[PATCH v2 0/5] add support for virtio-user server mode

[zhiyong.yang@intel.com]

In a container environment if the vhost-user backend restarts, there's no way
for it to reconnect to virtio-user currently. To address this, support for
server mode is added. In this mode the socket file is created by virtio-user,
which the backend then connects to. This means that if the backend restarts,
it can reconnect to virtio-user and continue communications.

The series add support for the feature and target for 18.05 release.

Virtio-user with server mode creates socket file and then starts to wait for the
first connection from vhost user with client mode in blocking mode.

Virtio-user with server mode supports many times' vhost reconnections with same configurations. 

Virtio-user supports only one connection at the same time in server/client mode.

How to test?
The following scripts are as reference.

./x86_64-native-linuxapp-gcc/app/testpmd -c 0x3 -n 4 -m 256,0 --no-pci \
--file-prefix=testpmd0 --vdev=net_virtio_user0,mac=00:11:22:33:44:10, \
path=/tmp/sock0,server=1,queues=1 -- -i --rxq=1 --txq=1 --no-numa

./x86_64-native-linuxapp-gcc/app/testpmd -c 0x3e000 -n 4 --socket-mem 256,0 \
--vdev 'net_vhost0,iface=/tmp/sock0,client=1,queues=1' -- -i --rxq=1 --txq=1 \
--nb-cores=1 --no-numa

step1 : at the virio-user side, run "start"
step2: at the vhost-user side run "start tx_first 40000"

Changes in V2:
1. split two patch 1/5 and 2/5 from v1 patchset to fix some existing issues which is not
strongly related to support for server mode according to Maxime's comments.
2. move fdset related functions to librte_eal from librte_vhost exposed as
new APIs according to Thomas' comments.
3. release note is added in the patch 5/5.
4. squash data structure change patch into 4/5 according to Maxime's suggestion.

Zhiyong Yang (5):
  net/virtio: fix add pointer checking
  net/virtio: add checking for cvq
  eal: expose fdset related APIs
  net/virtio-user: add support for server mode
  net/vhost: add memory checking

 doc/guides/rel_notes/release_18_05.rst             |   7 +
 drivers/net/vhost/rte_eth_vhost.c                  |   9 +
 drivers/net/virtio/virtio_ethdev.c                 |  10 +-
 drivers/net/virtio/virtio_user/vhost_user.c        |  77 +++++-
 drivers/net/virtio/virtio_user/virtio_user_dev.c   |  44 ++--
 drivers/net/virtio/virtio_user/virtio_user_dev.h   |   8 +
 drivers/net/virtio/virtio_user_ethdev.c            |  82 +++++-
 lib/librte_eal/common/include/rte_eal_interrupts.h |  56 +++++
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       | 257 +++++++++++++++++++
 lib/librte_eal/rte_eal_version.map                 |  10 +
 lib/librte_vhost/Makefile                          |   2 +-
 lib/librte_vhost/fd_man.c                          | 274 ---------------------
 lib/librte_vhost/fd_man.h                          |  40 ---
 lib/librte_vhost/socket.c                          |  22 +-
 14 files changed, 548 insertions(+), 350 deletions(-)
 delete mode 100644 lib/librte_vhost/fd_man.c
 delete mode 100644 lib/librte_vhost/fd_man.h

-- 
2.14.3