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v4.6
 
  1/*
  2 * An implementation of file copy service.
  3 *
  4 * Copyright (C) 2014, Microsoft, Inc.
  5 *
  6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
  7 *
  8 * This program is free software; you can redistribute it and/or modify it
  9 * under the terms of the GNU General Public License version 2 as published
 10 * by the Free Software Foundation.
 11 *
 12 * This program is distributed in the hope that it will be useful, but
 13 * WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 15 * NON INFRINGEMENT.  See the GNU General Public License for more
 16 * details.
 17 *
 18 */
 19
 20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 21
 22#include <linux/nls.h>
 23#include <linux/workqueue.h>
 24#include <linux/hyperv.h>
 25#include <linux/sched.h>
 
 26
 27#include "hyperv_vmbus.h"
 28#include "hv_utils_transport.h"
 29
 30#define WIN8_SRV_MAJOR		1
 31#define WIN8_SRV_MINOR		1
 32#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 33
 
 
 
 
 
 
 
 
 
 
 34/*
 35 * Global state maintained for transaction that is being processed.
 36 * For a class of integration services, including the "file copy service",
 37 * the specified protocol is a "request/response" protocol which means that
 38 * there can only be single outstanding transaction from the host at any
 39 * given point in time. We use this to simplify memory management in this
 40 * driver - we cache and process only one message at a time.
 41 *
 42 * While the request/response protocol is guaranteed by the host, we further
 43 * ensure this by serializing packet processing in this driver - we do not
 44 * read additional packets from the VMBUs until the current packet is fully
 45 * handled.
 46 */
 47
 48static struct {
 49	int state;   /* hvutil_device_state */
 50	int recv_len; /* number of bytes received. */
 51	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
 52	struct vmbus_channel *recv_channel; /* chn we got the request */
 53	u64 recv_req_id; /* request ID. */
 54} fcopy_transaction;
 55
 56static void fcopy_respond_to_host(int error);
 57static void fcopy_send_data(struct work_struct *dummy);
 58static void fcopy_timeout_func(struct work_struct *dummy);
 59static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
 60static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
 61static const char fcopy_devname[] = "vmbus/hv_fcopy";
 62static u8 *recv_buffer;
 63static struct hvutil_transport *hvt;
 64/*
 65 * This state maintains the version number registered by the daemon.
 66 */
 67static int dm_reg_value;
 68
 69static void fcopy_poll_wrapper(void *channel)
 70{
 71	/* Transaction is finished, reset the state here to avoid races. */
 72	fcopy_transaction.state = HVUTIL_READY;
 73	hv_fcopy_onchannelcallback(channel);
 74}
 75
 76static void fcopy_timeout_func(struct work_struct *dummy)
 77{
 78	/*
 79	 * If the timer fires, the user-mode component has not responded;
 80	 * process the pending transaction.
 81	 */
 82	fcopy_respond_to_host(HV_E_FAIL);
 83	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 84}
 85
 
 
 
 
 
 
 86static int fcopy_handle_handshake(u32 version)
 87{
 88	u32 our_ver = FCOPY_CURRENT_VERSION;
 89
 90	switch (version) {
 91	case FCOPY_VERSION_0:
 92		/* Daemon doesn't expect us to reply */
 93		dm_reg_value = version;
 94		break;
 95	case FCOPY_VERSION_1:
 96		/* Daemon expects us to reply with our own version */
 97		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver)))
 
