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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}
v5.4
  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
 17#include "hyperv_vmbus.h"
 18#include "hv_utils_transport.h"
 19
 20#define WIN8_SRV_MAJOR		1
 21#define WIN8_SRV_MINOR		1
 22#define WIN8_SRV_VERSION	(WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
 23
 24#define FCOPY_VER_COUNT 1
 25static const int fcopy_versions[] = {
 26	WIN8_SRV_VERSION
 27};
 28
 29#define FW_VER_COUNT 1
 30static const int fw_versions[] = {
 31	UTIL_FW_VERSION
 32};
 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 void fcopy_register_done(void)
 87{
 88	pr_debug("FCP: userspace daemon registered\n");
 89	hv_poll_channel(fcopy_transaction.recv_channel, fcopy_poll_wrapper);
 90}
 91
 92static int fcopy_handle_handshake(u32 version)
 93{
 94	u32 our_ver = FCOPY_CURRENT_VERSION;
 95
 96	switch (version) {
 97	case FCOPY_VERSION_0:
 98		/* Daemon doesn't expect us to reply */
 99		dm_reg_value = version;
100		break;
101	case FCOPY_VERSION_1:
102		/* Daemon expects us to reply with our own version */
103		if (hvutil_transport_send(hvt, &our_ver, sizeof(our_ver),
104		    fcopy_register_done))
105			return -EFAULT;
106		dm_reg_value = version;
107		break;
108	default:
109		/*
110		 * For now we will fail the registration.
111		 * If and when we have multiple versions to
112		 * deal with, we will be backward compatible.
113		 * We will add this code when needed.
114		 */
115		return -EINVAL;
116	}
117	pr_debug("FCP: userspace daemon ver. %d connected\n", version);
 
118	return 0;
119}
120
121static void fcopy_send_data(struct work_struct *dummy)
122{
123	struct hv_start_fcopy *smsg_out = NULL;
124	int operation = fcopy_transaction.fcopy_msg->operation;
125	struct hv_start_fcopy *smsg_in;
126	void *out_src;
127	int rc, out_len;
128
129	/*
130	 * The  strings sent from the host are encoded in
131	 * in utf16; convert it to utf8 strings.
132	 * The host assures us that the utf16 strings will not exceed
133	 * the max lengths specified. We will however, reserve room
134	 * for the string terminating character - in the utf16s_utf8s()
135	 * function we limit the size of the buffer where the converted
136	 * string is placed to W_MAX_PATH -1 to guarantee
137	 * that the strings can be properly terminated!
138	 */
139
140	switch (operation) {
141	case START_FILE_COPY:
142		out_len = sizeof(struct hv_start_fcopy);
143		smsg_out = kzalloc(sizeof(*smsg_out), GFP_KERNEL);
144		if (!smsg_out)
145			return;
146
147		smsg_out->hdr.operation = operation;
148		smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
149
150		utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
151				UTF16_LITTLE_ENDIAN,
152				(__u8 *)&smsg_out->file_name, W_MAX_PATH - 1);
153
154		utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
155				UTF16_LITTLE_ENDIAN,
156				(__u8 *)&smsg_out->path_name, W_MAX_PATH - 1);
157
158		smsg_out->copy_flags = smsg_in->copy_flags;
159		smsg_out->file_size = smsg_in->file_size;
160		out_src = smsg_out;
161		break;
162
163	case WRITE_TO_FILE:
164		out_src = fcopy_transaction.fcopy_msg;
165		out_len = sizeof(struct hv_do_fcopy);
166		break;
167	default:
168		out_src = fcopy_transaction.fcopy_msg;
169		out_len = fcopy_transaction.recv_len;
170		break;
171	}
172
173	fcopy_transaction.state = HVUTIL_USERSPACE_REQ;
174	rc = hvutil_transport_send(hvt, out_src, out_len, NULL);
175	if (rc) {
176		pr_debug("FCP: failed to communicate to the daemon: %d\n", rc);
177		if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
178			fcopy_respond_to_host(HV_E_FAIL);
179			fcopy_transaction.state = HVUTIL_READY;
180		}
181	}
182	kfree(smsg_out);
 
