Description of problem

I configured kata-runtime to use vsocks on ubuntu 18.04 with kata-runtime 1.2. But the detection of vsock support failed. It seems that the code explicitly looks for /dev/vsock and /dev/vhost-vsock. Those are only present after loading the vsock and vhost_vsock modules.

Aug 14 07:33:39 hix kata-runtime[29715]: time="2018-08-14T07:33:39.953266567+02:00" level=warning msg="No vsock support, falling back to legacy serial port" arch=amd64 command=create name=kata-runtime pid=29715 source=runtime

After loading the module:

Aug 14 07:48:03 hix kata-runtime[30209]: time="2018-08-14T07:48:03.900473483+02:00" level=info msg="vsock supported" arch=amd64 command=create name=kata-runtime pid=30209 source=runtime
Aug 14 07:48:03 hix kata-runtime[30209]: time="2018-08-14T07:48:03.90062639+02:00" level=info msg="VSOCK supported, configure to not use proxy" arch=amd64 command=create name=kata-runtime pid=30209 source=runtime

kata-runtime : 1.2.0
commit : 0bcb32f
OCI specs: 1.0.1

Expected result

kata runtime detects vsock support even if the kernel modules are not loaded.
The modules are autoloaded when used, probably by calling socket(AF_VSOCK, ...).

Actual result

Vsock support was detected only after manually loading all relevant kernel modules, i.e., modprobe vhost_vsock.