Description of problem:
- When running VM with NVDIMM device attached, the memory usage percentage in WebAdmin is always around 100% although the actual usage inside the VM is around 1%
- When removing NVDIMM and running the same VM again, the memory usage is displayed correctly.

--------------------
VM memory configuration and usage:
[root@dhcp16-201-114 ~]# ndctl list --namespaces
[
  {
    "dev":"namespace0.0",
    "mode":"raw",
    "size":266153754624,
    "sector_size":512,
    "blockdev":"pmem0"
  }
]
[root@dhcp16-201-114 ~]# ndctl list --regions
[
  {
    "dev":"region0",
    "size":266153754624,
    "available_size":0,
    "max_available_extent":0,
    "type":"pmem",
    "persistence_domain":"unknown"
  }
]
[root@dhcp16-201-114 ~]# dmesg | grep pmem
[    4.628930] pmem0: detected capacity change from 0 to 266153754624
[root@dhcp16-201-114 ~]# cat /proc/meminfo | grep -i memtotal
MemTotal:        7951468 kB
[root@dhcp16-201-114 ~]# free
              total        used        free      shared  buff/cache   available
Mem:        7951468      184188     7541536        8796      225744     7516956
Swap:             0           0           0
[root@dhcp16-201-114 ~]# 


------------------
VM domxml:
[root@intel-purley-04 images]# virsh -r dumpxml 16 | grep -i memory
    <ovirt-vm:minGuaranteedMemoryMb type="int">8192</ovirt-vm:minGuaranteedMemoryMb>
  <maxMemory slots='16' unit='KiB'>293472256</maxMemory>
  <memory unit='KiB'>268306432</memory>
  <currentMemory unit='KiB'>8388608</currentMemory>
      <cell id='0' cpus='0-15' memory='8388608' unit='KiB'/>
    <memory model='nvdimm' access='shared'>
    </memory>

Version-Release number of selected component (if applicable):
ovirt-engine-4.4.3.8-0.1.el8ev
vdsm-4.40.35-1.el8ev.x86_64
libvirt-daemon-6.6.0-6.module+el8.3.0+8125+aefcf088.x86_64
qemu-kvm-5.1.0-13.module+el8.3.0+8382+afc3bbea.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Run VM with NVDIMM device. 
2. Observe WebAdmin -> Compute -> VMs, memory column
3.

Actual results:
Memory usage is always 97%

Expected results:
Memory usage should display to the actual usage.

Additional info:
VMs domxml of same VM with/without NVDIMM device attached.
VM qemu log and engine.log attached
vdsm.log attached:
VM without NVDIMM dtarted at: 2020-11-02 08:51:02,445-0500 INFO  (jsonrpc/3) [api.virt] START create(vmParams={'vmId': 'a125d2eb-91fa-4399-b931-6c1aea6d9d55'
VM with NVDIMM started at: 2020-11-02 09:25:54,813-0500 INFO  (jsonrpc/6) [api.virt] START create(vmParams={'vmId': 'a125d2eb-91fa-4399-b931-6c1aea6d9d55',