1 // SPDX-License-Identifier: GPL-2.0-only
3 * Hyper-V transport for vsock
5 * Hyper-V Sockets supplies a byte-stream based communication mechanism
6 * between the host and the VM. This driver implements the necessary
7 * support in the VM by introducing the new vsock transport.
9 * Copyright (c) 2017, Microsoft Corporation.
11 #include <linux/module.h>
12 #include <linux/vmalloc.h>
13 #include <linux/hyperv.h>
15 #include <net/af_vsock.h>
16 #include <asm/hyperv-tlfs.h>
18 /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some
19 * stricter requirements on the hv_sock ring buffer size of six 4K pages.
20 * hyperv-tlfs defines HV_HYP_PAGE_SIZE as 4K. Newer hosts don't have this
21 * limitation; but, keep the defaults the same for compat.
23 #define RINGBUFFER_HVS_RCV_SIZE (HV_HYP_PAGE_SIZE * 6)
24 #define RINGBUFFER_HVS_SND_SIZE (HV_HYP_PAGE_SIZE * 6)
25 #define RINGBUFFER_HVS_MAX_SIZE (HV_HYP_PAGE_SIZE * 64)
27 /* The MTU is 16KB per the host side's design */
28 #define HVS_MTU_SIZE (1024 * 16)
30 /* How long to wait for graceful shutdown of a connection */
31 #define HVS_CLOSE_TIMEOUT (8 * HZ)
33 struct vmpipe_proto_header {
38 /* For recv, we use the VMBus in-place packet iterator APIs to directly copy
39 * data from the ringbuffer into the userspace buffer.
42 /* The header before the payload data */
43 struct vmpipe_proto_header hdr;
46 u8 data[HVS_MTU_SIZE];
49 /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use
50 * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the
51 * guest and the host processing as one VMBUS packet is the smallest processing
54 * Note: the buffer can be eliminated in the future when we add new VMBus
55 * ringbuffer APIs that allow us to directly copy data from userspace buffer
56 * to VMBus ringbuffer.
58 #define HVS_SEND_BUF_SIZE \
59 (HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header))
62 /* The header before the payload data */
63 struct vmpipe_proto_header hdr;
66 u8 data[HVS_SEND_BUF_SIZE];
69 #define HVS_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \
70 sizeof(struct vmpipe_proto_header))
72 /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and
73 * __hv_pkt_iter_next().
75 #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64))
77 #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \
78 ALIGN((payload_len), 8) + \
79 VMBUS_PKT_TRAILER_SIZE)
81 union hvs_service_id {
85 unsigned int svm_port;
86 unsigned char b[sizeof(guid_t) - sizeof(unsigned int)];
90 /* Per-socket state (accessed via vsk->trans) */
92 struct vsock_sock *vsk;
97 struct vmbus_channel *chan;
98 struct vmpacket_descriptor *recv_desc;
100 /* The length of the payload not delivered to userland yet */
102 /* The offset of the payload */
105 /* Have we sent the zero-length packet (FIN)? */
109 /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is
110 * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here:
111 * when we write apps to connect to the host, we can only use VMADDR_CID_ANY
112 * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we
113 * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY
116 * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV:
117 * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-
118 * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with
119 * the below sockaddr:
123 * ADDRESS_FAMILY Family;
128 * Note: VmID is not used by Linux VM and actually it isn't transmitted via
129 * VMBus, because here it's obvious the host and the VM can easily identify
130 * each other. Though the VmID is useful on the host, especially in the case
131 * of Windows container, Linux VM doesn't need it at all.
133 * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit
134 * the available GUID space of SOCKADDR_HV so that we can create a mapping
135 * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing
136 * Hyper-V Sockets apps on the host and in Linux VM is:
138 ****************************************************************************
139 * The only valid Service GUIDs, from the perspectives of both the host and *
140 * Linux VM, that can be connected by the other end, must conform to this *
141 * format: <port>-facb-11e6-bd58-64006a7986d3. *
142 ****************************************************************************
144 * When we write apps on the host to connect(), the GUID ServiceID is used.
145 * When we write apps in Linux VM to connect(), we only need to specify the
146 * port and the driver will form the GUID and use that to request the host.
