vdpa: Add reset callback in vdpa_config_ops

This adds a new callback to support device specific reset
behavior. The vdpa bus driver will call the reset function
instead of setting status to zero during resetting.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210831103634.33-6-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -222,17 +222,6 @@ static void ifcvf_vdpa_set_status(struct vdpa_device *vdpa_dev, u8 status)
 	if (status_old == status)
 		return;
 
-	if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) &&
-	    !(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
-		ifcvf_stop_datapath(adapter);
-		ifcvf_free_irq(adapter, vf->nr_vring);
-	}
-
-	if (status == 0) {
-		ifcvf_reset_vring(adapter);
-		return;
-	}
-
 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
 	    !(status_old & VIRTIO_CONFIG_S_DRIVER_OK)) {
 		ret = ifcvf_request_irq(adapter);
@@ -252,6 +241,29 @@ static void ifcvf_vdpa_set_status(struct vdpa_device *vdpa_dev, u8 status)
 	ifcvf_set_status(vf, status);
 }
 
+static int ifcvf_vdpa_reset(struct vdpa_device *vdpa_dev)
+{
+	struct ifcvf_adapter *adapter;
+	struct ifcvf_hw *vf;
+	u8 status_old;
+
+	vf  = vdpa_to_vf(vdpa_dev);
+	adapter = vdpa_to_adapter(vdpa_dev);
+	status_old = ifcvf_get_status(vf);
+
+	if (status_old == 0)
+		return 0;
+
+	if (status_old & VIRTIO_CONFIG_S_DRIVER_OK) {
+		ifcvf_stop_datapath(adapter);
+		ifcvf_free_irq(adapter, vf->nr_vring);
+	}
+
+	ifcvf_reset_vring(adapter);
+
+	return 0;
+}
+
 static u16 ifcvf_vdpa_get_vq_num_max(struct vdpa_device *vdpa_dev)
 {
 	return IFCVF_QUEUE_MAX;
@@ -435,6 +447,7 @@ static const struct vdpa_config_ops ifc_vdpa_ops = {
 	.set_features	= ifcvf_vdpa_set_features,
 	.get_status	= ifcvf_vdpa_get_status,
 	.set_status	= ifcvf_vdpa_set_status,
+	.reset		= ifcvf_vdpa_reset,
 	.get_vq_num_max	= ifcvf_vdpa_get_vq_num_max,
 	.get_vq_state	= ifcvf_vdpa_get_vq_state,
 	.set_vq_state	= ifcvf_vdpa_set_vq_state,

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -2154,22 +2154,6 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 	int err;
 
 	print_status(mvdev, status, true);
-	if (!status) {
-		mlx5_vdpa_info(mvdev, "performing device reset\n");
-		teardown_driver(ndev);
-		clear_vqs_ready(ndev);
-		mlx5_vdpa_destroy_mr(&ndev->mvdev);
-		ndev->mvdev.status = 0;
-		ndev->mvdev.mlx_features = 0;
-		memset(ndev->event_cbs, 0, sizeof(ndev->event_cbs));
-		ndev->mvdev.actual_features = 0;
-		++mvdev->generation;
-		if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
-			if (mlx5_vdpa_create_mr(mvdev, NULL))
-				mlx5_vdpa_warn(mvdev, "create MR failed\n");
-		}
-		return;
-	}
 
 	if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) {
 		if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
@@ -2192,6 +2176,29 @@ err_setup:
 	ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED;
 }
 
+static int mlx5_vdpa_reset(struct vdpa_device *vdev)
+{
+	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
+	struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
+
+	print_status(mvdev, 0, true);
+	mlx5_vdpa_info(mvdev, "performing device reset\n");
+	teardown_driver(ndev);
+	clear_vqs_ready(ndev);
+	mlx5_vdpa_destroy_mr(&ndev->mvdev);
+	ndev->mvdev.status = 0;
+	ndev->mvdev.mlx_features = 0;
+	memset(ndev->event_cbs, 0, sizeof(ndev->event_cbs));
+	ndev->mvdev.actual_features = 0;
+	++mvdev->generation;
+	if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
+		if (mlx5_vdpa_create_mr(mvdev, NULL))
+			mlx5_vdpa_warn(mvdev, "create MR failed\n");
+	}
+
+	return 0;
+}
+
 static size_t mlx5_vdpa_get_config_size(struct vdpa_device *vdev)
 {
 	return sizeof(struct virtio_net_config);
@@ -2305,6 +2312,7 @@ static const struct vdpa_config_ops mlx5_vdpa_ops = {
 	.get_vendor_id = mlx5_vdpa_get_vendor_id,
 	.get_status = mlx5_vdpa_get_status,
 	.set_status = mlx5_vdpa_set_status,
+	.reset = mlx5_vdpa_reset,
 	.get_config_size = mlx5_vdpa_get_config_size,
 	.get_config = mlx5_vdpa_get_config,
 	.set_config = mlx5_vdpa_set_config,

drivers/vdpa/vdpa_sim/vdpa_sim.c

@@ -92,7 +92,7 @@ static void vdpasim_vq_reset(struct vdpasim *vdpasim,
 	vq->vring.notify = NULL;
 }
 
