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 "host-trust-limitation" 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. Please apply. Changes since RFCv2: * Rebased * Removed preliminary SEV cleanups (they've been merged) * Changed name to "host trust limitation" * Added migration blocker to the PEF code (based on SEV's version) Changes since RFCv1: * Rebased * Fixed some errors pointed out by Dave Gilbert David Gibson (9): host trust limitation: Introduce new host trust limitation interface host trust limitation: Handle memory encryption via interface host trust limitation: Move side effect out of machine_set_memory_encryption() host trust limitation: Rework the "memory-encryption" property host trust limitation: Decouple kvm_memcrypt_*() helpers from KVM host trust limitation: Add Error ** to HostTrustLimitation::kvm_init spapr: Add PEF based host trust limitation spapr: PEF: block migration host trust limitation: Alter virtio default properties for protected guests accel/kvm/kvm-all.c | 40 ++------ accel/kvm/sev-stub.c | 7 +- accel/stubs/kvm-stub.c | 10 -- backends/Makefile.objs | 2 + backends/host-trust-limitation.c | 29 ++++++ hw/core/machine.c | 61 +++++++++-- hw/i386/pc_sysfw.c | 6 +- include/exec/host-trust-limitation.h | 72 +++++++++++++ include/hw/boards.h | 2 +- include/qemu/typedefs.h | 1 + include/sysemu/kvm.h | 17 ---- include/sysemu/sev.h | 4 +- target/i386/sev.c | 146 ++++++++++++--------------- target/ppc/Makefile.objs | 2 +- target/ppc/pef.c | 89 ++++++++++++++++ 15 files changed, 325 insertions(+), 163 deletions(-) create mode 100644 backends/host-trust-limitation.c create mode 100644 include/exec/host-trust-limitation.h create mode 100644 target/ppc/pef.c -- 2.26.2