Hi,

Henry(@MrXinWang) and I are developers of ARM. We are working to enable Cloud-hypervisor on AArch64. Now an initial version is ready, although all functionalities are not supported.

As a minimal implementation, it supports a small set of devices: including serial device, RTC and Virtio devices with MMIO transport option. We are about to submit the code as a starting point, all other devices and functionalities will be added in steps.

Before coding, we made an analysis of the gap to fully support AArch64, which could be taken as a TODO list: (updated)

• Build on AArch64: AArch64 initial build #1168
  • Fix build warnings and errors
  • Add cross-build workflows in PR Check
• FDT and architecture specific devices: AArch64: Adding AArch64 arch-related files #1223
• Device Manager:
  • Hide Port-IO
  • Add legacy devices to MMIO bus.
• Allocators:
  • GsiAllocator: Update IRQ and GSI allocation algorithm.
• Ioapic: Refactor IOAPIC #1232
  • Now Ioapic is directly referenced in device manager, but it is architecutre specific. A way to improve could be refactoring: introduce a architecture agnostic Interrupt Controller trait. Different architecture provides its own implementation: for X86 it's Ioapic; for Aarch64 it would be GIC.
• Booting:
  • A fundamental requirement for Aarch64 is: VCPU's have to be created before GIC. But in current Cloud-Hypervisor the VCPU's are created in late stage of booting. We need to refactor the steps in booting a guest to work with both architecture at first: vmm: Change booting process to cover AArch64 requirements #1238
  • And populate Arm64 specific booting source code: Enable AArch64 #1126
• Virtio:
  • MMIO transport: Add device info to FDT
  • PCI transport: Add PCI bus info to FDT
• Migration:
  • Enable dependencies for AArch64: kvm-bindings, kvm-ioctls.
• Vhost-user-*:
  • To be tested and determined.
• VFIO:
  • To be tested and determined.
• CI:
  • Update Dockerfile.
  • Get guest disk images for integration tests.
  • Add and setup CI machines.
  • Enable Aarch64 CI.