Questions about the ownership of /var/cache/libvirt/qemu

[Peng Liang]

Hi all,
  When we change the user for QEMU process (change "user" and "group" in
/etc/libvirt/qemu.conf) to a normal user, we found that libvirtd will
also change the ownership of /var/cache/libvirt/qemu but will keep the
ownership of /var/cache/libvirt/qemu/capabilities as root.
  Is it secure to put files/directories owned by root in a directory
owned by a normal user?  Could the normal user replace the root's file
with a new one?  Does it need to set sticky bit on
/var/cache/libvirt/qemu or keep the ownership of /var/cache/libvirt/qemu
as root?