[mirror_ubuntu-bionic-kernel.git] / drivers / hv / hv_util.c

/*
 * Copyright (c) 2010, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/reboot.h>
#include <linux/hyperv.h>

static void shutdown_onchannelcallback(void *context);
static struct hv_util_service util_shutdown = {
	.util_cb = shutdown_onchannelcallback,
};

static void timesync_onchannelcallback(void *context);
static struct hv_util_service util_timesynch = {
	.util_cb = timesync_onchannelcallback,
};

static void heartbeat_onchannelcallback(void *context);
static struct hv_util_service util_heartbeat = {
	.util_cb = heartbeat_onchannelcallback,
};

static struct hv_util_service util_kvp = {
	.util_cb = hv_kvp_onchannelcallback,
	.util_init = hv_kvp_init,
	.util_deinit = hv_kvp_deinit,
};

static void perform_shutdown(struct work_struct *dummy)
{
	orderly_poweroff(true);
}

/*
 * Perform the shutdown operation in a thread context.
 */
static DECLARE_WORK(shutdown_work, perform_shutdown);

static void shutdown_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	u8  execute_shutdown = false;
	u8  *shut_txf_buf = util_shutdown.recv_buffer;

	struct shutdown_msg_data *shutdown_msg;

	struct icmsg_hdr *icmsghdrp;
	struct icmsg_negotiate *negop = NULL;

	vmbus_recvpacket(channel, shut_txf_buf,
			 PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
			sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			vmbus_prep_negotiate_resp(icmsghdrp, negop,
					shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
		} else {
			shutdown_msg =
				(struct shutdown_msg_data *)&shut_txf_buf[
					sizeof(struct vmbuspipe_hdr) +
					sizeof(struct icmsg_hdr)];

			switch (shutdown_msg->flags) {
			case 0:
			case 1:
				icmsghdrp->status = HV_S_OK;
				execute_shutdown = true;

				pr_info("Shutdown request received -"
					    " graceful shutdown initiated\n");
				break;
			default:
				icmsghdrp->status = HV_E_FAIL;
				execute_shutdown = false;

				pr_info("Shutdown request received -"
					    " Invalid request\n");
				break;
			}
		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, shut_txf_buf,
				       recvlen, requestid,
				       VM_PKT_DATA_INBAND, 0);
	}

	if (execute_shutdown == true)
		schedule_work(&shutdown_work);
}

/*
 * Set guest time to host UTC time.
 */
static inline void do_adj_guesttime(u64 hosttime)
{
	s64 host_tns;
	struct timespec host_ts;

	host_tns = (hosttime - WLTIMEDELTA) * 100;
	host_ts = ns_to_timespec(host_tns);

	do_settimeofday(&host_ts);
}

/*
 * Set the host time in a process context.
 */

struct adj_time_work {
	struct work_struct work;
	u64	host_time;
};

static void hv_set_host_time(struct work_struct *work)
{
	struct adj_time_work	*wrk;

	wrk = container_of(work, struct adj_time_work, work);
	do_adj_guesttime(wrk->host_time);
	kfree(wrk);
}

/*
 * Synchronize time with host after reboot, restore, etc.
 *
 * ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
 * After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
 * message after the timesync channel is opened. Since the hv_utils module is
 * loaded after hv_vmbus, the first message is usually missed. The other
 * thing is, systime is automatically set to emulated hardware clock which may
 * not be UTC time or in the same time zone. So, to override these effects, we
 * use the first 50 time samples for initial system time setting.
 */
static inline void adj_guesttime(u64 hosttime, u8 flags)
{
	struct adj_time_work    *wrk;
	static s32 scnt = 50;

	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
	if (wrk == NULL)
		return;

	wrk->host_time = hosttime;
	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
		INIT_WORK(&wrk->work, hv_set_host_time);
		schedule_work(&wrk->work);
		return;
	}

	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
		scnt--;
		INIT_WORK(&wrk->work, hv_set_host_time);
		schedule_work(&wrk->work);
	} else
		kfree(wrk);
}