 
183}
184
185/*
186 * Send a response back to the host.
187 */
188
189static void
190fcopy_respond_to_host(int error)
191{
192	struct icmsg_hdr *icmsghdr;
193	u32 buf_len;
194	struct vmbus_channel *channel;
195	u64 req_id;
196
197	/*
198	 * Copy the global state for completing the transaction. Note that
199	 * only one transaction can be active at a time. This is guaranteed
200	 * by the file copy protocol implemented by the host. Furthermore,
201	 * the "transaction active" state we maintain ensures that there can
202	 * only be one active transaction at a time.
203	 */
204
205	buf_len = fcopy_transaction.recv_len;
206	channel = fcopy_transaction.recv_channel;
207	req_id = fcopy_transaction.recv_req_id;
208
209	icmsghdr = (struct icmsg_hdr *)
210			&recv_buffer[sizeof(struct vmbuspipe_hdr)];
211
212	if (channel->onchannel_callback == NULL)
213		/*
214		 * We have raced with util driver being unloaded;
215		 * silently return.
216		 */
217		return;
218
219	icmsghdr->status = error;
220	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
221	vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
222				VM_PKT_DATA_INBAND, 0);
223}
224
225void hv_fcopy_onchannelcallback(void *context)
226{
227	struct vmbus_channel *channel = context;
228	u32 recvlen;
229	u64 requestid;
230	struct hv_fcopy_hdr *fcopy_msg;
231	struct icmsg_hdr *icmsghdr;
 
 
232	int fcopy_srv_version;
233
234	if (fcopy_transaction.state > HVUTIL_READY)
235		return;
236
237	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
238			 &requestid);
239	if (recvlen <= 0)
240		return;
241
242	icmsghdr = (struct icmsg_hdr *)&recv_buffer[
243			sizeof(struct vmbuspipe_hdr)];
244	if (icmsghdr->icmsgtype == ICMSGTYPE_NEGOTIATE) {
245		if (vmbus_prep_negotiate_resp(icmsghdr, recv_buffer,
246				fw_versions, FW_VER_COUNT,
247				fcopy_versions, FCOPY_VER_COUNT,
248				NULL, &fcopy_srv_version)) {
249
250			pr_info("FCopy IC version %d.%d\n",
251				fcopy_srv_version >> 16,
252				fcopy_srv_version & 0xFFFF);
253		}
254	} else {
255		fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
256				sizeof(struct vmbuspipe_hdr) +
257				sizeof(struct icmsg_hdr)];
258
259		/*
260		 * Stash away this global state for completing the
261		 * transaction; note transactions are serialized.
262		 */
263
264		fcopy_transaction.recv_len = recvlen;
265		fcopy_transaction.recv_req_id = requestid;
266		fcopy_transaction.fcopy_msg = fcopy_msg;
267
268		if (fcopy_transaction.state < HVUTIL_READY) {
269			/* Userspace is not registered yet */
270			fcopy_respond_to_host(HV_E_FAIL);
271			return;
272		}
273		fcopy_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
274
275		/*
276		 * Send the information to the user-level daemon.
277		 */
278		schedule_work(&fcopy_send_work);
279		schedule_delayed_work(&fcopy_timeout_work,
280				      HV_UTIL_TIMEOUT * HZ);
281		return;
282	}
283	icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
284	vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
285			VM_PKT_DATA_INBAND, 0);
286}
287
288/* Callback when data is received from userspace */
289static int fcopy_on_msg(void *msg, int len)
290{
291	int *val = (int *)msg;
292
293	if (len != sizeof(int))
294		return -EINVAL;
295
296	if (fcopy_transaction.state == HVUTIL_DEVICE_INIT)
297		return fcopy_handle_handshake(*val);
298
299	if (fcopy_transaction.state != HVUTIL_USERSPACE_REQ)
300		return -EINVAL;
301
302	/*
303	 * Complete the transaction by forwarding the result
304	 * to the host. But first, cancel the timeout.
305	 */
306	if (cancel_delayed_work_sync(&fcopy_timeout_work)) {
307		fcopy_transaction.state = HVUTIL_USERSPACE_RECV;
308		fcopy_respond_to_host(*val);
309		hv_poll_channel(fcopy_transaction.recv_channel,
310				fcopy_poll_wrapper);
311	}
312
313	return 0;
314}
315
316static void fcopy_on_reset(void)
317{
318	/*
319	 * The daemon has exited; reset the state.
320	 */
321	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
322
323	if (cancel_delayed_work_sync(&fcopy_timeout_work))
324		fcopy_respond_to_host(HV_E_FAIL);
325}
326
327int hv_fcopy_init(struct hv_util_service *srv)
328{
329	recv_buffer = srv->recv_buffer;
330	fcopy_transaction.recv_channel = srv->channel;
331
332	/*
333	 * When this driver loads, the user level daemon that
334	 * processes the host requests may not yet be running.
335	 * Defer processing channel callbacks until the daemon
336	 * has registered.
337	 */
338	fcopy_transaction.state = HVUTIL_DEVICE_INIT;
339
340	hvt = hvutil_transport_init(fcopy_devname, 0, 0,
341				    fcopy_on_msg, fcopy_on_reset);
342	if (!hvt)
343		return -EFAULT;
344
345	return 0;
346}
347
348void hv_fcopy_deinit(void)
349{
350	fcopy_transaction.state = HVUTIL_DEVICE_DYING;
351	cancel_delayed_work_sync(&fcopy_timeout_work);
352	hvutil_transport_destroy(hvt);
353}