Add support for VSOCK to engine/net.c
* configure: add option to enable/disable vsock support
* engines/net.c: add vsock support
The VSOCK address family facilitates communication between virtual
machines and the host they are running on.
The addressing is formed by 2 integers: <CID, port>
- CID: Context ID, it is the ID assigned to the VM
0, 1, 2 CIDs are reserved:
0 - hypervisor CID (rarely used)
1 - local communication (loopback)
2 - host CID (the guest can always reach the host using CID=2)
- port: port number on 32bit to reach a specific process
* examples: add 3 simple job files for vsock (one sender, one receiver
and one that uses vsock loopback interface similar to
examples/netio.fio)
* fio.1: add vsock to supported protocols together with the required
parameters
* HOWTO.rst: add vsock to supported protocols together with the required
parameters
Signed-off-by: Marco Pinna <marco.pinn95@gmail.com>