/*
 * Time Sync Channel message handler.
 */
static void timesync_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct ictimesync_data *timedatap;
	u8 *time_txf_buf = util_timesynch.recv_buffer;

	vmbus_recvpacket(channel, time_txf_buf,
			 PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
				sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
						MAX_SRV_VER, MAX_SRV_VER);
		} else {
			timedatap = (struct ictimesync_data *)&time_txf_buf[
				sizeof(struct vmbuspipe_hdr) +
				sizeof(struct icmsg_hdr)];
			adj_guesttime(timedatap->parenttime, timedatap->flags);
		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, time_txf_buf,
				recvlen, requestid,
				VM_PKT_DATA_INBAND, 0);
	}
}

/*
 * Heartbeat functionality.
 * Every two seconds, Hyper-V send us a heartbeat request message.
 * we respond to this message, and Hyper-V knows we are alive.
 */
static void heartbeat_onchannelcallback(void *context)
{
	struct vmbus_channel *channel = context;
	u32 recvlen;
	u64 requestid;
	struct icmsg_hdr *icmsghdrp;
	struct heartbeat_msg_data *heartbeat_msg;
	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;

	vmbus_recvpacket(channel, hbeat_txf_buf,
			 PAGE_SIZE, &recvlen, &requestid);

	if (recvlen > 0) {
		icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
				sizeof(struct vmbuspipe_hdr)];

		if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
			vmbus_prep_negotiate_resp(icmsghdrp, NULL,
				hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
		} else {
			heartbeat_msg =
				(struct heartbeat_msg_data *)&hbeat_txf_buf[
					sizeof(struct vmbuspipe_hdr) +
					sizeof(struct icmsg_hdr)];

			heartbeat_msg->seq_num += 1;
		}

		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
			| ICMSGHDRFLAG_RESPONSE;

		vmbus_sendpacket(channel, hbeat_txf_buf,
				       recvlen, requestid,
				       VM_PKT_DATA_INBAND, 0);
	}
}

static int util_probe(struct hv_device *dev,
			const struct hv_vmbus_device_id *dev_id)
{
	struct hv_util_service *srv =
		(struct hv_util_service *)dev_id->driver_data;
	int ret;

	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
	if (!srv->recv_buffer)
		return -ENOMEM;
	if (srv->util_init) {
		ret = srv->util_init(srv);
		if (ret) {
			ret = -ENODEV;
			goto error1;
		}
	}

	/*
	 * The set of services managed by the util driver are not performance
	 * critical and do not need batched reading. Furthermore, some services
	 * such as KVP can only handle one message from the host at a time.
	 * Turn off batched reading for all util drivers before we open the
	 * channel.
	 */

	set_channel_read_state(dev->channel, false);

	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
			srv->util_cb, dev->channel);
	if (ret)
		goto error;

	hv_set_drvdata(dev, srv);
	return 0;

error:
	if (srv->util_deinit)
		srv->util_deinit();
error1:
	kfree(srv->recv_buffer);
	return ret;
}

static int util_remove(struct hv_device *dev)
{
	struct hv_util_service *srv = hv_get_drvdata(dev);

	vmbus_close(dev->channel);
	if (srv->util_deinit)
		srv->util_deinit();
	kfree(srv->recv_buffer);

	return 0;
}

static const struct hv_vmbus_device_id id_table[] = {
	/* Shutdown guid */
	{ HV_SHUTDOWN_GUID,
	  .driver_data = (unsigned long)&util_shutdown
	},
	/* Time synch guid */
	{ HV_TS_GUID,
	  .driver_data = (unsigned long)&util_timesynch
	},
	/* Heartbeat guid */
	{ HV_HEART_BEAT_GUID,
	  .driver_data = (unsigned long)&util_heartbeat
	},
	/* KVP guid */
	{ HV_KVP_GUID,
	  .driver_data = (unsigned long)&util_kvp
	},
	{ },
};

MODULE_DEVICE_TABLE(vmbus, id_table);

