[PATCH v3 0/2] KVM: x86: guest interface for SEV live migration

From: Paolo Bonzini
Date: Thu Apr 29 2021 - 06:47:19 EST


This is a reviewed version of the guest interface (hypercall+MSR)
for SEV live migration. The differences lie mostly in the API
for userspace. In particular:

- the CPUID feature is not exposed in KVM_GET_SUPPORTED_CPUID

- the hypercall must be enabled manually with KVM_ENABLE_CAP

- the MSR has sensible behavior if not filtered

Compared to v2, the KVM-provided behavior of the MSR is different:
it is set to 0 if the guest memory is encrypted, and 1 if it is not.
The idea is that the MSR is read-only if KVM_FEATURE_HC_PAGE_ENC_STATUS
is not exposed to the guest (it should only be exposed if the guest has
encrypted memory), but it also has a sensible value for non-encrypted
guests. QEMU could however expose a "0" value for the special "-cpu
host,migratable=no" mode if it wanted.

Because of this new behavior, the CPUID bit are split.

Paolo

Ashish Kalra (1):
KVM: X86: Introduce KVM_HC_PAGE_ENC_STATUS hypercall

Paolo Bonzini (1):
KVM: x86: add MSR_KVM_MIGRATION_CONTROL

Documentation/virt/kvm/api.rst | 14 +++++++
Documentation/virt/kvm/cpuid.rst | 9 +++++
Documentation/virt/kvm/hypercalls.rst | 21 ++++++++++
Documentation/virt/kvm/msr.rst | 14 +++++++
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 3 ++
arch/x86/include/uapi/asm/kvm_para.h | 5 +++
arch/x86/kvm/cpuid.c | 3 +-
arch/x86/kvm/svm/svm.c | 1 +
arch/x86/kvm/vmx/vmx.c | 7 ++++
arch/x86/kvm/x86.c | 56 +++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 1 +
include/uapi/linux/kvm_para.h | 1 +
13 files changed, 135 insertions(+), 1 deletion(-)

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2.26.2