The weapon to enter the virtualization Detailed Intel VT technology

At the moment, cloud computing and virtualization are hot topics in the industry. But virtualization is not a new thing. As early as the mainframe era, virtualization technology has been applied to servers and mainframes. In this way, the emergence and application of virtualization technology has been around for decades. With the continuous advancement of IT technology and the continuous growth of PC performance, the application of virtualization technology has gradually spread to the field of x86 architecture. The depth of virtualization has also gone from pure software to processor-level virtualization, platform-level virtualization, and input/output. Level virtualization. As the leader in the semiconductor industry, Intel has introduced its own technology in these areas, collectively known as Intel Virtualization Technology, Intel Virtualization Technology (also known as Intel VT technology).

VT technology covers all virtualization hardware-assisted technologies provided by Intel across the entire system platform (CPU, chipset, I/O). Specifically, it includes Intel VT-x technology for processors, Intel VT-d technology for chipsets, and Intel VT-c technology for networks.

VT-x

VT-x technology provides virtualization hardware accessibility in all Intel Xeon processors, reducing VMM intervention and providing a transport platform between VMM and guest operating systems Control provides powerful hardware support. VT-x technologies include Intel Virtual Flex Migration Technology (Intel VT FlexMigration), Intel VT FlexPriority, Intel VT Extended Page Tables, and more.

- When a processor performs a task, it often receives requests or "interrupt" commands from other devices or applications that require attention. To minimize the impact on performance, a dedicated register (APIC Task Priority Register, or TPR) within the processor will monitor the task priority. As a result, only interrupts with a higher priority than the currently running task will be noticed in time. Intel VT FlexPriority technology enables significant performance gains in 32-bit operating systems that use TPR frequently by creating a virtual copy of TPR6 that can be read and, in some cases, can be changed by the guest operating system.

- Intel Virtual Flex Migration Technology (Intel VT FlexMigration) provides compatibility with dynamic partition migration across server resource pools, and applications create a consistent set of instructions across all servers in the migration pool to implement workloads Seamless migration. This creates a more flexible, unified server resource pool that can run seamlessly across multiple generations of hardware.

VT-d

VT-d technology provides virtualization hardware accessibility in all Intel chipsets. Each device has a dedicated area in system memory that only the device and its assigned guest operating system can access. The Virtual Machine Monitor (VMM) securely assigns specific I/O devices to specific guest operating systems, and data can be transferred directly between the guest operating system and the devices assigned to it. This reduces the need for virtual machine monitors (VMMs) to participate in managing I/O traffic, speeding up data transfers and reducing most of the performance overhead.

VT-c

VT-c technology provides virtualization hardware accessibility across all Intel networks and I/O devices for further network optimization of virtualization for faster delivery Reduce the load of the VMM and the server processor. Intel VT-c includes the following two key technologies:

-- Virtual Machine Device Queue (VMDq): The VMM can classify each packet by dedicated hardware in the Intel Server NIC, VMM It is only responsible for sending the pre-classified packet group to the appropriate guest operating system. This will slow down I/O latency, reduce I/O bottlenecks, and allow the processor to get more cycles available to handle business applications.

-- Virtual Machine Direct Interconnect (VMDc): SR-IOV can extend this by supporting multiple direct communication channels per I/O port. Virtual Machine Direct Interconnect (VMDc) enables virtual machines to directly access network I/O hardware, dramatically improving virtual performance. For example, a single Intel 10 Gigabit Server NIC can be assigned a protected, 1 Gb/sec dedicated link for each of the 10 guest operating systems. These direct communication links bypass the VMM switch, further improving I/O performance and reducing the load on the server processor.