olafhering/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,jfehlig/libvirt,eskultety/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,eskultety/libvirt