 98			return -EFAULT;
 99		dm_reg_value = version;
100		break;
101	default:
102		/*
103		 * For now we will fail the registration.
104		 * If and when we have multiple versions to
105		 * deal with, we will be backward compatible.
106		 * We will add this code when needed.
107		 */
108		return -EINVAL;
109	}
110	pr_debug("FCP: userspace daemon ver. %d registered\n", version);
111	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
112	return 0;
113}
114
115static void fcopy_send_data(struct work_struct *dummy)
116{
117	struct hv_start_fcopy *smsg_out = NULL;
118	int operation = fcopy_transaction.fcopy_msg->operation;
119	struct hv_start_fcopy *smsg_in;
120	void *out_src;
121	int rc, out_len;
122
123	/*
124	 * The  strings sent from the host are encoded in
125	 * in utf16; convert it to utf8 strings.
126	 * The host assures us that the utf16 strings will not exceed
127	 * the max lengths specified. We will however, reserve room
128	 * for the string terminating character - in the utf16s_utf8s()
129	 * function we limit the size of the buffer where the converted
130	 * string is placed to W_MAX_PATH -1 to guarantee
131	 * that the strings can be properly terminated!
132	 */
133
134	switch (operation) {
135	case START_FILE_COPY:
136		out_len = sizeof(struct hv_start_fcopy);
137		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
138		if (!smsg_out)
139			return;
140
141		smsg_out->hdr.operation = operation;
142		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
143
144		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
145				UTF16_LITTLE_ENDIAN,
146				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
147
148		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
149				UTF16_LITTLE_ENDIAN,
150				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
151
152		smsg_out->copy_flags = smsg_in->copy_flags;
153		smsg_out->file_size = smsg_in->file_size;
154		out_src = smsg_out;
155		break;
156
 
 
 
 
157	default:
158		out_src = fcopy_transaction.fcopy_msg;
159		out_len = fcopy_transaction.recv_len;
160		break;
161	}
162
163	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
164	rc = hvutil_transport_send(hvt, out_src, out_len);
165	if (rc) {
166		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
167		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
168			fcopy_respond_to_host(HV_E_FAIL);
169			fcopy_transaction.state = HVUTIL_READY;
170		}
171	}
172	kfree(smsg_out);
173
174	return;
175}
176
177/*
178 * Send a response back to the host.
179 */
180
181static void
182fcopy_respond_to_host(int error)
183{
184	struct icmsg_hdr *icmsghdr;
185	u32 buf_len;
186	struct vmbus_channel *channel;
187	u64 req_id;
188
189	/*
190	 * Copy the global state for completing the transaction. Note that
191	 * only one transaction can be active at a time. This is guaranteed
192	 * by the file copy protocol implemented by the host. Furthermore,
193	 * the "transaction active" state we maintain ensures that there can
194	 * only be one active transaction at a time.
195	 */
196
197	buf_len = fcopy_transaction.recv_len;
198	channel = fcopy_transaction.recv_channel;
199	req_id = fcopy_transaction.recv_req_id;
200
201	icmsghdr = (struct icmsg_hdr *)
202			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
203
204	if (channel->onchannel_callback == NULL)
205		/*
206		 * We have raced with util driver being unloaded;
207		 * silently return.
208		 */
209		return;
210
211	icmsghdr->status = error;
212	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
213	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
214				VM_PKT_DATA_INBAND, 0);
215}
216
217void hv_fcopy_onchannelcallback(void *context)
218{
219	struct vmbus_channel *channel = context;
220	u32 recvlen;
221	u64 requestid;
222	struct hv_fcopy_hdr *fcopy_msg;
223	struct icmsg_hdr *icmsghdr;
224	struct icmsg_negotiate *negop = NULL;
225	int util_fw_version;
226	int fcopy_srv_version;
227
228	if (fcopy_transaction.state > HVUTIL_READY)
229		return;
230
231	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
232			 &requestid);
233	if (recvlen <= 0)
234		return;
 
 
 
 
 
 
 
 
 
 
 
235
236	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
237			sizeof(struct vmbuspipe_hdr)];
 
238	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
239		util_fw_version = UTIL_FW_VERSION;
240		fcopy_srv_version = WIN8_SRV_VERSION;
241		vmbus_prep_negotiate_resp(icmsghdr, negop, recv_buffer,
242				util_fw_version, fcopy_srv_version);
243	} else {
244		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
245				sizeof(struct vmbuspipe_hdr) +
246				sizeof(struct icmsg_hdr)];
 
 
 
 
 
 
 
 
 
