xref: /openbmc/linux/drivers/net/hyperv/netvsc.c (revision 0a94608f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2009, Microsoft Corporation.
4  *
5  * Authors:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  *   Hank Janssen  <hjanssen@microsoft.com>
8  */
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/wait.h>
14 #include <linux/mm.h>
15 #include <linux/delay.h>
16 #include <linux/io.h>
17 #include <linux/slab.h>
18 #include <linux/netdevice.h>
19 #include <linux/if_ether.h>
20 #include <linux/vmalloc.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/prefetch.h>
23 
24 #include <asm/sync_bitops.h>
25 #include <asm/mshyperv.h>
26 
27 #include "hyperv_net.h"
28 #include "netvsc_trace.h"
29 
30 /*
31  * Switch the data path from the synthetic interface to the VF
32  * interface.
33  */
34 int netvsc_switch_datapath(struct net_device *ndev, bool vf)
35 {
36 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
37 	struct hv_device *dev = net_device_ctx->device_ctx;
38 	struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
39 	struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
40 	int ret, retry = 0;
41 
42 	/* Block sending traffic to VF if it's about to be gone */
43 	if (!vf)
44 		net_device_ctx->data_path_is_vf = vf;
45 
46 	memset(init_pkt, 0, sizeof(struct nvsp_message));
47 	init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
48 	if (vf)
49 		init_pkt->msg.v4_msg.active_dp.active_datapath =
50 			NVSP_DATAPATH_VF;
51 	else
52 		init_pkt->msg.v4_msg.active_dp.active_datapath =
53 			NVSP_DATAPATH_SYNTHETIC;
54 
55 again:
56 	trace_nvsp_send(ndev, init_pkt);
57 
58 	ret = vmbus_sendpacket(dev->channel, init_pkt,
59 			       sizeof(struct nvsp_message),
60 			       (unsigned long)init_pkt, VM_PKT_DATA_INBAND,
61 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
62 
63 	/* If failed to switch to/from VF, let data_path_is_vf stay false,
64 	 * so we use synthetic path to send data.
65 	 */
66 	if (ret) {
67 		if (ret != -EAGAIN) {
68 			netdev_err(ndev,
69 				   "Unable to send sw datapath msg, err: %d\n",
70 				   ret);
71 			return ret;
72 		}
73 
74 		if (retry++ < RETRY_MAX) {
75 			usleep_range(RETRY_US_LO, RETRY_US_HI);
76 			goto again;
77 		} else {
78 			netdev_err(
79 				ndev,
80 				"Retry failed to send sw datapath msg, err: %d\n",
81 				ret);
82 			return ret;
83 		}
84 	}
85 
86 	wait_for_completion(&nv_dev->channel_init_wait);
87 	net_device_ctx->data_path_is_vf = vf;
88 
89 	return 0;
90 }
91 
92 /* Worker to setup sub channels on initial setup
93  * Initial hotplug event occurs in softirq context
94  * and can't wait for channels.
95  */
96 static void netvsc_subchan_work(struct work_struct *w)
97 {
98 	struct netvsc_device *nvdev =
99 		container_of(w, struct netvsc_device, subchan_work);
100 	struct rndis_device *rdev;
101 	int i, ret;
102 
103 	/* Avoid deadlock with device removal already under RTNL */
104 	if (!rtnl_trylock()) {
105 		schedule_work(w);
106 		return;
107 	}
108 
109 	rdev = nvdev->extension;
110 	if (rdev) {
111 		ret = rndis_set_subchannel(rdev->ndev, nvdev, NULL);
112 		if (ret == 0) {
113 			netif_device_attach(rdev->ndev);
114 		} else {
115 			/* fallback to only primary channel */
116 			for (i = 1; i < nvdev->num_chn; i++)
117 				netif_napi_del(&nvdev->chan_table[i].napi);
118 
119 			nvdev->max_chn = 1;
120 			nvdev->num_chn = 1;
121 		}
122 	}
123 
124 	rtnl_unlock();
125 }
126 
127 static struct netvsc_device *alloc_net_device(void)
128 {
129 	struct netvsc_device *net_device;
130 
131 	net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
132 	if (!net_device)
133 		return NULL;
134 
135 	init_waitqueue_head(&net_device->wait_drain);
136 	net_device->destroy = false;
137 	net_device->tx_disable = true;
138 
139 	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
140 	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
141 
142 	init_completion(&net_device->channel_init_wait);
143 	init_waitqueue_head(&net_device->subchan_open);
144 	INIT_WORK(&net_device->subchan_work, netvsc_subchan_work);
145 
146 	return net_device;
147 }
148 
149 static void free_netvsc_device(struct rcu_head *head)
150 {
151 	struct netvsc_device *nvdev
152 		= container_of(head, struct netvsc_device, rcu);
153 	int i;
154 
155 	kfree(nvdev->extension);
156 
157 	if (nvdev->recv_original_buf)
158 		vfree(nvdev->recv_original_buf);
159 	else
160 		vfree(nvdev->recv_buf);
161 
162 	if (nvdev->send_original_buf)
163 		vfree(nvdev->send_original_buf);
164 	else
165 		vfree(nvdev->send_buf);
166 
167 	bitmap_free(nvdev->send_section_map);
168 
169 	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
170 		xdp_rxq_info_unreg(&nvdev->chan_table[i].xdp_rxq);
171 		kfree(nvdev->chan_table[i].recv_buf);
172 		vfree(nvdev->chan_table[i].mrc.slots);
173 	}
174 
175 	kfree(nvdev);
176 }
177 
178 static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
179 {
180 	call_rcu(&nvdev->rcu, free_netvsc_device);
181 }
182 
183 static void netvsc_revoke_recv_buf(struct hv_device *device,
184 				   struct netvsc_device *net_device,
185 				   struct net_device *ndev)
186 {
187 	struct nvsp_message *revoke_packet;
188 	int ret;
189 
190 	/*
191 	 * If we got a section count, it means we received a
192 	 * SendReceiveBufferComplete msg (ie sent
193 	 * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
194 	 * to send a revoke msg here
195 	 */
196 	if (net_device->recv_section_cnt) {
197 		/* Send the revoke receive buffer */
198 		revoke_packet = &net_device->revoke_packet;
199 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
200 
201 		revoke_packet->hdr.msg_type =
202 			NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
203 		revoke_packet->msg.v1_msg.
204 		revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
205 
206 		trace_nvsp_send(ndev, revoke_packet);
207 
208 		ret = vmbus_sendpacket(device->channel,
209 				       revoke_packet,
210 				       sizeof(struct nvsp_message),
211 				       VMBUS_RQST_ID_NO_RESPONSE,
212 				       VM_PKT_DATA_INBAND, 0);
213 		/* If the failure is because the channel is rescinded;
214 		 * ignore the failure since we cannot send on a rescinded
215 		 * channel. This would allow us to properly cleanup
216 		 * even when the channel is rescinded.
217 		 */
218 		if (device->channel->rescind)
219 			ret = 0;
220 		/*
221 		 * If we failed here, we might as well return and
222 		 * have a leak rather than continue and a bugchk
223 		 */
224 		if (ret != 0) {
225 			netdev_err(ndev, "unable to send "
226 				"revoke receive buffer to netvsp\n");
227 			return;
228 		}
229 		net_device->recv_section_cnt = 0;
230 	}
231 }
232 
233 static void netvsc_revoke_send_buf(struct hv_device *device,
234 				   struct netvsc_device *net_device,
235 				   struct net_device *ndev)
236 {
237 	struct nvsp_message *revoke_packet;
238 	int ret;
239 
240 	/* Deal with the send buffer we may have setup.
241 	 * If we got a  send section size, it means we received a
242 	 * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
243 	 * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
244 	 * to send a revoke msg here
245 	 */
246 	if (net_device->send_section_cnt) {
247 		/* Send the revoke receive buffer */
248 		revoke_packet = &net_device->revoke_packet;
249 		memset(revoke_packet, 0, sizeof(struct nvsp_message));
250 
251 		revoke_packet->hdr.msg_type =
252 			NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
253 		revoke_packet->msg.v1_msg.revoke_send_buf.id =
254 			NETVSC_SEND_BUFFER_ID;
255 
256 		trace_nvsp_send(ndev, revoke_packet);
257 
258 		ret = vmbus_sendpacket(device->channel,
259 				       revoke_packet,
260 				       sizeof(struct nvsp_message),
261 				       VMBUS_RQST_ID_NO_RESPONSE,
262 				       VM_PKT_DATA_INBAND, 0);
263 
264 		/* If the failure is because the channel is rescinded;
265 		 * ignore the failure since we cannot send on a rescinded
266 		 * channel. This would allow us to properly cleanup
267 		 * even when the channel is rescinded.
