Indeed, you don't see. As the article makes plain: It's an entire hardware stack specifically designed for virtualization from the ground up, and a correspondi

Indeed, you don't see. As the article makes plain: It's an entire hardware stack specifically designed for virtualization from the ground up, and a corresponding software stack to utilize and manage it. There is no traditional HAL in Nitro because the hardware itself handles virtualization and resource isolation. You can't do that with traditional PC server hardware where a NIC is just a NIC and a SAS card is just a SAS card. Xen, on the other hand, is designed to use standard PC hardware, with all the virtualization handled in software. The only VM-specific hardware support in Xen is the hypervisor support built in to modern CPUs, and occasionally some helper functions in NIC firmware. But you still have a 100% software-based HAL to provide the isolation and bare-metal simulation. Imagine a NIC, for example, that instead of presenting itself to the OS as a single card with however many ports, can generate new virtual NICs, in hardware, and present them to the OS for assignment to a VM. The card itself manages bandwidth allocation, aggregation, encryption, and communication with cards in other hosts to create and manage VPCs.