 
247
248		/*
249		 * Stash away this global state for completing the
250		 * transaction; note transactions are serialized.
251		 */
252
253		fcopy_transaction.recv_len = recvlen;
254		fcopy_transaction.recv_req_id = requestid;
255		fcopy_transaction.fcopy_msg = fcopy_msg;
256
257		if (fcopy_transaction.state < HVUTIL_READY) {
258			/* Userspace is not registered yet */
259			fcopy_respond_to_host(HV_E_FAIL);
260			return;
261		}
262		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
263
264		/*
265		 * Send the information to the user-level daemon.
266		 */
267		schedule_work(&fcopy_send_work);
268		schedule_delayed_work(&fcopy_timeout_work,
269				      HV_UTIL_TIMEOUT * HZ);
270		return;
 
 
 
 
271	}
272	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
273	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
274			VM_PKT_DATA_INBAND, 0);
275}
276
277/* Callback when data is received from userspace */
278static int fcopy_on_msg(void *msg, int len)
279{
280	int *val = (int *)msg;
281
282	if (len != sizeof(int))
283		return -EINVAL;
284
285	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
286		return fcopy_handle_handshake(*val);
287
288	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
289		return -EINVAL;
290
291	/*
292	 * Complete the transaction by forwarding the result
293	 * to the host. But first, cancel the timeout.
294	 */
295	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
296		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
297		fcopy_respond_to_host(*val);
298		hv_poll_channel(fcopy_transaction.recv_channel,
299				fcopy_poll_wrapper);
300	}
301
302	return 0;
303}
304
305static void fcopy_on_reset(void)
306{
307	/*
308	 * The daemon has exited; reset the state.
309	 */
310	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
311
312	if (cancel_delayed_work_sync(&fcopy_timeout_work))
313		fcopy_respond_to_host(HV_E_FAIL);
314}
315
316int hv_fcopy_init(struct hv_util_service *srv)
317{
318	recv_buffer = srv->recv_buffer;
319	fcopy_transaction.recv_channel = srv->channel;
 
320
321	/*
322	 * When this driver loads, the user level daemon that
323	 * processes the host requests may not yet be running.
324	 * Defer processing channel callbacks until the daemon
325	 * has registered.
326	 */
327	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
328
329	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
330				    fcopy_on_msg, fcopy_on_reset);
331	if (!hvt)
332		return -EFAULT;
333
334	return 0;
335}
336
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
337void hv_fcopy_deinit(void)
338{
339	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
340	cancel_delayed_work_sync(&fcopy_timeout_work);
 
 
341	hvutil_transport_destroy(hvt);
342}
v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * An implementation of file copy service.
  4 *
  5 * Copyright (C) 2014, Microsoft, Inc.
  6 *
  7 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
 
 
 
 
 
 
 
 
 
 
 
