Add warning that "Windows 10 guest not seeing free memory with balloon driver"

[xalt7x]

Basically I've faced an issue #586 from kvm-guest-drivers-windows.

Installation of "Balloon" (virtio-balloon) driver system from "virtio-win-gt-x64.msi / virtio-win-guest-tools.exe / virtio-win.iso v 0.1.225" on Windows 22H2 x64 , makes guest system think that ~85% of RAM (3.4/4 GB) is occupied. it greatly hurts performance and makes programs unusable.

To revert this behaviour user needs to either:

• disable VirtIO Balloon Driver (Win+R > devmgmt.msc > System devices > right click on "VirtIO Balloon Driver" > Disable device
• remove Balloon driver
• uncheck it during "Virtio-win-driver" installation

To Reproduce
Steps to reproduce the behavior:

1. Install full set of drivers including Balloon from "virtio-win-gt-x64.msi / virtio-win-guest-tools.exe / virtio-win.iso v 0.1.225" on Windows 22H2 x64
2. Check Task Manager. It will show enormous RAM usage

Expected behavior
Windows show usual amount of RAM

Comparison screenshots:

"VirtIO Balloon Driver" disabled - 1.5/4.0 GB (38%) used

"VirtIO Balloon Driver" enabled - 3.8/4.0 GB (88%) used