Users of librte_vhost currently implement the vring call operation
themselves. Each caller performs the operation slightly differently.
This patch introduces a new librte_vhost API called
rte_vhost_vring_call() that performs the operation so that vhost-user
applications don't have to duplicate it.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
lib/librte_vhost/rte_vhost.h | 15 +++++++++++++++
examples/vhost/virtio_net.c | 11 ++---------
examples/vhost_scsi/vhost_scsi.c | 6 +++---
lib/librte_vhost/vhost.c | 21 +++++++++++++++++++++
lib/librte_vhost/rte_vhost_version.map | 7 +++++++
5 files changed, 48 insertions(+), 12 deletions(-)
diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
index f65364495..890f8a831 100644
--- a/lib/librte_vhost/rte_vhost.h
+++ b/lib/librte_vhost/rte_vhost.h
@@ -86,7 +86,9 @@ struct rte_vhost_vring {
struct vring_used *used;
uint64_t log_guest_addr;
+ /** Deprecated, use rte_vhost_vring_call() instead. */
int callfd;
+
int kickfd;
uint16_t size;
};
@@ -436,6 +438,19 @@ int rte_vhost_get_mem_table(int vid, struct
rte_vhost_memory **mem);
int rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
struct rte_vhost_vring *vring);
+/**
+ * Notify the guest that used descriptors have been added to the vring. This
+ * function acts as a memory barrier.
+ *
+ * @param vid
+ * vhost device ID
+ * @param vring_idx
+ * vring index
+ * @return
+ * 0 on success, -1 on failure
+ */
+int rte_vhost_vring_call(int vid, uint16_t vring_idx);
+
/**
* Get vhost RX queue avail count.
*
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c
index 1ab57f526..252c5b8ce 100644
--- a/examples/vhost/virtio_net.c
+++ b/examples/vhost/virtio_net.c
@@ -207,13 +207,8 @@ vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
*(volatile uint16_t *)&vr->used->idx += count;
queue->last_used_idx += count;
- /* flush used->idx update before we read avail->flags. */
- rte_mb();
+ rte_vhost_vring_call(dev->vid, queue_id);
- /* Kick the guest if necessary. */
- if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
- && (vr->callfd >= 0))
- eventfd_write(vr->callfd, (eventfd_t)1);
return count;
}
@@ -396,9 +391,7 @@ vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
vr->used->idx += i;
- if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
- && (vr->callfd >= 0))
- eventfd_write(vr->callfd, (eventfd_t)1);
+ rte_vhost_vring_call(dev->vid, queue_id);
return i;
}
diff --git a/examples/vhost_scsi/vhost_scsi.c b/examples/vhost_scsi/vhost_scsi.c
index b4f1f8d27..e30e61f6d 100644
--- a/examples/vhost_scsi/vhost_scsi.c
+++ b/examples/vhost_scsi/vhost_scsi.c
@@ -110,7 +110,7 @@ descriptor_is_wr(struct vring_desc *cur_desc)
}
static void
-submit_completion(struct vhost_scsi_task *task)
+submit_completion(struct vhost_scsi_task *task, uint32_t q_idx)
{
struct rte_vhost_vring *vq;
struct vring_used *used;
@@ -131,7 +131,7 @@ submit_completion(struct vhost_scsi_task *task)
/* Send an interrupt back to the guest VM so that it knows
* a completion is ready to be processed.
*/
- eventfd_write(vq->callfd, (eventfd_t)1);
+ rte_vhost_vring_call(task->bdev->vid, q_idx);
}
static void
@@ -263,7 +263,7 @@ process_requestq(struct vhost_scsi_ctrlr *ctrlr, uint32_t
q_idx)
task->resp->status = 0;
task->resp->resid = 0;
}
- submit_completion(task);
+ submit_completion(task, q_idx);
rte_free(task);
}
}
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index 4f8b73a09..1244d76d4 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -519,6 +519,27 @@ rte_vhost_get_vhost_vring(int vid, uint16_t vring_idx,
return 0;
}
+int
+rte_vhost_vring_call(int vid, uint16_t vring_idx)
+{
+ struct virtio_net *dev;
+ struct vhost_virtqueue *vq;
+
+ dev = get_device(vid);
+ if (!dev)
+ return -1;
+
+ if (vring_idx >= VHOST_MAX_VRING)
+ return -1;
+
+ vq = dev->virtqueue[vring_idx];
+ if (!vq)
+ return -1;
+
+ vhost_vring_call(vq);
+ return 0;
+}
+
uint16_t
rte_vhost_avail_entries(int vid, uint16_t queue_id)
{
diff --git a/lib/librte_vhost/rte_vhost_version.map
b/lib/librte_vhost/rte_vhost_version.map
index 1e7049535..b30187601 100644
--- a/lib/librte_vhost/rte_vhost_version.map
+++ b/lib/librte_vhost/rte_vhost_version.map
@@ -52,3 +52,10 @@ DPDK_17.08 {
rte_vhost_rx_queue_count;
} DPDK_17.05;
+
+EXPERIMENTAL {
+ global:
+
+ rte_vhost_vring_call;
+
+} DPDK_17.08
--
2.14.3
