Re: [PATCH vhost next 06/10] vdpa: Add means to communicate vq status on get_vq_state

[Jason Wang]

On 2020/7/16 下午3:23, Eli Cohen wrote:

Currently, get_vq_state() is used only to pass the available index value
of a vq. Extend the struct to return status on the VQ to the caller.
For now, define VQ_STATE_NOT_READY. In the future it will be extended to
include other infomration.

Modify current vdpa driver to update this field.

Reviewed-by: Parav Pandit <pa...@mellanox.com>
Signed-off-by: Eli Cohen <e...@mellanox.com>

What's the difference between this and get_vq_ready()?

Thanks

---
  drivers/vdpa/ifcvf/ifcvf_main.c  | 1 +
  drivers/vdpa/vdpa_sim/vdpa_sim.c | 1 +
  include/linux/vdpa.h             | 9 +++++++++
  3 files changed, 11 insertions(+)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 69032ee97824..77e3b3d91167 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -240,6 +240,7 @@ static void ifcvf_vdpa_get_vq_state(struct vdpa_device 
*vdpa_dev, u16 qid,
  {
        struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);

+ state->state = vf->vring[qid].ready ? 0 : BIT(VQ_STATE_NOT_READY);

        state->avail_index = ifcvf_get_vq_state(vf, qid);
  }

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c

index 599519039f8d..06d974b4bd7b 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -434,6 +434,7 @@ static void vdpasim_get_vq_state(struct vdpa_device *vdpa, 
u16 idx,
        struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
        struct vringh *vrh = &vq->vring;

+ state->state = vq->ready ? 0 : BIT(VQ_STATE_NOT_READY);

        state->avail_index = vrh->last_avail_idx;
  }

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h

index 7b088bebffe8..bcefa30a3b2f 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -27,12 +27,21 @@ struct vdpa_notification_area {
        resource_size_t size;
  };

+/**

+ * Bitmask describing the status of the vq
+ */
+enum {
+       VQ_STATE_NOT_READY = 0,
+};
+
  /**
   * vDPA vq_state definition
   * @avail_index: available index
+ * @state: returned status from get_vq_state
   */
  struct vdpa_vq_state {
        u16     avail_index;
+       u32     state;
  };

/**