Performance By Design

Intercepts, interrupts and Hypercalls Three interfaces exist that allow for interaction and communication between the hypervisor, the Root partition and the guest partitions: intercepts, interrupts, and the direct Hypercall interface. These interfaces are necessary for the virtualization scheme to function properly, and their usage accounts for much of the overhead virtualization adds to the system. Hyper-V measures and reports on the rate these different interfaces are used, which is, of course, workload dependent. Frankly, the measurements that show the rate that the hypervisor processes interrupts and Hypercalls is seldom of interest outside the Microsoft developers working on Hyper-V performance itself. But these measurements do provide insight into the Hyper-V architecture and can help us understand how the performance of the applications running on guest machines is impacted due to virtualization. Figure 3 is a graph showing these three major sources of virtualization overhead...

this is a continuation of an earlier post: see  http://performancebydesign.blogspot.com/2017/12/hyper-v-performance-introduction.html , Hyper-V Architecture Hyper-V installs a hypervisor that gains control of the hardware immediately following a boot, and works in tandem with additional components that are installed in the Root partition. Hyper-V even installs a few components into Windows guest machines (e.g., synthetic device drivers, enlightenments). This section looks at how all these architectural components work together to provide a complete set of virtualization services to guest machines. Hyper-V uses a compact hypervisor component that installs at boot time. There is one version for Intel machines, Hvix64.exe, and a separate version for the slightly different AMD hardware, Hvax64.exe. The hypervisor is responsible for scheduling the processor hardware and apportioning physical memory to the various guest machines. It also provides a centralized timekeeping facility ...