/* The one and only one */
static  struct hv_driver util_drv = {
	.name = "hv_util",
	.id_table = id_table,
	.probe =  util_probe,
	.remove =  util_remove,
};

static int __init init_hyperv_utils(void)
{
	pr_info("Registering HyperV Utility Driver\n");

	return vmbus_driver_register(&util_drv);
}

static void exit_hyperv_utils(void)
{
	pr_info("De-Registered HyperV Utility Driver\n");

	vmbus_driver_unregister(&util_drv);
}

module_init(init_hyperv_utils);
module_exit(exit_hyperv_utils);

MODULE_DESCRIPTION("Hyper-V Utilities");
MODULE_VERSION(HV_DRV_VERSION);
MODULE_LICENSE("GPL");
Commit	Line	Data
c88c4e4c HJ	1	/*
	2	* Copyright (c) 2010, Microsoft Corporation.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms and conditions of the GNU General Public License,
	6	* version 2, as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	15	* Place - Suite 330, Boston, MA 02111-1307 USA.
	16	*
	17	* Authors:
	18	* Haiyang Zhang <haiyangz@microsoft.com>
	19	* Hank Janssen <hjanssen@microsoft.com>
	20	*/
af7a5b6e HJ	21	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
af7a5b6e HJ	22
c88c4e4c HJ	23	#include <linux/kernel.h>
	24	#include <linux/init.h>
	25	#include <linux/module.h>
	26	#include <linux/slab.h>
	27	#include <linux/sysctl.h>
9e629075	28	#include <linux/reboot.h>
46a97191	29	#include <linux/hyperv.h>
c88c4e4c	30
a29b643c S	31	static void shutdown_onchannelcallback(void *context);
	32	static struct hv_util_service util_shutdown = {
	33	.util_cb = shutdown_onchannelcallback,
	34	};
	35
	36	static void timesync_onchannelcallback(void *context);
	37	static struct hv_util_service util_timesynch = {
	38	.util_cb = timesync_onchannelcallback,
	39	};
	40
	41	static void heartbeat_onchannelcallback(void *context);
	42	static struct hv_util_service util_heartbeat = {
	43	.util_cb = heartbeat_onchannelcallback,
	44	};
	45
	46	static struct hv_util_service util_kvp = {
	47	.util_cb = hv_kvp_onchannelcallback,
	48	.util_init = hv_kvp_init,
	49	.util_deinit = hv_kvp_deinit,
	50	};
c88c4e4c	51
3dd6cb49 S	52	static void perform_shutdown(struct work_struct *dummy)
	53	{
	54	orderly_poweroff(true);
	55	}
	56
	57	/*
	58	* Perform the shutdown operation in a thread context.
	59	*/
	60	static DECLARE_WORK(shutdown_work, perform_shutdown);
	61
6610944a	62	static void shutdown_onchannelcallback(void *context)
c88c4e4c HJ	63	{
c88c4e4c HJ	64	struct vmbus_channel *channel = context;
45241e50	65	u32 recvlen;
c88c4e4c HJ	66	u64 requestid;
c88c4e4c HJ	67	u8 execute_shutdown = false;
a29b643c	68	u8 *shut_txf_buf = util_shutdown.recv_buffer;
c88c4e4c HJ	69
	70	struct shutdown_msg_data *shutdown_msg;
	71
	72	struct icmsg_hdr *icmsghdrp;
	73	struct icmsg_negotiate *negop = NULL;
	74
45241e50 HJ	75	vmbus_recvpacket(channel, shut_txf_buf,
45241e50 HJ	76	PAGE_SIZE, &recvlen, &requestid);
c88c4e4c HJ	77
c88c4e4c HJ	78	if (recvlen > 0) {
45241e50	79	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
c88c4e4c HJ	80	sizeof(struct vmbuspipe_hdr)];
	81
	82	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