268 		 */
269 		if (device->channel->rescind)
270 			ret = 0;
271 
272 		/* If we failed here, we might as well return and
273 		 * have a leak rather than continue and a bugchk
274 		 */
275 		if (ret != 0) {
276 			netdev_err(ndev, "unable to send "
277 				   "revoke send buffer to netvsp\n");
278 			return;
279 		}
280 		net_device->send_section_cnt = 0;
281 	}
282 }
283 
284 static void netvsc_teardown_recv_gpadl(struct hv_device *device,
285 				       struct netvsc_device *net_device,
286 				       struct net_device *ndev)
287 {
288 	int ret;
289 
290 	if (net_device->recv_buf_gpadl_handle.gpadl_handle) {
291 		ret = vmbus_teardown_gpadl(device->channel,
292 					   &net_device->recv_buf_gpadl_handle);
293 
294 		/* If we failed here, we might as well return and have a leak
295 		 * rather than continue and a bugchk
296 		 */
297 		if (ret != 0) {
298 			netdev_err(ndev,
299 				   "unable to teardown receive buffer's gpadl\n");
300 			return;
301 		}
302 	}
303 }
304 
305 static void netvsc_teardown_send_gpadl(struct hv_device *device,
306 				       struct netvsc_device *net_device,
307 				       struct net_device *ndev)
308 {
309 	int ret;
310 
311 	if (net_device->send_buf_gpadl_handle.gpadl_handle) {
312 		ret = vmbus_teardown_gpadl(device->channel,
313 					   &net_device->send_buf_gpadl_handle);
314 
315 		/* If we failed here, we might as well return and have a leak
316 		 * rather than continue and a bugchk
317 		 */
318 		if (ret != 0) {
319 			netdev_err(ndev,
320 				   "unable to teardown send buffer's gpadl\n");
321 			return;
322 		}
323 	}
324 }
325 
326 int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
327 {
328 	struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
329 	int node = cpu_to_node(nvchan->channel->target_cpu);
330 	size_t size;
331 
332 	size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
333 	nvchan->mrc.slots = vzalloc_node(size, node);
334 	if (!nvchan->mrc.slots)
335 		nvchan->mrc.slots = vzalloc(size);
336 
337 	return nvchan->mrc.slots ? 0 : -ENOMEM;
338 }
339 
340 static int netvsc_init_buf(struct hv_device *device,
341 			   struct netvsc_device *net_device,
342 			   const struct netvsc_device_info *device_info)
343 {
344 	struct nvsp_1_message_send_receive_buffer_complete *resp;
345 	struct net_device *ndev = hv_get_drvdata(device);
346 	struct nvsp_message *init_packet;
347 	unsigned int buf_size;
348 	int i, ret = 0;
349 	void *vaddr;
350 
351 	/* Get receive buffer area. */
352 	buf_size = device_info->recv_sections * device_info->recv_section_size;
353 	buf_size = roundup(buf_size, PAGE_SIZE);
354 
355 	/* Legacy hosts only allow smaller receive buffer */
356 	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
357 		buf_size = min_t(unsigned int, buf_size,
358 				 NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
359 
360 	net_device->recv_buf = vzalloc(buf_size);
361 	if (!net_device->recv_buf) {
362 		netdev_err(ndev,
363 			   "unable to allocate receive buffer of size %u\n",
364 			   buf_size);
365 		ret = -ENOMEM;
366 		goto cleanup;
367 	}
368 
369 	net_device->recv_buf_size = buf_size;
370 
371 	/*
372 	 * Establish the gpadl handle for this buffer on this
373 	 * channel.  Note: This call uses the vmbus connection rather
374 	 * than the channel to establish the gpadl handle.
375 	 */
376 	ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
377 				    buf_size,
378 				    &net_device->recv_buf_gpadl_handle);
379 	if (ret != 0) {
380 		netdev_err(ndev,
381 			"unable to establish receive buffer's gpadl\n");
382 		goto cleanup;
383 	}
384 
385 	if (hv_isolation_type_snp()) {
386 		vaddr = hv_map_memory(net_device->recv_buf, buf_size);
387 		if (!vaddr) {
388 			ret = -ENOMEM;
389 			goto cleanup;
390 		}
391 
392 		net_device->recv_original_buf = net_device->recv_buf;
393 		net_device->recv_buf = vaddr;
394 	}
395 
396 	/* Notify the NetVsp of the gpadl handle */
397 	init_packet = &net_device->channel_init_pkt;
398 	memset(init_packet, 0, sizeof(struct nvsp_message));
399 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
400 	init_packet->msg.v1_msg.send_recv_buf.
401 		gpadl_handle = net_device->recv_buf_gpadl_handle.gpadl_handle;
402 	init_packet->msg.v1_msg.
403 		send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
404 
405 	trace_nvsp_send(ndev, init_packet);
406 
407 	/* Send the gpadl notification request */
408 	ret = vmbus_sendpacket(device->channel, init_packet,
409 			       sizeof(struct nvsp_message),
410 			       (unsigned long)init_packet,
411 			       VM_PKT_DATA_INBAND,
412 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
413 	if (ret != 0) {
414 		netdev_err(ndev,
415 			"unable to send receive buffer's gpadl to netvsp\n");
416 		goto cleanup;
417 	}
418 
419 	wait_for_completion(&net_device->channel_init_wait);
420 
421 	/* Check the response */
422 	resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
423 	if (resp->status != NVSP_STAT_SUCCESS) {
424 		netdev_err(ndev,
425 			   "Unable to complete receive buffer initialization with NetVsp - status %d\n",
426 			   resp->status);
427 		ret = -EINVAL;
428 		goto cleanup;
429 	}
430 
431 	/* Parse the response */
432 	netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
433 		   resp->num_sections, resp->sections[0].sub_alloc_size,
434 		   resp->sections[0].num_sub_allocs);
435 
436 	/* There should only be one section for the entire receive buffer */
437 	if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
438 		ret = -EINVAL;
439 		goto cleanup;
440 	}
441 
442 	net_device->recv_section_size = resp->sections[0].sub_alloc_size;
443 	net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
444 
445 	/* Ensure buffer will not overflow */
446 	if (net_device->recv_section_size < NETVSC_MTU_MIN || (u64)net_device->recv_section_size *
447 	    (u64)net_device->recv_section_cnt > (u64)buf_size) {
448 		netdev_err(ndev, "invalid recv_section_size %u\n",
449 			   net_device->recv_section_size);
450 		ret = -EINVAL;
451 		goto cleanup;
452 	}
453 
454 	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
455 		struct netvsc_channel *nvchan = &net_device->chan_table[i];
456 
457 		nvchan->recv_buf = kzalloc(net_device->recv_section_size, GFP_KERNEL);
458 		if (nvchan->recv_buf == NULL) {
459 			ret = -ENOMEM;
460 			goto cleanup;
461 		}
462 	}
463 
464 	/* Setup receive completion ring.
465 	 * Add 1 to the recv_section_cnt because at least one entry in a
466 	 * ring buffer has to be empty.
467 	 */
468 	net_device->recv_completion_cnt = net_device->recv_section_cnt + 1;
469 	ret = netvsc_alloc_recv_comp_ring(net_device, 0);
470 	if (ret)
471 		goto cleanup;
472 
473 	/* Now setup the send buffer. */
474 	buf_size = device_info->send_sections * device_info->send_section_size;
475 	buf_size = round_up(buf_size, PAGE_SIZE);
476 
477 	net_device->send_buf = vzalloc(buf_size);
478 	if (!net_device->send_buf) {
479 		netdev_err(ndev, "unable to allocate send buffer of size %u\n",
480 			   buf_size);
481 		ret = -ENOMEM;
482 		goto cleanup;
483 	}
484 	net_device->send_buf_size = buf_size;
485 
486 	/* Establish the gpadl handle for this buffer on this
487 	 * channel.  Note: This call uses the vmbus connection rather
488 	 * than the channel to establish the gpadl handle.
