Sorry, for previous blank reply.

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

Lock protection is needed during the vhost notifies the application of
device readiness, so the first patch is to add lock protection. After
performing locking, existed async vhost registration functions will cause
deadlock, as they acquire lock too. So the second patch is to provide
unsafe registration functions to support calling within vhost callback
functions.

I agree the callback should be always protected, and in that case having
a new thread-unsafe API makes sense for async registration.

Regarding backport, I'm not sure what we should do.

Backporting new API is a no-go, but with only backporting patch 1 async
feature will be always broken on 20.11 LTS, right?

What do you think?

Thanks,
Maxime

Jiayu Hu (2):
  vhost: fix lock on device readiness notification
  vhost: add thread unsafe async registration functions

 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 +++++++++++++++++++++++++++---------
 lib/vhost/vhost_user.c              |   5 +-
 5 files changed, 180 insertions(+), 44 deletions(-)