1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Hyper-V transport for vsock |
4 | * |
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. |
8 | * |
9 | * Copyright (c) 2017, Microsoft Corporation. |
10 | */ |
11 | #include <linux/module.h> |
12 | #include <linux/vmalloc.h> |
13 | #include <linux/hyperv.h> |
14 | #include <net/sock.h> |
15 | #include <net/af_vsock.h> |
16 | #include <asm/hyperv-tlfs.h> |
17 | |
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. |
22 | */ |
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) |
26 | |
27 | /* The MTU is 16KB per the host side's design */ |
28 | #define HVS_MTU_SIZE (1024 * 16) |
29 | |
30 | /* How long to wait for graceful shutdown of a connection */ |
31 | #define HVS_CLOSE_TIMEOUT (8 * HZ) |
32 | |
33 | struct { |
34 | u32 ; |
35 | u32 ; |
36 | }; |
37 | |
38 | /* For recv, we use the VMBus in-place packet iterator APIs to directly copy |
39 | * data from the ringbuffer into the userspace buffer. |
40 | */ |
41 | struct hvs_recv_buf { |
42 | /* The header before the payload data */ |
43 | struct vmpipe_proto_header hdr; |
44 | |
45 | /* The payload */ |
46 | u8 data[HVS_MTU_SIZE]; |
47 | }; |
48 | |
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 |
52 | * unit. |
53 | * |
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. |
57 | */ |
58 | #define HVS_SEND_BUF_SIZE \ |
59 | (HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header)) |
60 | |
61 | struct hvs_send_buf { |
62 | /* The header before the payload data */ |
63 | struct vmpipe_proto_header hdr; |
64 | |
65 | /* The payload */ |
66 | u8 data[HVS_SEND_BUF_SIZE]; |
67 | }; |
68 | |
69 | #define (sizeof(struct vmpacket_descriptor) + \ |
70 | sizeof(struct vmpipe_proto_header)) |
71 | |
72 | /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and |
73 | * __hv_pkt_iter_next(). |
74 | */ |
75 | #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64)) |
76 | |
77 | #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \ |
78 | ALIGN((payload_len), 8) + \ |
79 | VMBUS_PKT_TRAILER_SIZE) |
80 | |
81 | /* Upper bound on the size of a VMbus packet for hv_sock */ |
82 | #define HVS_MAX_PKT_SIZE HVS_PKT_LEN(HVS_MTU_SIZE) |
83 | |
84 | union hvs_service_id { |
85 | guid_t srv_id; |
86 | |
87 | struct { |
88 | unsigned int svm_port; |
89 | unsigned char b[sizeof(guid_t) - sizeof(unsigned int)]; |
90 | }; |
91 | }; |
92 | |
93 | /* Per-socket state (accessed via vsk->trans) */ |
94 | struct hvsock { |
95 | struct vsock_sock *vsk; |
96 | |
97 | guid_t vm_srv_id; |
98 | guid_t host_srv_id; |
99 | |
100 | struct vmbus_channel *chan; |
101 | struct vmpacket_descriptor *recv_desc; |
102 | |
103 | /* The length of the payload not delivered to userland yet */ |
104 | u32 recv_data_len; |
105 | /* The offset of the payload */ |
106 | u32 recv_data_off; |
107 | |
108 | /* Have we sent the zero-length packet (FIN)? */ |
109 | bool fin_sent; |
110 | }; |
111 | |
112 | /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is |
113 | * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here: |
114 | * when we write apps to connect to the host, we can only use VMADDR_CID_ANY |
115 | * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we |
116 | * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY |
117 | * as the local cid. |
118 | * |
119 | * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV: |
120 | * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user- |
121 | * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with |
122 | * the below sockaddr: |
123 | * |
124 | * struct SOCKADDR_HV |
125 | * { |
126 | * ADDRESS_FAMILY Family; |
127 | * USHORT Reserved; |
128 | * GUID VmId; |
129 | * GUID ServiceId; |
130 | * }; |
131 | * Note: VmID is not used by Linux VM and actually it isn't transmitted via |
