AMD IOMMU emulation

by Eduard - Gabriel Munteanu for QEMU development team

AMD has designed and implemented an IOMMU that benefits virtualization by providing a means to assign devices to virtual machines. Also, by design, the IOMMU lends itself to emulation in a VM. The emulation can provide IOMMU capabilities to guests, making it possible to assign devices to nested guests. This proposal aims to implement an emulated AMD IOMMU in QEMU/KVM.