1 files changed, 372 insertions, 7 deletions

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 900b9cf20ca5..0604b49a4d32 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -24,6 +24,295 @@
 #define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
 #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
 
+static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
+
+static int match_apqn(struct device *dev, const void *data)
+{
+	struct vfio_ap_queue *q = dev_get_drvdata(dev);
+
+	return (q->apqn == *(int *)(data)) ? 1 : 0;
+}
+
+/**
+ * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
+ * @matrix_mdev: the associated mediated matrix
+ * @apqn: The queue APQN
+ *
+ * Retrieve a queue with a specific APQN from the list of the
+ * devices of the vfio_ap_drv.
+ * Verify that the APID and the APQI are set in the matrix.
+ *
+ * Returns the pointer to the associated vfio_ap_queue
+ */
+static struct vfio_ap_queue *vfio_ap_get_queue(
+					struct ap_matrix_mdev *matrix_mdev,
+					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);
+
+	return q;
+}
+
+/**
+ * vfio_ap_wait_for_irqclear
+ * @apqn: The AP Queue number
+ *
+ * Checks the IRQ bit for the status of this APQN using ap_tapq.
+ * Returns if the ap_tapq function succeeded and the bit is clear.
+ * Returns if ap_tapq function failed with invalid, deconfigured or
+ * checkstopped AP.
+ * Otherwise retries up to 5 times after waiting 20ms.
+ *
+ */
+static void vfio_ap_wait_for_irqclear(int apqn)
+{
+	struct ap_queue_status status;
+	int retry = 5;
+
+	do {
+		status = ap_tapq(apqn, NULL);
+		switch (status.response_code) {
+		case AP_RESPONSE_NORMAL:
+		case AP_RESPONSE_RESET_IN_PROGRESS:
+			if (!status.irq_enabled)
+				return;
+			/* Fall through */
+		case AP_RESPONSE_BUSY:
+			msleep(20);
+			break;
+		case AP_RESPONSE_Q_NOT_AVAIL:
+		case AP_RESPONSE_DECONFIGURED:
+		case AP_RESPONSE_CHECKSTOPPED:
+		default:
+			WARN_ONCE(1, "%s: tapq rc %02x: %04x\n", __func__,
+				  status.response_code, apqn);
+			return;
+		}
+	} while (--retry);
+
+	WARN_ONCE(1, "%s: tapq rc %02x: %04x could not clear IR bit\n",
+		  __func__, status.response_code, apqn);
+}
+
+/**
+ * vfio_ap_free_aqic_resources
+ * @q: The vfio_ap_queue
+ *
+ * Unregisters the ISC in the GIB when the saved ISC not invalid.
+ * Unpin the guest's page holding the NIB when it exist.
+ * Reset the saved_pfn and saved_isc to invalid values.
+ *
+ */
+static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
+{
+	if (q->saved_isc != VFIO_AP_ISC_INVALID && q->matrix_mdev)
+		kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
+	if (q->saved_pfn && 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;
+}
+
+/**
+ * vfio_ap_irq_disable
+ * @q: The vfio_ap_queue
+ *
+ * Uses ap_aqic to disable the interruption and in case of success, reset
+ * in progress or IRQ disable command already proceeded: calls
+ * vfio_ap_wait_for_irqclear() to check for the IRQ bit to be clear
+ * and calls vfio_ap_free_aqic_resources() to free the resources associated
+ * with the AP interrupt handling.
+ *
+ * In the case the AP is busy, or a reset is in progress,
+ * retries after 20ms, up to 5 times.
+ *
+ * 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)
+{
+	struct ap_qirq_ctrl aqic_gisa = {};
+	struct ap_queue_status status;
+	int retries = 5;
+
+	do {
+		status = ap_aqic(q->apqn, aqic_gisa, NULL);
+		switch (status.response_code) {
+		case AP_RESPONSE_OTHERWISE_CHANGED:
+		case AP_RESPONSE_NORMAL:
+			vfio_ap_wait_for_irqclear(q->apqn);
+			goto end_free;
+		case AP_RESPONSE_RESET_IN_PROGRESS:
+		case AP_RESPONSE_BUSY:
+			msleep(20);
+			break;
+		case AP_RESPONSE_Q_NOT_AVAIL:
+		case AP_RESPONSE_DECONFIGURED:
+		case AP_RESPONSE_CHECKSTOPPED:
+		case AP_RESPONSE_INVALID_ADDRESS:
+		default:
+			/* All cases in default means AP not operational */
+			WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
+				  status.response_code);
+			goto end_free;
+		}
+	} while (retries--);
+
+	WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
+		  status.response_code);
+end_free:
+	vfio_ap_free_aqic_resources(q);
