QEMU 10.2 will introduce MSHV as a new accelerator option for Linux hosts.

MSHV is a kernel driver maintained by Microsoft's Linux System Group that aims to expose HyperV capabilities to users in various virtualization topologies: on bare metal, in nested virtualization and most recently via a new model called "Direct Virtualization".

Direct virtualization will allow owners of an L1 VM to commit parts of their assigned resources (CPU, RAM, Peripherals) to virtual L2 guests, that are technically L1 siblings. Users can take advantage of the hypervisor's isolation boundaries without the performance and functional limitations of a nested guest. Untrusted code can be sandboxed with near-native performance and access to GPUs or NVMe controllers.

Adding support for MSHV acceleration to QEMU aims to broaden the reach of this technology to a Linux audience. The talk will cover the current state of the implementation, challenges that remain and future plans for both MSHV and QEMU.