489 	 */
490 	ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
491 				    buf_size,
492 				    &net_device->send_buf_gpadl_handle);
493 	if (ret != 0) {
494 		netdev_err(ndev,
495 			   "unable to establish send buffer's gpadl\n");
496 		goto cleanup;
497 	}
498 
499 	if (hv_isolation_type_snp()) {
500 		vaddr = hv_map_memory(net_device->send_buf, buf_size);
501 		if (!vaddr) {
502 			ret = -ENOMEM;
503 			goto cleanup;
504 		}
505 
506 		net_device->send_original_buf = net_device->send_buf;
507 		net_device->send_buf = vaddr;
508 	}
509 
510 	/* Notify the NetVsp of the gpadl handle */
511 	init_packet = &net_device->channel_init_pkt;
512 	memset(init_packet, 0, sizeof(struct nvsp_message));
513 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
514 	init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
515 		net_device->send_buf_gpadl_handle.gpadl_handle;
516 	init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
517 
518 	trace_nvsp_send(ndev, init_packet);
519 
520 	/* Send the gpadl notification request */
521 	ret = vmbus_sendpacket(device->channel, init_packet,
522 			       sizeof(struct nvsp_message),
523 			       (unsigned long)init_packet,
524 			       VM_PKT_DATA_INBAND,
525 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
526 	if (ret != 0) {
527 		netdev_err(ndev,
528 			   "unable to send send buffer's gpadl to netvsp\n");
529 		goto cleanup;
530 	}
531 
532 	wait_for_completion(&net_device->channel_init_wait);
533 
534 	/* Check the response */
535 	if (init_packet->msg.v1_msg.
536 	    send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
537 		netdev_err(ndev, "Unable to complete send buffer "
538 			   "initialization with NetVsp - status %d\n",
539 			   init_packet->msg.v1_msg.
540 			   send_send_buf_complete.status);
541 		ret = -EINVAL;
542 		goto cleanup;
543 	}
544 
545 	/* Parse the response */
546 	net_device->send_section_size = init_packet->msg.
547 				v1_msg.send_send_buf_complete.section_size;
548 	if (net_device->send_section_size < NETVSC_MTU_MIN) {
549 		netdev_err(ndev, "invalid send_section_size %u\n",
550 			   net_device->send_section_size);
551 		ret = -EINVAL;
552 		goto cleanup;
553 	}
554 
555 	/* Section count is simply the size divided by the section size. */
556 	net_device->send_section_cnt = buf_size / net_device->send_section_size;
557 
558 	netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
559 		   net_device->send_section_size, net_device->send_section_cnt);
560 
561 	/* Setup state for managing the send buffer. */
562 	net_device->send_section_map = bitmap_zalloc(net_device->send_section_cnt,
563 						     GFP_KERNEL);
564 	if (!net_device->send_section_map) {
565 		ret = -ENOMEM;
566 		goto cleanup;
567 	}
568 
569 	goto exit;
570 
571 cleanup:
572 	netvsc_revoke_recv_buf(device, net_device, ndev);
573 	netvsc_revoke_send_buf(device, net_device, ndev);
574 	netvsc_teardown_recv_gpadl(device, net_device, ndev);
575 	netvsc_teardown_send_gpadl(device, net_device, ndev);
576 
577 exit:
578 	return ret;
579 }
580 
581 /* Negotiate NVSP protocol version */
582 static int negotiate_nvsp_ver(struct hv_device *device,
583 			      struct netvsc_device *net_device,
584 			      struct nvsp_message *init_packet,
585 			      u32 nvsp_ver)
586 {
587 	struct net_device *ndev = hv_get_drvdata(device);
588 	int ret;
589 
590 	memset(init_packet, 0, sizeof(struct nvsp_message));
591 	init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
592 	init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
593 	init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
594 	trace_nvsp_send(ndev, init_packet);
595 
596 	/* Send the init request */
597 	ret = vmbus_sendpacket(device->channel, init_packet,
598 			       sizeof(struct nvsp_message),
599 			       (unsigned long)init_packet,
600 			       VM_PKT_DATA_INBAND,
601 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
602 
603 	if (ret != 0)
604 		return ret;
605 
606 	wait_for_completion(&net_device->channel_init_wait);
607 
608 	if (init_packet->msg.init_msg.init_complete.status !=
609 	    NVSP_STAT_SUCCESS)
610 		return -EINVAL;
611 
612 	if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
613 		return 0;
614 
615 	/* NVSPv2 or later: Send NDIS config */
616 	memset(init_packet, 0, sizeof(struct nvsp_message));
617 	init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
618 	init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
619 	init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
620 
621 	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
622 		if (hv_is_isolation_supported())
623 			netdev_info(ndev, "SR-IOV not advertised by guests on the host supporting isolation\n");
624 		else
625 			init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
626 
627 		/* Teaming bit is needed to receive link speed updates */
628 		init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
629 	}
630 
631 	if (nvsp_ver >= NVSP_PROTOCOL_VERSION_61)
632 		init_packet->msg.v2_msg.send_ndis_config.capability.rsc = 1;
633 
634 	trace_nvsp_send(ndev, init_packet);
635 
636 	ret = vmbus_sendpacket(device->channel, init_packet,
637 				sizeof(struct nvsp_message),
638 				VMBUS_RQST_ID_NO_RESPONSE,
639 				VM_PKT_DATA_INBAND, 0);
640 
641 	return ret;
642 }
643 
644 static int netvsc_connect_vsp(struct hv_device *device,
645 			      struct netvsc_device *net_device,
646 			      const struct netvsc_device_info *device_info)
647 {
648 	struct net_device *ndev = hv_get_drvdata(device);
649 	static const u32 ver_list[] = {
650 		NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
651 		NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5,
652 		NVSP_PROTOCOL_VERSION_6, NVSP_PROTOCOL_VERSION_61
653 	};
654 	struct nvsp_message *init_packet;
655 	int ndis_version, i, ret;
656 
657 	init_packet = &net_device->channel_init_pkt;
658 
659 	/* Negotiate the latest NVSP protocol supported */
660 	for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
661 		if (negotiate_nvsp_ver(device, net_device, init_packet,
662 				       ver_list[i])  == 0) {
663 			net_device->nvsp_version = ver_list[i];
664 			break;
665 		}
666 
667 	if (i < 0) {
668 		ret = -EPROTO;
669 		goto cleanup;
670 	}
671 
672 	if (hv_is_isolation_supported() && net_device->nvsp_version < NVSP_PROTOCOL_VERSION_61) {
673 		netdev_err(ndev, "Invalid NVSP version 0x%x (expected >= 0x%x) from the host supporting isolation\n",
674 			   net_device->nvsp_version, NVSP_PROTOCOL_VERSION_61);
675 		ret = -EPROTO;
676 		goto cleanup;
677 	}
678 
679 	pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
680 
681 	/* Send the ndis version */
682 	memset(init_packet, 0, sizeof(struct nvsp_message));
683 
684 	if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
685 		ndis_version = 0x00060001;
686 	else
687 		ndis_version = 0x0006001e;
688 
689 	init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
690 	init_packet->msg.v1_msg.
691 		send_ndis_ver.ndis_major_ver =
692 				(ndis_version & 0xFFFF0000) >> 16;
693 	init_packet->msg.v1_msg.
694 		send_ndis_ver.ndis_minor_ver =
695 				ndis_version & 0xFFFF;
696 
697 	trace_nvsp_send(ndev, init_packet);
698 
699 	/* Send the init request */
700 	ret = vmbus_sendpacket(device->channel, init_packet,
701 				sizeof(struct nvsp_message),
702 				VMBUS_RQST_ID_NO_RESPONSE,
703 				VM_PKT_DATA_INBAND, 0);
704 	if (ret != 0)
705 		goto cleanup;
706 
707 
708 	ret = netvsc_init_buf(device, net_device, device_info);
709 
710 cleanup:
711 	return ret;
712 }
713 
714 /*
715  * netvsc_device_remove - Callback when the root bus device is removed
716  */
717 void netvsc_device_remove(struct hv_device *device)
718 {
719 	struct net_device *ndev = hv_get_drvdata(device);
720 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
721 	struct netvsc_device *net_device
722 		= rtnl_dereference(net_device_ctx->nvdev);
723 	int i;
724 
725 	/*
726 	 * Revoke receive buffer. If host is pre-Win2016 then tear down
727 	 * receive buffer GPADL. Do the same for send buffer.
