[libvirt] logging: Libvirtd could not create its own logfile, when the path /var/log/libvirt is not exist.

Hi all: Libvirtd could not create its own logfile, such as /var/log/libvirt/libvirtd.log, when the path /var/log/libvirt is not exist. It may be a problem,I think,so try to make patch when open file failed in virLogAddOutputToFile. or any better idea? ------------ Libvirtd just creates its logfile, such as /var/log/libvirt/libvirtd.log, DURING INSTALLATION. If the logfile(we mean its path here,that's /var/log/libvirt/) is deleted during its runtime, even if we restart libvirtd, such file would not be generated automatically, thus, the logs are all missing after then, it becomes impossible to debug problems after then as well. So, we try to mkdir the deleted path after restarting libvirtd. Or, any better idea? Thanks in advance. Wei Fuqiang