diff --git a/include/hw/vmbus/vmbus-proto.h b/include/hw/vmbus/vmbus-proto.h
new file mode 100644
index 0000000000..80882e4fc6
--- /dev/null
+++ b/include/hw/vmbus/vmbus-proto.h
@@ -0,0 +1,222 @@
+/*
+ * QEMU Hyper-V VMBus support
+ *
+ * Copyright (c) 2017-2018 Virtuozzo International GmbH.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef VMBUS_PROTO_H
+#define VMBUS_PROTO_H
+
+#define VMBUS_VERSION_WS2008                    ((0 << 16) | (13))
+#define VMBUS_VERSION_WIN7                      ((1 << 16) | (1))
+#define VMBUS_VERSION_WIN8                      ((2 << 16) | (4))
+#define VMBUS_VERSION_WIN8_1                    ((3 << 16) | (0))
+#define VMBUS_VERSION_WIN10                     ((4 << 16) | (0))
+#define VMBUS_VERSION_INVAL                     -1
+#define VMBUS_VERSION_CURRENT                   VMBUS_VERSION_WIN10
+
+#define VMBUS_MESSAGE_CONNECTION_ID             1
+#define VMBUS_EVENT_CONNECTION_ID               2
+#define VMBUS_MONITOR_CONNECTION_ID             3
+#define VMBUS_SINT                              2
+
+#define VMBUS_MSG_INVALID               0
+#define VMBUS_MSG_OFFERCHANNEL          1
+#define VMBUS_MSG_RESCIND_CHANNELOFFER  2
+#define VMBUS_MSG_REQUESTOFFERS         3
+#define VMBUS_MSG_ALLOFFERS_DELIVERED   4
+#define VMBUS_MSG_OPENCHANNEL           5
+#define VMBUS_MSG_OPENCHANNEL_RESULT    6
+#define VMBUS_MSG_CLOSECHANNEL          7
+#define VMBUS_MSG_GPADL_HEADER          8
+#define VMBUS_MSG_GPADL_BODY            9
+#define VMBUS_MSG_GPADL_CREATED         10
+#define VMBUS_MSG_GPADL_TEARDOWN        11
+#define VMBUS_MSG_GPADL_TORNDOWN        12
+#define VMBUS_MSG_RELID_RELEASED        13
+#define VMBUS_MSG_INITIATE_CONTACT      14
+#define VMBUS_MSG_VERSION_RESPONSE      15
+#define VMBUS_MSG_UNLOAD                16
+#define VMBUS_MSG_UNLOAD_RESPONSE       17
+#define VMBUS_MSG_COUNT                 18
+
+#define VMBUS_MESSAGE_SIZE_ALIGN        sizeof(uint64_t)
+
+#define VMBUS_PACKET_INVALID                    0x0
+#define VMBUS_PACKET_SYNCH                      0x1
+#define VMBUS_PACKET_ADD_XFER_PAGESET           0x2
+#define VMBUS_PACKET_RM_XFER_PAGESET            0x3
+#define VMBUS_PACKET_ESTABLISH_GPADL            0x4
+#define VMBUS_PACKET_TEARDOWN_GPADL             0x5
+#define VMBUS_PACKET_DATA_INBAND                0x6
+#define VMBUS_PACKET_DATA_USING_XFER_PAGES      0x7
+#define VMBUS_PACKET_DATA_USING_GPADL           0x8
+#define VMBUS_PACKET_DATA_USING_GPA_DIRECT      0x9
+#define VMBUS_PACKET_CANCEL_REQUEST             0xa
+#define VMBUS_PACKET_COMP                       0xb
+#define VMBUS_PACKET_DATA_USING_ADDITIONAL_PKT  0xc
+#define VMBUS_PACKET_ADDITIONAL_DATA            0xd
+
+#define VMBUS_CHANNEL_USER_DATA_SIZE            120
+
+#define VMBUS_OFFER_MONITOR_ALLOCATED           0x1
+#define VMBUS_OFFER_INTERRUPT_DEDICATED         0x1
+
+#define VMBUS_RING_BUFFER_FEAT_PENDING_SZ       (1ul << 0)
+
+#define VMBUS_CHANNEL_ENUMERATE_DEVICE_INTERFACE      0x1
+#define VMBUS_CHANNEL_SERVER_SUPPORTS_TRANSFER_PAGES  0x2
+#define VMBUS_CHANNEL_SERVER_SUPPORTS_GPADLS          0x4
+#define VMBUS_CHANNEL_NAMED_PIPE_MODE                 0x10
+#define VMBUS_CHANNEL_LOOPBACK_OFFER                  0x100
+#define VMBUS_CHANNEL_PARENT_OFFER                    0x200
+#define VMBUS_CHANNEL_REQUEST_MONITORED_NOTIFICATION  0x400
+#define VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER            0x2000
+
+#define VMBUS_PACKET_FLAG_REQUEST_COMPLETION    1
+
+typedef struct vmbus_message_header {
+    uint32_t message_type;
+    uint32_t _padding;
+} vmbus_message_header;
+
+typedef struct vmbus_message_initiate_contact {
+    vmbus_message_header header;
+    uint32_t version_requested;
