After studying this chapter, you should be able to: Describe the various approaches to virtualization, understand the processor issues involved in implementing a virtual machine, understand the memory management issues involved in implementing a virtual machine, understand the I/O management issues involved in implementing a virtual machine,. | CSC 322 Operating Systems Concepts Lecture - 24: by Ahmed Mumtaz Mustehsan Special Thanks To: Tanenbaum, Modern Operating Systems 3 e, (c) 2008 Prentice-Hall, Inc. (Chapter-5) Silberschatz, Galvin and Gagne 2002, Operating System Concepts, Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad 1 Chapter 5 Input/ Output Principals of I/O Hardware (contd ) Principals of I/O Software Lecture-24 2 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad The connections between the devices and the interrupt controller use interrupt lines on the bus rather than dedicated wires. (sets interrupt bit) PC interrupt structure Lecture-24 3 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad Each devise asserts a signal on a bus assigned until attended by Interrupt controller. Controller detects and distinguish the interrupt signal by the device. If no other interrupt pending it immediately process the interrupt. Otherwise process high priority interrupt, and ignores the interrupt. Controller puts number on address . | CSC 322 Operating Systems Concepts Lecture - 24: by Ahmed Mumtaz Mustehsan Special Thanks To: Tanenbaum, Modern Operating Systems 3 e, (c) 2008 Prentice-Hall, Inc. (Chapter-5) Silberschatz, Galvin and Gagne 2002, Operating System Concepts, Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad 1 Chapter 5 Input/ Output Principals of I/O Hardware (contd ) Principals of I/O Software Lecture-24 2 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad The connections between the devices and the interrupt controller use interrupt lines on the bus rather than dedicated wires. (sets interrupt bit) PC interrupt structure Lecture-24 3 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad Each devise asserts a signal on a bus assigned until attended by Interrupt controller. Controller detects and distinguish the interrupt signal by the device. If no other interrupt pending it immediately process the interrupt. Otherwise process high priority interrupt, and ignores the interrupt. Controller puts number on address line telling CPU which device wants attention Table (interrupt vector) points to interrupt service routine Number on address line acts as index into interrupt vector Interrupt vector contains PC which points to start of service routine Interrupt processing Lecture-24 4 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad Interrupt service routine acknowledge interrupt Saves information about interrupted program Where to save information User process stack, kernel stack are both possibilities Both have problems User process, stack pointer might me illegal may cause fatal error or stack pointer at the end of page may cause page fault, interrupt causing interrupt, difficult to handle that where to save state? Save to kernel stack, legal stack pointer, but trap to kernel space, change MMU, will invalidate TLB and cache, reloading all these is time consuming Interrupt processing Lecture-24 5 Ahmed Mumtaz Mustehsan, GM-IT, CIIT, Islamabad PC (Program Counter) is saved in a known place. All .
