* Sean Christopherson (sean.j.christopherson@xxxxxxxxx) wrote: > On Thu, May 21, 2020 at 01:42:46PM +1000, David Gibson wrote: > > A number of hardware platforms are implementing mechanisms whereby the > > hypervisor does not have unfettered access to guest memory, in order > > to mitigate the security impact of a compromised hypervisor. > > > > AMD's SEV implements this with in-cpu memory encryption, and Intel has > > its own memory encryption mechanism. POWER has an upcoming mechanism > > to accomplish this in a different way, using a new memory protection > > level plus a small trusted ultravisor. s390 also has a protected > > execution environment. > > > > The current code (committed or draft) for these features has each > > platform's version configured entirely differently. That doesn't seem > > ideal for users, or particularly for management layers. > > > > AMD SEV introduces a notionally generic machine option > > "machine-encryption", but it doesn't actually cover any cases other > > than SEV. > > > > This series is a proposal to at least partially unify configuration > > for these mechanisms, by renaming and generalizing AMD's > > "memory-encryption" property. It is replaced by a > > "guest-memory-protection" property pointing to a platform specific > > object which configures and manages the specific details. > > > > For now this series covers just AMD SEV and POWER PEF. I'm hoping it > > can be extended to cover the Intel and s390 mechanisms as well, > > though. > > > > Note: I'm using the term "guest memory protection" throughout to refer > > to mechanisms like this. I don't particular like the term, it's both > > long and not really precise. If someone can think of a succinct way > > of saying "a means of protecting guest memory from a possibly > > compromised hypervisor", I'd be grateful for the suggestion. > > Many of the features are also going far beyond just protecting memory, so > even the "memory" part feels wrong. Maybe something like protected-guest > or secure-guest? > > A little imprecision isn't necessarily a bad thing, e.g. memory-encryption > is quite precise, but also wrong once it encompasses anything beyond plain > old encryption. The common thread I think is 'untrusted host' - but I don't know of a better way to describe that. Dave -- Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
