[dpdk-dev] [RFC 1/2] vhost-user: don't allocate new queue once device is running
Maxime Coquelin
maxime.coquelin at redhat.com
Fri Jan 12 16:50:15 CET 2018
Once the device is created, it is not possible to hot-add new
queues. If it happens, it could confuse the application, as
the new queue might not be initialized but nr_vring is
incremented.
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
lib/librte_vhost/vhost_user.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index e54795a41..f94fd16cf 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1220,13 +1220,23 @@ vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev, VhostUserMsg *msg)
if (vring_idx >= VHOST_MAX_VRING) {
RTE_LOG(ERR, VHOST_CONFIG,
"invalid vring index: %u\n", vring_idx);
- return -1;
+ return -EINVAL;
}
if (dev->virtqueue[vring_idx])
return 0;
- return alloc_vring_queue(dev, vring_idx);
+ /* Queues cannot be added dynamically */
+ if (dev->flags & VIRTIO_DEV_RUNNING) {
+ RTE_LOG(DEBUG, VHOST_CONFIG,
+ "Cannot allocate new queue, device is running\n");
+ return -EPERM;
+ }
+
+ if (alloc_vring_queue(dev, vring_idx) < 0)
+ return -ENOMEM;
+
+ return 0;
}
int
@@ -1274,7 +1284,10 @@ vhost_user_msg_handler(int vid, int fd)
vhost_message_str[msg.request.master]);
ret = vhost_user_check_and_alloc_queue_pair(dev, &msg);
- if (ret < 0) {
+ if (ret == -EPERM) {
+ RTE_LOG(DEBUG, VHOST_CONFIG, "Skipping message\n");
+ goto out;
+ } else if (ret < 0) {
RTE_LOG(ERR, VHOST_CONFIG,
"failed to alloc queue\n");
return -1;
@@ -1383,6 +1396,7 @@ vhost_user_msg_handler(int vid, int fd)
}
+out:
if (msg.flags & VHOST_USER_NEED_REPLY) {
msg.payload.u64 = !!ret;
msg.size = sizeof(msg.payload.u64);
--
2.14.3
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