1 files changed, 558 insertions, 127 deletions

diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 2f561c5dfe24..7e9c8e169c66 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * 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>
@@ -27,15 +15,122 @@
 #include <linux/sysctl.h>
 #include <linux/reboot.h>
 #include <linux/hyperv.h>
+#include <linux/clockchips.h>
+#include <linux/ptp_clock_kernel.h>
+#include <asm/mshyperv.h>
+
+#include "hyperv_vmbus.h"
+
+#define SD_MAJOR	3
+#define SD_MINOR	0
+#define SD_MINOR_1	1
+#define SD_MINOR_2	2
+#define SD_VERSION_3_1	(SD_MAJOR << 16 | SD_MINOR_1)
+#define SD_VERSION_3_2	(SD_MAJOR << 16 | SD_MINOR_2)
+#define SD_VERSION	(SD_MAJOR << 16 | SD_MINOR)
+
+#define SD_MAJOR_1	1
+#define SD_VERSION_1	(SD_MAJOR_1 << 16 | SD_MINOR)
+
+#define TS_MAJOR	4
+#define TS_MINOR	0
+#define TS_VERSION	(TS_MAJOR << 16 | TS_MINOR)
+
+#define TS_MAJOR_1	1
+#define TS_VERSION_1	(TS_MAJOR_1 << 16 | TS_MINOR)
+
+#define TS_MAJOR_3	3
+#define TS_VERSION_3	(TS_MAJOR_3 << 16 | TS_MINOR)
+
+#define HB_MAJOR	3
+#define HB_MINOR	0
+#define HB_VERSION	(HB_MAJOR << 16 | HB_MINOR)
+
+#define HB_MAJOR_1	1
+#define HB_VERSION_1	(HB_MAJOR_1 << 16 | HB_MINOR)
+
+static int sd_srv_version;
+static int ts_srv_version;
+static int hb_srv_version;
+
+#define SD_VER_COUNT 4
+static const int sd_versions[] = {
+	SD_VERSION_3_2,
+	SD_VERSION_3_1,
+	SD_VERSION,
+	SD_VERSION_1
+};
+
+#define TS_VER_COUNT 3
+static const int ts_versions[] = {
+	TS_VERSION,
+	TS_VERSION_3,
+	TS_VERSION_1
+};
+
+#define HB_VER_COUNT 2
+static const int hb_versions[] = {
+	HB_VERSION,
+	HB_VERSION_1
+};
+
+#define FW_VER_COUNT 2
+static const int fw_versions[] = {
+	UTIL_FW_VERSION,
+	UTIL_WS2K8_FW_VERSION
+};
+
+/*
+ * Send the "hibernate" udev event in a thread context.
+ */
+struct hibernate_work_context {
+	struct work_struct work;
+	struct hv_device *dev;
+};
+
+static struct hibernate_work_context hibernate_context;
+static bool hibernation_supported;
+
+static void send_hibernate_uevent(struct work_struct *work)
+{
+	char *uevent_env[2] = { "EVENT=hibernate", NULL };
+	struct hibernate_work_context *ctx;
+
+	ctx = container_of(work, struct hibernate_work_context, work);
+
+	kobject_uevent_env(&ctx->dev->device.kobj, KOBJ_CHANGE, uevent_env);
+
+	pr_info("Sent hibernation uevent\n");
+}
+
+static int hv_shutdown_init(struct hv_util_service *srv)
+{
+	struct vmbus_channel *channel = srv->channel;
+
+	INIT_WORK(&hibernate_context.work, send_hibernate_uevent);
+	hibernate_context.dev = channel->device_obj;
+
+	hibernation_supported = hv_is_hibernation_supported();
+
+	return 0;
+}
 
 static void shutdown_onchannelcallback(void *context);
 static struct hv_util_service util_shutdown = {
 	.util_cb = shutdown_onchannelcallback,
+	.util_init = hv_shutdown_init,
 };
 
