PVHbased

PVHbased refers to virtualization environments that implement the PVH interface, a hybrid approach that combines paravirtualization (PV) with hardware-assisted virtualization (HVM). PVH is designed to reduce the overhead of native paravirtualization while avoiding the full emulation required by traditional hardware virtualization, thereby delivering improved performance for guest operating systems, particularly Linux-based workloads.

The concept originated within the Xen virtualization project as a PVH mode that allows a guest to run with a minimal hypervisor interface while still using paravirtualized drivers for I/O and other services. Over time, PVH-based techniques have influenced other hypervisors and kernel-level virtualization work, with Linux kernels and related tooling providing support for PVH-based guests. In this approach, a guest presents a compact interface to the hypervisor and uses virtio and other paravirtual devices, while hardware-assisted virtualization features are leveraged for memory management and execution.

Implementation typically involves a PVH-capable kernel and a hypervisor that exposes a PVH-friendly API. It aims to offer fast boot, low interrupt latency, and high I/O throughput compared with purely PV or fully emulated guests. PVH-based deployments are common in cloud environments that require efficient Linux guests, and they can coexist with traditional PV and HVM guests depending on hypervisor capabilities and configuration.

Limitations include the need for kernel and hypervisor support, potential feature gaps compared to full PV or HVM paths, and the need for compatible tooling and drivers. See also: Paravirtualization, Xen, PV, HVM, virtio.