Post Syndicated from original https://lwn.net/Articles/928328/

Operating systems have traditionally used all of the memory that the
hardware provides to them. The advent of virtualization and confidential
computing is changing this picture somewhat, though; the system can now be
more picky about which memory it will use. Patches to add support for
explicit memory acceptance when running under AMD’s Secure Encrypted
Virtualization and Secure Nested Paging (SEV-SNP), though, have run
into some turbulence over how to handle a backward-compatibility issue.