[PATCH v15 05/13] s390/vfio-ap: introduce shadow APCB

Tony Krowiak
2021-04-06T15:31:52Z

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@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 10 ++++++----
drivers/s390/crypto/vfio_ap_private.h | 2 ++
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 8bc21f3ec2b4..ce57d7f24f74 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -327,6 +327,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
matrix_mdev->mdev = mdev;
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
init_waitqueue_head(&matrix_mdev->wait_for_kvm);
+ vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
hash_init(matrix_mdev->qtable);
mdev_set_drvdata(mdev, matrix_mdev);
matrix_mdev->pqap_hook.hook = handle_pqap;
@@ -1201,12 +1202,13 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
}

kvm_get_kvm(kvm);
+ memcpy(&matrix_mdev->shadow_apcb, &matrix_mdev->matrix,
+ sizeof(struct ap_matrix));
matrix_mdev->kvm_busy = true;
mutex_unlock(&matrix_dev->lock);
- kvm_arch_crypto_set_masks(kvm,
- matrix_mdev->matrix.apm,
- matrix_mdev->matrix.aqm,
- matrix_mdev->matrix.adm);
+ kvm_arch_crypto_set_masks(kvm, matrix_mdev->shadow_apcb.apm,
+ matrix_mdev->shadow_apcb.aqm,
+ matrix_mdev->shadow_apcb.adm);
mutex_lock(&matrix_dev->lock);
kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
matrix_mdev->kvm = kvm;
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index af3f53a3ea4c..6f4f1f5bd611 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -75,6 +75,7 @@ struct ap_matrix {
* @list: allows the ap_matrix_mdev struct to be added to a list
* @matrix: the adapters, usage domains and control domains assigned to the
* mediated matrix device.
+ * @shadow_apcb: the shadow copy of the APCB field of the KVM guest's CRYCB
* @group_notifier: notifier block used for specifying callback function for
* handling the VFIO_GROUP_NOTIFY_SET_KVM event
* @kvm: the struct holding guest's state
@@ -82,6 +83,7 @@ struct ap_matrix {
struct ap_matrix_mdev {
struct list_head node;
struct ap_matrix matrix;
+ struct ap_matrix shadow_apcb;
struct notifier_block group_notifier;
struct notifier_block iommu_notifier;
bool kvm_busy;
--
2.21.3