RE: [PATCH v2] Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)

[Michael Kelley]

From: Dexuan Cui <decui@xxxxxxxxxxxxx> Sent: Sunday, January 19, 2020 3:29 PM
> 
> When a Linux hv_sock app tries to connect to a Service GUID on which no
> host app is listening, a recent host (RS3+) sends a
> CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such
> a warning:
> 
> unknown msgtype=23
> WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc
> 
> Actually Linux can safely ignore the message because the Linux app's
> connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT
> and vsock_stream_connect(). We don't bother to make use of the message
> because: 1) it's only supported on recent hosts; 2) a non-trivial effort
> is required to use the message in Linux, but the benefit is small.
> 
> So, let's not see the warning by silently ignoring the message.
> 
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> ---
> 
> In v2 (followed Michael Kelley's suggestions):
>     Removed the redundant code in vmbus_onmessage()
>     Added the new enries into channel_message_table[].
> 
>  drivers/hv/channel_mgmt.c | 21 +++++++--------------
>  drivers/hv/vmbus_drv.c    |  4 ++++
>  include/linux/hyperv.h    |  2 ++
>  3 files changed, 13 insertions(+), 14 deletions(-)
> 

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>