+static int hv_timesync_init(struct hv_util_service *srv);
+static int hv_timesync_pre_suspend(void);
+static void hv_timesync_deinit(void);
+
 static void timesync_onchannelcallback(void *context);
 static struct hv_util_service util_timesynch = {
 	.util_cb = timesync_onchannelcallback,
+	.util_init = hv_timesync_init,
+	.util_pre_suspend = hv_timesync_pre_suspend,
+	.util_deinit = hv_timesync_deinit,
 };
 
 static void heartbeat_onchannelcallback(void *context);
@@ -46,12 +141,18 @@ static struct hv_util_service util_heartbeat = {
 static struct hv_util_service util_kvp = {
 	.util_cb = hv_kvp_onchannelcallback,
 	.util_init = hv_kvp_init,
+	.util_init_transport = hv_kvp_init_transport,
+	.util_pre_suspend = hv_kvp_pre_suspend,
+	.util_pre_resume = hv_kvp_pre_resume,
 	.util_deinit = hv_kvp_deinit,
 };
 
 static struct hv_util_service util_vss = {
 	.util_cb = hv_vss_onchannelcallback,
 	.util_init = hv_vss_init,
+	.util_init_transport = hv_vss_init_transport,
+	.util_pre_suspend = hv_vss_pre_suspend,
+	.util_pre_resume = hv_vss_pre_resume,
 	.util_deinit = hv_vss_deinit,
 };
 
@@ -60,101 +161,209 @@ static void perform_shutdown(struct work_struct *dummy)
 	orderly_poweroff(true);
 }
 
+static void perform_restart(struct work_struct *dummy)
+{
+	orderly_reboot();
+}
+
 /*
  * Perform the shutdown operation in a thread context.
  */
 static DECLARE_WORK(shutdown_work, perform_shutdown);
 
+/*
+ * Perform the restart operation in a thread context.
+ */
+static DECLARE_WORK(restart_work, perform_restart);
+
 static void shutdown_onchannelcallback(void *context)
 {
 	struct vmbus_channel *channel = context;
+	struct work_struct *work = NULL;
 	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 (vmbus_recvpacket(channel, shut_txf_buf, HV_HYP_PAGE_SIZE, &recvlen, &requestid)) {
+		pr_err_ratelimited("Shutdown request received. Could not read into shut txf buf\n");
+		return;
+	}
 
-	if (recvlen > 0) {
-		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
-			sizeof(struct vmbuspipe_hdr)];
+	if (!recvlen)
+		return;
 
-		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;
+	/* Ensure recvlen is big enough to read header data */
+	if (recvlen < ICMSG_HDR) {
+		pr_err_ratelimited("Shutdown request received. Packet length too small: %d\n",
+				   recvlen);
+		return;
+	}
 
-				pr_info("Shutdown request received -"
-					    " Invalid request\n");
-				break;
-			}
+	icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[sizeof(struct vmbuspipe_hdr)];
+
+	if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+		if (vmbus_prep_negotiate_resp(icmsghdrp,
+				shut_txf_buf, recvlen,
+				fw_versions, FW_VER_COUNT,
+				sd_versions, SD_VER_COUNT,
+				NULL, &sd_srv_version)) {
+			pr_info("Shutdown IC version %d.%d\n",
+				sd_srv_version >> 16,
+				sd_srv_version & 0xFFFF);
+		}
+	} else if (icmsghdrp->icmsgtype == ICMSGTYPE_SHUTDOWN) {
+		/* Ensure recvlen is big enough to contain shutdown_msg_data struct */
+		if (recvlen < ICMSG_HDR + sizeof(struct shutdown_msg_data)) {
+			pr_err_ratelimited("Invalid shutdown msg data. Packet length too small: %u\n",
+					   recvlen);
+			return;
 		}
 
