SDEI clientSDEI clientEL3EL3SDEISDEIRAS DriverRAS Driver[1]SDEI_EVENT_REGISTER(ev, handler, ...)[2]success[3]SDEI_EVENT_ENABLE(ev)[4]success[5]SDEI_PE_UNMASK()[6]1<<Business as usual>>[7]CRITICAL EVENTCritical event triage[8]dispatch to handleCritical event handling[9]sdei_dispatch_event(ev)Prepare SDEI dispatch[10]dispatchSDEI handler[11]SDEI_EVENT_COMPLETE()Complete SDEI dispatch[12]return[13]error handling done[14]resumes preempted execution<<Normal execution resumes>>