On Tue, Nov 19, 2019 at 12:01:15PM +0100, Stefano Garzarella wrote:
> This series introduces a new transport (vsock_loopback) to handle
> local communication.
> This could be useful to test vsock core itself and to allow developers
> to test their applications without launching a VM.
> 
> Before this series, vmci and virtio transports allowed this behavior,
> but only in the guest.
> We are moving the loopback handling in a new transport, because it
> might be useful to provide this feature also in the host or when
> no H2G/G2H transports (hyperv, virtio, vmci) are loaded.
> 
> The user can use the loopback with the new VMADDR_CID_LOCAL (that
> replaces VMADDR_CID_RESERVED) in any condition.
> Otherwise, if the G2H transport is loaded, it can also use the guest
> local CID as previously supported by vmci and virtio transports.
> If G2H transport is not loaded, the user can also use VMADDR_CID_HOST
> for local communication.
> 
> Patch 1 is a cleanup to build virtio_transport_common without virtio
> Patch 2 adds the new VMADDR_CID_LOCAL, replacing VMADDR_CID_RESERVED
> Patch 3 adds a new feature flag to register a loopback transport
> Patch 4 adds the new vsock_loopback transport based on the loopback
>         implementation of virtio_transport
> Patch 5 implements the logic to use the local transport for loopback
>         communication
> Patch 6 removes the loopback from virtio_transport
> 
> @Jorgen: Do you think it might be a problem to replace
> VMADDR_CID_RESERVED with VMADDR_CID_LOCAL?
> 
> Thanks,
> Stefano
> 
> Stefano Garzarella (6):
>   vsock/virtio_transport_common: remove unused virtio header includes
>   vsock: add VMADDR_CID_LOCAL definition
>   vsock: add local transport support in the vsock core
>   vsock: add vsock_loopback transport
>   vsock: use local transport when it is loaded
>   vsock/virtio: remove loopback handling
> 
>  MAINTAINERS                             |   1 +
>  include/net/af_vsock.h                  |   2 +
>  include/uapi/linux/vm_sockets.h         |   8 +-
>  net/vmw_vsock/Kconfig                   |  12 ++
>  net/vmw_vsock/Makefile                  |   1 +
>  net/vmw_vsock/af_vsock.c                |  49 +++++-
>  net/vmw_vsock/virtio_transport.c        |  61 +------
>  net/vmw_vsock/virtio_transport_common.c |   3 -
>  net/vmw_vsock/vmci_transport.c          |   2 +-
>  net/vmw_vsock/vsock_loopback.c          | 217 ++++++++++++++++++++++++
>  10 files changed, 283 insertions(+), 73 deletions(-)
>  create mode 100644 net/vmw_vsock/vsock_loopback.c

Please see my comments.  Otherwise:

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>