Hello David, David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> writes: > 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 Thank you very much for this series! Using a machine property is a nice way of configuring this. >From an end-user perspective, `-M pseries,guest-memory-protection` in the command line already expresses everything that QEMU needs to know, so having to add `-object pef-guest,id=pef0` seems a bit redundant. Is it possible to make QEMU create the pef-guest object behind the scenes when the guest-memory-protection property is specified? Regardless, I was able to successfuly launch POWER PEF guests using these patches: Tested-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> > 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. Is "opaque guest memory" any better? It's slightly shorter, and slightly more precise about what the main characteristic this guest property conveys. -- Thiago Jung Bauermann IBM Linux Technology Center
