vdpa_sim: remove hard-coded virtq count

Add a new attribute that will define the number of virt queues to be
created for the vdpasim device.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
[sgarzare: replace kmalloc_array() with kcalloc()]
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20201215144256.155342-4-sgarzare@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -63,7 +63,7 @@ static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
 /* State of each vdpasim device */
 struct vdpasim {
 	struct vdpa_device vdpa;
-	struct vdpasim_virtqueue vqs[VDPASIM_VQ_NUM];
+	struct vdpasim_virtqueue *vqs;
 	struct work_struct work;
 	/* spinlock to synchronize virtqueue state */
 	spinlock_t lock;
@@ -73,6 +73,7 @@ struct vdpasim {
 	u32 status;
 	u32 generation;
 	u64 features;
+	int nvqs;
 	/* spinlock to synchronize iommu table */
 	spinlock_t iommu_lock;
 };
@@ -137,7 +138,7 @@ static void vdpasim_reset(struct vdpasim *vdpasim)
 {
 	int i;
 
-	for (i = 0; i < VDPASIM_VQ_NUM; i++)
+	for (i = 0; i < vdpasim->nvqs; i++)
 		vdpasim_vq_reset(&vdpasim->vqs[i]);
 
 	spin_lock(&vdpasim->iommu_lock);
@@ -343,7 +344,7 @@ static struct vdpasim *vdpasim_create(void)
 	const struct vdpa_config_ops *ops;
 	struct vdpasim *vdpasim;
 	struct device *dev;
-	int ret = -ENOMEM;
+	int i, ret = -ENOMEM;
 
 	if (batch_mapping)
 		ops = &vdpasim_net_batch_config_ops;
@@ -354,6 +355,7 @@ static struct vdpasim *vdpasim_create(void)
 	if (!vdpasim)
 		goto err_alloc;
 
+	vdpasim->nvqs = VDPASIM_VQ_NUM;
 	INIT_WORK(&vdpasim->work, vdpasim_work);
 	spin_lock_init(&vdpasim->lock);
 	spin_lock_init(&vdpasim->iommu_lock);
@@ -364,6 +366,11 @@ static struct vdpasim *vdpasim_create(void)
 		goto err_iommu;
 	set_dma_ops(dev, &vdpasim_dma_ops);
 
+	vdpasim->vqs = kcalloc(vdpasim->nvqs, sizeof(struct vdpasim_virtqueue),
+			       GFP_KERNEL);
+	if (!vdpasim->vqs)
+		goto err_iommu;
+
 	vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
 	if (!vdpasim->iommu)
 		goto err_iommu;
@@ -382,8 +389,8 @@ static struct vdpasim *vdpasim_create(void)
 		eth_random_addr(vdpasim->config.mac);
 	}
 
-	vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
-	vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
+	for (i = 0; i < vdpasim->nvqs; i++)
+		vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu);
 
 	vdpasim->vdpa.dma_dev = dev;
 	ret = vdpa_register_device(&vdpasim->vdpa);
@@ -652,6 +659,7 @@ static void vdpasim_free(struct vdpa_device *vdpa)
 	kfree(vdpasim->buffer);
 	if (vdpasim->iommu)
 		vhost_iotlb_free(vdpasim->iommu);
+	kfree(vdpasim->vqs);
 }
 
 static const struct vdpa_config_ops vdpasim_net_config_ops = {