AMDVi

AMD-Vi, short for AMD I/O Memory Management Unit, is a virtualization-oriented hardware feature implemented by AMD. It provides DMA remapping and interrupt remapping to allow the CPU and multiple virtual machines to safely share PCIe devices. By translating device-accessed addresses, AMD-Vi helps protect host memory from stray or malicious device accesses while enabling direct device assignment to virtual machines.

DMA remapping creates a separate address space for each device and remaps its DMA operations to the host's physical memory through an IOMMU. Interrupt remapping routes hardware interrupts to the appropriate VM or host context. Together, these capabilities enable PCIe device passthrough, allowing a virtual machine to own a real graphics card, network card, or other PCIe device with near-native performance and isolation.

AMD-Vi is commonly used in enterprise and data center virtualization environments with platforms such as Linux KVM, VMware, and Xen, typically via the VFIO or equivalent IOMMU drivers. It also supports multi-VM isolation and secure boot of devices, reducing the risk of cross-VM memory corruption and device misuse.

Implementation requires compatible AMD CPUs and motherboard firmware, plus active IOMMU support in the operating system. In Linux, this is commonly enabled by using the amd_iommu kernel parameter and corresponding IOMMU drivers. AMD-Vi is a standard feature in many AMD processors and remains a core part of AMD's virtualization ecosystem.