132 | * VMBus, because here it's obvious the host and the VM can easily identify |
133 | * each other. Though the VmID is useful on the host, especially in the case |
134 | * of Windows container, Linux VM doesn't need it at all. |
135 | * |
136 | * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit |
137 | * the available GUID space of SOCKADDR_HV so that we can create a mapping |
138 | * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing |
139 | * Hyper-V Sockets apps on the host and in Linux VM is: |
140 | * |
141 | **************************************************************************** |
142 | * The only valid Service GUIDs, from the perspectives of both the host and * |
143 | * Linux VM, that can be connected by the other end, must conform to this * |
144 | * format: <port>-facb-11e6-bd58-64006a7986d3. * |
145 | **************************************************************************** |
146 | * |
147 | * When we write apps on the host to connect(), the GUID ServiceID is used. |
148 | * When we write apps in Linux VM to connect(), we only need to specify the |
149 | * port and the driver will form the GUID and use that to request the host. |
150 | * |
151 | */ |
152 | |
153 | /* 00000000-facb-11e6-bd58-64006a7986d3 */ |
154 | static const guid_t srv_id_template = |
155 | GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, |
156 | 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); |
157 | |
158 | static bool hvs_check_transport(struct vsock_sock *vsk); |
159 | |
160 | static bool is_valid_srv_id(const guid_t *id) |
161 | { |
162 | return !memcmp(p: &id->b[4], q: &srv_id_template.b[4], size: sizeof(guid_t) - 4); |
163 | } |
164 | |
165 | static unsigned int get_port_by_srv_id(const guid_t *svr_id) |
166 | { |
167 | return *((unsigned int *)svr_id); |
168 | } |
169 | |
170 | static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id) |
171 | { |
172 | unsigned int port = get_port_by_srv_id(svr_id); |
173 | |
174 | vsock_addr_init(addr, VMADDR_CID_ANY, port); |
175 | } |
176 | |
177 | static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan) |
178 | { |
179 | set_channel_pending_send_size(c: chan, |
180 | HVS_PKT_LEN(HVS_SEND_BUF_SIZE)); |
181 | |
182 | virt_mb(); |
183 | } |
184 | |
185 | static bool hvs_channel_readable(struct vmbus_channel *chan) |
186 | { |
187 | u32 readable = hv_get_bytes_to_read(rbi: &chan->inbound); |
188 | |
189 | /* 0-size payload means FIN */ |
190 | return readable >= HVS_PKT_LEN(0); |
191 | } |
192 | |
193 | static int hvs_channel_readable_payload(struct vmbus_channel *chan) |
194 | { |
195 | u32 readable = hv_get_bytes_to_read(rbi: &chan->inbound); |
196 | |
197 | if (readable > HVS_PKT_LEN(0)) { |
198 | /* At least we have 1 byte to read. We don't need to return |
199 | * the exact readable bytes: see vsock_stream_recvmsg() -> |
200 | * vsock_stream_has_data(). |
201 | */ |
202 | return 1; |
203 | } |
204 | |
205 | if (readable == HVS_PKT_LEN(0)) { |
206 | /* 0-size payload means FIN */ |
207 | return 0; |
208 | } |
209 | |
210 | /* No payload or FIN */ |
211 | return -1; |
212 | } |
213 | |
214 | static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan) |
215 | { |
216 | u32 writeable = hv_get_bytes_to_write(rbi: &chan->outbound); |
217 | size_t ret; |
218 | |
219 | /* The ringbuffer mustn't be 100% full, and we should reserve a |
220 | * zero-length-payload packet for the FIN: see hv_ringbuffer_write() |
221 | * and hvs_shutdown(). |
222 | */ |
223 | if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0)) |
224 | return 0; |
225 | |
226 | ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0); |
227 | |
228 | return round_down(ret, 8); |
229 | } |
230 | |
