vdpa: remove hard coded virtq num

This will enable vdpa providers to add support for multi queue feature
and publish it to upper layers (vhost and virtio).

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200804162048.22587-7-eli@mellanox.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -431,7 +431,8 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	}
 
 	adapter = vdpa_alloc_device(struct ifcvf_adapter, vdpa,
-				    dev, &ifc_vdpa_ops);
+				    dev, &ifc_vdpa_ops,
+				    IFCVF_MAX_QUEUE_PAIRS * 2);
 	if (adapter == NULL) {
 		IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
 		return -ENOMEM;

drivers/vdpa/vdpa.c

@@ -61,6 +61,7 @@ static void vdpa_release_dev(struct device *d)
  * initialized but before registered.
  * @parent: the parent device
  * @config: the bus operations that is supported by this device
+ * @nvqs: number of virtqueues supported by this device
  * @size: size of the parent structure that contains private data
  *
  * Driver should use vdpa_alloc_device() wrapper macro instead of
@@ -71,6 +72,7 @@ static void vdpa_release_dev(struct device *d)
  */
 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 					const struct vdpa_config_ops *config,
+					int nvqs,
 					size_t size)
 {
 	struct vdpa_device *vdev;
@@ -97,6 +99,7 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 	vdev->index = err;
 	vdev->config = config;
 	vdev->features_valid = false;
+	vdev->nvqs = nvqs;
 
 	err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
 	if (err)

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -65,7 +65,7 @@ static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
 /* State of each vdpasim device */
 struct vdpasim {
 	struct vdpa_device vdpa;
-	struct vdpasim_virtqueue vqs[2];
+	struct vdpasim_virtqueue vqs[VDPASIM_VQ_NUM];
 	struct work_struct work;
 	/* spinlock to synchronize virtqueue state */
 	spinlock_t lock;
@@ -352,7 +352,7 @@ static struct vdpasim *vdpasim_create(void)
 	else
 		ops = &vdpasim_net_config_ops;
 
-	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops);
+	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops, VDPASIM_VQ_NUM);
 	if (!vdpasim)
 		goto err_alloc;
 

drivers/vhost/vdpa.c

@@ -32,9 +32,6 @@ enum {
 	(1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
 };
 
-/* Currently, only network backend w/o multiqueue is supported. */
-#define VHOST_VDPA_VQ_MAX	2
-
 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
 
 struct vhost_vdpa {
@@ -930,7 +927,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 {
 	const struct vdpa_config_ops *ops = vdpa->config;
 	struct vhost_vdpa *v;
-	int minor, nvqs = VHOST_VDPA_VQ_MAX;
+	int minor;
 	int r;
 
 	/* Currently, we only accept the network devices. */
@@ -951,14 +948,14 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
 	atomic_set(&v->opened, 0);
 	v->minor = minor;
 	v->vdpa = vdpa;
-	v->nvqs = nvqs;
+	v->nvqs = vdpa->nvqs;
 	v->virtio_id = ops->get_device_id(vdpa);
 
 	device_initialize(&v->dev);
 	v->dev.release = vhost_vdpa_release_dev;
 	v->dev.parent = &vdpa->dev;
 	v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
-	v->vqs = kmalloc_array(nvqs, sizeof(struct vhost_virtqueue),
+	v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
 			       GFP_KERNEL);
 	if (!v->vqs) {
 		r = -ENOMEM;

include/linux/vdpa.h

@@ -41,6 +41,7 @@ struct vdpa_device {
 	const struct vdpa_config_ops *config;
 	unsigned int index;
 	bool features_valid;
+	int nvqs;
 };
 
 /**
@@ -218,11 +219,12 @@ struct vdpa_config_ops {
 
 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 					const struct vdpa_config_ops *config,
+					int nvqs,
 					size_t size);
 
-#define vdpa_alloc_device(dev_struct, member, parent, config)   \
+#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs)   \
 			  container_of(__vdpa_alloc_device( \
-				       parent, config, \
+				       parent, config, nvqs, \
 				       sizeof(dev_struct) + \
 				       BUILD_BUG_ON_ZERO(offsetof( \
 				       dev_struct, member))), \