150 /* 00000000-facb-11e6-bd58-64006a7986d3 */
151 static const guid_t srv_id_template =
152 GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58,
153 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3);
155 static bool hvs_check_transport(struct vsock_sock *vsk);
157 static bool is_valid_srv_id(const guid_t *id)
159 return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4);
162 static unsigned int get_port_by_srv_id(const guid_t *svr_id)
164 return *((unsigned int *)svr_id);
167 static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id)
169 unsigned int port = get_port_by_srv_id(svr_id);
171 vsock_addr_init(addr, VMADDR_CID_ANY, port);
174 static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan)
176 set_channel_pending_send_size(chan,
177 HVS_PKT_LEN(HVS_SEND_BUF_SIZE));
182 static bool hvs_channel_readable(struct vmbus_channel *chan)
184 u32 readable = hv_get_bytes_to_read(&chan->inbound);
186 /* 0-size payload means FIN */
187 return readable >= HVS_PKT_LEN(0);
190 static int hvs_channel_readable_payload(struct vmbus_channel *chan)
192 u32 readable = hv_get_bytes_to_read(&chan->inbound);
194 if (readable > HVS_PKT_LEN(0)) {
195 /* At least we have 1 byte to read. We don't need to return
196 * the exact readable bytes: see vsock_stream_recvmsg() ->
197 * vsock_stream_has_data().
202 if (readable == HVS_PKT_LEN(0)) {
203 /* 0-size payload means FIN */
207 /* No payload or FIN */
211 static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan)
213 u32 writeable = hv_get_bytes_to_write(&chan->outbound);
216 /* The ringbuffer mustn't be 100% full, and we should reserve a
217 * zero-length-payload packet for the FIN: see hv_ringbuffer_write()
218 * and hvs_shutdown().
220 if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0))
223 ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0);
225 return round_down(ret, 8);
228 static int __hvs_send_data(struct vmbus_channel *chan,
229 struct vmpipe_proto_header *hdr,
233 hdr->data_size = to_write;
234 return vmbus_sendpacket(chan, hdr, sizeof(*hdr) + to_write,
235 0, VM_PKT_DATA_INBAND, 0);
238 static int hvs_send_data(struct vmbus_channel *chan,
239 struct hvs_send_buf *send_buf, size_t to_write)
241 return __hvs_send_data(chan, &send_buf->hdr, to_write);
244 static void hvs_channel_cb(void *ctx)
246 struct sock *sk = (struct sock *)ctx;
247 struct vsock_sock *vsk = vsock_sk(sk);
248 struct hvsock *hvs = vsk->trans;
249 struct vmbus_channel *chan = hvs->chan;
251 if (hvs_channel_readable(chan))
252 sk->sk_data_ready(sk);
254 if (hv_get_bytes_to_write(&chan->outbound) > 0)
255 sk->sk_write_space(sk);
258 static void hvs_do_close_lock_held(struct vsock_sock *vsk,
261 struct sock *sk = sk_vsock(vsk);
263 sock_set_flag(sk, SOCK_DONE);
264 vsk->peer_shutdown = SHUTDOWN_MASK;
265 if (vsock_stream_has_data(vsk) <= 0)
266 sk->sk_state = TCP_CLOSING;
267 sk->sk_state_change(sk);
268 if (vsk->close_work_scheduled &&
269 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
270 vsk->close_work_scheduled = false;
271 vsock_remove_sock(vsk);
273 /* Release the reference taken while scheduling the timeout */
278 static void hvs_close_connection(struct vmbus_channel *chan)
280 struct sock *sk = get_per_channel_state(chan);
283 hvs_do_close_lock_held(vsock_sk(sk), true);
286 /* Release the refcnt for the channel that's opened in
287 * hvs_open_connection().
292 static void hvs_open_connection(struct vmbus_channel *chan)
294 guid_t *if_instance, *if_type;
295 unsigned char conn_from_host;
297 struct sockaddr_vm addr;
298 struct sock *sk, *new = NULL;
299 struct vsock_sock *vnew = NULL;
300 struct hvsock *hvs = NULL;
301 struct hvsock *hvs_new = NULL;
306 if_type = &chan->offermsg.offer.if_type;
307 if_instance = &chan->offermsg.offer.if_instance;
308 conn_from_host = chan->offermsg.offer.u.pipe.user_def[0];
309 if (!is_valid_srv_id(if_type))
312 hvs_addr_init(&addr, conn_from_host ? if_type : if_instance);
313 sk = vsock_find_bound_socket(&addr);
318 if ((conn_from_host && sk->sk_state != TCP_LISTEN) ||
319 (!conn_from_host && sk->sk_state != TCP_SYN_SENT))
322 if (conn_from_host) {
323 if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog)
326 new = vsock_create_connected(sk);
330 new->sk_state = TCP_SYN_SENT;
331 vnew = vsock_sk(new);
333 hvs_addr_init(&vnew->local_addr, if_type);
335 /* Remote peer is always the host */
336 vsock_addr_init(&vnew->remote_addr,
337 VMADDR_CID_HOST, VMADDR_PORT_ANY);
338 vnew->remote_addr.svm_port = get_port_by_srv_id(if_instance);
339 ret = vsock_assign_transport(vnew, vsock_sk(sk));
340 /* Transport assigned (looking at remote_addr) must be the
341 * same where we received the request.
