Permission denied when using pty type serial device with stdio_handler = "file"

Issue

• Below error occurs during start VM when using pty type serial device with stdio_handler = "file"

  1. Confirm qemu.conf whether stdio_handler is setting to file

     # cat /etc/libvirt/qemu.conf
     ...
     stdio_handler = 'file'
     

  2. Check if pty serial type is in use

     #virsh dumpxml  <vm>
     ...
      <serial type='pty'>
           <log file='/var/lib/libvirt/console.log1'/>
     

  3. Check owership of /var/lib/libvirt/console.log1 is root:root

  4. Start Virtual Machine

     # virsh start <vm>
     internal error: qemu unexpectedly closed the monitor:
     qemu-kvm -chardev pty,id=charserial0,logfile=/var/lib/libvirt/<vm>/console.log:  Unable to open logfile var/lib/libvirt/<vm>/console.log
     Permission Denied.