728 	 */
729 	netvsc_revoke_recv_buf(device, net_device, ndev);
730 	if (vmbus_proto_version < VERSION_WIN10)
731 		netvsc_teardown_recv_gpadl(device, net_device, ndev);
732 
733 	netvsc_revoke_send_buf(device, net_device, ndev);
734 	if (vmbus_proto_version < VERSION_WIN10)
735 		netvsc_teardown_send_gpadl(device, net_device, ndev);
736 
737 	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
738 
739 	/* Disable NAPI and disassociate its context from the device. */
740 	for (i = 0; i < net_device->num_chn; i++) {
741 		/* See also vmbus_reset_channel_cb(). */
742 		napi_disable(&net_device->chan_table[i].napi);
743 		netif_napi_del(&net_device->chan_table[i].napi);
744 	}
745 
746 	/*
747 	 * At this point, no one should be accessing net_device
748 	 * except in here
749 	 */
750 	netdev_dbg(ndev, "net device safe to remove\n");
751 
752 	/* Now, we can close the channel safely */
753 	vmbus_close(device->channel);
754 
755 	/*
756 	 * If host is Win2016 or higher then we do the GPADL tear down
757 	 * here after VMBus is closed.
758 	*/
759 	if (vmbus_proto_version >= VERSION_WIN10) {
760 		netvsc_teardown_recv_gpadl(device, net_device, ndev);
761 		netvsc_teardown_send_gpadl(device, net_device, ndev);
762 	}
763 
764 	if (net_device->recv_original_buf)
765 		hv_unmap_memory(net_device->recv_buf);
766 
767 	if (net_device->send_original_buf)
768 		hv_unmap_memory(net_device->send_buf);
769 
770 	/* Release all resources */
771 	free_netvsc_device_rcu(net_device);
772 }
773 
774 #define RING_AVAIL_PERCENT_HIWATER 20
775 #define RING_AVAIL_PERCENT_LOWATER 10
776 
777 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
778 					 u32 index)
779 {
780 	sync_change_bit(index, net_device->send_section_map);
781 }
782 
783 static void netvsc_send_tx_complete(struct net_device *ndev,
784 				    struct netvsc_device *net_device,
785 				    struct vmbus_channel *channel,
786 				    const struct vmpacket_descriptor *desc,
787 				    int budget)
788 {
789 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
790 	struct sk_buff *skb;
791 	u16 q_idx = 0;
792 	int queue_sends;
793 	u64 cmd_rqst;
794 
795 	cmd_rqst = channel->request_addr_callback(channel, (u64)desc->trans_id);
796 	if (cmd_rqst == VMBUS_RQST_ERROR) {
797 		netdev_err(ndev, "Incorrect transaction id\n");
798 		return;
799 	}
800 
801 	skb = (struct sk_buff *)(unsigned long)cmd_rqst;
802 
803 	/* Notify the layer above us */
804 	if (likely(skb)) {
805 		struct hv_netvsc_packet *packet
806 			= (struct hv_netvsc_packet *)skb->cb;
807 		u32 send_index = packet->send_buf_index;
808 		struct netvsc_stats *tx_stats;
809 
810 		if (send_index != NETVSC_INVALID_INDEX)
811 			netvsc_free_send_slot(net_device, send_index);
812 		q_idx = packet->q_idx;
813 
814 		tx_stats = &net_device->chan_table[q_idx].tx_stats;
815 
816 		u64_stats_update_begin(&tx_stats->syncp);
817 		tx_stats->packets += packet->total_packets;
818 		tx_stats->bytes += packet->total_bytes;
819 		u64_stats_update_end(&tx_stats->syncp);
820 
821 		netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
822 		napi_consume_skb(skb, budget);
823 	}
824 
825 	queue_sends =
826 		atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
827 
828 	if (unlikely(net_device->destroy)) {
829 		if (queue_sends == 0)
830 			wake_up(&net_device->wait_drain);
831 	} else {
832 		struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
833 
834 		if (netif_tx_queue_stopped(txq) && !net_device->tx_disable &&
835 		    (hv_get_avail_to_write_percent(&channel->outbound) >
836 		     RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) {
837 			netif_tx_wake_queue(txq);
838 			ndev_ctx->eth_stats.wake_queue++;
839 		}
840 	}
841 }
842 
843 static void netvsc_send_completion(struct net_device *ndev,
844 				   struct netvsc_device *net_device,
845 				   struct vmbus_channel *incoming_channel,
846 				   const struct vmpacket_descriptor *desc,
847 				   int budget)
848 {
849 	const struct nvsp_message *nvsp_packet;
850 	u32 msglen = hv_pkt_datalen(desc);
851 	struct nvsp_message *pkt_rqst;
852 	u64 cmd_rqst;
853 
854 	/* First check if this is a VMBUS completion without data payload */
855 	if (!msglen) {
856 		cmd_rqst = incoming_channel->request_addr_callback(incoming_channel,
857 								   (u64)desc->trans_id);
858 		if (cmd_rqst == VMBUS_RQST_ERROR) {
859 			netdev_err(ndev, "Invalid transaction id\n");
860 			return;
861 		}
862 
863 		pkt_rqst = (struct nvsp_message *)(uintptr_t)cmd_rqst;
864 		switch (pkt_rqst->hdr.msg_type) {
865 		case NVSP_MSG4_TYPE_SWITCH_DATA_PATH:
866 			complete(&net_device->channel_init_wait);
867 			break;
868 
869 		default:
870 			netdev_err(ndev, "Unexpected VMBUS completion!!\n");
871 		}
872 		return;
873 	}
874 
875 	/* Ensure packet is big enough to read header fields */
876 	if (msglen < sizeof(struct nvsp_message_header)) {
877 		netdev_err(ndev, "nvsp_message length too small: %u\n", msglen);
878 		return;
879 	}
880 
881 	nvsp_packet = hv_pkt_data(desc);
882 	switch (nvsp_packet->hdr.msg_type) {
883 	case NVSP_MSG_TYPE_INIT_COMPLETE:
884 		if (msglen < sizeof(struct nvsp_message_header) +
885 				sizeof(struct nvsp_message_init_complete)) {
886 			netdev_err(ndev, "nvsp_msg length too small: %u\n",
887 				   msglen);
888 			return;
889 		}
890 		fallthrough;
891 
892 	case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
893 		if (msglen < sizeof(struct nvsp_message_header) +
894 				sizeof(struct nvsp_1_message_send_receive_buffer_complete)) {
895 			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
896 				   msglen);
897 			return;
898 		}
899 		fallthrough;
900 
901 	case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
902 		if (msglen < sizeof(struct nvsp_message_header) +
903 				sizeof(struct nvsp_1_message_send_send_buffer_complete)) {
904 			netdev_err(ndev, "nvsp_msg1 length too small: %u\n",
905 				   msglen);
906 			return;
907 		}
908 		fallthrough;
909 
910 	case NVSP_MSG5_TYPE_SUBCHANNEL:
911 		if (msglen < sizeof(struct nvsp_message_header) +
912 				sizeof(struct nvsp_5_subchannel_complete)) {
913 			netdev_err(ndev, "nvsp_msg5 length too small: %u\n",
914 				   msglen);
915 			return;
916 		}
917 		/* Copy the response back */
918 		memcpy(&net_device->channel_init_pkt, nvsp_packet,
919 		       sizeof(struct nvsp_message));
920 		complete(&net_device->channel_init_wait);
921 		break;
922 
923 	case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
924 		netvsc_send_tx_complete(ndev, net_device, incoming_channel,
925 					desc, budget);
926 		break;
927 
928 	default:
929 		netdev_err(ndev,
930 			   "Unknown send completion type %d received!!\n",
931 			   nvsp_packet->hdr.msg_type);
932 	}
933 }
934 
935 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
936 {
937 	unsigned long *map_addr = net_device->send_section_map;
938 	unsigned int i;
939 
940 	for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
941 		if (sync_test_and_set_bit(i, map_addr) == 0)
942 			return i;
943 	}
944 
945 	return NETVSC_INVALID_INDEX;
946 }
947 
948 static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
949 				    unsigned int section_index,
950 				    u32 pend_size,
951 				    struct hv_netvsc_packet *packet,
952 				    struct rndis_message *rndis_msg,
953 				    struct hv_page_buffer *pb,
954 				    bool xmit_more)
955 {
956 	char *start = net_device->send_buf;
957 	char *dest = start + (section_index * net_device->send_section_size)
958 		     + pend_size;
959 	int i;
960 	u32 padding = 0;
961 	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
962 		packet->page_buf_cnt;
963 	u32 remain;
964 
965 	/* Add padding */
966 	remain = packet->total_data_buflen & (net_device->pkt_align - 1);
967 	if (xmit_more && remain) {
968 		padding = net_device->pkt_align - remain;
969 		rndis_msg->msg_len += padding;
970 		packet->total_data_buflen += padding;
971 	}
972 
973 	for (i = 0; i < page_count; i++) {
974 		char *src = phys_to_virt(pb[i].pfn << HV_HYP_PAGE_SHIFT);
975 		u32 offset = pb[i].offset;
976 		u32 len = pb[i].len;
977 
978 		memcpy(dest, (src + offset), len);
979 		dest += len;
980 	}
981 
982 	if (padding)
983 		memset(dest, 0, padding);
984 }
985 
986 void netvsc_dma_unmap(struct hv_device *hv_dev,
987 		      struct hv_netvsc_packet *packet)
988 {
989 	u32 page_count = packet->cp_partial ?