343 if (ret || !hvs_check_transport(vnew)) {
347 hvs_new = vnew->trans;
348 hvs_new->chan = chan;
350 hvs = vsock_sk(sk)->trans;
354 set_channel_read_mode(chan, HV_CALL_DIRECT);
356 /* Use the socket buffer sizes as hints for the VMBUS ring size. For
357 * server side sockets, 'sk' is the parent socket and thus, this will
358 * allow the child sockets to inherit the size from the parent. Keep
359 * the mins to the default value and align to page size as per VMBUS
361 * For the max, the socket core library will limit the socket buffer
362 * size that can be set by the user, but, since currently, the hv_sock
363 * VMBUS ring buffer is physically contiguous allocation, restrict it
365 * Older versions of hv_sock host side code cannot handle bigger VMBUS
366 * ring buffer size. Use the version number to limit the change to newer
369 if (vmbus_proto_version < VERSION_WIN10_V5) {
370 sndbuf = RINGBUFFER_HVS_SND_SIZE;
371 rcvbuf = RINGBUFFER_HVS_RCV_SIZE;
373 sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE);
374 sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE);
375 sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE);
376 rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE);
377 rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE);
378 rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE);
381 ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb,
382 conn_from_host ? new : sk);
384 if (conn_from_host) {
385 hvs_new->chan = NULL;
393 set_per_channel_state(chan, conn_from_host ? new : sk);
395 /* This reference will be dropped by hvs_close_connection(). */
396 sock_hold(conn_from_host ? new : sk);
397 vmbus_set_chn_rescind_callback(chan, hvs_close_connection);
399 /* Set the pending send size to max packet size to always get
400 * notifications from the host when there is enough writable space.
401 * The host is optimized to send notifications only when the pending
402 * size boundary is crossed, and not always.
404 hvs_set_channel_pending_send_size(chan);
406 if (conn_from_host) {
407 new->sk_state = TCP_ESTABLISHED;
408 sk_acceptq_added(sk);
410 hvs_new->vm_srv_id = *if_type;
411 hvs_new->host_srv_id = *if_instance;
413 vsock_insert_connected(vnew);
415 vsock_enqueue_accept(sk, new);
417 sk->sk_state = TCP_ESTABLISHED;
418 sk->sk_socket->state = SS_CONNECTED;
420 vsock_insert_connected(vsock_sk(sk));
423 sk->sk_state_change(sk);
426 /* Release refcnt obtained when we called vsock_find_bound_socket() */
432 static u32 hvs_get_local_cid(void)
434 return VMADDR_CID_ANY;
437 static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk)
440 struct sock *sk = sk_vsock(vsk);
442 hvs = kzalloc(sizeof(*hvs), GFP_KERNEL);
448 sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE;
449 sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE;
453 static int hvs_connect(struct vsock_sock *vsk)
455 union hvs_service_id vm, host;
456 struct hvsock *h = vsk->trans;
458 vm.srv_id = srv_id_template;
459 vm.svm_port = vsk->local_addr.svm_port;
460 h->vm_srv_id = vm.srv_id;
462 host.srv_id = srv_id_template;
463 host.svm_port = vsk->remote_addr.svm_port;
464 h->host_srv_id = host.srv_id;
466 return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id);
469 static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode)
471 struct vmpipe_proto_header hdr;
473 if (hvs->fin_sent || !hvs->chan)
476 /* It can't fail: see hvs_channel_writable_bytes(). */
477 (void)__hvs_send_data(hvs->chan, &hdr, 0);
478 hvs->fin_sent = true;
481 static int hvs_shutdown(struct vsock_sock *vsk, int mode)