-		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
-			| ICMSGHDRFLAG_RESPONSE;
-
-		vmbus_sendpacket(channel, shut_txf_buf,
-				       recvlen, requestid,
-				       VM_PKT_DATA_INBAND, 0);
+		shutdown_msg = (struct shutdown_msg_data *)&shut_txf_buf[ICMSG_HDR];
+
+		/*
+		 * shutdown_msg->flags can be 0(shut down), 2(reboot),
+		 * or 4(hibernate). It may bitwise-OR 1, which means
+		 * performing the request by force. Linux always tries
+		 * to perform the request by force.
+		 */
+		switch (shutdown_msg->flags) {
+		case 0:
+		case 1:
+			icmsghdrp->status = HV_S_OK;
+			work = &shutdown_work;
+			pr_info("Shutdown request received - graceful shutdown initiated\n");
+			break;
+		case 2:
+		case 3:
+			icmsghdrp->status = HV_S_OK;
+			work = &restart_work;
+			pr_info("Restart request received - graceful restart initiated\n");
+			break;
+		case 4:
+		case 5:
+			pr_info("Hibernation request received\n");
+			icmsghdrp->status = hibernation_supported ?
+				HV_S_OK : HV_E_FAIL;
+			if (hibernation_supported)
+				work = &hibernate_context.work;
+			break;
+		default:
+			icmsghdrp->status = HV_E_FAIL;
+			pr_info("Shutdown request received - Invalid request\n");
+			break;
+		}
+	} else {
+		icmsghdrp->status = HV_E_FAIL;
+		pr_err_ratelimited("Shutdown request received. Invalid msg type: %d\n",
+				   icmsghdrp->icmsgtype);
 	}
 
-	if (execute_shutdown == true)
-		schedule_work(&shutdown_work);
+	icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
+		| ICMSGHDRFLAG_RESPONSE;
+
+	vmbus_sendpacket(channel, shut_txf_buf,
+			 recvlen, requestid,
+			 VM_PKT_DATA_INBAND, 0);
+
+	if (work)
+		schedule_work(work);
 }
 
 /*
- * Set guest time to host UTC time.
+ * Set the host time in a process context.
  */
-static inline void do_adj_guesttime(u64 hosttime)
-{
-	s64 host_tns;
-	struct timespec host_ts;
+static struct work_struct adj_time_work;
+
+/*
+ * The last time sample, received from the host. PTP device responds to
+ * requests by using this data and the current partition-wide time reference
+ * count.
+ */
+static struct {
+	u64				host_time;
+	u64				ref_time;
+	spinlock_t			lock;
+} host_ts;
 
-	host_tns = (hosttime - WLTIMEDELTA) * 100;
-	host_ts = ns_to_timespec(host_tns);
+static bool timesync_implicit;
 
-	do_settimeofday(&host_ts);
+module_param(timesync_implicit, bool, 0644);
+MODULE_PARM_DESC(timesync_implicit, "If set treat SAMPLE as SYNC when clock is behind");
+
+static inline u64 reftime_to_ns(u64 reftime)
+{
+	return (reftime - WLTIMEDELTA) * 100;
 }
 
 /*
- * Set the host time in a process context.
+ * Hard coded threshold for host timesync delay: 600 seconds
  */
+static const u64 HOST_TIMESYNC_DELAY_THRESH = 600 * (u64)NSEC_PER_SEC;
 
-struct adj_time_work {
-	struct work_struct work;
-	u64	host_time;
-};
+static int hv_get_adj_host_time(struct timespec64 *ts)
+{
+	u64 newtime, reftime, timediff_adj;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&host_ts.lock, flags);
+	reftime = hv_read_reference_counter();
+
+	/*
+	 * We need to let the caller know that last update from host
+	 * is older than the max allowable threshold. clock_gettime()
+	 * and PTP ioctl do not have a documented error that we could
+	 * return for this specific case. Use ESTALE to report this.
+	 */
+	timediff_adj = reftime - host_ts.ref_time;
+	if (timediff_adj * 100 > HOST_TIMESYNC_DELAY_THRESH) {
+		pr_warn_once("TIMESYNC IC: Stale time stamp, %llu nsecs old\n",
+			     (timediff_adj * 100));
+		ret = -ESTALE;
+	}
+
+	newtime = host_ts.host_time + timediff_adj;
+	*ts = ns_to_timespec64(reftime_to_ns(newtime));
+	spin_unlock_irqrestore(&host_ts.lock, flags);
+
+	return ret;
+}
 
