On Fri, 21 Aug 2020 15:56:06 -0400 Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote: > The APCB is a field within the CRYCB that provides the AP configuration > to a KVM guest. Let's introduce a shadow copy of the KVM guest's APCB and > maintain it for the lifespan of the guest. > > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > --- > drivers/s390/crypto/vfio_ap_ops.c | 32 ++++++++++++++++++++++----- > drivers/s390/crypto/vfio_ap_private.h | 2 ++ > 2 files changed, 29 insertions(+), 5 deletions(-) (...) > @@ -1202,13 +1223,12 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > if (ret) > return NOTIFY_DONE; > > - /* If there is no CRYCB pointer, then we can't copy the masks */ > - if (!matrix_mdev->kvm->arch.crypto.crycbd) > + if (!vfio_ap_mdev_has_crycb(matrix_mdev)) > return NOTIFY_DONE; > > - kvm_arch_crypto_set_masks(matrix_mdev->kvm, matrix_mdev->matrix.apm, > - matrix_mdev->matrix.aqm, > - matrix_mdev->matrix.adm); > + memcpy(&matrix_mdev->shadow_apcb, &matrix_mdev->matrix, > + sizeof(matrix_mdev->shadow_apcb)); > + vfio_ap_mdev_commit_crycb(matrix_mdev); We are sure that the shadow APCB always matches up as we are the only ones manipulating the APCB in the CRYCB, right? > > return NOTIFY_OK; > }