#!/bin/bash
TOTAL_CORES='0-31'
TOTAL_CORES_MASK=FFFFFFFF    # bitmask 0b11111111111111111111111111111111
HOST_CORES='2-3,16-31'       # Cores reserved for host
HOST_CORES_MASK=FFFF000C     # bitmask 0b11111111111111110000000000001100
VIRT_CORES='4-15'            # Cores reserved for virtual machine(s)
VIRT_CORES_MASK=FFF0         # bitmask 0b00000000000000001111111111110000

VM_NAME="$1"
VM_ACTION="$2/$3"

echo $(date) QEMU hooks: $VM_NAME - $VM_ACTION >> /var/log/libvirthook.log

if [[ "$VM_NAME" = "Win10" ]]; then
    if [[ "$VM_ACTION" = "prepare/begin" ]]; then
        echo $(date) Setting host cores $HOST_CORES  >> /var/log/libvirthook.log
        systemctl set-property --runtime -- system.slice AllowedCPUs=$HOST_CORES
        systemctl set-property --runtime -- user.slice AllowedCPUs=$HOST_CORES
        systemctl set-property --runtime -- init.scope AllowedCPUs=$HOST_CORES

        echo $HOST_CORES_MASK > /sys/bus/workqueue/devices/writeback/cpumask
        echo 0 > /sys/bus/workqueue/devices/writeback/numa
        echo 3 > /proc/sys/vm/drop_caches

        for i in {0..1}; do
          sudo cpufreq-set -c ${i} -g performance --min 4000Mhz --max 4000Mhz;
          echo "performance" > /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor;
        done
        for i in {4..15}; do
            sudo cpufreq-set -c ${i} -g performance --min 5700Mhz --max 5700Mhz;
            echo "performance" > /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor;
        done
        echo $(date) Successfully reserved CPUs $VIRT_CORES >> /var/log/libvirthook.log

    elif [[ "$VM_ACTION" == "started/begin" ]]; then
        if pid=$(pidof qemu-system-x86_64); then
          chrt -fifo -p 1 $pid
          echo $(date) Changing scheduling to fifo for pid $pid >> /var/log/libvirthook.log
        fi

    elif [[ "$VM_ACTION" == "release/end" ]]; then
        systemctl set-property --runtime -- system.slice AllowedCPUs=$TOTAL_CORES
        systemctl set-property --runtime -- user.slice AllowedCPUs=$TOTAL_CORES
        systemctl set-property --runtime -- init.scope AllowedCPUs=$TOTAL_CORES

        echo $TOTAL_CORES_MASK > /sys/bus/workqueue/devices/writeback/cpumask
        echo 1 > /sys/bus/workqueue/devices/writeback/numa

        echo $(date) Successfully released CPUs $VIRT_CORES >> /var/log/libvirthook.log

        for file in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do
            echo "powersave" > $file;
        done

        for i in {0..15}; do
          sudo cpufreq-set -c ${i} -g powersave --min 800Mhz --max 5800Mhz;
        done

  	    sleep 3
	    systemctl restart nvidia-persistenced.service
    fi
fi