On 1/11/21 5:50 PM, Halil Pasic wrote:
On Tue, 22 Dec 2020 20:15:58 -0500
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>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 15 +++++++++++++++
drivers/s390/crypto/vfio_ap_private.h | 2 ++
2 files changed, 17 insertions(+)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 2d58b39977be..44b3a81cadfb 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -293,6 +293,20 @@ static void vfio_ap_matrix_init(struct ap_config_info *info,
matrix->adm_max = info->apxa ? info->Nd : 15;
}
+static bool vfio_ap_mdev_has_crycb(struct ap_matrix_mdev *matrix_mdev)
+{
+ return (matrix_mdev->kvm && matrix_mdev->kvm->arch.crypto.crycbd);
+}
+
+static void vfio_ap_mdev_commit_shadow_apcb(struct ap_matrix_mdev *matrix_mdev)
+{
+ if (vfio_ap_mdev_has_crycb(matrix_mdev))
+ kvm_arch_crypto_set_masks(matrix_mdev->kvm,
+ matrix_mdev->shadow_apcb.apm,
+ matrix_mdev->shadow_apcb.aqm,
+ matrix_mdev->shadow_apcb.adm);
+}
+
static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev;
@@ -308,6 +322,7 @@ 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);
+ 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;
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 4e5cc72fc0db..d2d26ba18602 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;
struct kvm *kvm;
What happened to the following hunk from v12?
That's a very good question, I'll reinstate it.
@@ -1218,13 +1233,9 @@ 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)
- 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_shadow_apcb(matrix_mdev);
return NOTIFY_OK;
}