+	q->matrix_mdev = NULL;
+	return status;
+}
+
+/**
+ * vfio_ap_setirq: Enable Interruption for a APQN
+ *
+ * @dev: the device associated with the ap_queue
+ * @q:	 the vfio_ap_queue holding AQIC parameters
+ *
+ * Pin the NIB saved in *q
+ * Register the guest ISC to GIB interface and retrieve the
+ * host ISC to issue the host side PQAP/AQIC
+ *
+ * Response.status may be set to AP_RESPONSE_INVALID_ADDRESS in case the
+ * vfio_pin_pages failed.
+ *
+ * Otherwise return the ap_queue_status returned by the ap_aqic(),
+ * all retry handling will be done by the guest.
+ */
+static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
+						 int isc,
+						 unsigned long nib)
+{
+	struct ap_qirq_ctrl aqic_gisa = {};
+	struct ap_queue_status status = {};
+	struct kvm_s390_gisa *gisa;
+	struct kvm *kvm;
+	unsigned long h_nib, g_pfn, h_pfn;
+	int ret;
+
+	g_pfn = nib >> PAGE_SHIFT;
+	ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1,
+			     IOMMU_READ | IOMMU_WRITE, &h_pfn);
+	switch (ret) {
+	case 1:
+		break;
+	default:
+		status.response_code = AP_RESPONSE_INVALID_ADDRESS;
+		return status;
+	}
+
+	kvm = q->matrix_mdev->kvm;
+	gisa = kvm->arch.gisa_int.origin;
+
+	h_nib = (h_pfn << PAGE_SHIFT) | (nib & ~PAGE_MASK);
+	aqic_gisa.gisc = isc;
+	aqic_gisa.isc = kvm_s390_gisc_register(kvm, isc);
+	aqic_gisa.ir = 1;
+	aqic_gisa.gisa = (uint64_t)gisa >> 4;
+
+	status = ap_aqic(q->apqn, aqic_gisa, (void *)h_nib);
+	switch (status.response_code) {
+	case AP_RESPONSE_NORMAL:
+		/* See if we did clear older IRQ configuration */
+		vfio_ap_free_aqic_resources(q);
+		q->saved_pfn = g_pfn;
+		q->saved_isc = isc;
+		break;
+	case AP_RESPONSE_OTHERWISE_CHANGED:
+		/* We could not modify IRQ setings: clear new configuration */
+		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1);
+		kvm_s390_gisc_unregister(kvm, isc);
+		break;
+	default:
+		pr_warn("%s: apqn %04x: response: %02x\n", __func__, q->apqn,
+			status.response_code);
+		vfio_ap_irq_disable(q);
+		break;
+	}
+
+	return status;
+}
+
+/**
+ * handle_pqap: PQAP instruction callback
+ *
+ * @vcpu: The vcpu on which we received the PQAP instruction
+ *
+ * Get the general register contents to initialize internal variables.
+ * REG[0]: APQN
+ * REG[1]: IR and ISC
+ * REG[2]: NIB
+ *
+ * Response.status may be set to following Response Code:
+ * - AP_RESPONSE_Q_NOT_AVAIL: if the queue is not available
+ * - AP_RESPONSE_DECONFIGURED: if the queue is not configured
+ * - AP_RESPONSE_NORMAL (0) : in case of successs
+ *   Check vfio_ap_setirq() and vfio_ap_clrirq() for other possible RC.
+ * We take the matrix_dev lock to ensure serialization on queues and
+ * mediated device access.
+ *
+ * Return 0 if we could handle the request inside KVM.
+ * otherwise, returns -EOPNOTSUPP to let QEMU handle the fault.
+ */
+static int handle_pqap(struct kvm_vcpu *vcpu)
+{
+	uint64_t status;
+	uint16_t apqn;
+	struct vfio_ap_queue *q;
+	struct ap_queue_status qstatus = {
+			       .response_code = AP_RESPONSE_Q_NOT_AVAIL, };
+	struct ap_matrix_mdev *matrix_mdev;
+
+	/* If we do not use the AIV facility just go to userland */
+	if (!(vcpu->arch.sie_block->eca & ECA_AIV))
+		return -EOPNOTSUPP;
+
+	apqn = vcpu->run->s.regs.gprs[0] & 0xffff;
+	mutex_lock(&matrix_dev->lock);
+
+	if (!vcpu->kvm->arch.crypto.pqap_hook)
+		goto out_unlock;
+	matrix_mdev = container_of(vcpu->kvm->arch.crypto.pqap_hook,
+				   struct ap_matrix_mdev, pqap_hook);
+
+	q = vfio_ap_get_queue(matrix_mdev, apqn);
+	if (!q)
+		goto out_unlock;
+
+	status = vcpu->run->s.regs.gprs[1];
+
+	/* If IR bit(16) is set we enable the interrupt */
+	if ((status >> (63 - 16)) & 0x01)
+		qstatus = vfio_ap_irq_enable(q, status & 0x07,
+					     vcpu->run->s.regs.gprs[2]);
+	else
+		qstatus = vfio_ap_irq_disable(q);
+
+out_unlock:
+	memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus));
+	vcpu->run->s.regs.gprs[1] >>= 32;
+	mutex_unlock(&matrix_dev->lock);
+	return 0;
+}
+
 static void vfio_ap_matrix_init(struct ap_config_info *info,
 				struct ap_matrix *matrix)
 {
@@ -45,8 +334,11 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
 		return -ENOMEM;
 	}
 