 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);
+	struct timespec64 ts;
+
+	if (!hv_get_adj_host_time(&ts))
+		do_settimeofday64(&ts);
+}
+
+/*
+ * Due to a bug on Hyper-V hosts, the sync flag may not always be sent on resume.
+ * Force a sync if the guest is behind.
+ */
+static inline bool hv_implicit_sync(u64 host_time)
+{
+	struct timespec64 new_ts;
+	struct timespec64 threshold_ts;
+
+	new_ts = ns_to_timespec64(reftime_to_ns(host_time));
+	ktime_get_real_ts64(&threshold_ts);
+
+	threshold_ts.tv_sec += 5;
+
+	/*
+	 * If guest behind the host by 5 or more seconds.
+	 */
+	if (timespec64_compare(&new_ts, &threshold_ts) >= 0)
+		return true;
+
+	return false;
 }
 
 /*
@@ -163,33 +372,43 @@ static void hv_set_host_time(struct work_struct *work)
  * 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.
+ * loaded after hv_vmbus, the first message is usually missed. This bit is
+ * considered a hard request to discipline the clock.
+ *
+ * ICTIMESYNCFLAG_SAMPLE bit indicates a time sample from host. This is
+ * typically used as a hint to the guest. The guest is under no obligation
+ * to discipline the clock.
  */
-static inline void adj_guesttime(u64 hosttime, u8 flags)
+static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 adj_flags)
 {
-	struct adj_time_work    *wrk;
-	static s32 scnt = 50;
+	unsigned long flags;
+	u64 cur_reftime;
 
-	wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
-	if (wrk == NULL)
-		return;
+	/*
+	 * Save the adjusted time sample from the host and the snapshot
+	 * of the current system time.
+	 */
+	spin_lock_irqsave(&host_ts.lock, flags);
 
-	wrk->host_time = hosttime;
-	if ((flags & ICTIMESYNCFLAG_SYNC) != 0) {
-		INIT_WORK(&wrk->work, hv_set_host_time);
-		schedule_work(&wrk->work);
-		return;
-	}
+	cur_reftime = hv_read_reference_counter();
+	host_ts.host_time = hosttime;
+	host_ts.ref_time = cur_reftime;
 
-	if ((flags & ICTIMESYNCFLAG_SAMPLE) != 0 && scnt > 0) {
-		scnt--;
-		INIT_WORK(&wrk->work, hv_set_host_time);
-		schedule_work(&wrk->work);
-	} else
-		kfree(wrk);
+	/*
+	 * TimeSync v4 messages contain reference time (guest's Hyper-V
+	 * clocksource read when the time sample was generated), we can
+	 * improve the precision by adding the delta between now and the
+	 * time of generation. For older protocols we set
+	 * reftime == cur_reftime on call.
+	 */
+	host_ts.host_time += (cur_reftime - reftime);
+
+	spin_unlock_irqrestore(&host_ts.lock, flags);
+
+	/* Schedule work to do do_settimeofday64() */
+	if ((adj_flags & ICTIMESYNCFLAG_SYNC) ||
+	    (timesync_implicit && hv_implicit_sync(host_ts.host_time)))
+		schedule_work(&adj_time_work);
 }
 
 /*
@@ -202,31 +421,84 @@ static void timesync_onchannelcallback(void *context)
 	u64 requestid;
 	struct icmsg_hdr *icmsghdrp;
 	struct ictimesync_data *timedatap;
+	struct ictimesync_ref_data *refdata;
 	u8 *time_txf_buf = util_timesynch.recv_buffer;
 
-	vmbus_recvpacket(channel, time_txf_buf,
-			 PAGE_SIZE, &recvlen, &requestid);
+	/*
+	 * Drain the ring buffer and use the last packet to update
+	 * host_ts
+	 */
+	while (1) {
+		int ret = vmbus_recvpacket(channel, time_txf_buf,
+					   HV_HYP_PAGE_SIZE, &recvlen,
+					   &requestid);
+		if (ret) {
+			pr_err_ratelimited("TimeSync IC pkt recv failed (Err: %d)\n",
+					   ret);
+			break;
+		}
+
+		if (!recvlen)
+			break;
+
+		/* Ensure recvlen is big enough to read header data */
+		if (recvlen < ICMSG_HDR) {
+			pr_err_ratelimited("Timesync request received. Packet length too small: %d\n",
+					   recvlen);
+			break;
+		}
 
