kernel code reading: vfio_iommu_spapr_tce
kernel code reading: vfio related
qemu code: vfio passthrough
qemu code reading: kvm init
qemu code reading: generic vcpu code
user space: Hello World of pure asm
qemu code reading: spapr iommu
qemu code reading: iommu_notification
asm_ppc64: one example for ppc64 assembly language