KVM Forum 2018

We start to see AArch64 servers with huge amount of physical processors, memory and IO devices. Virtual machines must scale with this trend. The ARM virt machine model had limitations with respect to virtual resource sizing. This talk aims at describing recent changes and work ongoing to achieve a better scalability.

Improvements related to vcpu, PCIe bus and memory sizing will be detailed. The talk will cover the support of larger guest physical address space and extension of existing RAM with DIMM slots. While reconsidering the RAM partitioning, we will discuss the challenge of assigned device IOVA reserved regions.

This is also an opportunity to draw a comparison between the ARM virt machine model and the PC Q35 machine model, in terms of virtual resources and vertical scalability. What bridges are left to cross to get feature parity?