What is missing for AxVisor in x86_64 architecture

[hky1999]

1. Emulated Local APIC support (WIP)

Including emulated xAPIC and x2APIC.

There is a work-in-progress repo x86_vlapic.

I believe @@aarkegz is working on that

Reference:

• ACRN's vlapic.c

2. Emulated ioapic support

Manage irq routing.

Reference:

• ACRN's vioapic.c
• Jailhouse ioapic.c

3. Emulated iommu (Intel VT-d) support

Essential for physical device assignment/passthrough; DMA remapping and interrupt remapping.

Refer to

• Jailhouse vtd
• ACRN's vtd

4. Emulated PCI bus

For virtio-pci support, because x86_64 do not support virtio-mmio transport layer.

There is a staging raw implementation at crates/pci

5. Virtio-PCI transport layer

Based on emulated PCI bus, it should coexist with virtio-mmio.

There is also a staging implementation at device/virtio/transport/virtio_pci.rs