1 files changed, 90 insertions, 59 deletions

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e0bde8518745..41fc2e4135fe 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -25,6 +25,7 @@
 #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
 
 static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
+static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
 
 static int match_apqn(struct device *dev, const void *data)
 {
@@ -49,20 +50,15 @@ static struct vfio_ap_queue *vfio_ap_get_queue(
 					int apqn)
 {
 	struct vfio_ap_queue *q;
-	struct device *dev;
 
 	if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
 		return NULL;
 	if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
 		return NULL;
 
-	dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
-				 &apqn, match_apqn);
-	if (!dev)
-		return NULL;
-	q = dev_get_drvdata(dev);
-	q->matrix_mdev = matrix_mdev;
-	put_device(dev);
+	q = vfio_ap_find_queue(apqn);
+	if (q)
+		q->matrix_mdev = matrix_mdev;
 
 	return q;
 }
@@ -119,13 +115,18 @@ static void vfio_ap_wait_for_irqclear(int apqn)
  */
 static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
 {
-	if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev)
+	if (!q)
+		return;
+	if (q->saved_isc != VFIO_AP_ISC_INVALID &&
+	    !WARN_ON(!(q->matrix_mdev && q->matrix_mdev->kvm))) {
 		kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
-	if (q->saved_pfn && q->matrix_mdev)
+		q->saved_isc = VFIO_AP_ISC_INVALID;
+	}
+	if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) {
 		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
 				 &q->saved_pfn, 1);
-	q->saved_pfn = 0;
-	q->saved_isc = VFIO_AP_ISC_INVALID;
+		q->saved_pfn = 0;
+	}
 }
 
 /**
@@ -144,7 +145,7 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
  * Returns if ap_aqic function failed with invalid, deconfigured or
  * checkstopped AP.
  */
-struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
+static struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
 {
 	struct ap_qirq_ctrl aqic_gisa = {};
 	struct ap_queue_status status;
@@ -1037,19 +1038,14 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
 {
 	struct ap_matrix_mdev *m;
 
-	mutex_lock(&matrix_dev->lock);
-
 	list_for_each_entry(m, &matrix_dev->mdev_list, node) {
-		if ((m != matrix_mdev) && (m->kvm == kvm)) {
-			mutex_unlock(&matrix_dev->lock);
+		if ((m != matrix_mdev) && (m->kvm == kvm))
 			return -EPERM;
-		}
 	}
 
 	matrix_mdev->kvm = kvm;
 	kvm_get_kvm(kvm);
 	kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
-	mutex_unlock(&matrix_dev->lock);
 
 	return 0;
 }
@@ -1083,79 +1079,118 @@ static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
+{
+	kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
+	matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
+	vfio_ap_mdev_reset_queues(matrix_mdev->mdev);
+	kvm_put_kvm(matrix_mdev->kvm);
+	matrix_mdev->kvm = NULL;
+}
+
 static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
 				       unsigned long action, void *data)
 {
-	int ret;
+	int ret, notify_rc = NOTIFY_OK;
 	struct ap_matrix_mdev *matrix_mdev;
 
 	if (action != VFIO_GROUP_NOTIFY_SET_KVM)
 		return NOTIFY_OK;
 
 	matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
+	mutex_lock(&matrix_dev->lock);
 
 	if (!data) {
-		matrix_mdev->kvm = NULL;
-		return NOTIFY_OK;
+		if (matrix_mdev->kvm)
+			vfio_ap_mdev_unset_kvm(matrix_mdev);
+		goto notify_done;
 	}
 
 	ret = vfio_ap_mdev_set_kvm(matrix_mdev, data);
-	if (ret)
-		return NOTIFY_DONE;
+	if (ret) {
+		notify_rc = NOTIFY_DONE;
+		goto 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;
+	if (!matrix_mdev->kvm->arch.crypto.crycbd) {
+		notify_rc = NOTIFY_DONE;
+		goto notify_done;
+	}
 
 	kvm_arch_crypto_set_masks(matrix_mdev->kvm, matrix_mdev->matrix.apm,
 				  matrix_mdev->matrix.aqm,
 				  matrix_mdev->matrix.adm);
 