c836d0ab S	83	vmbus_prep_negotiate_resp(icmsghdrp, negop,
c836d0ab S	84	shut_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
c88c4e4c	85	} else {
45241e50 HJ	86	shutdown_msg =
	87	(struct shutdown_msg_data *)&shut_txf_buf[
	88	sizeof(struct vmbuspipe_hdr) +
	89	sizeof(struct icmsg_hdr)];
c88c4e4c HJ	90
	91	switch (shutdown_msg->flags) {
	92	case 0:
	93	case 1:
	94	icmsghdrp->status = HV_S_OK;
	95	execute_shutdown = true;
	96
af7a5b6e	97	pr_info("Shutdown request received -"
32235b07	98	" graceful shutdown initiated\n");
c88c4e4c HJ	99	break;
	100	default:
	101	icmsghdrp->status = HV_E_FAIL;
	102	execute_shutdown = false;
	103
af7a5b6e HJ	104	pr_info("Shutdown request received -"
af7a5b6e HJ	105	" Invalid request\n");
c88c4e4c	106	break;
95cd17c9	107	}
c88c4e4c HJ	108	}
	109
	110	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	111	\| ICMSGHDRFLAG_RESPONSE;
	112
45241e50	113	vmbus_sendpacket(channel, shut_txf_buf,
c88c4e4c	114	recvlen, requestid,
415f2287	115	VM_PKT_DATA_INBAND, 0);
c88c4e4c HJ	116	}
c88c4e4c HJ	117
c88c4e4c	118	if (execute_shutdown == true)
3dd6cb49	119	schedule_work(&shutdown_work);
c88c4e4c HJ	120	}
c88c4e4c HJ	121
39c4e9c3	122	/*
e9ec3603	123	* Set guest time to host UTC time.
39c4e9c3	124	*/
e9ec3603	125	static inline void do_adj_guesttime(u64 hosttime)
39c4e9c3 HZ	126	{
	127	s64 host_tns;
	128	struct timespec host_ts;
39c4e9c3 HZ	129
	130	host_tns = (hosttime - WLTIMEDELTA) * 100;
	131	host_ts = ns_to_timespec(host_tns);
	132
e9ec3603 HZ	133	do_settimeofday(&host_ts);
	134	}
	135
95ff7cde S	136	/*
	137	* Set the host time in a process context.
	138	*/
	139
	140	struct adj_time_work {
	141	struct work_struct work;
	142	u64 host_time;
	143	};
	144
	145	static void hv_set_host_time(struct work_struct *work)
	146	{
	147	struct adj_time_work *wrk;
	148
	149	wrk = container_of(work, struct adj_time_work, work);
	150	do_adj_guesttime(wrk->host_time);
	151	kfree(wrk);
	152	}
	153
e9ec3603 HZ	154	/*
	155	* Synchronize time with host after reboot, restore, etc.
	156	*
	157	* ICTIMESYNCFLAG_SYNC flag bit indicates reboot, restore events of the VM.
	158	* After reboot the flag ICTIMESYNCFLAG_SYNC is included in the first time
	159	* message after the timesync channel is opened. Since the hv_utils module is
	160	* loaded after hv_vmbus, the first message is usually missed. The other
	161	* thing is, systime is automatically set to emulated hardware clock which may
	162	* not be UTC time or in the same time zone. So, to override these effects, we
	163	* use the first 50 time samples for initial system time setting.
	164	*/
	165	static inline void adj_guesttime(u64 hosttime, u8 flags)
	166	{
95ff7cde	167	struct adj_time_work *wrk;
e9ec3603 HZ	168	static s32 scnt = 50;
e9ec3603 HZ	169
95ff7cde S	170	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
	171	if (wrk == NULL)
	172	return;
	173
	174	wrk->host_time = hosttime;
39c4e9c3	175	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
95ff7cde S	176	INIT_WORK(&wrk->work, hv_set_host_time);
95ff7cde S	177	schedule_work(&wrk->work);
39c4e9c3 HZ	178	return;
