From: Jorgen Hansen <redacted>
Date: Tue, 21 Nov 2017 02:46:24 -0800

When using the host personality, VMCI will grab a mutex for any
queue pair access. In the detach callback for the vmci vsock
transport, we call vsock_stream_has_data while holding a spinlock,
and vsock_stream_has_data will access a queue pair.

To avoid this, we can simply omit calling vsock_stream_has_data
for host side queue pairs, since the QPs are empty per default
when the guest has detached.

This bug affects users of VMware Workstation using kernel version
4.4 and later.

Testing: Ran vsock tests between guest and host, and verified that
with this change, the host isn't calling vsock_stream_has_data
during detach. Ran mixedTest between guest and host using both
guest and host as server.

Reviewed-by: Adit Ranadive <redacted>
Reviewed-by: Aditya Sarwade <redacted>
Signed-off-by: Jorgen Hansen <redacted>

This doesn't apply cleanly to the current 'net' GIT tree.