vdpa: set the virtqueue num during register

This patch delay the queue number setting to vDPA device
registering. This allows us to probe the virtqueue numbers between
device allocation and registering.
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210223061905.422659-3-jasowang@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -431,8 +431,7 @@ 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,
-				    IFCVF_MAX_QUEUE_PAIRS * 2, NULL);
+				    dev, &ifc_vdpa_ops, NULL);
 	if (adapter == NULL) {
 		IFCVF_ERR(pdev, "Failed to allocate vDPA structure");
 		return -ENOMEM;
@@ -456,7 +455,7 @@ static int ifcvf_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	for (i = 0; i < IFCVF_MAX_QUEUE_PAIRS * 2; i++)
 		vf->vring[i].irq = -EINVAL;
 
-	ret = vdpa_register_device(&adapter->vdpa);
+	ret = vdpa_register_device(&adapter->vdpa, IFCVF_MAX_QUEUE_PAIRS * 2);
 	if (ret) {
 		IFCVF_ERR(pdev, "Failed to register ifcvf to vdpa bus");
 		goto err;

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -1982,7 +1982,7 @@ static int mlx5v_probe(struct auxiliary_device *adev,
 	max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
 
 	ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
-				 2 * mlx5_vdpa_max_qps(max_vqs), NULL);
+				 NULL);
 	if (IS_ERR(ndev))
 		return PTR_ERR(ndev);
 
@@ -2009,7 +2009,7 @@ static int mlx5v_probe(struct auxiliary_device *adev,
 	if (err)
 		goto err_res;
 
-	err = vdpa_register_device(&mvdev->vdev);
+	err = vdpa_register_device(&mvdev->vdev, 2 * mlx5_vdpa_max_qps(max_vqs));
 	if (err)
 		goto err_reg;
 

drivers/vdpa/vdpa.c

@@ -69,7 +69,6 @@ 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
  * @name: name of the vdpa device; optional.
  *
@@ -81,7 +80,7 @@ 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, const char *name)
+					size_t size, const char *name)
 {
 	struct vdpa_device *vdev;
 	int err = -EINVAL;
@@ -107,7 +106,6 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 	vdev->index = err;
 	vdev->config = config;
 	vdev->features_valid = false;
-	vdev->nvqs = nvqs;
 
 	if (name)
 		err = dev_set_name(&vdev->dev, "%s", name);
@@ -136,10 +134,12 @@ static int vdpa_name_match(struct device *dev, const void *data)
 	return (strcmp(dev_name(&vdev->dev), data) == 0);
 }
 
-static int __vdpa_register_device(struct vdpa_device *vdev)
+static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
 {
 	struct device *dev;
 
+	vdev->nvqs = nvqs;
+
 	lockdep_assert_held(&vdpa_dev_mutex);
 	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);
 	if (dev) {
@@ -155,15 +155,16 @@ static int __vdpa_register_device(struct vdpa_device *vdev)
  * Caller must invoke this routine in the management device dev_add()
  * callback after setting up valid mgmtdev for this vdpa device.
  * @vdev: the vdpa device to be registered to vDPA bus
+ * @nvqs: number of virtqueues supported by this device
  *
  * Returns an error when fail to add device to vDPA bus
  */
-int _vdpa_register_device(struct vdpa_device *vdev)
+int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
 {
 	if (!vdev->mdev)
 		return -EINVAL;
 
-	return __vdpa_register_device(vdev);
+	return __vdpa_register_device(vdev, nvqs);
 }
 EXPORT_SYMBOL_GPL(_vdpa_register_device);
 
@@ -171,15 +172,16 @@ EXPORT_SYMBOL_GPL(_vdpa_register_device);
  * vdpa_register_device - register a vDPA device
  * Callers must have a succeed call of vdpa_alloc_device() before.
  * @vdev: the vdpa device to be registered to vDPA bus
+ * @nvqs: number of virtqueues supported by this device
  *
  * Returns an error when fail to add to vDPA bus
  */
-int vdpa_register_device(struct vdpa_device *vdev)
+int vdpa_register_device(struct vdpa_device *vdev, int nvqs)
 {
 	int err;
 
 	mutex_lock(&vdpa_dev_mutex);
-	err = __vdpa_register_device(vdev);
+	err = __vdpa_register_device(vdev, nvqs);
 	mutex_unlock(&vdpa_dev_mutex);
 	return err;
 }

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -235,7 +235,7 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
 		ops = &vdpasim_config_ops;
 
 	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, ops,
-				    dev_attr->nvqs, dev_attr->name);
+				    dev_attr->name);
 	if (!vdpasim)
 		goto err_alloc;
 

drivers/vdpa/vdpa_sim/vdpa_sim_net.c

@@ -147,7 +147,7 @@ static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
 	if (IS_ERR(simdev))
 		return PTR_ERR(simdev);
 
-	ret = _vdpa_register_device(&simdev->vdpa);
+	ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM);
 	if (ret)
 		goto reg_err;
 

include/linux/vdpa.h

@@ -250,20 +250,20 @@ struct vdpa_config_ops {
 
 struct vdpa_device *__vdpa_alloc_device(struct device *parent,
 					const struct vdpa_config_ops *config,
-					int nvqs, size_t size, const char *name);
+					size_t size, const char *name);
 
-#define vdpa_alloc_device(dev_struct, member, parent, config, nvqs, name)   \
+#define vdpa_alloc_device(dev_struct, member, parent, config, name)   \
 			  container_of(__vdpa_alloc_device( \
-				       parent, config, nvqs, \
+				       parent, config, \
 				       sizeof(dev_struct) + \
 				       BUILD_BUG_ON_ZERO(offsetof( \
 				       dev_struct, member)), name), \
 				       dev_struct, member)
 
-int vdpa_register_device(struct vdpa_device *vdev);
+int vdpa_register_device(struct vdpa_device *vdev, int nvqs);
 void vdpa_unregister_device(struct vdpa_device *vdev);
 
-int _vdpa_register_device(struct vdpa_device *vdev);
+int _vdpa_register_device(struct vdpa_device *vdev, int nvqs);
 void _vdpa_unregister_device(struct vdpa_device *vdev);
 
 /**