| Message ID | 20210914190125.3289256-1-pgonda@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V2] KVM: SEV: Disable KVM_CAP_VM_COPY_ENC_CONTEXT_FROM for SEV-ES | expand |
On Tue, Sep 14, 2021, Peter Gonda wrote: > Copying an ASID into new vCPUs will not work for SEV-ES since the vCPUs > VMSAs need to be setup and measured before SEV_LAUNCH_FINISH. Return an > error if a users tries to KVM_CAP_VM_COPY_ENC_CONTEXT_FROM from an > SEV-ES guest. The destination VM is already checked for SEV and SEV-ES > with sev_guest(), so this ioctl already fails if the destination is SEV > enabled. > > Enabling mirroring a VM or copying its encryption context with an SEV-ES > VM is more involved and should happen in its own feature patch if that's > needed. This is because the vCPUs of SEV-ES VMs need to be updated with > LAUNCH_UPDATE_VMSA before LAUNCH_FINISH. This needs KVM changes because > the mirror VM has all its SEV ioctls blocked and the original VM doesn't > know about the mirrors vCPUs. mirror's, or I guess mirrors'? :-) > Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context") > > V2: > * Updated changelog with more information and added stable CC. Nit, but this in the section ignored by git (below the ---) so that omitted from the committed changelog. > Signed-off-by: Peter Gonda <pgonda@google.com> > Cc: Marc Orr <marcorr@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Nathan Tempelman <natet@google.com> > Cc: Brijesh Singh <brijesh.singh@amd.com> > Cc: kvm@vger.kernel.org > Cc: stable@vger.kernel.org > Cc: linux-kernel@vger.kernel.org Reviewed-by: Sean Christopherson <seanjc@google.com> > --- Git ignores stuff in this section. > arch/x86/kvm/svm/sev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 75e0b21ad07c..8a279027425f 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -1728,7 +1728,7 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) > source_kvm = source_kvm_file->private_data; > mutex_lock(&source_kvm->lock); > > - if (!sev_guest(source_kvm)) { > + if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) { > ret = -EINVAL; > goto e_source_unlock; > } > -- > 2.33.0.309.g3052b89438-goog >
On Tue, Sep 14, 2021 at 12:01 PM Peter Gonda <pgonda@google.com> wrote: > > Copying an ASID into new vCPUs will not work for SEV-ES since the vCPUs > VMSAs need to be setup and measured before SEV_LAUNCH_FINISH. Return an > error if a users tries to KVM_CAP_VM_COPY_ENC_CONTEXT_FROM from an > SEV-ES guest. The destination VM is already checked for SEV and SEV-ES > with sev_guest(), so this ioctl already fails if the destination is SEV > enabled. > > Enabling mirroring a VM or copying its encryption context with an SEV-ES > VM is more involved and should happen in its own feature patch if that's > needed. This is because the vCPUs of SEV-ES VMs need to be updated with > LAUNCH_UPDATE_VMSA before LAUNCH_FINISH. This needs KVM changes because > the mirror VM has all its SEV ioctls blocked and the original VM doesn't > know about the mirrors vCPUs. > > Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context") > > V2: > * Updated changelog with more information and added stable CC. > > Signed-off-by: Peter Gonda <pgonda@google.com> > Cc: Marc Orr <marcorr@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Nathan Tempelman <natet@google.com> > Cc: Brijesh Singh <brijesh.singh@amd.com> > Cc: kvm@vger.kernel.org > Cc: stable@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > arch/x86/kvm/svm/sev.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 75e0b21ad07c..8a279027425f 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -1728,7 +1728,7 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) > source_kvm = source_kvm_file->private_data; > mutex_lock(&source_kvm->lock); > > - if (!sev_guest(source_kvm)) { > + if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) { > ret = -EINVAL; > goto e_source_unlock; > } > -- > 2.33.0.309.g3052b89438-goog > Reviewed-by: Marc Orr <marcorr@google.com>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 75e0b21ad07c..8a279027425f 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -1728,7 +1728,7 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) source_kvm = source_kvm_file->private_data; mutex_lock(&source_kvm->lock); - if (!sev_guest(source_kvm)) { + if (!sev_guest(source_kvm) || sev_es_guest(source_kvm)) { ret = -EINVAL; goto e_source_unlock; }
Copying an ASID into new vCPUs will not work for SEV-ES since the vCPUs VMSAs need to be setup and measured before SEV_LAUNCH_FINISH. Return an error if a users tries to KVM_CAP_VM_COPY_ENC_CONTEXT_FROM from an SEV-ES guest. The destination VM is already checked for SEV and SEV-ES with sev_guest(), so this ioctl already fails if the destination is SEV enabled. Enabling mirroring a VM or copying its encryption context with an SEV-ES VM is more involved and should happen in its own feature patch if that's needed. This is because the vCPUs of SEV-ES VMs need to be updated with LAUNCH_UPDATE_VMSA before LAUNCH_FINISH. This needs KVM changes because the mirror VM has all its SEV ioctls blocked and the original VM doesn't know about the mirrors vCPUs. Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context") V2: * Updated changelog with more information and added stable CC. Signed-off-by: Peter Gonda <pgonda@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Nathan Tempelman <natet@google.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- arch/x86/kvm/svm/sev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)