Libvirt is executing qemu requiring it to execute pulseaudio which would
require the folowing permissions,
#============= svirt_t ==============
allow svirt_t admin_home_t:dir setattr;
allow svirt_t admin_home_t:file { read write };
allow svirt_t pulseaudio_port_t:tcp_socket name_connect;
allow svirt_t svirt_tmpfs_t:file read;
allow svirt_t user_tmpfs_t:file read;
Since qemu(svirt_t) is not allowed these permissions, pulseaudio crashes
and qemu dies.
I believe you need to run without sound if you are running as root.