Commit a127c5bb authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

vhost-vdpa: fix backend feature ioctls 



Commit 653055b9 ("vhost-vdpa: support get/set backend features")
introduces two malfunction backend features ioctls:

1) the ioctls was blindly added to vring ioctl instead of vdpa device
   ioctl
2) vhost_set_backend_features() was called when dev mutex has already
   been held which will lead a deadlock

This patch fixes the above issues.

Cc: Eli Cohen <elic@nvidia.com>
Reported-by: default avatarZhu Lingshan <lingshan.zhu@intel.com>
Fixes: 653055b9 ("vhost-vdpa: support get/set backend features")
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200907104343.31141-1-jasowang@redhat.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 71c548c2

drivers/vhost/vdpa.c

+16 −14
Original line number Diff line number Diff line
@@ -353,8 +353,6 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, 
	struct vdpa_callback cb;

	struct vhost_virtqueue *vq;

	struct vhost_vring_state s;

	u64 __user *featurep = argp;

	u64 features;

	u32 idx;

	long r;
@@ -381,18 +379,6 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd, 


		vq->last_avail_idx = vq_state.avail_index;

		break;

	case VHOST_GET_BACKEND_FEATURES:

		features = VHOST_VDPA_BACKEND_FEATURES;

		if (copy_to_user(featurep, &features, sizeof(features)))

			return -EFAULT;

		return 0;

	case VHOST_SET_BACKEND_FEATURES:

		if (copy_from_user(&features, featurep, sizeof(features)))

			return -EFAULT;

		if (features & ~VHOST_VDPA_BACKEND_FEATURES)

			return -EOPNOTSUPP;

		vhost_set_backend_features(&v->vdev, features);

		return 0;

	}



	r = vhost_vring_ioctl(&v->vdev, cmd, argp);
@@ -440,8 +426,20 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, 
	struct vhost_vdpa *v = filep->private_data;

	struct vhost_dev *d = &v->vdev;

	void __user *argp = (void __user *)arg;

	u64 __user *featurep = argp;

	u64 features;

	long r;



	if (cmd == VHOST_SET_BACKEND_FEATURES) {

		r = copy_from_user(&features, featurep, sizeof(features));

		if (r)

			return r;

		if (features & ~VHOST_VDPA_BACKEND_FEATURES)

			return -EOPNOTSUPP;

		vhost_set_backend_features(&v->vdev, features);

		return 0;

	}



	mutex_lock(&d->mutex);



	switch (cmd) {
@@ -476,6 +474,10 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, 
	case VHOST_VDPA_SET_CONFIG_CALL:

		r = vhost_vdpa_set_config_call(v, argp);

		break;

	case VHOST_GET_BACKEND_FEATURES:

		features = VHOST_VDPA_BACKEND_FEATURES;

		r = copy_to_user(featurep, &features, sizeof(features));

		break;

	default:

		r = vhost_dev_ioctl(&v->vdev, cmd, argp);

		if (r == -ENOIOCTLCMD)

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