	179	}
	180
e9ec3603	181	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
39c4e9c3	182	scnt--;
95ff7cde S	183	INIT_WORK(&wrk->work, hv_set_host_time);
	184	schedule_work(&wrk->work);
	185	} else
	186	kfree(wrk);
39c4e9c3 HZ	187	}
	188
	189	/*
	190	* Time Sync Channel message handler.
	191	*/
	192	static void timesync_onchannelcallback(void *context)
	193	{
	194	struct vmbus_channel *channel = context;
45241e50	195	u32 recvlen;
39c4e9c3 HZ	196	u64 requestid;
	197	struct icmsg_hdr *icmsghdrp;
	198	struct ictimesync_data *timedatap;
a29b643c	199	u8 *time_txf_buf = util_timesynch.recv_buffer;
39c4e9c3	200
45241e50 HJ	201	vmbus_recvpacket(channel, time_txf_buf,
45241e50 HJ	202	PAGE_SIZE, &recvlen, &requestid);
39c4e9c3 HZ	203
39c4e9c3 HZ	204	if (recvlen > 0) {
45241e50	205	icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
39c4e9c3 HZ	206	sizeof(struct vmbuspipe_hdr)];
	207
	208	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
c836d0ab S	209	vmbus_prep_negotiate_resp(icmsghdrp, NULL, time_txf_buf,
c836d0ab S	210	MAX_SRV_VER, MAX_SRV_VER);
39c4e9c3	211	} else {
45241e50	212	timedatap = (struct ictimesync_data *)&time_txf_buf[
39c4e9c3 HZ	213	sizeof(struct vmbuspipe_hdr) +
	214	sizeof(struct icmsg_hdr)];
	215	adj_guesttime(timedatap->parenttime, timedatap->flags);
	216	}
	217
	218	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	219	\| ICMSGHDRFLAG_RESPONSE;
	220
45241e50	221	vmbus_sendpacket(channel, time_txf_buf,
39c4e9c3	222	recvlen, requestid,
415f2287	223	VM_PKT_DATA_INBAND, 0);
39c4e9c3	224	}
39c4e9c3 HZ	225	}
39c4e9c3 HZ	226
9153f7b9 HJ	227	/*
	228	* Heartbeat functionality.
	229	* Every two seconds, Hyper-V send us a heartbeat request message.
	230	* we respond to this message, and Hyper-V knows we are alive.
	231	*/
	232	static void heartbeat_onchannelcallback(void *context)
	233	{
	234	struct vmbus_channel *channel = context;
45241e50	235	u32 recvlen;
9153f7b9 HJ	236	u64 requestid;
	237	struct icmsg_hdr *icmsghdrp;
	238	struct heartbeat_msg_data *heartbeat_msg;
a29b643c	239	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
9153f7b9	240
45241e50 HJ	241	vmbus_recvpacket(channel, hbeat_txf_buf,
45241e50 HJ	242	PAGE_SIZE, &recvlen, &requestid);
9153f7b9 HJ	243
9153f7b9 HJ	244	if (recvlen > 0) {
45241e50	245	icmsghdrp = (struct icmsg_hdr *)&hbeat_txf_buf[
9153f7b9 HJ	246	sizeof(struct vmbuspipe_hdr)];
	247
	248	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
c836d0ab S	249	vmbus_prep_negotiate_resp(icmsghdrp, NULL,
c836d0ab S	250	hbeat_txf_buf, MAX_SRV_VER, MAX_SRV_VER);
9153f7b9	251	} else {
45241e50 HJ	252	heartbeat_msg =
	253	(struct heartbeat_msg_data *)&hbeat_txf_buf[
	254	sizeof(struct vmbuspipe_hdr) +
	255	sizeof(struct icmsg_hdr)];
9153f7b9	256
9153f7b9 HJ	257	heartbeat_msg->seq_num += 1;
	258	}
	259
	260	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
	261	\| ICMSGHDRFLAG_RESPONSE;
	262
45241e50	263	vmbus_sendpacket(channel, hbeat_txf_buf,
9153f7b9	264	recvlen, requestid,
415f2287	265	VM_PKT_DATA_INBAND, 0);
9153f7b9	266	}
9153f7b9	267	}
39c4e9c3	268
