[dpdk-dev,v2] doc: add virtio lsc note

  Virtio PMD has already supported link status change(lsc), but VM which
must be created by qemu 2.7.0 and above can support it when vhost
user disconnects, since the capability to detect vhost user disconnection
is introduced in qemu 2.7.0. The patch updates doc to let user know that.

Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
---

Changes in v2:
reword the doc and commit log.

 doc/guides/nics/virtio.rst | 5 +++++
 1 file changed, 5 insertions(+)
  

> -----Original Message-----
> From: Yang, Zhiyong
> Sent: Tuesday, October 10, 2017 5:51 AM
> To: dev@dpdk.org
> Cc: yliu@fridaylinux.org; Mcnamara, John <john.mcnamara@intel.com>; Yigit,
> Ferruh <ferruh.yigit@intel.com>; Yang, Zhiyong <zhiyong.yang@intel.com>
> Subject: [PATCH v2] doc: add virtio lsc note
> 
> Virtio PMD has already supported link status change(lsc), but VM which
> must be created by qemu 2.7.0 and above can support it when vhost user
> disconnects, since the capability to detect vhost user disconnection is
> introduced in qemu 2.7.0. The patch updates doc to let user know that.
> 
> Signed-off-by: Zhiyong Yang <zhiyong.yang@intel.com>
> ---
> 
> Changes in v2:
> reword the doc and commit log.
> 
>  doc/guides/nics/virtio.rst | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/doc/guides/nics/virtio.rst b/doc/guides/nics/virtio.rst index
> 4d6a83768..abf42dff5 100644
> --- a/doc/guides/nics/virtio.rst
> +++ b/doc/guides/nics/virtio.rst
> @@ -291,6 +291,11 @@ interrupt, Rx interrupts, and Tx interrupts. Config
> interrupt is used for  notification of device configuration changes,
> especially link status (lsc).
>  Interrupt mode is translated into Rx interrupts in the context of DPDK.
> 
> +.. Note:: Virtio PMD has already supported to receive lsc from qemu
> +when link status changes, especially when vhost user disconnects, but
> +it fails to do that if VM is created by qemu 2.6.2 or below, since the
> +capability to detect vhost user disconnection is introduced in qemu


Hi,

If you are using the Note: directive the text needs to be separated by a
blank line and also indented. Otherwise it throws a doc build warning.

I'd suggest something like this with some minor changes to the text
included:

.. Note::

   Virtio PMD already has support for receiving lsc from qemu when the link
   status changes, especially when vhost user disconnects. However, it fails
   to do that if the VM is created by qemu 2.6.2 or below, since the
   capability to detect vhost user disconnection is introduced in qemu 2.7.0.

Reviewed-by: John McNamara <john.mcnamara@intel.com>

John