  8 */
  9
 10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 11
 12#include <linux/nls.h>
 13#include <linux/workqueue.h>
 14#include <linux/hyperv.h>
 15#include <linux/sched.h>
 16#include <asm/hyperv-tlfs.h>
 17
 18#include "hyperv_vmbus.h"
 19#include "hv_utils_transport.h"
 20
 21#define WIN8_SRV_MAJOR		1
 22#define WIN8_SRV_MINOR		1
 23#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 24
 25#define FCOPY_VER_COUNT 1
 26static const int fcopy_versions[] = {
 27	WIN8_SRV_VERSION
 28};
 29
 30#define FW_VER_COUNT 1
 31static const int fw_versions[] = {
 32	UTIL_FW_VERSION
 33};
 34
 35/*
 36 * Global state maintained for transaction that is being processed.
 37 * For a class of integration services, including the "file copy service",
 38 * the specified protocol is a "request/response" protocol which means that
 39 * there can only be single outstanding transaction from the host at any
 40 * given point in time. We use this to simplify memory management in this
 41 * driver - we cache and process only one message at a time.
 42 *
 43 * While the request/response protocol is guaranteed by the host, we further
 44 * ensure this by serializing packet processing in this driver - we do not
 45 * read additional packets from the VMBUs until the current packet is fully
 46 * handled.
 47 */
 48
 49static struct {
 50	int state;   /* hvutil_device_state */
 51	int recv_len; /* number of bytes received. */
 52	struct hv_fcopy_hdr  *fcopy_msg; /* current message */
 53	struct vmbus_channel *recv_channel; /* chn we got the request */
 54	u64 recv_req_id; /* request ID. */
 55} fcopy_transaction;
 56
 57static void fcopy_respond_to_host(int error);
 58static void fcopy_send_data(struct work_struct *dummy);
 59static void fcopy_timeout_func(struct work_struct *dummy);
 60static DECLARE_DELAYED_WORK(fcopy_timeout_work, fcopy_timeout_func);
 61static DECLARE_WORK(fcopy_send_work, fcopy_send_data);
 62static const char fcopy_devname[] = "vmbus/hv_fcopy";
 63static u8 *recv_buffer;
 64static struct hvutil_transport *hvt;
 65/*
 66 * This state maintains the version number registered by the daemon.
 67 */
 68static int dm_reg_value;
 69
 70static void fcopy_poll_wrapper(void *channel)
 71{
 72	/* Transaction is finished, reset the state here to avoid races. */
 73	fcopy_transaction.state = HVUTIL_READY;
 74	tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
 75}
 76
 77static void fcopy_timeout_func(struct work_struct *dummy)
 78{
 79	/*
 80	 * If the timer fires, the user-mode component has not responded;
 81	 * process the pending transaction.
 82	 */
 83	fcopy_respond_to_host(HV_E_FAIL);
 84	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 85}
 86
 87static void fcopy_register_done(void)
 88{
 89	pr_debug("FCP: userspace daemon registered\n");
 90	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 91}
 92
 93static int fcopy_handle_handshake(u32 version)
 94{
 95	u32 our_ver = FCOPY_CURRENT_VERSION;
 96
 97	switch (version) {
 98	case FCOPY_VERSION_0:
 99		/* Daemon doesn't expect us to reply */
100		dm_reg_value = version;
101		break;
102	case FCOPY_VERSION_1:
103		/* Daemon expects us to reply with our own version */
104		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
105		    fcopy_register_done))
106			return -EFAULT;
107		dm_reg_value = version;
108		break;
109	default:
110		/*
111		 * For now we will fail the registration.
112		 * If and when we have multiple versions to
113		 * deal with, we will be backward compatible.
114		 * We will add this code when needed.
115		 */
116		return -EINVAL;
117	}
118	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
 
119	return 0;
120}
121
122static void fcopy_send_data(struct work_struct *dummy)
123{
124	struct hv_start_fcopy *smsg_out = NULL;
125	int operation = fcopy_transaction.fcopy_msg->operation;
126	struct hv_start_fcopy *smsg_in;
127	void *out_src;
128	int rc, out_len;
129
130	/*
131	 * The  strings sent from the host are encoded in
132	 * utf16; convert it to utf8 strings.
133	 * The host assures us that the utf16 strings will not exceed
134	 * the max lengths specified. We will however, reserve room
135	 * for the string terminating character - in the utf16s_utf8s()
136	 * function we limit the size of the buffer where the converted
137	 * string is placed to W_MAX_PATH -1 to guarantee
138	 * that the strings can be properly terminated!
139	 */
140
141	switch (operation) {
142	case START_FILE_COPY:
143		out_len = sizeof(struct hv_start_fcopy);
144		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
145		if (!smsg_out)
146			return;
147
148		smsg_out->hdr.operation = operation;
149		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
150
151		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
152				UTF16_LITTLE_ENDIAN,
153				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
154
155		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
156				UTF16_LITTLE_ENDIAN,
157				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
158
159		smsg_out->copy_flags = smsg_in->copy_flags;
160		smsg_out->file_size = smsg_in->file_size;
161		out_src = smsg_out;
162		break;
163
164	case WRITE_TO_FILE:
165		out_src = fcopy_transaction.fcopy_msg;
166		out_len = sizeof(struct hv_do_fcopy);
167		break;
168	default:
169		out_src = fcopy_transaction.fcopy_msg;
170		out_len = fcopy_transaction.recv_len;
171		break;
172	}
173
174	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
175	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
176	if (rc) {
177		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
178		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
179			fcopy_respond_to_host(HV_E_FAIL);
180			fcopy_transaction.state = HVUTIL_READY;
181		}
182	}
183	kfree(smsg_out);
 
