ifcvf: implement vdpa_config_ops.get_vq_irq()

This commit implemented vdpa_config_ops.get_vq_irq() in ifcvf,
and initialized vq irq to -EINVAL. So that ifcvf can report
irq number of a vq, or -EINVAL if the vq is not assigned an
irq number.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200731065533.4144-6-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -50,8 +50,10 @@ static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues)
 	int i;
 
 
-	for (i = 0; i < queues; i++)
+	for (i = 0; i < queues; i++) {
 		devm_free_irq(&pdev->dev, vf->vring[i].irq, &vf->vring[i]);
+		vf->vring[i].irq = -EINVAL;
+	}
 
 	ifcvf_free_irq_vectors(pdev);
 }
@@ -352,6 +354,14 @@ static void ifcvf_vdpa_set_config_cb(struct vdpa_device *vdpa_dev,
 	vf->config_cb.private = cb->private;
 }
 
+static int ifcvf_vdpa_get_vq_irq(struct vdpa_device *vdpa_dev,
+				 u16 qid)
+{
+	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
+
+	return vf->vring[qid].irq;
+}
+
 /*
  * IFCVF currently does't have on-chip IOMMU, so not
  * implemented set_map()/dma_map()/dma_unmap()
@@ -369,6 +379,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {
 	.get_vq_ready	= ifcvf_vdpa_get_vq_ready,
 	.set_vq_num	= ifcvf_vdpa_set_vq_num,
 	.set_vq_address	= ifcvf_vdpa_set_vq_address,
+	.get_vq_irq	= ifcvf_vdpa_get_vq_irq,
 	.kick_vq	= ifcvf_vdpa_kick_vq,
 	.get_generation	= ifcvf_vdpa_get_generation,
 	.get_device_id	= ifcvf_vdpa_get_device_id,
@@ -384,7 +395,7 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	struct device *dev = &pdev->dev;
 	struct ifcvf_adapter *adapter;
 	struct ifcvf_hw *vf;
-	int ret;
+	int ret, i;
 
 	ret = pcim_enable_device(pdev);
 	if (ret) {
@@ -441,6 +452,9 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto err;
 	}
 
+	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++)
+		vf->vring[i].irq = -EINVAL;
+
 	ret = vdpa_register_device(&adapter->vdpa);
 	if (ret) {
 		IFCVF_ERR(pdev, "Failed to register ifcvf to vdpa bus");