231 | static int __hvs_send_data(struct vmbus_channel *chan, |
232 | struct vmpipe_proto_header *hdr, |
233 | size_t to_write) |
234 | { |
235 | hdr->pkt_type = 1; |
236 | hdr->data_size = to_write; |
237 | return vmbus_sendpacket(channel: chan, buffer: hdr, bufferLen: sizeof(*hdr) + to_write, |
238 | requestid: 0, type: VM_PKT_DATA_INBAND, flags: 0); |
239 | } |
240 | |
241 | static int hvs_send_data(struct vmbus_channel *chan, |
242 | struct hvs_send_buf *send_buf, size_t to_write) |
243 | { |
244 | return __hvs_send_data(chan, hdr: &send_buf->hdr, to_write); |
245 | } |
246 | |
247 | static void hvs_channel_cb(void *ctx) |
248 | { |
249 | struct sock *sk = (struct sock *)ctx; |
250 | struct vsock_sock *vsk = vsock_sk(sk); |
251 | struct hvsock *hvs = vsk->trans; |
252 | struct vmbus_channel *chan = hvs->chan; |
253 | |
254 | if (hvs_channel_readable(chan)) |
255 | sk->sk_data_ready(sk); |
256 | |
257 | if (hv_get_bytes_to_write(rbi: &chan->outbound) > 0) |
258 | sk->sk_write_space(sk); |
259 | } |
260 | |
261 | static void hvs_do_close_lock_held(struct vsock_sock *vsk, |
262 | bool cancel_timeout) |
263 | { |
264 | struct sock *sk = sk_vsock(vsk); |
265 | |
266 | sock_set_flag(sk, flag: SOCK_DONE); |
267 | vsk->peer_shutdown = SHUTDOWN_MASK; |
268 | if (vsock_stream_has_data(vsk) <= 0) |
269 | sk->sk_state = TCP_CLOSING; |
270 | sk->sk_state_change(sk); |
271 | if (vsk->close_work_scheduled && |
272 | (!cancel_timeout || cancel_delayed_work(dwork: &vsk->close_work))) { |
273 | vsk->close_work_scheduled = false; |
274 | vsock_remove_sock(vsk); |
275 | |
276 | /* Release the reference taken while scheduling the timeout */ |
277 | sock_put(sk); |
278 | } |
279 | } |
280 | |
281 | static void hvs_close_connection(struct vmbus_channel *chan) |
282 | { |
283 | struct sock *sk = get_per_channel_state(c: chan); |
284 | |
285 | lock_sock(sk); |
286 | hvs_do_close_lock_held(vsock_sk(sk), cancel_timeout: true); |
287 | release_sock(sk); |
288 | |
289 | /* Release the refcnt for the channel that's opened in |
290 | * hvs_open_connection(). |
291 | */ |
292 | sock_put(sk); |
293 | } |
294 | |
295 | static void hvs_open_connection(struct vmbus_channel *chan) |
296 | { |
297 | guid_t *if_instance, *if_type; |
298 | unsigned char conn_from_host; |
299 | |
300 | struct sockaddr_vm addr; |
301 | struct sock *sk, *new = NULL; |
302 | struct vsock_sock *vnew = NULL; |
303 | struct hvsock *hvs = NULL; |
304 | struct hvsock *hvs_new = NULL; |
305 | int rcvbuf; |
306 | int ret; |
307 | int sndbuf; |
308 | |
309 | if_type = &chan->offermsg.offer.if_type; |
310 | if_instance = &chan->offermsg.offer.if_instance; |
311 | conn_from_host = chan->offermsg.offer.u.pipe.user_def[0]; |
312 | if (!is_valid_srv_id(id: if_type)) |
313 | return; |
314 | |
315 | hvs_addr_init(addr: &addr, svr_id: conn_from_host ? if_type : if_instance); |
316 | sk = vsock_find_bound_socket(addr: &addr); |
317 | if (!sk) |
318 | return; |
319 | |
320 | lock_sock(sk); |
321 | if ((conn_from_host && sk->sk_state != TCP_LISTEN) || |
322 | (!conn_from_host && sk->sk_state != TCP_SYN_SENT)) |
323 | goto out; |
324 | |
325 | if (conn_from_host) { |
326 | if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) |
327 | goto out; |
328 | |
329 | new = vsock_create_connected(parent: sk); |
330 | if (!new) |
331 | goto out; |
332 | |
333 | new->sk_state = TCP_SYN_SENT; |
334 | vnew = vsock_sk(new); |
335 | |
336 | hvs_addr_init(addr: &vnew->local_addr, svr_id: if_type); |
337 | |
338 | /* Remote peer is always the host */ |
339 | vsock_addr_init(addr: &vnew->remote_addr, |
340 | VMADDR_CID_HOST, VMADDR_PORT_ANY); |
341 | vnew->remote_addr.svm_port = get_port_by_srv_id(svr_id: if_instance); |
342 | ret = vsock_assign_transport(vsk: vnew, vsock_sk(sk)); |
