On Fri, Dec 04, 2020 at 02:02:05PM +0100, Cornelia Huck wrote: > On Fri, 4 Dec 2020 09:06:50 +0100 > Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote: > > > On 04.12.20 06:44, 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 > > > "securable-guest-memory" property pointing to a platform specific > > > > Can we do "securable-guest" ? > > s390x also protects registers and integrity. memory is only one piece > > of the puzzle and what we protect might differ from platform to > > platform. > > I agree. Even technologies that currently only do memory encryption may > be enhanced with more protections later. That's a good point. I've focused on the memory aspect because that's what's most immediately relevant to qemu - the fact that we can't directly access guest memory is something we have to deal with, and has some uniformity regardless of the details of the protection scheme. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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