 
184}
185
186/*
187 * Send a response back to the host.
188 */
189
190static void
191fcopy_respond_to_host(int error)
192{
193	struct icmsg_hdr *icmsghdr;
194	u32 buf_len;
195	struct vmbus_channel *channel;
196	u64 req_id;
197
198	/*
199	 * Copy the global state for completing the transaction. Note that
200	 * only one transaction can be active at a time. This is guaranteed
201	 * by the file copy protocol implemented by the host. Furthermore,
202	 * the "transaction active" state we maintain ensures that there can
203	 * only be one active transaction at a time.
204	 */
205
206	buf_len = fcopy_transaction.recv_len;
207	channel = fcopy_transaction.recv_channel;
208	req_id = fcopy_transaction.recv_req_id;
209
210	icmsghdr = (struct icmsg_hdr *)
211			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
212
213	if (channel->onchannel_callback == NULL)
214		/*
215		 * We have raced with util driver being unloaded;
216		 * silently return.
217		 */
218		return;
219
220	icmsghdr->status = error;
221	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
222	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
223				VM_PKT_DATA_INBAND, 0);
224}
225
226void hv_fcopy_onchannelcallback(void *context)
227{
228	struct vmbus_channel *channel = context;
229	u32 recvlen;
230	u64 requestid;
231	struct hv_fcopy_hdr *fcopy_msg;
232	struct icmsg_hdr *icmsghdr;
 
 
233	int fcopy_srv_version;
234
235	if (fcopy_transaction.state > HVUTIL_READY)
236		return;
237
238	if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen, &requestid)) {
239		pr_err_ratelimited("Fcopy request received. Could not read into recv buf\n");
 