343 | /* Transport assigned (looking at remote_addr) must be the |
344 | * same where we received the request. |
345 | */ |
346 | if (ret || !hvs_check_transport(vsk: vnew)) { |
347 | sock_put(sk: new); |
348 | goto out; |
349 | } |
350 | hvs_new = vnew->trans; |
351 | hvs_new->chan = chan; |
352 | } else { |
353 | hvs = vsock_sk(sk)->trans; |
354 | hvs->chan = chan; |
355 | } |
356 | |
357 | set_channel_read_mode(c: chan, mode: HV_CALL_DIRECT); |
358 | |
359 | /* Use the socket buffer sizes as hints for the VMBUS ring size. For |
360 | * server side sockets, 'sk' is the parent socket and thus, this will |
361 | * allow the child sockets to inherit the size from the parent. Keep |
362 | * the mins to the default value and align to page size as per VMBUS |
363 | * requirements. |
364 | * For the max, the socket core library will limit the socket buffer |
365 | * size that can be set by the user, but, since currently, the hv_sock |
366 | * VMBUS ring buffer is physically contiguous allocation, restrict it |
367 | * further. |
368 | * Older versions of hv_sock host side code cannot handle bigger VMBUS |
369 | * ring buffer size. Use the version number to limit the change to newer |
370 | * versions. |
371 | */ |
372 | if (vmbus_proto_version < VERSION_WIN10_V5) { |
373 | sndbuf = RINGBUFFER_HVS_SND_SIZE; |
374 | rcvbuf = RINGBUFFER_HVS_RCV_SIZE; |
375 | } else { |
376 | sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE); |
377 | sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE); |
378 | sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE); |
379 | rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE); |
380 | rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE); |
381 | rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE); |
382 | } |
383 | |
384 | chan->max_pkt_size = HVS_MAX_PKT_SIZE; |
385 | |
386 | ret = vmbus_open(channel: chan, send_ringbuffersize: sndbuf, recv_ringbuffersize: rcvbuf, NULL, userdatalen: 0, onchannel_callback: hvs_channel_cb, |
387 | context: conn_from_host ? new : sk); |
388 | if (ret != 0) { |
389 | if (conn_from_host) { |
390 | hvs_new->chan = NULL; |
391 | sock_put(sk: new); |
392 | } else { |
393 | hvs->chan = NULL; |
394 | } |
395 | goto out; |
396 | } |
397 | |
398 | set_per_channel_state(c: chan, s: conn_from_host ? new : sk); |
399 | |
400 | /* This reference will be dropped by hvs_close_connection(). */ |
401 | sock_hold(sk: conn_from_host ? new : sk); |
402 | vmbus_set_chn_rescind_callback(channel: chan, chn_rescind_cb: hvs_close_connection); |
403 | |
404 | /* Set the pending send size to max packet size to always get |
405 | * notifications from the host when there is enough writable space. |
406 | * The host is optimized to send notifications only when the pending |
407 | * size boundary is crossed, and not always. |
408 | */ |
409 | hvs_set_channel_pending_send_size(chan); |
410 | |
411 | if (conn_from_host) { |
412 | new->sk_state = TCP_ESTABLISHED; |
413 | sk_acceptq_added(sk); |
414 | |
415 | hvs_new->vm_srv_id = *if_type; |
416 | hvs_new->host_srv_id = *if_instance; |
417 | |
418 | vsock_insert_connected(vsk: vnew); |
419 | |
420 | vsock_enqueue_accept(listener: sk, connected: new); |
421 | } else { |
422 | sk->sk_state = TCP_ESTABLISHED; |
423 | sk->sk_socket->state = SS_CONNECTED; |
424 | |
425 | vsock_insert_connected(vsock_sk(sk)); |
426 | } |
427 | |
428 | sk->sk_state_change(sk); |
429 | |
430 | out: |
431 | /* Release refcnt obtained when we called vsock_find_bound_socket() */ |
432 | sock_put(sk); |
433 | |
434 | release_sock(sk); |
435 | } |
436 | |
437 | static u32 hvs_get_local_cid(void) |
438 | { |
439 | return VMADDR_CID_ANY; |
440 | } |
441 | |
442 | static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk) |
443 | { |