84946899 S	269	static int util_probe(struct hv_device *dev,
84946899 S	270	const struct hv_vmbus_device_id *dev_id)
283f2129	271	{
a29b643c S	272	struct hv_util_service *srv =
	273	(struct hv_util_service *)dev_id->driver_data;
	274	int ret;
	275
9b595780	276	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
a29b643c S	277	if (!srv->recv_buffer)
	278	return -ENOMEM;
	279	if (srv->util_init) {
	280	ret = srv->util_init(srv);
	281	if (ret) {
4e65f6e8 S	282	ret = -ENODEV;
4e65f6e8 S	283	goto error1;
a29b643c S	284	}
	285	}
	286
7ae3e035 S	287	/*
	288	* The set of services managed by the util driver are not performance
	289	* critical and do not need batched reading. Furthermore, some services
	290	* such as KVP can only handle one message from the host at a time.
	291	* Turn off batched reading for all util drivers before we open the
	292	* channel.
	293	*/
	294
	295	set_channel_read_state(dev->channel, false);
	296
9b595780	297	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
4e65f6e8 S	298	srv->util_cb, dev->channel);
	299	if (ret)
	300	goto error;
	301
a29b643c	302	hv_set_drvdata(dev, srv);
283f2129	303	return 0;
4e65f6e8 S	304
	305	error:
	306	if (srv->util_deinit)
	307	srv->util_deinit();
	308	error1:
	309	kfree(srv->recv_buffer);
	310	return ret;
283f2129 S	311	}
	312
	313	static int util_remove(struct hv_device *dev)
	314	{
a29b643c S	315	struct hv_util_service *srv = hv_get_drvdata(dev);
a29b643c S	316
4e65f6e8	317	vmbus_close(dev->channel);
a29b643c S	318	if (srv->util_deinit)
	319	srv->util_deinit();
	320	kfree(srv->recv_buffer);
	321
283f2129 S	322	return 0;
	323	}
	324
	325	static const struct hv_vmbus_device_id id_table[] = {
c45cf2d4	326	/* Shutdown guid */
d13984e5 S	327	{ HV_SHUTDOWN_GUID,
	328	.driver_data = (unsigned long)&util_shutdown
	329	},
c45cf2d4	330	/* Time synch guid */
d13984e5 S	331	{ HV_TS_GUID,
	332	.driver_data = (unsigned long)&util_timesynch
	333	},
c45cf2d4	334	/* Heartbeat guid */
d13984e5 S	335	{ HV_HEART_BEAT_GUID,
	336	.driver_data = (unsigned long)&util_heartbeat
	337	},
c45cf2d4	338	/* KVP guid */
d13984e5 S	339	{ HV_KVP_GUID,
	340	.driver_data = (unsigned long)&util_kvp
	341	},
c45cf2d4	342	{ },
283f2129 S	343	};
	344
	345	MODULE_DEVICE_TABLE(vmbus, id_table);
	346
	347	/* The one and only one */
	348	static struct hv_driver util_drv = {
768fa219	349	.name = "hv_util",
283f2129 S	350	.id_table = id_table,
	351	.probe = util_probe,
	352	.remove = util_remove,
	353	};
	354
c88c4e4c HJ	355	static int __init init_hyperv_utils(void)
c88c4e4c HJ	356	{
af7a5b6e	357	pr_info("Registering HyperV Utility Driver\n");
c88c4e4c	358
4e65f6e8	359	return vmbus_driver_register(&util_drv);
c88c4e4c HJ	360	}
	361
	362	static void exit_hyperv_utils(void)
	363	{
af7a5b6e	364	pr_info("De-Registered HyperV Utility Driver\n");
c88c4e4c	365
768fa219	366	vmbus_driver_unregister(&util_drv);
c88c4e4c HJ	367	}
	368
	369	module_init(init_hyperv_utils);
	370	module_exit(exit_hyperv_utils);
	371
	372	MODULE_DESCRIPTION("Hyper-V Utilities");
	373	MODULE_VERSION(HV_DRV_VERSION);
	374	MODULE_LICENSE("GPL");