+	matrix_mdev->mdev = mdev;
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
 	mdev_set_drvdata(mdev, matrix_mdev);
+	matrix_mdev->pqap_hook.hook = handle_pqap;
+	matrix_mdev->pqap_hook.owner = THIS_MODULE;
 	mutex_lock(&matrix_dev->lock);
 	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
 	mutex_unlock(&matrix_dev->lock);
@@ -62,6 +354,7 @@ static int vfio_ap_mdev_remove(struct mdev_device *mdev)
 		return -EBUSY;
 
 	mutex_lock(&matrix_dev->lock);
+	vfio_ap_mdev_reset_queues(mdev);
 	list_del(&matrix_mdev->node);
 	mutex_unlock(&matrix_dev->lock);
 
@@ -754,11 +1047,42 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
 	}
 
 	matrix_mdev->kvm = kvm;
+	kvm_get_kvm(kvm);
+	kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
 	mutex_unlock(&matrix_dev->lock);
 
 	return 0;
 }
 
+/*
+ * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback
+ *
+ * @nb: The notifier block
+ * @action: Action to be taken
+ * @data: data associated with the request
+ *
+ * For an UNMAP request, unpin the guest IOVA (the NIB guest address we
+ * pinned before). Other requests are ignored.
+ *
+ */
+static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
+				       unsigned long action, void *data)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+
+	matrix_mdev = container_of(nb, struct ap_matrix_mdev, iommu_notifier);
+
+	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
+		struct vfio_iommu_type1_dma_unmap *unmap = data;
+		unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;
+
+		vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
 static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
 				       unsigned long action, void *data)
 {
@@ -790,15 +1114,36 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
 	return NOTIFY_OK;
 }
 
-static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
-				    unsigned int retry)
+static void vfio_ap_irq_disable_apqn(int apqn)
+{
+	struct device *dev;
+	struct vfio_ap_queue *q;
+
+	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);
+	}
+}
+
+int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
+			     unsigned int retry)
 {
 	struct ap_queue_status status;
+	int retry2 = 2;
+	int apqn = AP_MKQID(apid, apqi);
 
 	do {
-		status = ap_zapq(AP_MKQID(apid, apqi));
+		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(retry <= 0);
 			return 0;
 		case AP_RESPONSE_RESET_IN_PROGRESS:
 		case AP_RESPONSE_BUSY:
@@ -832,6 +1177,7 @@ static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
 			 */
 			if (ret)
 				rc = ret;
+			vfio_ap_irq_disable_apqn(AP_MKQID(apid, apqi));
 		}
 	}
 
@@ -858,20 +1204,37 @@ static int vfio_ap_mdev_open(struct mdev_device *mdev)
 		return ret;
 	}
 
-	return 0;
+	matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier;
+	events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
+	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+				     &events, &matrix_mdev->iommu_notifier);
+	if (!ret)
+		return ret;
+
+	vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+				 &matrix_mdev->group_notifier);
+	module_put(THIS_MODULE);
+	return ret;
 }
 
 static void vfio_ap_mdev_release(struct mdev_device *mdev)
 {
 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
 
-	if (matrix_mdev->kvm)
+	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;
+	}
+	mutex_unlock(&matrix_dev->lock);
 
-	vfio_ap_mdev_reset_queues(mdev);
+	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+				 &matrix_mdev->iommu_notifier);
 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
 				 &matrix_mdev->group_notifier);
-	matrix_mdev->kvm = NULL;
 	module_put(THIS_MODULE);
 }
 
@@ -900,6 +1263,7 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
 {
 	int ret;
 
+	mutex_lock(&matrix_dev->lock);
 	switch (cmd) {
 	case VFIO_DEVICE_GET_INFO:
 		ret = vfio_ap_mdev_get_device_info(arg);
@@ -911,6 +1275,7 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
 		ret = -EOPNOTSUPP;
 		break;
 	}
+	mutex_unlock(&matrix_dev->lock);
 
 	return ret;
 }