bedna

Tried this?
https://gist.github.com/c0m4r/b3fea6342bcf5a1b25b608fc36100d68#pwm-fan-control
 
Ie: download the script and systemd service, edit the script to your liking (or try default) and activate the service.
As default It configures to user_space and checks temps every 10s.
 
https://raw.githubusercontent.com/c0m4r/radxa_rock5c_lite/refs/heads/main/usr/local/bin/rock5c_fan_pwm
########################################################## # Radxa Rock 5C fan PWM control script # Author: https:///github.com/c0m4r # License: Public Domain ########################################################## # PWM control path PWM_PATH="/sys/devices/platform/pwm-fan/hwmon" # Configuration INTERVAL=10 # Temperature check interval (seconds) FAN_OFF=1 # 1 = turn off fan below MIN_TEMP after cooldown, 0 = keep at min RPM COOLDOWN=300 # time to wait before turning off the fan when FAN_OFF=1 # Critical temp protection POWEROFF_ON_CRIT=1 # 1 = shutdown when the temperature reaches a critical value, 0 = disable CRITICAL_TEMP=70 # Critical temperature (shutdown) # PWM Values (proper) SAFE_PWM_MIN=105 # Safe minimum PWM to keep fan spinning PWM_LOW=125 # 45–50°C (~50% speed) PWM_MID=165 # 50–55°C (~65% speed) PWM_HIGH=200 # 55–60°C (~80% speed) PWM_MAX=255 # >60°C (100% speed) # PWM Values (temporary - use these instead of proper if the fan spins at max all the time) #SAFE_PWM_MIN=50 # Safe minimum PWM to keep fan spinning #PWM_LOW=60 # 45–50°C (~50% speed) #PWM_MID=70 # 50–55°C (~65% speed) #PWM_HIGH=80 # 55–60°C (~80% speed) #PWM_MAX=255 # >60°C (100% speed) # Constants (requires also changes in code) MIN_TEMP=47 # Minimum temperature (PWM_MIN) MAX_TEMP=60 # Maximum temperature (PWM_MAX) # Set thermal policy thermal_zones=$(ls -1 /sys/class/thermal | grep thermal_zone) if [[ "$thermal_zones" ]]; then for i in /sys/class/thermal/thermal_zone*/policy ; do echo "user_space" > "$i" done else echo "No sensors found, check kernel support, setting fan to high for now!" echo $PWM_HIGH > ${PWM_PATH}/hwmon*/pwm1 exit 1 fi # Set PWM_MIN based on FAN_OFF mode if [ "$FAN_OFF" -eq 1 ]; then PWM_MIN=0 # Allow fan to turn off after cooldown else PWM_MIN=$SAFE_PWM_MIN # Keep fan at minimal safe RPM all the time fi # Validate PWM path if [ ! -d "$PWM_PATH" ]; then echo "Error: PWM control file not found: $PWM_PATH" exit 1 fi # Initialize variables current_pwm=$(cat ${PWM_PATH}/hwmon*/pwm1) # Start at current PWM last_high_temp_time=0 # Track last high temp for cooldown echo "Initializing fan at PWM $current_pwm" echo "$current_pwm" > ${PWM_PATH}/hwmon*/pwm1 # Main loop while true; do for i in /sys/class/thermal/thermal_zone*/policy ; do echo "user_space" > "$i" done <snip>  

I do not know what software you use to create the virtual machine, but this is question for them to answer.