Why are volume groups and logical volumes from a guest displayed in the output of vgs and lvs on the host?

Issue

• Logical volumes and volume groups for a KVM guest are seen on the host. This is for a single virtual machine only. All the other volume groups from virtual machines running on the same host are not seen by the host. Why is this?
• The hosts systems are clustered via RHCS. For each virtual machine, we present one or more LUNs from the SAN and created a clustered volume group for the VM. Then we created logical volumes within the volume group that we present to the virtual machine. The problematic host was rebooted after all VMs were migrated to the remaining node. Now we don't see the guests' volume groups in the host after reboot.
• When I create a logical volume on the guest system, then do vgscan or pvscan on the host, we get the logical volumes from the guest on host. How can I resolve this?