990 		packet->page_buf_cnt - packet->rmsg_pgcnt :
991 		packet->page_buf_cnt;
992 	int i;
993 
994 	if (!hv_is_isolation_supported())
995 		return;
996 
997 	if (!packet->dma_range)
998 		return;
999 
1000 	for (i = 0; i < page_count; i++)
1001 		dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,
1002 				 packet->dma_range[i].mapping_size,
1003 				 DMA_TO_DEVICE);
1004 
1005 	kfree(packet->dma_range);
1006 }
1007 
1008 /* netvsc_dma_map - Map swiotlb bounce buffer with data page of
1009  * packet sent by vmbus_sendpacket_pagebuffer() in the Isolation
1010  * VM.
1011  *
1012  * In isolation VM, netvsc send buffer has been marked visible to
1013  * host and so the data copied to send buffer doesn't need to use
1014  * bounce buffer. The data pages handled by vmbus_sendpacket_pagebuffer()
1015  * may not be copied to send buffer and so these pages need to be
1016  * mapped with swiotlb bounce buffer. netvsc_dma_map() is to do
1017  * that. The pfns in the struct hv_page_buffer need to be converted
1018  * to bounce buffer's pfn. The loop here is necessary because the
1019  * entries in the page buffer array are not necessarily full
1020  * pages of data.  Each entry in the array has a separate offset and
1021  * len that may be non-zero, even for entries in the middle of the
1022  * array.  And the entries are not physically contiguous.  So each
1023  * entry must be individually mapped rather than as a contiguous unit.
1024  * So not use dma_map_sg() here.
1025  */
1026 static int netvsc_dma_map(struct hv_device *hv_dev,
1027 			  struct hv_netvsc_packet *packet,
1028 			  struct hv_page_buffer *pb)
1029 {
1030 	u32 page_count =  packet->cp_partial ?
1031 		packet->page_buf_cnt - packet->rmsg_pgcnt :
1032 		packet->page_buf_cnt;
1033 	dma_addr_t dma;
1034 	int i;
1035 
1036 	if (!hv_is_isolation_supported())
1037 		return 0;
1038 
1039 	packet->dma_range = kcalloc(page_count,
1040 				    sizeof(*packet->dma_range),
1041 				    GFP_KERNEL);
1042 	if (!packet->dma_range)
1043 		return -ENOMEM;
1044 
1045 	for (i = 0; i < page_count; i++) {
1046 		char *src = phys_to_virt((pb[i].pfn << HV_HYP_PAGE_SHIFT)
1047 					 + pb[i].offset);
1048 		u32 len = pb[i].len;
1049 
1050 		dma = dma_map_single(&hv_dev->device, src, len,
1051 				     DMA_TO_DEVICE);
1052 		if (dma_mapping_error(&hv_dev->device, dma)) {
1053 			kfree(packet->dma_range);
1054 			return -ENOMEM;
1055 		}
1056 
1057 		/* pb[].offset and pb[].len are not changed during dma mapping
1058 		 * and so not reassign.
1059 		 */
1060 		packet->dma_range[i].dma = dma;
1061 		packet->dma_range[i].mapping_size = len;
1062 		pb[i].pfn = dma >> HV_HYP_PAGE_SHIFT;
1063 	}
1064 
1065 	return 0;
1066 }
1067 
1068 static inline int netvsc_send_pkt(
1069 	struct hv_device *device,
1070 	struct hv_netvsc_packet *packet,
1071 	struct netvsc_device *net_device,
1072 	struct hv_page_buffer *pb,
1073 	struct sk_buff *skb)
1074 {
1075 	struct nvsp_message nvmsg;
1076 	struct nvsp_1_message_send_rndis_packet *rpkt =
1077 		&nvmsg.msg.v1_msg.send_rndis_pkt;
1078 	struct netvsc_channel * const nvchan =
1079 		&net_device->chan_table[packet->q_idx];
1080 	struct vmbus_channel *out_channel = nvchan->channel;
1081 	struct net_device *ndev = hv_get_drvdata(device);
1082 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1083 	struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
1084 	u64 req_id;
1085 	int ret;
1086 	u32 ring_avail = hv_get_avail_to_write_percent(&out_channel->outbound);
1087 
1088 	memset(&nvmsg, 0, sizeof(struct nvsp_message));
1089 	nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
1090 	if (skb)
1091 		rpkt->channel_type = 0;		/* 0 is RMC_DATA */
1092 	else
1093 		rpkt->channel_type = 1;		/* 1 is RMC_CONTROL */
1094 
1095 	rpkt->send_buf_section_index = packet->send_buf_index;
1096 	if (packet->send_buf_index == NETVSC_INVALID_INDEX)
1097 		rpkt->send_buf_section_size = 0;
1098 	else
1099 		rpkt->send_buf_section_size = packet->total_data_buflen;
1100 
1101 	req_id = (ulong)skb;
1102 
1103 	if (out_channel->rescind)
1104 		return -ENODEV;
1105 
1106 	trace_nvsp_send_pkt(ndev, out_channel, rpkt);
1107 
1108 	packet->dma_range = NULL;
1109 	if (packet->page_buf_cnt) {
1110 		if (packet->cp_partial)
1111 			pb += packet->rmsg_pgcnt;
1112 
1113 		ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);
1114 		if (ret) {
1115 			ret = -EAGAIN;
1116 			goto exit;
1117 		}
1118 
1119 		ret = vmbus_sendpacket_pagebuffer(out_channel,
1120 						  pb, packet->page_buf_cnt,
1121 						  &nvmsg, sizeof(nvmsg),
1122 						  req_id);
1123 
1124 		if (ret)
1125 			netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
1126 	} else {
1127 		ret = vmbus_sendpacket(out_channel,
1128 				       &nvmsg, sizeof(nvmsg),
1129 				       req_id, VM_PKT_DATA_INBAND,
1130 				       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1131 	}
1132 
1133 exit:
1134 	if (ret == 0) {
1135 		atomic_inc_return(&nvchan->queue_sends);
1136 
1137 		if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
1138 			netif_tx_stop_queue(txq);
1139 			ndev_ctx->eth_stats.stop_queue++;
1140 		}
1141 	} else if (ret == -EAGAIN) {
1142 		netif_tx_stop_queue(txq);
1143 		ndev_ctx->eth_stats.stop_queue++;
1144 	} else {
1145 		netdev_err(ndev,
1146 			   "Unable to send packet pages %u len %u, ret %d\n",
1147 			   packet->page_buf_cnt, packet->total_data_buflen,
1148 			   ret);
1149 	}
1150 
1151 	if (netif_tx_queue_stopped(txq) &&
1152 	    atomic_read(&nvchan->queue_sends) < 1 &&
1153 	    !net_device->tx_disable) {
1154 		netif_tx_wake_queue(txq);
1155 		ndev_ctx->eth_stats.wake_queue++;
1156 		if (ret == -EAGAIN)
1157 			ret = -ENOSPC;
1158 	}
1159 
1160 	return ret;
1161 }
1162 
1163 /* Move packet out of multi send data (msd), and clear msd */
1164 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
1165 				struct sk_buff **msd_skb,
1166 				struct multi_send_data *msdp)
1167 {
1168 	*msd_skb = msdp->skb;
1169 	*msd_send = msdp->pkt;
1170 	msdp->skb = NULL;
1171 	msdp->pkt = NULL;
1172 	msdp->count = 0;
1173 }
1174 
1175 /* RCU already held by caller */
1176 /* Batching/bouncing logic is designed to attempt to optimize
1177  * performance.
1178  *
1179  * For small, non-LSO packets we copy the packet to a send buffer
1180  * which is pre-registered with the Hyper-V side. This enables the
1181  * hypervisor to avoid remapping the aperture to access the packet
1182  * descriptor and data.
