[v2,3/4] vdpa: add get_backend_features vdpa operation
Commit Message
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: Eugenio PĂ©rez <eperezma@redhat.com>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
---
drivers/vhost/vdpa.c | 12 ++++++++++++
include/linux/vdpa.h | 4 ++++
2 files changed, 16 insertions(+)
@@ -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;
@@ -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,