-----Original Message-----
From: Maxime Coquelin <redacted>
Sent: Friday, July 2, 2021 3:41 PM
To: Hu, Jiayu <redacted>; dev@dpdk.org
Cc: Xia, Chenbo <redacted>; Wang, Yinan
[off-list ref]
Subject: Re: [PATCH 2/2] vhost: add thread unsafe async registration
functions



On 5/28/21 10:11 AM, Jiayu Hu wrote:

quoted

This patch is to add thread unsafe version for async register and

s/is to add/adds/

quoted

unregister functions.

Signed-off-by: Jiayu Hu <redacted>
---
 doc/guides/prog_guide/vhost_lib.rst |  12 +++
 lib/vhost/rte_vhost_async.h         |  42 ++++++++++
 lib/vhost/version.map               |   4 +
 lib/vhost/vhost.c                   | 161 +++++++++++++++++++++++++++---------
 4 files changed, 178 insertions(+), 41 deletions(-)

diff --git a/doc/guides/prog_guide/vhost_lib.rst

b/doc/guides/prog_guide/vhost_lib.rst
index d18fb98..6b2745f 100644

--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst

@@ -253,6 +253,12 @@ The following is an overview of some key Vhost

API functions:

quoted

     vhost invokes this function to get the copy data completed by async
     devices.

+* ``rte_vhost_async_channel_register_thread_unsafe(vid, queue_id,
+features, ops)``
+  Register a vhost queue with async copy device channel without
+  performing any locking.
+
+  This function is only safe to call from within vhost callback functions.

I'm not sure with this, AFAICS .new_device() is called without the lock held,
so is that safe? Since .new_device() is the first time the app gets required
device info to use the Vhost API, that might not be an issue, though.

I think so. Although new_device() is called without lock, no data plane threads
can operate vrings if device is not created.

Thanks,
Jiayu