-	return NOTIFY_OK;
+notify_done:
+	mutex_unlock(&matrix_dev->lock);
+	return notify_rc;
 }
 
-static void vfio_ap_irq_disable_apqn(int apqn)
+static struct vfio_ap_queue *vfio_ap_find_queue(int apqn)
 {
 	struct device *dev;
-	struct vfio_ap_queue *q;
+	struct vfio_ap_queue *q = NULL;
 
 	dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
 				 &apqn, match_apqn);
 	if (dev) {
 		q = dev_get_drvdata(dev);
-		vfio_ap_irq_disable(q);
 		put_device(dev);
 	}
+
+	return q;
 }
 
-int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
+int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
 			     unsigned int retry)
 {
 	struct ap_queue_status status;
+	int ret;
 	int retry2 = 2;
-	int apqn = AP_MKQID(apid, apqi);
 
-	do {
-		status = ap_zapq(apqn);
-		switch (status.response_code) {
-		case AP_RESPONSE_NORMAL:
-			while (!status.queue_empty && retry2--) {
-				msleep(20);
-				status = ap_tapq(apqn, NULL);
-			}
-			WARN_ON_ONCE(retry2 <= 0);
-			return 0;
-		case AP_RESPONSE_RESET_IN_PROGRESS:
-		case AP_RESPONSE_BUSY:
+	if (!q)
+		return 0;
+
+retry_zapq:
+	status = ap_zapq(q->apqn);
+	switch (status.response_code) {
+	case AP_RESPONSE_NORMAL:
+		ret = 0;
+		break;
+	case AP_RESPONSE_RESET_IN_PROGRESS:
+		if (retry--) {
 			msleep(20);
-			break;
-		default:
-			/* things are really broken, give up */
-			return -EIO;
+			goto retry_zapq;
 		}
-	} while (retry--);
+		ret = -EBUSY;
+		break;
+	case AP_RESPONSE_Q_NOT_AVAIL:
+	case AP_RESPONSE_DECONFIGURED:
+	case AP_RESPONSE_CHECKSTOPPED:
+		WARN_ON_ONCE(status.irq_enabled);
+		ret = -EBUSY;
+		goto free_resources;
+	default:
+		/* things are really broken, give up */
+		WARN(true, "PQAP/ZAPQ completed with invalid rc (%x)\n",
+		     status.response_code);
+		return -EIO;
+	}
+
+	/* wait for the reset to take effect */
+	while (retry2--) {
+		if (status.queue_empty && !status.irq_enabled)
+			break;
+		msleep(20);
+		status = ap_tapq(q->apqn, NULL);
+	}
+	WARN_ON_ONCE(retry2 <= 0);
 
-	return -EBUSY;
+free_resources:
+	vfio_ap_free_aqic_resources(q);
+
+	return ret;
 }
 
 static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
@@ -1163,13 +1198,15 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
 	int ret;
 	int rc = 0;
 	unsigned long apid, apqi;
+	struct vfio_ap_queue *q;
 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
 
 	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
 			     matrix_mdev->matrix.apm_max + 1) {
 		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
 				     matrix_mdev->matrix.aqm_max + 1) {
-			ret = vfio_ap_mdev_reset_queue(apid, apqi, 1);
+			q = vfio_ap_find_queue(AP_MKQID(apid, apqi));
+			ret = vfio_ap_mdev_reset_queue(q, 1);
 			/*
 			 * Regardless whether a queue turns out to be busy, or
 			 * is not operational, we need to continue resetting
@@ -1177,7 +1214,6 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
 			 */
 			if (ret)
 				rc = ret;
-			vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi));
 		}
 	}
 
@@ -1222,13 +1258,8 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev)
 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
 
 	mutex_lock(&matrix_dev->lock);
-	if (matrix_mdev->kvm) {
-		kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
-		matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
-		vfio_ap_mdev_reset_queues(mdev);
-		kvm_put_kvm(matrix_mdev->kvm);
-		matrix_mdev->kvm = NULL;
-	}
+	if (matrix_mdev->kvm)
+		vfio_ap_mdev_unset_kvm(matrix_mdev);
 	mutex_unlock(&matrix_dev->lock);
 
 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,