Unmapped Private Memory for Confidential Guests

Explore the concept of Unmapped Private Memory (UPM) for KVM guests in this 20-minute conference talk from the Linux Plumbers Conference 2022. Delve into the proposed new method for managing private guest memory, focusing on its application to confidential guests. Examine key topics such as the design of KVM/memfd interfaces, pre-populating private memory for in-place encryption during guest startup, preventing double-allocations, and performance considerations. Gain insights into the development and planning of UPM support, addressing outstanding issues and potential implementations for technologies like SEV and SEV-SNP.