What does the “Additional dom0 memory” setting in Qubes Glocal Config do?
Specifically:
Qubes Global Config → General Settings → Memory balancing → Additional dom0 memory
I see that this manages the dom0-mem-boost setting in /etc/qubes/qmemman.conf, a filed read by qmemmand. I tried increasing this to give the dom0 VM more RAM but it had no effect even after reboot. Then I found the dom0_mem=max:####M flag in /etc/default/grub, boosted that, updated GRUB (grub2-mkconfig -o /boot/grub2/grub.cfg), rebooted, and voila, more RAM assigned to dom0. But I’m left wondering, what does dom0-mem-boost in /etc/qubes/qmemman.conf do? How does it interact with dom0_mem=max:####M and dom0_mem=min:####M?
And that got me wondering on a tangent:
How does the “Minimum qube memory” setting in Qubes Glocal Config interact with qvm-prefs memory settings?
Specifically:
Qubes Global Config → General Settings → Memory balancing → Minimum qube memory
(vm-min-mem in /etc/qubes/qmemman.conf)
Versus:
qvm-prefs VM memory← effectively a lower bound
qvm-prefs VM maxmem← effectively an upper bound