-static void vdpasim_reset(struct vdpasim *vdpasim)
+static void vdpasim_do_reset(struct vdpasim *vdpasim)
 {
 	int i;
 
@@ -460,11 +460,21 @@ static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
 
 	spin_lock(&vdpasim->lock);
 	vdpasim->status = status;
-	if (status == 0)
-		vdpasim_reset(vdpasim);
 	spin_unlock(&vdpasim->lock);
 }
 
+static int vdpasim_reset(struct vdpa_device *vdpa)
+{
+	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
+
+	spin_lock(&vdpasim->lock);
+	vdpasim->status = 0;
+	vdpasim_do_reset(vdpasim);
+	spin_unlock(&vdpasim->lock);
+
+	return 0;
+}
+
 static size_t vdpasim_get_config_size(struct vdpa_device *vdpa)
 {
 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
@@ -608,6 +618,7 @@ static const struct vdpa_config_ops vdpasim_config_ops = {
 	.get_vendor_id          = vdpasim_get_vendor_id,
 	.get_status             = vdpasim_get_status,
 	.set_status             = vdpasim_set_status,
+	.reset			= vdpasim_reset,
 	.get_config_size        = vdpasim_get_config_size,
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,
@@ -636,6 +647,7 @@ static const struct vdpa_config_ops vdpasim_batch_config_ops = {
 	.get_vendor_id          = vdpasim_get_vendor_id,
 	.get_status             = vdpasim_get_status,
 	.set_status             = vdpasim_set_status,
+	.reset			= vdpasim_reset,
 	.get_config_size        = vdpasim_get_config_size,
 	.get_config             = vdpasim_get_config,
 	.set_config             = vdpasim_set_config,

drivers/vdpa/virtio_pci/vp_vdpa.c

@@ -189,10 +189,20 @@ static void vp_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
 	}
 
 	vp_modern_set_status(mdev, status);
+}
 
-	if (!(status & VIRTIO_CONFIG_S_DRIVER_OK) &&
-	    (s & VIRTIO_CONFIG_S_DRIVER_OK))
+static int vp_vdpa_reset(struct vdpa_device *vdpa)
+{
+	struct vp_vdpa *vp_vdpa = vdpa_to_vp(vdpa);
+	struct virtio_pci_modern_device *mdev = &vp_vdpa->mdev;
+	u8 s = vp_vdpa_get_status(vdpa);
+
+	vp_modern_set_status(mdev, 0);
+
+	if (s & VIRTIO_CONFIG_S_DRIVER_OK)
 		vp_vdpa_free_irq(vp_vdpa);
+
+	return 0;
 }
 
 static u16 vp_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
@@ -398,6 +408,7 @@ static const struct vdpa_config_ops vp_vdpa_ops = {
 	.set_features	= vp_vdpa_set_features,
 	.get_status	= vp_vdpa_get_status,
 	.set_status	= vp_vdpa_set_status,
+	.reset		= vp_vdpa_reset,
 	.get_vq_num_max	= vp_vdpa_get_vq_num_max,
 	.get_vq_state	= vp_vdpa_get_vq_state,
 	.get_vq_notification = vp_vdpa_get_vq_notification,

drivers/vhost/vdpa.c

@@ -157,7 +157,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	struct vdpa_device *vdpa = v->vdpa;
 	const struct vdpa_config_ops *ops = vdpa->config;
 	u8 status, status_old;
-	int nvqs = v->nvqs;
+	int ret, nvqs = v->nvqs;
 	u16 i;
 
 	if (copy_from_user(&status, statusp, sizeof(status)))
@@ -172,7 +172,12 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
 		return -EINVAL;
 
-	ops->set_status(vdpa, status);
+	if (status == 0) {
+		ret = ops->reset(vdpa);
+		if (ret)
+			return ret;
+	} else
+		ops->set_status(vdpa, status);
 
 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 		for (i = 0; i < nvqs; i++)

include/linux/vdpa.h

@@ -171,6 +171,9 @@ struct vdpa_iova_range {
  * @set_status:			Set the device status
  *				@vdev: vdpa device
  *				@status: virtio device status
+ * @reset:			Reset device
+ *				@vdev: vdpa device
+ *				Returns integer: success (0) or error (< 0)
  * @get_config_size:		Get the size of the configuration space
  *				@vdev: vdpa device
  *				Returns size_t: configuration size
@@ -255,6 +258,7 @@ struct vdpa_config_ops {
 	u32 (*get_vendor_id)(struct vdpa_device *vdev);
 	u8 (*get_status)(struct vdpa_device *vdev);
 	void (*set_status)(struct vdpa_device *vdev, u8 status);
+	int (*reset)(struct vdpa_device *vdev);
 	size_t (*get_config_size)(struct vdpa_device *vdev);
 	void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
 			   void *buf, unsigned int len);
@@ -348,12 +352,12 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
 	return vdev->dma_dev;
 }
 
-static inline void vdpa_reset(struct vdpa_device *vdev)
+static inline int vdpa_reset(struct vdpa_device *vdev)
 {
 	const struct vdpa_config_ops *ops = vdev->config;
 
 	vdev->features_valid = false;
-	ops->set_status(vdev, 0);
+	return ops->reset(vdev);
 }
 
 static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)