1183  *
1184  * If we already started using a buffer and the netdev is transmitting
1185  * a burst of packets, keep on copying into the buffer until it is
1186  * full or we are done collecting a burst. If there is an existing
1187  * buffer with space for the RNDIS descriptor but not the packet, copy
1188  * the RNDIS descriptor to the buffer, keeping the packet in place.
1189  *
1190  * If we do batching and send more than one packet using a single
1191  * NetVSC message, free the SKBs of the packets copied, except for the
1192  * last packet. This is done to streamline the handling of the case
1193  * where the last packet only had the RNDIS descriptor copied to the
1194  * send buffer, with the data pointers included in the NetVSC message.
1195  */
1196 int netvsc_send(struct net_device *ndev,
1197 		struct hv_netvsc_packet *packet,
1198 		struct rndis_message *rndis_msg,
1199 		struct hv_page_buffer *pb,
1200 		struct sk_buff *skb,
1201 		bool xdp_tx)
1202 {
1203 	struct net_device_context *ndev_ctx = netdev_priv(ndev);
1204 	struct netvsc_device *net_device
1205 		= rcu_dereference_bh(ndev_ctx->nvdev);
1206 	struct hv_device *device = ndev_ctx->device_ctx;
1207 	int ret = 0;
1208 	struct netvsc_channel *nvchan;
1209 	u32 pktlen = packet->total_data_buflen, msd_len = 0;
1210 	unsigned int section_index = NETVSC_INVALID_INDEX;
1211 	struct multi_send_data *msdp;
1212 	struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
1213 	struct sk_buff *msd_skb = NULL;
1214 	bool try_batch, xmit_more;
1215 
1216 	/* If device is rescinded, return error and packet will get dropped. */
1217 	if (unlikely(!net_device || net_device->destroy))
1218 		return -ENODEV;
1219 
1220 	nvchan = &net_device->chan_table[packet->q_idx];
1221 	packet->send_buf_index = NETVSC_INVALID_INDEX;
1222 	packet->cp_partial = false;
1223 
1224 	/* Send a control message or XDP packet directly without accessing
1225 	 * msd (Multi-Send Data) field which may be changed during data packet
1226 	 * processing.
1227 	 */
1228 	if (!skb || xdp_tx)
1229 		return netvsc_send_pkt(device, packet, net_device, pb, skb);
1230 
1231 	/* batch packets in send buffer if possible */
1232 	msdp = &nvchan->msd;
1233 	if (msdp->pkt)
1234 		msd_len = msdp->pkt->total_data_buflen;
1235 
1236 	try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
1237 	if (try_batch && msd_len + pktlen + net_device->pkt_align <
1238 	    net_device->send_section_size) {
1239 		section_index = msdp->pkt->send_buf_index;
1240 
1241 	} else if (try_batch && msd_len + packet->rmsg_size <
1242 		   net_device->send_section_size) {
1243 		section_index = msdp->pkt->send_buf_index;
1244 		packet->cp_partial = true;
1245 
1246 	} else if (pktlen + net_device->pkt_align <
1247 		   net_device->send_section_size) {
1248 		section_index = netvsc_get_next_send_section(net_device);
1249 		if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
1250 			++ndev_ctx->eth_stats.tx_send_full;
1251 		} else {
1252 			move_pkt_msd(&msd_send, &msd_skb, msdp);
1253 			msd_len = 0;
1254 		}
1255 	}
1256 
1257 	/* Keep aggregating only if stack says more data is coming
1258 	 * and not doing mixed modes send and not flow blocked
1259 	 */
1260 	xmit_more = netdev_xmit_more() &&
1261 		!packet->cp_partial &&
1262 		!netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
1263 
1264 	if (section_index != NETVSC_INVALID_INDEX) {
1265 		netvsc_copy_to_send_buf(net_device,
1266 					section_index, msd_len,
1267 					packet, rndis_msg, pb, xmit_more);
1268 
1269 		packet->send_buf_index = section_index;
1270 
1271 		if (packet->cp_partial) {
1272 			packet->page_buf_cnt -= packet->rmsg_pgcnt;
1273 			packet->total_data_buflen = msd_len + packet->rmsg_size;
1274 		} else {
1275 			packet->page_buf_cnt = 0;
1276 			packet->total_data_buflen += msd_len;
1277 		}
1278 
1279 		if (msdp->pkt) {
1280 			packet->total_packets += msdp->pkt->total_packets;
1281 			packet->total_bytes += msdp->pkt->total_bytes;
1282 		}
1283 
1284 		if (msdp->skb)
1285 			dev_consume_skb_any(msdp->skb);
1286 
1287 		if (xmit_more) {
1288 			msdp->skb = skb;
1289 			msdp->pkt = packet;
1290 			msdp->count++;
1291 		} else {
1292 			cur_send = packet;
1293 			msdp->skb = NULL;
1294 			msdp->pkt = NULL;
1295 			msdp->count = 0;
1296 		}
1297 	} else {
1298 		move_pkt_msd(&msd_send, &msd_skb, msdp);
1299 		cur_send = packet;
1300 	}
1301 
1302 	if (msd_send) {
1303 		int m_ret = netvsc_send_pkt(device, msd_send, net_device,
1304 					    NULL, msd_skb);
1305 
1306 		if (m_ret != 0) {
1307 			netvsc_free_send_slot(net_device,
1308 					      msd_send->send_buf_index);
1309 			dev_kfree_skb_any(msd_skb);
1310 		}
1311 	}
1312 
1313 	if (cur_send)
1314 		ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1315 
1316 	if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1317 		netvsc_free_send_slot(net_device, section_index);
1318 
1319 	return ret;
1320 }
1321 
1322 /* Send pending recv completions */
1323 static int send_recv_completions(struct net_device *ndev,
1324 				 struct netvsc_device *nvdev,
1325 				 struct netvsc_channel *nvchan)
1326 {
1327 	struct multi_recv_comp *mrc = &nvchan->mrc;
1328 	struct recv_comp_msg {
1329 		struct nvsp_message_header hdr;
1330 		u32 status;
1331 	}  __packed;
1332 	struct recv_comp_msg msg = {
1333 		.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1334 	};
1335 	int ret;
1336 
1337 	while (mrc->first != mrc->next) {
1338 		const struct recv_comp_data *rcd
1339 			= mrc->slots + mrc->first;
1340 
1341 		msg.status = rcd->status;
1342 		ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1343 				       rcd->tid, VM_PKT_COMP, 0);
1344 		if (unlikely(ret)) {
1345 			struct net_device_context *ndev_ctx = netdev_priv(ndev);
1346 
1347 			++ndev_ctx->eth_stats.rx_comp_busy;
1348 			return ret;
1349 		}
1350 
1351 		if (++mrc->first == nvdev->recv_completion_cnt)
1352 			mrc->first = 0;
1353 	}
1354 
1355 	/* receive completion ring has been emptied */
1356 	if (unlikely(nvdev->destroy))
1357 		wake_up(&nvdev->wait_drain);
1358 
1359 	return 0;
1360 }
1361 
1362 /* Count how many receive completions are outstanding */
1363 static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1364 				 const struct multi_recv_comp *mrc,
1365 				 u32 *filled, u32 *avail)
1366 {
1367 	u32 count = nvdev->recv_completion_cnt;
1368 
1369 	if (mrc->next >= mrc->first)
1370 		*filled = mrc->next - mrc->first;
1371 	else
1372 		*filled = (count - mrc->first) + mrc->next;
1373 
1374 	*avail = count - *filled - 1;
1375 }
1376 
1377 /* Add receive complete to ring to send to host. */
1378 static void enq_receive_complete(struct net_device *ndev,
1379 				 struct netvsc_device *nvdev, u16 q_idx,
1380 				 u64 tid, u32 status)
1381 {
1382 	struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1383 	struct multi_recv_comp *mrc = &nvchan->mrc;
1384 	struct recv_comp_data *rcd;
1385 	u32 filled, avail;
1386 
1387 	recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1388 
1389 	if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1390 		send_recv_completions(ndev, nvdev, nvchan);
1391 		recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1392 	}
1393 
1394 	if (unlikely(!avail)) {
1395 		netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1396 			   q_idx, tid);
1397 		return;
1398 	}
1399 
1400 	rcd = mrc->slots + mrc->next;
1401 	rcd->tid = tid;
1402 	rcd->status = status;
1403 
1404 	if (++mrc->next == nvdev->recv_completion_cnt)
1405 		mrc->next = 0;
1406 }
1407 
1408 static int netvsc_receive(struct net_device *ndev,
1409 			  struct netvsc_device *net_device,
1410 			  struct netvsc_channel *nvchan,
1411 			  const struct vmpacket_descriptor *desc)
1412 {
1413 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1414 	struct vmbus_channel *channel = nvchan->channel;
1415 	const struct vmtransfer_page_packet_header *vmxferpage_packet
1416 		= container_of(desc, const struct vmtransfer_page_packet_header, d);
1417 	const struct nvsp_message *nvsp = hv_pkt_data(desc);
