Create a structure to hold a power state change callback
#include <qvm/guest.h>
struct guest_power_state_notify* guest_power_state_notify_create(struct guest_system *gsp)
After you have created the structure, you must call guest_power_state_notify_register() to set its characteristics. When you are finished with the structure, call guest_power_state_notify_delete() to remove it.
If successful, a pointer to the structure; otherwise NULL.