For those like me who don't know what Intel Fred is: "a new feature called flexible return and event delivery (FRED). The FRED architecture defines simple new

For those like me who don't know what Intel Fred is: "a new feature called flexible return and event delivery (FRED). The FRED architecture defines simple new transitions that change privilege level (ringtransitions). The FRED architecture was designed with the following goals: • Improve overall performance and response time by replacing event delivery through the interrupt descriptor table (IDT event delivery) and event return by the IRET instruction with lower latency transitions. • Improve software robustness by ensuring that event delivery establishes the full supervisor context and that event return establishes the full user context."[0] [0] https://www.intel.com/content/www/us/en/content-details/779982/flexible-return-and-event-delivery-fred-specification.html https://www.intel.com/content/www/us/en/content-details/7799...