+    uint32_t target_vcpu;
+    uint64_t interrupt_page;
+    uint64_t monitor_page1;
+    uint64_t monitor_page2;
+} vmbus_message_initiate_contact;
+
+typedef struct vmbus_message_version_response {
+    vmbus_message_header header;
+    uint8_t version_supported;
+    uint8_t status;
+} vmbus_message_version_response;
+
+typedef struct vmbus_message_offer_channel {
+    vmbus_message_header header;
+    uint8_t  type_uuid[16];
+    uint8_t  instance_uuid[16];
+    uint64_t _reserved1;
+    uint64_t _reserved2;
+    uint16_t channel_flags;
+    uint16_t mmio_size_mb;
+    uint8_t  user_data[VMBUS_CHANNEL_USER_DATA_SIZE];
+    uint16_t sub_channel_index;
+    uint16_t _reserved3;
+    uint32_t child_relid;
+    uint8_t  monitor_id;
+    uint8_t  monitor_flags;      // VMBUS_OFFER_MONITOR_*
+    uint16_t interrupt_flags;    // VMBUS_OFFER_INTERRUPT_*
+    uint32_t connection_id;
+} vmbus_message_offer_channel;
+
+typedef struct vmbus_message_rescind_channel_offer {
+    vmbus_message_header header;
+    uint32_t child_relid;
+} vmbus_message_rescind_channel_offer;
+
+typedef struct vmbus_gpa_range {
+    uint32_t byte_count;
+    uint32_t byte_offset;
+    uint64_t pfn_array[0];
+} vmbus_gpa_range;
+
+typedef struct vmbus_message_gpadl_header {
+    vmbus_message_header header;
+    uint32_t child_relid;
+    uint32_t gpadl_id;
+    uint16_t range_buflen;
+    uint16_t rangecount;
+    vmbus_gpa_range range;
+} QEMU_PACKED vmbus_message_gpadl_header;
+
+typedef struct vmbus_message_gpadl_body {
+    vmbus_message_header header;
+    uint32_t message_number;
+    uint32_t gpadl_id;
+    uint64_t pfn_array[0];
+} vmbus_message_gpadl_body;
+
+typedef struct vmbus_message_gpadl_created {
+    vmbus_message_header header;
+    uint32_t child_relid;
+    uint32_t gpadl_id;
+    uint32_t status;
+} vmbus_message_gpadl_created;
+
+typedef struct vmbus_message_gpadl_teardown {
+    vmbus_message_header header;
+    uint32_t child_relid;
+    uint32_t gpadl_id;
+} vmbus_message_gpadl_teardown;
+
+typedef struct vmbus_message_gpadl_torndown {
+    vmbus_message_header header;
+    uint32_t gpadl_id;
+} vmbus_message_gpadl_torndown;
+
+typedef struct vmbus_message_open_channel {
+    vmbus_message_header header;
+    uint32_t child_relid;
+    uint32_t open_id;
+    uint32_t ring_buffer_gpadl_id;
+    uint32_t target_vp;
+    uint32_t ring_buffer_offset;
+    uint8_t  user_data[VMBUS_CHANNEL_USER_DATA_SIZE];
+} vmbus_message_open_channel;
+
+typedef struct vmbus_message_open_result {
+    vmbus_message_header header;
+    uint32_t child_relid;
+    uint32_t open_id;
+    uint32_t status;
+} vmbus_message_open_result;
+
+typedef struct vmbus_message_close_channel {
+    vmbus_message_header header;
+    uint32_t child_relid;
+} vmbus_message_close_channel;
+
+typedef struct vmbus_ring_buffer {
+    uint32_t write_index;
+    uint32_t read_index;
+    uint32_t interrupt_mask;
+    uint32_t pending_send_sz;
+    uint32_t _reserved1[12];
+    uint32_t feature_bits;     // VMBUS_RING_BUFFER_FEAT_*
+} vmbus_ring_buffer;
+
+typedef struct vmbus_packet_hdr {
+    uint16_t type;
+    uint16_t offset_qwords;
+    uint16_t len_qwords;
+    uint16_t flags;
+    uint64_t transaction_id;
+} vmbus_packet_hdr;
+
+typedef struct vmbus_pkt_gpa_direct {
+    uint32_t _reserved;
+    uint32_t rangecount;
+    vmbus_gpa_range range[0];
+} vmbus_pkt_gpa_direct;
+
+typedef struct vmbus_xferpg_range {
+    uint32_t byte_count;
+    uint32_t byte_offset;
+} vmbus_xferpg_range;
+
+typedef struct vmbus_pkt_xferpg {
+    uint16_t buffer_id;
+    uint8_t sender_owns_set;
+    uint8_t _reserved;
+    uint32_t rangecount;
+    vmbus_xferpg_range range[0];
+} vmbus_pkt_xferpg;
+
+#endif