483 if (!(mode & SEND_SHUTDOWN))
486 hvs_shutdown_lock_held(vsk->trans, mode);
490 static void hvs_close_timeout(struct work_struct *work)
492 struct vsock_sock *vsk =
493 container_of(work, struct vsock_sock, close_work.work);
494 struct sock *sk = sk_vsock(vsk);
498 if (!sock_flag(sk, SOCK_DONE))
499 hvs_do_close_lock_held(vsk, false);
501 vsk->close_work_scheduled = false;
506 /* Returns true, if it is safe to remove socket; false otherwise */
507 static bool hvs_close_lock_held(struct vsock_sock *vsk)
509 struct sock *sk = sk_vsock(vsk);
511 if (!(sk->sk_state == TCP_ESTABLISHED ||
512 sk->sk_state == TCP_CLOSING))
515 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
516 hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK);
518 if (sock_flag(sk, SOCK_DONE))
521 /* This reference will be dropped by the delayed close routine */
523 INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout);
524 vsk->close_work_scheduled = true;
525 schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT);
529 static void hvs_release(struct vsock_sock *vsk)
533 remove_sock = hvs_close_lock_held(vsk);
535 vsock_remove_sock(vsk);
538 static void hvs_destruct(struct vsock_sock *vsk)
540 struct hvsock *hvs = vsk->trans;
541 struct vmbus_channel *chan = hvs->chan;
544 vmbus_hvsock_device_unregister(chan);
549 static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr)
554 static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
555 size_t len, int flags)
560 static int hvs_dgram_enqueue(struct vsock_sock *vsk,
561 struct sockaddr_vm *remote, struct msghdr *msg,
567 static bool hvs_dgram_allow(u32 cid, u32 port)
572 static int hvs_update_recv_data(struct hvsock *hvs)
574 struct hvs_recv_buf *recv_buf;
577 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
578 payload_len = recv_buf->hdr.data_size;
580 if (payload_len > HVS_MTU_SIZE)
583 if (payload_len == 0)
584 hvs->vsk->peer_shutdown |= SEND_SHUTDOWN;
586 hvs->recv_data_len = payload_len;
587 hvs->recv_data_off = 0;
592 static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
593 size_t len, int flags)
595 struct hvsock *hvs = vsk->trans;
596 bool need_refill = !hvs->recv_desc;
597 struct hvs_recv_buf *recv_buf;
601 if (flags & MSG_PEEK)
605 hvs->recv_desc = hv_pkt_iter_first_raw(hvs->chan);
606 ret = hvs_update_recv_data(hvs);
611 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
612 to_read = min_t(u32, len, hvs->recv_data_len);
613 ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read);
617 hvs->recv_data_len -= to_read;
618 if (hvs->recv_data_len == 0) {
619 hvs->recv_desc = hv_pkt_iter_next_raw(hvs->chan, hvs->recv_desc);
620 if (hvs->recv_desc) {
621 ret = hvs_update_recv_data(hvs);
626 hvs->recv_data_off += to_read;
632 static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
635 struct hvsock *hvs = vsk->trans;
636 struct vmbus_channel *chan = hvs->chan;
637 struct hvs_send_buf *send_buf;
638 ssize_t to_write, max_writable;
640 ssize_t bytes_written = 0;
642 BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE);
644 send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL);
648 /* Reader(s) could be draining data from the channel as we write.
649 * Maximize bandwidth, by iterating until the channel is found to be
653 max_writable = hvs_channel_writable_bytes(chan);
656 to_write = min_t(ssize_t, len, max_writable);
657 to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE);
658 /* memcpy_from_msg is safe for loop as it advances the offsets
659 * within the message iterator.
