#!/bin/bash
#/etc/libvirt/hooks/qemu

HCPUS=8-15,24-31
MCPUS=0-7,16-23
ACPUS=0-31

disable_isolation () {
            systemctl set-property --runtime -- user.slice AllowedCPUs=$ACPUS
            systemctl set-property --runtime -- system.slice AllowedCPUs=$ACPUS
            systemctl set-property --runtime -- init.scope AllowedCPUs=$ACPUS

            taskset -pc $ACPUS 2  # kthreadd reset
}

enable_isolation () {
            systemctl set-property --runtime -- user.slice AllowedCPUs=$HCPUS
            systemctl set-property --runtime -- system.slice AllowedCPUs=$HCPUS
            systemctl set-property --runtime -- init.scope AllowedCPUs=$HCPUS

            irq-affinity mask $MCPUS

            taskset -pc $MCPUS 2  # kthreadd only on host cores
}

case "$2" in
"prepare")
        enable_isolation
        echo "prepared" >> /home/username/qemu_hook.log
        ;;
"started")
        echo "started" >> /home/username/qemu_hook.log
        ;;
"release")
        disable_isolation
        echo "released" >> /home/username/qemu_hook.log
        ;;
esac