Speakers
Description
Modern cloud computing increasingly relies on confidential virtual machines (VMs) - isolated environments
where sensitive workloads run securely, even from the underlying hypervisor. A key challenge in this space
is enabling these confidential VMs to safely communicate with hardware devices without exposing their data
to the host system or hypervisor.
Virtual IOMMU (vIOMMU) is an extended feature of AMD's IOMMU that allows IOMMU hardware to directly access
and process virtual machine data structures. Building on this foundation, AMD's Secure vIOMMU extends
vIOMMU capabilities to support SEV-TIO (Secure Encrypted Virtualization - Trusted IO) device assignment to
confidential virtual machines. Specifically, it enables secure communication channels between confidential
virtual machine and IOMMU hardware enabling reliable management of device DMAs including guest TLBs without
hypervisor intervention.
This presentation introduces the Secure vIOMMU architecture and explains how its components work together
-- including the IOMMU, AMD's Security Processor, the hypervisor, Virtual Machine Manager (VMM) and
confidential VMs. We will also cover supported operational modes (vTOM and Guest Page Table) for secure
data transmission between Trusted I/O devices and confidential VM.
Finally, we will discuss the interface challenges that arise across various kernel modules including IOMMU,
ccp, KVM, SEV-TIO, etc, and explore potential approaches to address them.
SEV-TIO specification: https://docs.amd.com/v/u/en-US/58271_0.91
Secure vIOMMU initial code: https://github.com/AMDESE/linux-iommu/tree/sviommu/tsm0407_v619_v0