zlacker

sys-net, sys-firewall and other administrative vms should slowly migrate to unikernels instead of running linux, which should help with ram usage. The mirage.io project seems to build a couple qubes vms, for example https://github.com/mirage/qubes-mirage-firewall is a firewall which they indicate to give 64Mb of ram.

edit: maybe i'm being a bit optimistic for sys-net, which is the vm hosting the driver for the network card: these drivers are included in the linux tree and would need to be extracted and packaged into an unikernel. But for every non-driver vm it "should be easy" to get an unikernel implementation (drivers for paravirtual devices are easy to write).