240		return;
241	}
242
243	if (!recvlen)
244		return;
245
246	/* Ensure recvlen is big enough to read header data */
247	if (recvlen < ICMSG_HDR) {
248		pr_err_ratelimited("Fcopy request received. Packet length too small: %d\n",
249				   recvlen);
250		return;
251	}
252
253	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
254			sizeof(struct vmbuspipe_hdr)];
255
256	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
257		if (vmbus_prep_negotiate_resp(icmsghdr,
258				recv_buffer, recvlen,
259				fw_versions, FW_VER_COUNT,
260				fcopy_versions, FCOPY_VER_COUNT,
261				NULL, &fcopy_srv_version)) {
262
263			pr_info("FCopy IC version %d.%d\n",
264				fcopy_srv_version >> 16,
265				fcopy_srv_version & 0xFFFF);
266		}
267	} else if (icmsghdr->icmsgtype == ICMSGTYPE_FCOPY) {
268		/* Ensure recvlen is big enough to contain hv_fcopy_hdr */
269		if (recvlen < ICMSG_HDR + sizeof(struct hv_fcopy_hdr)) {
270			pr_err_ratelimited("Invalid Fcopy hdr. Packet length too small: %u\n",
271					   recvlen);
272			return;
273		}
274		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[ICMSG_HDR];
275
276		/*
277		 * Stash away this global state for completing the
278		 * transaction; note transactions are serialized.
279		 */
280
281		fcopy_transaction.recv_len = recvlen;
282		fcopy_transaction.recv_req_id = requestid;
283		fcopy_transaction.fcopy_msg = fcopy_msg;
284
285		if (fcopy_transaction.state < HVUTIL_READY) {
286			/* Userspace is not registered yet */
287			fcopy_respond_to_host(HV_E_FAIL);
288			return;
289		}
290		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
291
292		/*
293		 * Send the information to the user-level daemon.
294		 */
295		schedule_work(&fcopy_send_work);
296		schedule_delayed_work(&fcopy_timeout_work,
297				      HV_UTIL_TIMEOUT * HZ);
298		return;
299	} else {
300		pr_err_ratelimited("Fcopy request received. Invalid msg type: %d\n",
301				   icmsghdr->icmsgtype);
302		return;
303	}
304	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
305	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
306			VM_PKT_DATA_INBAND, 0);
307}
308
309/* Callback when data is received from userspace */
310static int fcopy_on_msg(void *msg, int len)
311{
312	int *val = (int *)msg;
313
314	if (len != sizeof(int))
315		return -EINVAL;
316
317	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
318		return fcopy_handle_handshake(*val);
319
320	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
321		return -EINVAL;
322
323	/*
324	 * Complete the transaction by forwarding the result
325	 * to the host. But first, cancel the timeout.
326	 */
327	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
328		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
329		fcopy_respond_to_host(*val);
330		hv_poll_channel(fcopy_transaction.recv_channel,
331				fcopy_poll_wrapper);
332	}
333
334	return 0;
335}
336
337static void fcopy_on_reset(void)
338{
339	/*
340	 * The daemon has exited; reset the state.
341	 */
342	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
343
344	if (cancel_delayed_work_sync(&fcopy_timeout_work))
345		fcopy_respond_to_host(HV_E_FAIL);
346}
347
348int hv_fcopy_init(struct hv_util_service *srv)
349{
350	recv_buffer = srv->recv_buffer;
351	fcopy_transaction.recv_channel = srv->channel;
352	fcopy_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2;
353
354	/*
355	 * When this driver loads, the user level daemon that
356	 * processes the host requests may not yet be running.
357	 * Defer processing channel callbacks until the daemon
358	 * has registered.
359	 */
360	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
361
362	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
363				    fcopy_on_msg, fcopy_on_reset);
364	if (!hvt)
365		return -EFAULT;
366
367	return 0;
368}
369
370static void hv_fcopy_cancel_work(void)
371{
372	cancel_delayed_work_sync(&fcopy_timeout_work);
373	cancel_work_sync(&fcopy_send_work);
374}
375
376int hv_fcopy_pre_suspend(void)
377{
378	struct vmbus_channel *channel = fcopy_transaction.recv_channel;
379	struct hv_fcopy_hdr *fcopy_msg;
380
381	/*
382	 * Fake a CANCEL_FCOPY message for the user space daemon in case the
383	 * daemon is in the middle of copying some file. It doesn't matter if
384	 * there is already a message pending to be delivered to the user
385	 * space since we force fcopy_transaction.state to be HVUTIL_READY, so
386	 * the user space daemon's write() will fail with EINVAL (see
387	 * fcopy_on_msg()), and the daemon will reset the device by closing
388	 * and re-opening it.
389	 */
390	fcopy_msg = kzalloc(sizeof(*fcopy_msg), GFP_KERNEL);
391	if (!fcopy_msg)
392		return -ENOMEM;
393
394	tasklet_disable(&channel->callback_event);
395
396	fcopy_msg->operation = CANCEL_FCOPY;
397
398	hv_fcopy_cancel_work();
399
400	/* We don't care about the return value. */
401	hvutil_transport_send(hvt, fcopy_msg, sizeof(*fcopy_msg), NULL);
402
403	kfree(fcopy_msg);
404
405	fcopy_transaction.state = HVUTIL_READY;
406
407	/* tasklet_enable() will be called in hv_fcopy_pre_resume(). */
408	return 0;
409}
410
411int hv_fcopy_pre_resume(void)
412{
413	struct vmbus_channel *channel = fcopy_transaction.recv_channel;
414
415	tasklet_enable(&channel->callback_event);
416
417	return 0;
418}
419
420void hv_fcopy_deinit(void)
421{
422	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
423
424	hv_fcopy_cancel_work();
425
426	hvutil_transport_destroy(hvt);
427}