444 | struct hvsock *hvs; |
445 | struct sock *sk = sk_vsock(vsk); |
446 | |
447 | hvs = kzalloc(size: sizeof(*hvs), GFP_KERNEL); |
448 | if (!hvs) |
449 | return -ENOMEM; |
450 | |
451 | vsk->trans = hvs; |
452 | hvs->vsk = vsk; |
453 | sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE; |
454 | sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE; |
455 | return 0; |
456 | } |
457 | |
458 | static int hvs_connect(struct vsock_sock *vsk) |
459 | { |
460 | union hvs_service_id vm, host; |
461 | struct hvsock *h = vsk->trans; |
462 | |
463 | vm.srv_id = srv_id_template; |
464 | vm.svm_port = vsk->local_addr.svm_port; |
465 | h->vm_srv_id = vm.srv_id; |
466 | |
467 | host.srv_id = srv_id_template; |
468 | host.svm_port = vsk->remote_addr.svm_port; |
469 | h->host_srv_id = host.srv_id; |
470 | |
471 | return vmbus_send_tl_connect_request(shv_guest_servie_id: &h->vm_srv_id, shv_host_servie_id: &h->host_srv_id); |
472 | } |
473 | |
474 | static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) |
475 | { |
476 | struct vmpipe_proto_header hdr; |
477 | |
478 | if (hvs->fin_sent || !hvs->chan) |
479 | return; |
480 | |
481 | /* It can't fail: see hvs_channel_writable_bytes(). */ |
482 | (void)__hvs_send_data(chan: hvs->chan, hdr: &hdr, to_write: 0); |
483 | hvs->fin_sent = true; |
484 | } |
485 | |
486 | static int hvs_shutdown(struct vsock_sock *vsk, int mode) |
487 | { |
488 | if (!(mode & SEND_SHUTDOWN)) |
489 | return 0; |
490 | |
491 | hvs_shutdown_lock_held(hvs: vsk->trans, mode); |
492 | return 0; |
493 | } |
494 | |
495 | static void hvs_close_timeout(struct work_struct *work) |
496 | { |
497 | struct vsock_sock *vsk = |
498 | container_of(work, struct vsock_sock, close_work.work); |
499 | struct sock *sk = sk_vsock(vsk); |
500 | |
501 | sock_hold(sk); |
502 | lock_sock(sk); |
503 | if (!sock_flag(sk, flag: SOCK_DONE)) |
504 | hvs_do_close_lock_held(vsk, cancel_timeout: false); |
505 | |
506 | vsk->close_work_scheduled = false; |
507 | release_sock(sk); |
508 | sock_put(sk); |
509 | } |
510 | |
511 | /* Returns true, if it is safe to remove socket; false otherwise */ |
512 | static bool hvs_close_lock_held(struct vsock_sock *vsk) |
513 | { |
514 | struct sock *sk = sk_vsock(vsk); |
515 | |
516 | if (!(sk->sk_state == TCP_ESTABLISHED || |
517 | sk->sk_state == TCP_CLOSING)) |
518 | return true; |
519 | |
520 | if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) |
521 | hvs_shutdown_lock_held(hvs: vsk->trans, SHUTDOWN_MASK); |
522 | |
523 | if (sock_flag(sk, flag: SOCK_DONE)) |
524 | return true; |
525 | |
526 | /* This reference will be dropped by the delayed close routine */ |
527 | sock_hold(sk); |
528 | INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout); |
529 | vsk->close_work_scheduled = true; |
530 | schedule_delayed_work(dwork: &vsk->close_work, HVS_CLOSE_TIMEOUT); |
531 | return false; |
532 | } |
533 | |
534 | static void hvs_release(struct vsock_sock *vsk) |
535 | { |
536 | bool remove_sock; |
537 | |
538 | remove_sock = hvs_close_lock_held(vsk); |
539 | if (remove_sock) |
540 | vsock_remove_sock(vsk); |
541 | } |
542 | |
543 | static void hvs_destruct(struct vsock_sock *vsk) |
544 | { |
545 | struct hvsock *hvs = vsk->trans; |
546 | struct vmbus_channel *chan = hvs->chan; |
547 | |
548 | if (chan) |
549 | vmbus_hvsock_device_unregister(channel: chan); |
550 | |
551 | kfree(objp: hvs); |
552 | } |
553 | |
554 | static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) |
555 | { |
556 | return -EOPNOTSUPP; |
557 | } |
558 | |
559 | static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, |
560 | size_t len, int flags) |
561 | { |
562 | return -EOPNOTSUPP; |
563 | } |
564 | |
565 | static int hvs_dgram_enqueue(struct vsock_sock *vsk, |