1418 	u32 msglen = hv_pkt_datalen(desc);
1419 	u16 q_idx = channel->offermsg.offer.sub_channel_index;
1420 	char *recv_buf = net_device->recv_buf;
1421 	u32 status = NVSP_STAT_SUCCESS;
1422 	int i;
1423 	int count = 0;
1424 
1425 	/* Ensure packet is big enough to read header fields */
1426 	if (msglen < sizeof(struct nvsp_message_header)) {
1427 		netif_err(net_device_ctx, rx_err, ndev,
1428 			  "invalid nvsp header, length too small: %u\n",
1429 			  msglen);
1430 		return 0;
1431 	}
1432 
1433 	/* Make sure this is a valid nvsp packet */
1434 	if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1435 		netif_err(net_device_ctx, rx_err, ndev,
1436 			  "Unknown nvsp packet type received %u\n",
1437 			  nvsp->hdr.msg_type);
1438 		return 0;
1439 	}
1440 
1441 	/* Validate xfer page pkt header */
1442 	if ((desc->offset8 << 3) < sizeof(struct vmtransfer_page_packet_header)) {
1443 		netif_err(net_device_ctx, rx_err, ndev,
1444 			  "Invalid xfer page pkt, offset too small: %u\n",
1445 			  desc->offset8 << 3);
1446 		return 0;
1447 	}
1448 
1449 	if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1450 		netif_err(net_device_ctx, rx_err, ndev,
1451 			  "Invalid xfer page set id - expecting %x got %x\n",
1452 			  NETVSC_RECEIVE_BUFFER_ID,
1453 			  vmxferpage_packet->xfer_pageset_id);
1454 		return 0;
1455 	}
1456 
1457 	count = vmxferpage_packet->range_cnt;
1458 
1459 	/* Check count for a valid value */
1460 	if (NETVSC_XFER_HEADER_SIZE(count) > desc->offset8 << 3) {
1461 		netif_err(net_device_ctx, rx_err, ndev,
1462 			  "Range count is not valid: %d\n",
1463 			  count);
1464 		return 0;
1465 	}
1466 
1467 	/* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1468 	for (i = 0; i < count; i++) {
1469 		u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1470 		u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1471 		void *data;
1472 		int ret;
1473 
1474 		if (unlikely(offset > net_device->recv_buf_size ||
1475 			     buflen > net_device->recv_buf_size - offset)) {
1476 			nvchan->rsc.cnt = 0;
1477 			status = NVSP_STAT_FAIL;
1478 			netif_err(net_device_ctx, rx_err, ndev,
1479 				  "Packet offset:%u + len:%u too big\n",
1480 				  offset, buflen);
1481 
1482 			continue;
1483 		}
1484 
1485 		/* We're going to copy (sections of) the packet into nvchan->recv_buf;
1486 		 * make sure that nvchan->recv_buf is large enough to hold the packet.
1487 		 */
1488 		if (unlikely(buflen > net_device->recv_section_size)) {
1489 			nvchan->rsc.cnt = 0;
1490 			status = NVSP_STAT_FAIL;
1491 			netif_err(net_device_ctx, rx_err, ndev,
1492 				  "Packet too big: buflen=%u recv_section_size=%u\n",
1493 				  buflen, net_device->recv_section_size);
1494 
1495 			continue;
1496 		}
1497 
1498 		data = recv_buf + offset;
1499 
1500 		nvchan->rsc.is_last = (i == count - 1);
1501 
1502 		trace_rndis_recv(ndev, q_idx, data);
1503 
1504 		/* Pass it to the upper layer */
1505 		ret = rndis_filter_receive(ndev, net_device,
1506 					   nvchan, data, buflen);
1507 
1508 		if (unlikely(ret != NVSP_STAT_SUCCESS)) {
1509 			/* Drop incomplete packet */
1510 			nvchan->rsc.cnt = 0;
1511 			status = NVSP_STAT_FAIL;
1512 		}
1513 	}
1514 
1515 	enq_receive_complete(ndev, net_device, q_idx,
1516 			     vmxferpage_packet->d.trans_id, status);
1517 
1518 	return count;
1519 }
1520 
1521 static void netvsc_send_table(struct net_device *ndev,
1522 			      struct netvsc_device *nvscdev,
1523 			      const struct nvsp_message *nvmsg,
1524 			      u32 msglen)
1525 {
1526 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1527 	u32 count, offset, *tab;
1528 	int i;
1529 
1530 	/* Ensure packet is big enough to read send_table fields */
1531 	if (msglen < sizeof(struct nvsp_message_header) +
1532 		     sizeof(struct nvsp_5_send_indirect_table)) {
1533 		netdev_err(ndev, "nvsp_v5_msg length too small: %u\n", msglen);
1534 		return;
1535 	}
1536 
1537 	count = nvmsg->msg.v5_msg.send_table.count;
1538 	offset = nvmsg->msg.v5_msg.send_table.offset;
1539 
1540 	if (count != VRSS_SEND_TAB_SIZE) {
1541 		netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1542 		return;
1543 	}
1544 
1545 	/* If negotiated version <= NVSP_PROTOCOL_VERSION_6, the offset may be
1546 	 * wrong due to a host bug. So fix the offset here.
1547 	 */
1548 	if (nvscdev->nvsp_version <= NVSP_PROTOCOL_VERSION_6 &&
1549 	    msglen >= sizeof(struct nvsp_message_header) +
1550 	    sizeof(union nvsp_6_message_uber) + count * sizeof(u32))
1551 		offset = sizeof(struct nvsp_message_header) +
1552 			 sizeof(union nvsp_6_message_uber);
1553 
1554 	/* Boundary check for all versions */
1555 	if (msglen < count * sizeof(u32) || offset > msglen - count * sizeof(u32)) {
1556 		netdev_err(ndev, "Received send-table offset too big:%u\n",
1557 			   offset);
1558 		return;
1559 	}
1560 
1561 	tab = (void *)nvmsg + offset;
1562 
1563 	for (i = 0; i < count; i++)
1564 		net_device_ctx->tx_table[i] = tab[i];
1565 }
1566 
1567 static void netvsc_send_vf(struct net_device *ndev,
1568 			   const struct nvsp_message *nvmsg,
1569 			   u32 msglen)
1570 {
1571 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1572 
1573 	/* Ensure packet is big enough to read its fields */
1574 	if (msglen < sizeof(struct nvsp_message_header) +
1575 		     sizeof(struct nvsp_4_send_vf_association)) {
1576 		netdev_err(ndev, "nvsp_v4_msg length too small: %u\n", msglen);
1577 		return;
1578 	}
1579 
1580 	net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1581 	net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1582 	netdev_info(ndev, "VF slot %u %s\n",
1583 		    net_device_ctx->vf_serial,
1584 		    net_device_ctx->vf_alloc ? "added" : "removed");
1585 }
1586 
1587 static void netvsc_receive_inband(struct net_device *ndev,
1588 				  struct netvsc_device *nvscdev,
1589 				  const struct vmpacket_descriptor *desc)
1590 {
1591 	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1592 	u32 msglen = hv_pkt_datalen(desc);
1593 
1594 	/* Ensure packet is big enough to read header fields */
1595 	if (msglen < sizeof(struct nvsp_message_header)) {
1596 		netdev_err(ndev, "inband nvsp_message length too small: %u\n", msglen);
1597 		return;
1598 	}
1599 
1600 	switch (nvmsg->hdr.msg_type) {
1601 	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1602 		netvsc_send_table(ndev, nvscdev, nvmsg, msglen);
1603 		break;
1604 
1605 	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1606 		if (hv_is_isolation_supported())
1607 			netdev_err(ndev, "Ignore VF_ASSOCIATION msg from the host supporting isolation\n");
1608 		else
1609 			netvsc_send_vf(ndev, nvmsg, msglen);
1610 		break;
1611 	}
1612 }
1613 
1614 static int netvsc_process_raw_pkt(struct hv_device *device,
1615 				  struct netvsc_channel *nvchan,
1616 				  struct netvsc_device *net_device,
1617 				  struct net_device *ndev,
1618 				  const struct vmpacket_descriptor *desc,
1619 				  int budget)
1620 {
1621 	struct vmbus_channel *channel = nvchan->channel;
1622 	const struct nvsp_message *nvmsg = hv_pkt_data(desc);
1623 
1624 	trace_nvsp_recv(ndev, channel, nvmsg);
1625 
1626 	switch (desc->type) {
1627 	case VM_PKT_COMP:
1628 		netvsc_send_completion(ndev, net_device, channel, desc, budget);
1629 		break;
1630 
1631 	case VM_PKT_DATA_USING_XFER_PAGES:
1632 		return netvsc_receive(ndev, net_device, nvchan, desc);
1633 
1634 	case VM_PKT_DATA_INBAND:
1635 		netvsc_receive_inband(ndev, net_device, desc);
1636 		break;
1637 
1638 	default:
1639 		netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1640 			   desc->type, desc->trans_id);
1641 		break;
1642 	}
1643 
1644 	return 0;
1645 }
1646 
1647 static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1648 {
1649 	struct vmbus_channel *primary = channel->primary_channel;
1650 
1651 	return primary ? primary->device_obj : channel->device_obj;
1652 }
1653 
1654 /* Network processing softirq
1655  * Process data in incoming ring buffer from host
1656  * Stops when ring is empty or budget is met or exceeded.
