[dpdk-dev] [PATCH v5 0/2] vhost: support inflight share memory protocol feature

[JinYu <jin.yu@intel.com>]

This patches introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
buffer between qemu and backend.
Now It can both support split and packed ring. The example code show
how these API work. The test has passed.

How to test the example:
1, Qemu need two patches.
https://patchwork.kernel.org/patch/10766813/
https://patchwork.kernel.org/patch/10861411/
it also needs some manual modifications:
we should confirm that before we send get inflight we have already
sent the set features but it seems Qemu didn't do like this. So we
manually revise this, we can add below code in vhost_dev_get_inflight
    int r;

    r = vhost_dev_set_features(dev, dev->log_enabled);
    if (r < 0) {
        return -errno;
    }
before get_inflight_fd.
2, Guest OS version >= 5.0
3, run the example
4, run the qemu with vhost-user-blk-pci.
 eg:
        -chardev socket,id=spdk_vhost_blk0,reconnect=1,path=xxxx\
        -device vhost-user-blk-pci,ring_packed=on,chardev=spdk_vhost_blk0,num-queues=1\
5, run fio in the guest
6, kill the example(vhost-user backend) and run again.
7, the fio in the guest should continue run without errors.

JinYu (2):
  vhost: support inflight share memory protocol feature
  vhost: add vhost-user-blk example which support inflight

 examples/vhost_blk/Makefile            |   67 ++
 examples/vhost_blk/blk.c               |  125 +++
 examples/vhost_blk/blk_spec.h          |   95 ++
 examples/vhost_blk/meson.build         |   20 +
 examples/vhost_blk/vhost_blk.c         | 1313 ++++++++++++++++++++++++
 examples/vhost_blk/vhost_blk.h         |  116 +++
 examples/vhost_blk/vhost_blk_compat.c  |  195 ++++
 lib/librte_vhost/rte_vhost.h           |  255 ++++-
 lib/librte_vhost/rte_vhost_version.map |   12 +
 lib/librte_vhost/vhost.c               |  396 ++++++-
 lib/librte_vhost/vhost.h               |   61 +-
 lib/librte_vhost/vhost_user.c          |  437 +++++++-
 lib/librte_vhost/vhost_user.h          |   13 +-
 13 files changed, 3059 insertions(+), 46 deletions(-)
 create mode 100644 examples/vhost_blk/Makefile
 create mode 100644 examples/vhost_blk/blk.c
 create mode 100644 examples/vhost_blk/blk_spec.h
 create mode 100644 examples/vhost_blk/meson.build
 create mode 100644 examples/vhost_blk/vhost_blk.c
 create mode 100644 examples/vhost_blk/vhost_blk.h
 create mode 100644 examples/vhost_blk/vhost_blk_compat.c

-- 
2.17.2