566 | struct sockaddr_vm *remote, struct msghdr *msg, |
567 | size_t dgram_len) |
568 | { |
569 | return -EOPNOTSUPP; |
570 | } |
571 | |
572 | static bool hvs_dgram_allow(u32 cid, u32 port) |
573 | { |
574 | return false; |
575 | } |
576 | |
577 | static int hvs_update_recv_data(struct hvsock *hvs) |
578 | { |
579 | struct hvs_recv_buf *recv_buf; |
580 | u32 pkt_len, payload_len; |
581 | |
582 | pkt_len = hv_pkt_len(desc: hvs->recv_desc); |
583 | |
584 | if (pkt_len < HVS_HEADER_LEN) |
585 | return -EIO; |
586 | |
587 | recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); |
588 | payload_len = recv_buf->hdr.data_size; |
589 | |
590 | if (payload_len > pkt_len - HVS_HEADER_LEN || |
591 | payload_len > HVS_MTU_SIZE) |
592 | return -EIO; |
593 | |
594 | if (payload_len == 0) |
595 | hvs->vsk->peer_shutdown |= SEND_SHUTDOWN; |
596 | |
597 | hvs->recv_data_len = payload_len; |
598 | hvs->recv_data_off = 0; |
599 | |
600 | return 0; |
601 | } |
602 | |
603 | static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg, |
604 | size_t len, int flags) |
605 | { |
606 | struct hvsock *hvs = vsk->trans; |
607 | bool need_refill = !hvs->recv_desc; |
608 | struct hvs_recv_buf *recv_buf; |
609 | u32 to_read; |
610 | int ret; |
611 | |
612 | if (flags & MSG_PEEK) |
613 | return -EOPNOTSUPP; |
614 | |
615 | if (need_refill) { |
616 | hvs->recv_desc = hv_pkt_iter_first(channel: hvs->chan); |
617 | if (!hvs->recv_desc) |
618 | return -ENOBUFS; |
619 | ret = hvs_update_recv_data(hvs); |
620 | if (ret) |
621 | return ret; |
622 | } |
623 | |
624 | recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); |
625 | to_read = min_t(u32, len, hvs->recv_data_len); |
626 | ret = memcpy_to_msg(msg, data: recv_buf->data + hvs->recv_data_off, len: to_read); |
627 | if (ret != 0) |
628 | return ret; |
629 | |
630 | hvs->recv_data_len -= to_read; |
631 | if (hvs->recv_data_len == 0) { |
632 | hvs->recv_desc = hv_pkt_iter_next(channel: hvs->chan, pkt: hvs->recv_desc); |
633 | if (hvs->recv_desc) { |
634 | ret = hvs_update_recv_data(hvs); |
635 | if (ret) |
636 | return ret; |
637 | } |
638 | } else { |
639 | hvs->recv_data_off += to_read; |
640 | } |
641 | |
642 | return to_read; |
643 | } |
644 | |
645 | static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, |
646 | size_t len) |
647 | { |
648 | struct hvsock *hvs = vsk->trans; |
649 | struct vmbus_channel *chan = hvs->chan; |
650 | struct hvs_send_buf *send_buf; |
651 | ssize_t to_write, max_writable; |
652 | ssize_t ret = 0; |
653 | ssize_t bytes_written = 0; |
654 | |
655 | BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE); |
656 | |
657 | send_buf = kmalloc(size: sizeof(*send_buf), GFP_KERNEL); |
658 | if (!send_buf) |
659 | return -ENOMEM; |
660 | |
661 | /* Reader(s) could be draining data from the channel as we write. |
662 | * Maximize bandwidth, by iterating until the channel is found to be |
663 | * full. |
664 | */ |
665 | while (len) { |
666 | max_writable = hvs_channel_writable_bytes(chan); |
667 | if (!max_writable) |
668 | break; |
669 | to_write = min_t(ssize_t, len, max_writable); |
670 | to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); |
671 | /* memcpy_from_msg is safe for loop as it advances the offsets |
672 | * within the message iterator. |
673 | */ |
674 | ret = memcpy_from_msg(data: send_buf->data, msg, len: to_write); |
675 | if (ret < 0) |
676 | goto out; |
677 | |
678 | ret = hvs_send_data(chan: hvs->chan, send_buf, to_write); |
679 | if (ret < 0) |
680 | goto out; |
681 | |
682 | bytes_written += to_write; |
683 | len -= to_write; |
684 | } |
685 | out: |
686 | /* If any data has been sent, return that */ |
687 | if (bytes_written) |
688 | ret = bytes_written; |
689 | kfree(objp: send_buf); |
690 | return ret; |
691 | } |
