Commit b63e5c70 authored by Eugenio Pérez's avatar Eugenio Pérez Committed by Michael S. Tsirkin
Browse files

vdpa: add get_backend_features vdpa operation 



This operation allow vdpa parent to expose its own backend feature bits.

Next patches introduce a feature not compatible with all parent drivers:
the ability to enable vq after driver_ok.  Each parent must declare if
it allows it or not.

Signed-off-by: default avatarEugenio Pérez <eperezma@redhat.com>
Acked-by: default avatarShannon Nelson <shannon.nelson@amd.com>
Message-Id: <20230609092127.170673-4-eperezma@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 9f09fd61

drivers/vhost/vdpa.c

+12 −0
Original line number Diff line number Diff line
@@ -403,6 +403,17 @@ static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) 
	return 0;

}



static u64 vhost_vdpa_get_backend_features(const struct vhost_vdpa *v)

{

	struct vdpa_device *vdpa = v->vdpa;

	const struct vdpa_config_ops *ops = vdpa->config;



	if (!ops->get_backend_features)

		return 0;

	else

		return ops->get_backend_features(vdpa);

}



static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)

{

	struct vdpa_device *vdpa = v->vdpa;
@@ -742,6 +753,7 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, 
			features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND);

		if (vhost_vdpa_can_resume(v))

			features |= BIT_ULL(VHOST_BACKEND_F_RESUME);

		features |= vhost_vdpa_get_backend_features(v);

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

			r = -EFAULT;

		break;

include/linux/vdpa.h

+4 −0
Original line number Diff line number Diff line
@@ -208,6 +208,9 @@ struct vdpa_map_file { 
 *				@vdev: vdpa device

 *				Returns the virtio features support by the

 *				device

 * @get_backend_features:	Get parent-specific backend features (optional)

 *				Returns the vdpa features supported by the

 *				device.

 * @set_driver_features:	Set virtio features supported by the driver

 *				@vdev: vdpa device

 *				@features: feature support by the driver
@@ -358,6 +361,7 @@ struct vdpa_config_ops { 
	u32 (*get_vq_align)(struct vdpa_device *vdev);

	u32 (*get_vq_group)(struct vdpa_device *vdev, u16 idx);

	u64 (*get_device_features)(struct vdpa_device *vdev);

	u64 (*get_backend_features)(const struct vdpa_device *vdev);

	int (*set_driver_features)(struct vdpa_device *vdev, u64 features);

	u64 (*get_driver_features)(struct vdpa_device *vdev);

	void (*set_config_cb)(struct vdpa_device *vdev,