core-agent-linux/qubes-rpc/prepare-suspend

#!/bin/sh

action=$1
[ -z "$action" ] && action=suspend

if [ x"$action" == x"suspend" ]; then
    nmcli nm sleep true || service NetworkManager stop
    # Force interfaces down, just in case when NM didn't done it
    for if in `ls /sys/class/net|grep -v "lo\|vif"`; do 
        ip l s $if down
    done
    modprobe -r uhci_hcd ehci_hcd
else
    modprobe ehci_hcd; modprobe uhci_hcd; 
    nmcli nm sleep false || { [ -x /bin/systemctl ] && systemctl start NetworkManager.service; } || service qubes-core-netvm start
fi