692 | |
693 | static s64 hvs_stream_has_data(struct vsock_sock *vsk) |
694 | { |
695 | struct hvsock *hvs = vsk->trans; |
696 | s64 ret; |
697 | |
698 | if (hvs->recv_data_len > 0) |
699 | return 1; |
700 | |
701 | switch (hvs_channel_readable_payload(chan: hvs->chan)) { |
702 | case 1: |
703 | ret = 1; |
704 | break; |
705 | case 0: |
706 | vsk->peer_shutdown |= SEND_SHUTDOWN; |
707 | ret = 0; |
708 | break; |
709 | default: /* -1 */ |
710 | ret = 0; |
711 | break; |
712 | } |
713 | |
714 | return ret; |
715 | } |
716 | |
717 | static s64 hvs_stream_has_space(struct vsock_sock *vsk) |
718 | { |
719 | struct hvsock *hvs = vsk->trans; |
720 | |
721 | return hvs_channel_writable_bytes(chan: hvs->chan); |
722 | } |
723 | |
724 | static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk) |
725 | { |
726 | return HVS_MTU_SIZE + 1; |
727 | } |
728 | |
729 | static bool hvs_stream_is_active(struct vsock_sock *vsk) |
730 | { |
731 | struct hvsock *hvs = vsk->trans; |
732 | |
733 | return hvs->chan != NULL; |
734 | } |
735 | |
736 | static bool hvs_stream_allow(u32 cid, u32 port) |
737 | { |
738 | if (cid == VMADDR_CID_HOST) |
739 | return true; |
740 | |
741 | return false; |
742 | } |
743 | |
744 | static |
745 | int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable) |
746 | { |
747 | struct hvsock *hvs = vsk->trans; |
748 | |
749 | *readable = hvs_channel_readable(chan: hvs->chan); |
750 | return 0; |
751 | } |
752 | |
753 | static |
754 | int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable) |
755 | { |
756 | *writable = hvs_stream_has_space(vsk) > 0; |
757 | |
758 | return 0; |
759 | } |
760 | |
761 | static |
762 | int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target, |
763 | struct vsock_transport_recv_notify_data *d) |
764 | { |
765 | return 0; |
766 | } |
767 | |
768 | static |
769 | int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target, |
770 | struct vsock_transport_recv_notify_data *d) |
771 | { |
772 | return 0; |
773 | } |
774 | |
775 | static |
776 | int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target, |
777 | struct vsock_transport_recv_notify_data *d) |
778 | { |
779 | return 0; |
780 | } |
781 | |
782 | static |
783 | int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target, |
784 | ssize_t copied, bool data_read, |
785 | struct vsock_transport_recv_notify_data *d) |
786 | { |
787 | return 0; |
788 | } |
789 | |
790 | static |
791 | int hvs_notify_send_init(struct vsock_sock *vsk, |
792 | struct vsock_transport_send_notify_data *d) |
793 | { |
794 | return 0; |
795 | } |
796 | |
797 | static |
798 | int hvs_notify_send_pre_block(struct vsock_sock *vsk, |
799 | struct vsock_transport_send_notify_data *d) |
800 | { |
801 | return 0; |
802 | } |
803 | |
804 | static |
805 | int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk, |
806 | struct vsock_transport_send_notify_data *d) |
807 | { |
808 | return 0; |
809 | } |
810 | |
811 | static |
812 | int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, |
813 | struct vsock_transport_send_notify_data *d) |
814 | { |
815 | return 0; |
816 | } |
817 | |
818 | static |
819 | int hvs_set_rcvlowat(struct vsock_sock *vsk, int val) |
820 | { |
821 | return -EOPNOTSUPP; |
822 | } |
823 | |
824 | static struct vsock_transport hvs_transport = { |
825 | .module = THIS_MODULE, |
826 | |
827 | .get_local_cid = hvs_get_local_cid, |
828 | |
829 | .init = hvs_sock_init, |
830 | .destruct = hvs_destruct, |
831 | .release = hvs_release, |
832 | .connect = hvs_connect, |
833 | .shutdown = hvs_shutdown, |
834 | |
835 | .dgram_bind = hvs_dgram_bind, |
836 | .dgram_dequeue = hvs_dgram_dequeue, |
837 | .dgram_enqueue = hvs_dgram_enqueue, |
838 | .dgram_allow = hvs_dgram_allow, |
839 | |