1657  */
1658 int netvsc_poll(struct napi_struct *napi, int budget)
1659 {
1660 	struct netvsc_channel *nvchan
1661 		= container_of(napi, struct netvsc_channel, napi);
1662 	struct netvsc_device *net_device = nvchan->net_device;
1663 	struct vmbus_channel *channel = nvchan->channel;
1664 	struct hv_device *device = netvsc_channel_to_device(channel);
1665 	struct net_device *ndev = hv_get_drvdata(device);
1666 	int work_done = 0;
1667 	int ret;
1668 
1669 	/* If starting a new interval */
1670 	if (!nvchan->desc)
1671 		nvchan->desc = hv_pkt_iter_first(channel);
1672 
1673 	while (nvchan->desc && work_done < budget) {
1674 		work_done += netvsc_process_raw_pkt(device, nvchan, net_device,
1675 						    ndev, nvchan->desc, budget);
1676 		nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1677 	}
1678 
1679 	/* Send any pending receive completions */
1680 	ret = send_recv_completions(ndev, net_device, nvchan);
1681 
1682 	/* If it did not exhaust NAPI budget this time
1683 	 *  and not doing busy poll
1684 	 * then re-enable host interrupts
1685 	 *  and reschedule if ring is not empty
1686 	 *   or sending receive completion failed.
1687 	 */
1688 	if (work_done < budget &&
1689 	    napi_complete_done(napi, work_done) &&
1690 	    (ret || hv_end_read(&channel->inbound)) &&
1691 	    napi_schedule_prep(napi)) {
1692 		hv_begin_read(&channel->inbound);
1693 		__napi_schedule(napi);
1694 	}
1695 
1696 	/* Driver may overshoot since multiple packets per descriptor */
1697 	return min(work_done, budget);
1698 }
1699 
1700 /* Call back when data is available in host ring buffer.
1701  * Processing is deferred until network softirq (NAPI)
1702  */
1703 void netvsc_channel_cb(void *context)
1704 {
1705 	struct netvsc_channel *nvchan = context;
1706 	struct vmbus_channel *channel = nvchan->channel;
1707 	struct hv_ring_buffer_info *rbi = &channel->inbound;
1708 
1709 	/* preload first vmpacket descriptor */
1710 	prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1711 
1712 	if (napi_schedule_prep(&nvchan->napi)) {
1713 		/* disable interrupts from host */
1714 		hv_begin_read(rbi);
1715 
1716 		__napi_schedule_irqoff(&nvchan->napi);
1717 	}
1718 }
1719 
1720 /*
1721  * netvsc_device_add - Callback when the device belonging to this
1722  * driver is added
1723  */
1724 struct netvsc_device *netvsc_device_add(struct hv_device *device,
1725 				const struct netvsc_device_info *device_info)
1726 {
1727 	int i, ret = 0;
1728 	struct netvsc_device *net_device;
1729 	struct net_device *ndev = hv_get_drvdata(device);
1730 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
1731 
1732 	net_device = alloc_net_device();
1733 	if (!net_device)
1734 		return ERR_PTR(-ENOMEM);
1735 
1736 	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1737 		net_device_ctx->tx_table[i] = 0;
1738 
1739 	/* Because the device uses NAPI, all the interrupt batching and
1740 	 * control is done via Net softirq, not the channel handling
1741 	 */
1742 	set_channel_read_mode(device->channel, HV_CALL_ISR);
1743 
1744 	/* If we're reopening the device we may have multiple queues, fill the
1745 	 * chn_table with the default channel to use it before subchannels are
1746 	 * opened.
1747 	 * Initialize the channel state before we open;
1748 	 * we can be interrupted as soon as we open the channel.
1749 	 */
1750 
1751 	for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1752 		struct netvsc_channel *nvchan = &net_device->chan_table[i];
1753 
1754 		nvchan->channel = device->channel;
1755 		nvchan->net_device = net_device;
1756 		u64_stats_init(&nvchan->tx_stats.syncp);
1757 		u64_stats_init(&nvchan->rx_stats.syncp);
1758 
1759 		ret = xdp_rxq_info_reg(&nvchan->xdp_rxq, ndev, i, 0);
1760 
1761 		if (ret) {
1762 			netdev_err(ndev, "xdp_rxq_info_reg fail: %d\n", ret);
1763 			goto cleanup2;
1764 		}
1765 
1766 		ret = xdp_rxq_info_reg_mem_model(&nvchan->xdp_rxq,
1767 						 MEM_TYPE_PAGE_SHARED, NULL);
1768 
1769 		if (ret) {
1770 			netdev_err(ndev, "xdp reg_mem_model fail: %d\n", ret);
1771 			goto cleanup2;
1772 		}
1773 	}
1774 
1775 	/* Enable NAPI handler before init callbacks */
1776 	netif_napi_add(ndev, &net_device->chan_table[0].napi,
1777 		       netvsc_poll, NAPI_POLL_WEIGHT);
1778 
1779 	/* Open the channel */
1780 	device->channel->next_request_id_callback = vmbus_next_request_id;
1781 	device->channel->request_addr_callback = vmbus_request_addr;
1782 	device->channel->rqstor_size = netvsc_rqstor_size(netvsc_ring_bytes);
1783 	device->channel->max_pkt_size = NETVSC_MAX_PKT_SIZE;
1784 
1785 	ret = vmbus_open(device->channel, netvsc_ring_bytes,
1786 			 netvsc_ring_bytes,  NULL, 0,
1787 			 netvsc_channel_cb, net_device->chan_table);
1788 
1789 	if (ret != 0) {
1790 		netdev_err(ndev, "unable to open channel: %d\n", ret);
1791 		goto cleanup;
1792 	}
1793 
1794 	/* Channel is opened */
1795 	netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1796 
1797 	napi_enable(&net_device->chan_table[0].napi);
1798 
1799 	/* Connect with the NetVsp */
1800 	ret = netvsc_connect_vsp(device, net_device, device_info);
1801 	if (ret != 0) {
1802 		netdev_err(ndev,
1803 			"unable to connect to NetVSP - %d\n", ret);
1804 		goto close;
1805 	}
1806 
1807 	/* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1808 	 * populated.
1809 	 */
1810 	rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1811 
1812 	return net_device;
1813 
1814 close:
1815 	RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1816 	napi_disable(&net_device->chan_table[0].napi);
1817 
1818 	/* Now, we can close the channel safely */
1819 	vmbus_close(device->channel);
1820 
1821 cleanup:
1822 	netif_napi_del(&net_device->chan_table[0].napi);
1823 
1824 cleanup2:
1825 	if (net_device->recv_original_buf)
1826 		hv_unmap_memory(net_device->recv_buf);
1827 
1828 	if (net_device->send_original_buf)
1829 		hv_unmap_memory(net_device->send_buf);
1830 
1831 	free_netvsc_device(&net_device->rcu);
1832 
1833 	return ERR_PTR(ret);
1834 }
1835