[PATCH net-next 00/14] vsock: add multi-transports support

[Stefano Garzarella <sgarzare@redhat.com>]

This series adds the multi-transports support to vsock, following
this proposal: https://www.spinics.net/lists/netdev/msg575792.html

With the multi-transports support, we can use VSOCK with nested VMs
(using also different hypervisors) loading both guest->host and
host->guest transports at the same time.
Before this series, vmci-transport supported this behavior but only
using VMware hypervisor on L0, L1, etc.

RFC: https://patchwork.ozlabs.org/cover/1168442/
RFC -> v1:
- Added R-b/A-b from Dexuan and Stefan
- Fixed comments and typos in several patches (Stefan)
- Patch 7: changed .notify_buffer_size return to void (Stefan)
- Added patch 8 to simplify the API exposed to the transports (Stefan)
- Patch 11:
  + documented VSOCK_TRANSPORT_F_* flags (Stefan)
  + fixed vsock_assign_transport() when the socket is already assigned
  + moved features outside of struct vsock_transport, and used as
    parameter of vsock_core_register() as a preparation of Patch 12
- Removed "vsock: add 'transport_hg' to handle g2h\h2g transports" patch
- Added patch 12 to register vmci_transport only when VMCI guest/host
  are active

The first 9 patches are cleanups and preparations, maybe some of
these can go regardless of this series.

Patch 10 changes the hvs_remote_addr_init(). setting the
VMADDR_CID_HOST as remote CID instead of VMADDR_CID_ANY to make
the choice of transport to be used work properly.

Patch 11 adds multi-transports support.

Patch 12 touch a little bit the vmci_transport and the vmci driver
to register the vmci_transport only when there are active host/guest.

Patch 13 prevents the transport modules unloading while sockets are
assigned to them.

Patch 14 fixes an issue in the bind() logic discoverable only with
the new multi-transport support.

I've tested this series with nested KVM (vsock-transport [L0,L1],
virtio-transport[L1,L2]) and with VMware (L0) + KVM (L1)
(vmci-transport [L0,L1], vhost-transport [L1], virtio-transport[L2]).

Dexuan successfully tested the RFC series on HyperV with a Linux guest.

Stefano Garzarella (14):
  vsock/vmci: remove unused VSOCK_DEFAULT_CONNECT_TIMEOUT
  vsock: remove vm_sockets_get_local_cid()
  vsock: remove include/linux/vm_sockets.h file
  vsock: add 'transport' member in the struct vsock_sock
  vsock/virtio: add transport parameter to the
    virtio_transport_reset_no_sock()
  vsock: add 'struct vsock_sock *' param to vsock_core_get_transport()
  vsock: handle buffer_size sockopts in the core
  vsock: add vsock_create_connected() called by transports
  vsock: move vsock_insert_unbound() in the vsock_create()
  hv_sock: set VMADDR_CID_HOST in the hvs_remote_addr_init()
  vsock: add multi-transports support
  vsock/vmci: register vmci_transport only when VMCI guest/host are
    active
  vsock: prevent transport modules unloading
  vsock: fix bind() behaviour taking care of CID

 drivers/misc/vmw_vmci/vmci_driver.c     |  50 ++++
 drivers/misc/vmw_vmci/vmci_driver.h     |   2 +
 drivers/misc/vmw_vmci/vmci_guest.c      |   2 +
 drivers/misc/vmw_vmci/vmci_host.c       |   7 +
 drivers/vhost/vsock.c                   |  96 +++---
 include/linux/virtio_vsock.h            |  18 +-
 include/linux/vm_sockets.h              |  15 -
 include/linux/vmw_vmci_api.h            |   2 +
 include/net/af_vsock.h                  |  44 +--
 include/net/vsock_addr.h                |   2 +-
 net/vmw_vsock/af_vsock.c                | 376 ++++++++++++++++++------
 net/vmw_vsock/hyperv_transport.c        |  70 ++---
 net/vmw_vsock/virtio_transport.c        | 177 ++++++-----
 net/vmw_vsock/virtio_transport_common.c | 131 +++------
 net/vmw_vsock/vmci_transport.c          | 137 +++------
 net/vmw_vsock/vmci_transport.h          |   3 -
 net/vmw_vsock/vmci_transport_notify.h   |   1 -
 17 files changed, 627 insertions(+), 506 deletions(-)
 delete mode 100644 include/linux/vm_sockets.h

-- 
2.21.0