661 ret = memcpy_from_msg(send_buf->data, msg, to_write);
665 ret = hvs_send_data(hvs->chan, send_buf, to_write);
669 bytes_written += to_write;
673 /* If any data has been sent, return that */
680 static s64 hvs_stream_has_data(struct vsock_sock *vsk)
682 struct hvsock *hvs = vsk->trans;
685 if (hvs->recv_data_len > 0)
688 switch (hvs_channel_readable_payload(hvs->chan)) {
693 vsk->peer_shutdown |= SEND_SHUTDOWN;
704 static s64 hvs_stream_has_space(struct vsock_sock *vsk)
706 struct hvsock *hvs = vsk->trans;
708 return hvs_channel_writable_bytes(hvs->chan);
711 static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk)
713 return HVS_MTU_SIZE + 1;
716 static bool hvs_stream_is_active(struct vsock_sock *vsk)
718 struct hvsock *hvs = vsk->trans;
720 return hvs->chan != NULL;
723 static bool hvs_stream_allow(u32 cid, u32 port)
725 if (cid == VMADDR_CID_HOST)
732 int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable)
734 struct hvsock *hvs = vsk->trans;
736 *readable = hvs_channel_readable(hvs->chan);
741 int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable)
743 *writable = hvs_stream_has_space(vsk) > 0;
749 int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target,
750 struct vsock_transport_recv_notify_data *d)
756 int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target,
757 struct vsock_transport_recv_notify_data *d)
763 int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target,
764 struct vsock_transport_recv_notify_data *d)
770 int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target,
771 ssize_t copied, bool data_read,
772 struct vsock_transport_recv_notify_data *d)
778 int hvs_notify_send_init(struct vsock_sock *vsk,
779 struct vsock_transport_send_notify_data *d)
785 int hvs_notify_send_pre_block(struct vsock_sock *vsk,
786 struct vsock_transport_send_notify_data *d)
792 int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk,
793 struct vsock_transport_send_notify_data *d)
799 int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
800 struct vsock_transport_send_notify_data *d)
805 static struct vsock_transport hvs_transport = {
806 .module = THIS_MODULE,
808 .get_local_cid = hvs_get_local_cid,
810 .init = hvs_sock_init,
811 .destruct = hvs_destruct,
812 .release = hvs_release,
813 .connect = hvs_connect,
814 .shutdown = hvs_shutdown,
816 .dgram_bind = hvs_dgram_bind,
817 .dgram_dequeue = hvs_dgram_dequeue,
818 .dgram_enqueue = hvs_dgram_enqueue,
819 .dgram_allow = hvs_dgram_allow,
821 .stream_dequeue = hvs_stream_dequeue,
822 .stream_enqueue = hvs_stream_enqueue,
823 .stream_has_data = hvs_stream_has_data,
824 .stream_has_space = hvs_stream_has_space,
825 .stream_rcvhiwat = hvs_stream_rcvhiwat,
826 .stream_is_active = hvs_stream_is_active,
827 .stream_allow = hvs_stream_allow,
829 .notify_poll_in = hvs_notify_poll_in,
830 .notify_poll_out = hvs_notify_poll_out,
831 .notify_recv_init = hvs_notify_recv_init,
832 .notify_recv_pre_block = hvs_notify_recv_pre_block,
833 .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue,
834 .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue,
835 .notify_send_init = hvs_notify_send_init,
836 .notify_send_pre_block = hvs_notify_send_pre_block,
837 .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue,
838 .notify_send_post_enqueue = hvs_notify_send_post_enqueue,
842 static bool hvs_check_transport(struct vsock_sock *vsk)
844 return vsk->transport == &hvs_transport;
847 static int hvs_probe(struct hv_device *hdev,
848 const struct hv_vmbus_device_id *dev_id)
850 struct vmbus_channel *chan = hdev->channel;
852 hvs_open_connection(chan);
854 /* Always return success to suppress the unnecessary error message
855 * in vmbus_probe(): on error the host will rescind the device in
856 * 30 seconds and we can do cleanup at that time in
857 * vmbus_onoffer_rescind().
862 static int hvs_remove(struct hv_device *hdev)
864 struct vmbus_channel *chan = hdev->channel;
871 /* hv_sock connections can not persist across hibernation, and all the hv_sock
872 * channels are forced to be rescinded before hibernation: see
873 * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume()
874 * are only needed because hibernation requires that every vmbus device's
875 * driver should have a .suspend and .resume callback: see vmbus_suspend().
877 static int hvs_suspend(struct hv_device *hv_dev)
883 static int hvs_resume(struct hv_device *dev)
889 /* This isn't really used. See vmbus_match() and vmbus_probe() */
890 static const struct hv_vmbus_device_id id_table[] = {
894 static struct hv_driver hvs_drv = {
897 .id_table = id_table,
899 .remove = hvs_remove,
900 .suspend = hvs_suspend,
901 .resume = hvs_resume,
904 static int __init hvs_init(void)
908 if (vmbus_proto_version < VERSION_WIN10)
911 ret = vmbus_driver_register(&hvs_drv);
915 ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H);
917 vmbus_driver_unregister(&hvs_drv);
924 static void __exit hvs_exit(void)
926 vsock_core_unregister(&hvs_transport);
927 vmbus_driver_unregister(&hvs_drv);
930 module_init(hvs_init);
931 module_exit(hvs_exit);
933 MODULE_DESCRIPTION("Hyper-V Sockets");
934 MODULE_VERSION("1.0.0");
935 MODULE_LICENSE("GPL");
936 MODULE_ALIAS_NETPROTO(PF_VSOCK);