840 | .stream_dequeue = hvs_stream_dequeue, |
841 | .stream_enqueue = hvs_stream_enqueue, |
842 | .stream_has_data = hvs_stream_has_data, |
843 | .stream_has_space = hvs_stream_has_space, |
844 | .stream_rcvhiwat = hvs_stream_rcvhiwat, |
845 | .stream_is_active = hvs_stream_is_active, |
846 | .stream_allow = hvs_stream_allow, |
847 | |
848 | .notify_poll_in = hvs_notify_poll_in, |
849 | .notify_poll_out = hvs_notify_poll_out, |
850 | .notify_recv_init = hvs_notify_recv_init, |
851 | .notify_recv_pre_block = hvs_notify_recv_pre_block, |
852 | .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue, |
853 | .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue, |
854 | .notify_send_init = hvs_notify_send_init, |
855 | .notify_send_pre_block = hvs_notify_send_pre_block, |
856 | .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, |
857 | .notify_send_post_enqueue = hvs_notify_send_post_enqueue, |
858 | |
859 | .set_rcvlowat = hvs_set_rcvlowat |
860 | }; |
861 | |
862 | static bool hvs_check_transport(struct vsock_sock *vsk) |
863 | { |
864 | return vsk->transport == &hvs_transport; |
865 | } |
866 | |
867 | static int hvs_probe(struct hv_device *hdev, |
868 | const struct hv_vmbus_device_id *dev_id) |
869 | { |
870 | struct vmbus_channel *chan = hdev->channel; |
871 | |
872 | hvs_open_connection(chan); |
873 | |
874 | /* Always return success to suppress the unnecessary error message |
875 | * in vmbus_probe(): on error the host will rescind the device in |
876 | * 30 seconds and we can do cleanup at that time in |
877 | * vmbus_onoffer_rescind(). |
878 | */ |
879 | return 0; |
880 | } |
881 | |
882 | static void hvs_remove(struct hv_device *hdev) |
883 | { |
884 | struct vmbus_channel *chan = hdev->channel; |
885 | |
886 | vmbus_close(channel: chan); |
887 | } |
888 | |
889 | /* hv_sock connections can not persist across hibernation, and all the hv_sock |
890 | * channels are forced to be rescinded before hibernation: see |
891 | * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume() |
892 | * are only needed because hibernation requires that every vmbus device's |
893 | * driver should have a .suspend and .resume callback: see vmbus_suspend(). |
894 | */ |
895 | static int hvs_suspend(struct hv_device *hv_dev) |
896 | { |
897 | /* Dummy */ |
898 | return 0; |
899 | } |
900 | |
901 | static int hvs_resume(struct hv_device *dev) |
902 | { |
903 | /* Dummy */ |
904 | return 0; |
905 | } |
906 | |
907 | /* This isn't really used. See vmbus_match() and vmbus_probe() */ |
908 | static const struct hv_vmbus_device_id id_table[] = { |
909 | {}, |
910 | }; |
911 | |
912 | static struct hv_driver hvs_drv = { |
913 | .name = "hv_sock" , |
914 | .hvsock = true, |
915 | .id_table = id_table, |
916 | .probe = hvs_probe, |
917 | .remove = hvs_remove, |
918 | .suspend = hvs_suspend, |
919 | .resume = hvs_resume, |
920 | }; |
921 | |
922 | static int __init hvs_init(void) |
923 | { |
924 | int ret; |
925 | |
926 | if (vmbus_proto_version < VERSION_WIN10) |
927 | return -ENODEV; |
928 | |
929 | ret = vmbus_driver_register(&hvs_drv); |
930 | if (ret != 0) |
931 | return ret; |
932 | |
933 | ret = vsock_core_register(t: &hvs_transport, VSOCK_TRANSPORT_F_G2H); |
934 | if (ret) { |
935 | vmbus_driver_unregister(hv_driver: &hvs_drv); |
936 | return ret; |
937 | } |
938 | |
939 | return 0; |
940 | } |
941 | |
942 | static void __exit hvs_exit(void) |
943 | { |
944 | vsock_core_unregister(t: &hvs_transport); |
945 | vmbus_driver_unregister(hv_driver: &hvs_drv); |
946 | } |
947 | |
948 | module_init(hvs_init); |
949 | module_exit(hvs_exit); |
950 | |
951 | MODULE_DESCRIPTION("Hyper-V Sockets" ); |
952 | MODULE_VERSION("1.0.0" ); |
953 | MODULE_LICENSE("GPL" ); |
954 | MODULE_ALIAS_NETPROTO(PF_VSOCK); |
955 | |