[PATCH V6 0/8] introduce Hyper-V VM Socket(hv_sock)

From: Dexuan Cui
Date: Tue Jan 26 2016 - 03:03:44 EST


Changes since v1:
- updated "[PATCH 6/7] hvsock: introduce Hyper-V VM Sockets feature"
- added __init and __exit for the module init/exit functions
- net/hv_sock/Kconfig: "default m" -> "default m if HYPERV"
- MODULE_LICENSE: "Dual MIT/GPL" -> "Dual BSD/GPL"

Changes since v2:
- fixed various coding issue pointed out by David Miller
- fixed indentation issues
- removed pr_debug in net/hv_sock/af_hvsock.c
- used reverse-Chrismas-tree style for local variables.
- EXPORT_SYMBOL -> EXPORT_SYMBOL_GPL

Changes since v3:
- fixed a few coding issue pointed by Vitaly Kuznetsov and Dan Carpenter
- fixed the ret value in vmbus_recvpacket_hvsock on error
- fixed the style of multi-line comment: vmbus_get_hvsock_rw_status()

Changes since v4 (https://lkml.org/lkml/2015/7/28/404):
- addressed all the comments about V4.
- treat the hvsock offers/channels as special VMBus devices
- add a mechanism to pass hvsock events to the hvsock driver
- fixed some corner cases with proper locking when a connection is closed
- rebased to the latest Greg's tree

Changes since v5 (https://lkml.org/lkml/2015/12/24/103):
- addressed the coding style issues (Vitaly Kuznetsov & David Miller, thanks!)
- used a better coding for the per-channel rescind callback (Thank Vitaly!)
- avoided the introduction of new VMBUS driver APIs vmbus_sendpacket_hvsock()
and vmbus_recvpacket_hvsock() and used vmbus_sendpacket()/vmbus_recvpacket()
in the higher level (i.e., the vmsock driver). Thank Vitaly!

Hyper-V VM Socket (hv_sock) is a byte-stream based communication mechanism
between Windowsd 10 (or later) host and a guest. It's kind of TCP over
VMBus, but the transportation layer (VMBus) is much simpler than IP.
With Hyper-V VM Sockets, applications between the host and a guest can
talk with each other directly by the traditional BSD-style socket APIs.

The patchset implements the necessary support in the guest side by adding
the necessary new APIs in the vmbus driver, and introducing a new driver
hv_sock.ko, which implements_a new socket address family AF_HYPERV.

I know the kernel has already had a VM Sockets driver (AF_VSOCK) based
on VMware's VMCI (net/vmw_vsock/, drivers/misc/vmw_vmci), and KVM is
proposing AF_VSOCK of virtio version:
http://thread.gmane.org/gmane.linux.network/365205.

However, though Hyper-V VM Sockets may seem conceptually similar to
AF_VOSCK, there are differences in the transportation layer, and IMO these
make the direct code reusing impractical:

1. In AF_VSOCK, the endpoint type is: <u32 ContextID, u32 Port>, but in
AF_HYPERV, the endpoint type is: <GUID VM_ID, GUID ServiceID>. Here GUID
is 128-bit.

2. AF_VSOCK supports SOCK_DGRAM, while AF_HYPERV doesn't.

3. AF_VSOCK supports some special sock opts, like SO_VM_SOCKETS_BUFFER_SIZE,
SO_VM_SOCKETS_BUFFER_MIN/MAX_SIZE and SO_VM_SOCKETS_CONNECT_TIMEOUT.
These are meaningless to AF_HYPERV.

4. Some AF_VSOCK's VMCI transportation ops are meanless to AF_HYPERV/VMBus,
like .notify_recv_init
.notify_recv_pre_block
.notify_recv_pre_dequeue
.notify_recv_post_dequeue
.notify_send_init
.notify_send_pre_block
.notify_send_pre_enqueue
.notify_send_post_enqueue
etc.

So I think we'd better introduce a new address family: AF_HYPERV.

Please review the patchset.

Looking forward to your comments!

Dexuan Cui (9):
Drivers: hv: vmbus: add a helper function to set a channel's pending
send size
Drivers: hv: vmbus: define the new offer type for Hyper-V socket
(hvsock)
Drivers: hv: vmbus: define a new VMBus message type for hvsock
Drivers: hv: ring_buffer: enhance hv_ringbuffer_read() to support
hvsock
Drivers: hv: vmbus: add APIs to send/recv hvsock packets
Drivers: hv: vmbus: add a hvsock flag in struct hv_driver
Drivers: hv: vmbus: add a mechanism to pass hvsock events to the
hvsock driver
Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()
hvsock: introduce Hyper-V VM Sockets feature

MAINTAINERS | 2 +
drivers/hv/channel.c | 84 ++-
drivers/hv/channel_mgmt.c | 53 +-
drivers/hv/connection.c | 4 +-
drivers/hv/hyperv_vmbus.h | 13 +-
drivers/hv/ring_buffer.c | 54 +-
drivers/hv/vmbus_drv.c | 4 +
include/linux/hyperv.h | 88 +++
include/linux/socket.h | 4 +-
include/net/af_hvsock.h | 44 ++
include/uapi/linux/hyperv.h | 16 +
net/Kconfig | 1 +
net/Makefile | 1 +
net/hv_sock/Kconfig | 10 +
net/hv_sock/Makefile | 3 +
net/hv_sock/af_hvsock.c | 1473 +++++++++++++++++++++++++++++++++++++++++++
16 files changed, 1830 insertions(+), 24 deletions(-)
create mode 100644 include/net/af_hvsock.h
create mode 100644 net/hv_sock/Kconfig
create mode 100644 net/hv_sock/Makefile
create mode 100644 net/hv_sock/af_hvsock.c

--
2.1.4

Dexuan Cui (8):
Drivers: hv: vmbus: add a helper function to set a channel's pending
send size
Drivers: hv: vmbus: define the new offer type for Hyper-V socket
(hvsock)
Drivers: hv: vmbus: vmbus_sendpacket_ctl: hvsock: avoid unnecessary
signaling
Drivers: hv: vmbus: define a new VMBus message type for hvsock
Drivers: hv: vmbus: add a hvsock flag in struct hv_driver
Drivers: hv: vmbus: add a per-channel rescind callback
Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()
hvsock: introduce Hyper-V Socket feature

MAINTAINERS | 2 +
drivers/hv/channel.c | 21 +-
drivers/hv/channel_mgmt.c | 46 +-
drivers/hv/connection.c | 4 +-
drivers/hv/vmbus_drv.c | 4 +
include/linux/hyperv.h | 67 ++
include/linux/socket.h | 4 +-
include/net/af_hvsock.h | 51 ++
include/uapi/linux/hyperv.h | 16 +
net/Kconfig | 1 +
net/Makefile | 1 +
net/hv_sock/Kconfig | 10 +
net/hv_sock/Makefile | 3 +
net/hv_sock/af_hvsock.c | 1480 +++++++++++++++++++++++++++++++++++++++++++
14 files changed, 1702 insertions(+), 8 deletions(-)
create mode 100644 include/net/af_hvsock.h
create mode 100644 net/hv_sock/Kconfig
create mode 100644 net/hv_sock/Makefile
create mode 100644 net/hv_sock/af_hvsock.c

--
2.1.0