ifcvf: move IRQ request/free to status change handlers

This commit move IRQ request and free operations from probe()
to VIRTIO status change handler to comply with VIRTIO spec.

VIRTIO spec 1.1, section 2.1.2 Device Requirements: Device Status Field
The device MUST NOT consume buffers or send any used buffer
notifications to the driver before DRIVER_OK.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Link: https://lore.kernel.org/r/1589270444-3669-1-git-send-email-lingshan.zhu@intel.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -28,6 +28,60 @@ static irqreturn_t ifcvf_intr_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static void ifcvf_free_irq_vectors(void *data)
+{
+	pci_free_irq_vectors(data);
+}
+
+static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues)
+{
+	struct pci_dev *pdev = adapter->pdev;
+	struct ifcvf_hw *vf = &adapter->vf;
+	int i;
+
+
+	for (i = 0; i < queues; i++)
+		devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]);
+
+	ifcvf_free_irq_vectors(pdev);
+}
+
+static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
+{
+	struct pci_dev *pdev = adapter->pdev;
+	struct ifcvf_hw *vf = &adapter->vf;
+	int vector, i, ret, irq;
+
+	ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR,
+				    IFCVF_MAX_INTR, PCI_IRQ_MSIX);
+	if (ret < 0) {
+		IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n");
+		return ret;
+	}
+
+	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
+		snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n",
+			 pci_name(pdev), i);
+		vector = i + IFCVF_MSI_QUEUE_OFF;
+		irq = pci_irq_vector(pdev, vector);
+		ret = devm_request_irq(&pdev->dev, irq,
+				       ifcvf_intr_handler, 0,
+				       vf->vring[i].msix_name,
+				       &vf->vring[i]);
+		if (ret) {
+			IFCVF_ERR(pdev,
+				  "Failed to request irq for vq %d\n", i);
+			ifcvf_free_irq(adapter, i);
+
+			return ret;
+		}
+
+		vf->vring[i].irq = irq;
+	}
+
+	return 0;
+}
+
 static int ifcvf_start_datapath(void *private)
 {
 	struct ifcvf_hw *vf = ifcvf_private_to_vf(private);
@@ -118,17 +172,34 @@ static void ifcvf_vdpa_set_status(struct vdpa_device *vdpa_dev, u8 status)
 {
 	struct ifcvf_adapter *adapter;
 	struct ifcvf_hw *vf;
+	u8 status_old;
+	int ret;
 
 	vf  = vdpa_to_vf(vdpa_dev);
 	adapter = dev_get_drvdata(vdpa_dev->dev.parent);
+	status_old = ifcvf_get_status(vf);
 
-	if (status == 0) {
+	if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) &&
+	    !(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 		ifcvf_stop_datapath(adapter);
+		ifcvf_free_irq(adapter, IFCVF_MAX_QUEUE_PAIRS * 2);
+	}
+
+	if (status == 0) {
 		ifcvf_reset_vring(adapter);
 		return;
 	}
 
-	if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
+	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+	    !(status_old & VIRTIO_CONFIG_S_DRIVER_OK)) {
+		ret = ifcvf_request_irq(adapter);
+		if (ret) {
+			status = ifcvf_get_status(vf);
+			status |= VIRTIO_CONFIG_S_FAILED;
+			ifcvf_set_status(vf, status);
+			return;
+		}
+
 		if (ifcvf_start_datapath(adapter) < 0)
 			IFCVF_ERR(adapter->pdev,
 				  "Failed to set ifcvf vdpa  status %u\n",
@@ -284,38 +355,6 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {
 	.set_config_cb  = ifcvf_vdpa_set_config_cb,
 };
 
-static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
-{
-	struct pci_dev *pdev = adapter->pdev;
-	struct ifcvf_hw *vf = &adapter->vf;
-	int vector, i, ret, irq;
-
-
-	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++) {
-		snprintf(vf->vring[i].msix_name, 256, "ifcvf[%s]-%d\n",
-			 pci_name(pdev), i);
-		vector = i + IFCVF_MSI_QUEUE_OFF;
-		irq = pci_irq_vector(pdev, vector);
-		ret = devm_request_irq(&pdev->dev, irq,
-				       ifcvf_intr_handler, 0,
-				       vf->vring[i].msix_name,
-				       &vf->vring[i]);
-		if (ret) {
-			IFCVF_ERR(pdev,
-				  "Failed to request irq for vq %d\n", i);
-			return ret;
-		}
-		vf->vring[i].irq = irq;
-	}
-
-	return 0;
-}
-
-static void ifcvf_free_irq_vectors(void *data)
-{
-	pci_free_irq_vectors(data);
-}
-
 static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct device *dev = &pdev->dev;
@@ -349,13 +388,6 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		return ret;
 	}
 
-	ret = pci_alloc_irq_vectors(pdev, IFCVF_MAX_INTR,
-				    IFCVF_MAX_INTR, PCI_IRQ_MSIX);
-	if (ret < 0) {
-		IFCVF_ERR(pdev, "Failed to alloc irq vectors\n");
-		return ret;
-	}
-
 	ret = devm_add_action_or_reset(dev, ifcvf_free_irq_vectors, pdev);
 	if (ret) {
 		IFCVF_ERR(pdev,
@@ -379,12 +411,6 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	adapter->pdev = pdev;
 	adapter->vdpa.dma_dev = &pdev->dev;
 
-	ret = ifcvf_request_irq(adapter);
-	if (ret) {
-		IFCVF_ERR(pdev, "Failed to request MSI-X irq\n");
-		goto err;
-	}
-
 	ret = ifcvf_init_hw(vf, pdev);
 	if (ret) {
 		IFCVF_ERR(pdev, "Failed to init IFCVF hw\n");