Description of problem:
On the topic of memory overhead calculations, I noticed starting a Windows VM (which initializes all guest memory shortly after boot time) with a very large memory request hits the KubevirtVmHighMemoryUsage alert a few min after boot up, while otherwise idle.

I did not reproduce with an 8Gi mem request, not sure where the threshold is yet.

Version-Release number of selected component (if applicable):
OCP 4.11.7
CNV 4.11.3-14

How reproducible:
When large mem requests are set

Steps to Reproduce:
1. Start very large memory request Win VM
2. Check for HighMem alert

Actual results:

VM definition based on 'windows10-desktop' templates but set to use:
resources:
requests:
memory: 700Gi

(i.e. 716800Mi)

virt-launcher pod mem requests got:
memory: 718448Mi

'oc adm top pod' shows virt launcher using: 721875Mi

container_memory_working_set_bytes

value is 756.9G

1. oc exec -it virt-launcher-win10-full-ct679 – ps aux
   USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
   qemu 1 0.0 0.0 1247280 16964 ? Ssl 18:12 0:00 /usr/bin/virt-launcher-monitor --qemu-timeout
   qemu 13 0.1 0.0 2886664 63032 ? Sl 18:12 0:02 /usr/bin/virt-launcher --qemu-timeout 328s --n
   qemu 27 0.0 0.0 1484592 27916 ? Sl 18:12 0:01 /usr/sbin/libvirtd -f /var/run/libvirt/libvirt
   qemu 28 0.0 0.0 222572 15740 ? Sl 18:12 0:00 /usr/sbin/virtlogd -f /etc/libvirt/virtlogd.co
   qemu 69 35.7 92.7 734858660 734117624 ? Sl 18:13 11:25 /usr/libexec/qemu-kvm -name guest=default_win1
   qemu 145 0.0 0.0 44692 3396 pts/0 Rs+ 18:45 0:00 ps aux

Expected results:
I didn't expect a large mem request to cause >3G extra overhead

Additional info:
I suspect this means a large memory "highperformance" Win VM (dedicatedCPU / mem limit will be set) may hit an OOM

If this is worth pursuing I can get more values at lower memory requests to see the overhead behavior.