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From:   Eli Cohen <eli@mellanox.com>
To:     mst@redhat.com, jasowang@redhat.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Cc:     shahafs@mellanox.com, saeedm@mellanox.com, parav@mellanox.com,
        Eli Cohen <eli@mellanox.com>
Subject: [PATCH V2 vhost next 06/10] vdpa: Modify get_vq_state() to return error code
Date:   Mon, 20 Jul 2020 10:14:12 +0300
Message-Id: <20200720071416.32112-7-eli@mellanox.com>
In-Reply-To: <20200720071416.32112-1-eli@mellanox.com>
References: <20200720071416.32112-1-eli@mellanox.com>
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Modify get_vq_state() so it returns an error code. In case of hardware
acceleration, the available index may be retrieved from the device, an
operation that can possibly fail.

Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
---
 drivers/vdpa/ifcvf/ifcvf_main.c  | 5 +++--
 drivers/vdpa/vdpa_sim/vdpa_sim.c | 5 +++--
 drivers/vhost/vdpa.c             | 5 ++++-
 include/linux/vdpa.h             | 4 ++--
 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index 69032ee97824..d9b5f465ac81 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -235,12 +235,13 @@ static u16 ifcvf_vdpa_get_vq_num_max(struct vdpa_device *vdpa_dev)
 	return IFCVF_QUEUE_MAX;
 }
 
-static void ifcvf_vdpa_get_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
-				    struct vdpa_vq_state *state)
+static int ifcvf_vdpa_get_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
+				   struct vdpa_vq_state *state)
 {
 	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
 
 	state->avail_index = ifcvf_get_vq_state(vf, qid);
+	return 0;
 }
 
 static int ifcvf_vdpa_set_vq_state(struct vdpa_device *vdpa_dev, u16 qid,
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 599519039f8d..ddf6086d43c2 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -427,14 +427,15 @@ static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx,
 	return 0;
 }
 
-static void vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
-				 struct vdpa_vq_state *state)
+static int vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx,
+				struct vdpa_vq_state *state)
 {
 	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
 	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
 	struct vringh *vrh = &vq->vring;
 
 	state->avail_index = vrh->last_avail_idx;
+	return 0;
 }
 
 static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index af98c11c9d26..fadad74f882e 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -360,7 +360,10 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
 	}
 
 	if (cmd == VHOST_GET_VRING_BASE) {
-		ops->get_vq_state(v->vdpa, idx, &vq_state);
+		r = ops->get_vq_state(v->vdpa, idx, &vq_state);
+		if (r)
+			return r;
+
 		vq->last_avail_idx = vq_state.avail_index;
 	}
 
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 7b088bebffe8..000d71a9f988 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -185,8 +185,8 @@ struct vdpa_config_ops {
 	bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
 	int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
 			    const struct vdpa_vq_state *state);
-	void (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
-			     struct vdpa_vq_state *state);
+	int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
+			    struct vdpa_vq_state *state);
 	struct vdpa_notification_area
 	(*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
 
-- 
2.26.0