-	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);
+			if (vmbus_prep_negotiate_resp(icmsghdrp,
+						time_txf_buf, recvlen,
+						fw_versions, FW_VER_COUNT,
+						ts_versions, TS_VER_COUNT,
+						NULL, &ts_srv_version)) {
+				pr_info("TimeSync IC version %d.%d\n",
+					ts_srv_version >> 16,
+					ts_srv_version & 0xFFFF);
+			}
+		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_TIMESYNC) {
+			if (ts_srv_version > TS_VERSION_3) {
+				/* Ensure recvlen is big enough to read ictimesync_ref_data */
+				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_ref_data)) {
+					pr_err_ratelimited("Invalid ictimesync ref data. Length too small: %u\n",
+							   recvlen);
+					break;
+				}
+				refdata = (struct ictimesync_ref_data *)&time_txf_buf[ICMSG_HDR];
+
+				adj_guesttime(refdata->parenttime,
+						refdata->vmreferencetime,
+						refdata->flags);
+			} else {
+				/* Ensure recvlen is big enough to read ictimesync_data */
+				if (recvlen < ICMSG_HDR + sizeof(struct ictimesync_data)) {
+					pr_err_ratelimited("Invalid ictimesync data. Length too small: %u\n",
+							   recvlen);
+					break;
+				}
+				timedatap = (struct ictimesync_data *)&time_txf_buf[ICMSG_HDR];
+
+				adj_guesttime(timedatap->parenttime,
+					      hv_read_reference_counter(),
+					      timedatap->flags);
+			}
 		} else {
-			timedatap = (struct ictimesync_data *)&time_txf_buf[
-				sizeof(struct vmbuspipe_hdr) +
-				sizeof(struct icmsg_hdr)];
-			adj_guesttime(timedatap->parenttime, timedatap->flags);
+			icmsghdrp->status = HV_E_FAIL;
+			pr_err_ratelimited("Timesync request received. Invalid msg type: %d\n",
+					   icmsghdrp->icmsgtype);
 		}
 
 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 			| ICMSGHDRFLAG_RESPONSE;
 
 		vmbus_sendpacket(channel, time_txf_buf,
-				recvlen, requestid,
-				VM_PKT_DATA_INBAND, 0);
+				 recvlen, requestid,
+				 VM_PKT_DATA_INBAND, 0);
 	}
 }
 
@@ -244,34 +516,69 @@ static void heartbeat_onchannelcallback(void *context)
 	struct heartbeat_msg_data *heartbeat_msg;
 	u8 *hbeat_txf_buf = util_heartbeat.recv_buffer;
 
-	vmbus_recvpacket(channel, hbeat_txf_buf,
-			 PAGE_SIZE, &recvlen, &requestid);
+	while (1) {
+
+		if (vmbus_recvpacket(channel, hbeat_txf_buf, HV_HYP_PAGE_SIZE,
+				     &recvlen, &requestid)) {
+			pr_err_ratelimited("Heartbeat request received. Could not read into hbeat txf buf\n");
+			return;
+		}
+
+		if (!recvlen)
+			break;
+
+		/* Ensure recvlen is big enough to read header data */
+		if (recvlen < ICMSG_HDR) {
+			pr_err_ratelimited("Heartbeat request received. Packet length too small: %d\n",
+					   recvlen);
+			break;
+		}
 
-	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)];
+			if (vmbus_prep_negotiate_resp(icmsghdrp,
+					hbeat_txf_buf, recvlen,
+					fw_versions, FW_VER_COUNT,
+					hb_versions, HB_VER_COUNT,
+					NULL, &hb_srv_version)) {
+
+				pr_info("Heartbeat IC version %d.%d\n",
+					hb_srv_version >> 16,
+					hb_srv_version & 0xFFFF);
+			}
+		} else if (icmsghdrp->icmsgtype == ICMSGTYPE_HEARTBEAT) {
+			/*
+			 * Ensure recvlen is big enough to read seq_num. Reserved area is not
+			 * included in the check as the host may not fill it up entirely
+			 */
+			if (recvlen < ICMSG_HDR + sizeof(u64)) {
+				pr_err_ratelimited("Invalid heartbeat msg data. Length too small: %u\n",
+						   recvlen);
+				break;
+			}
+			heartbeat_msg = (struct heartbeat_msg_data *)&hbeat_txf_buf[ICMSG_HDR];
 
 			heartbeat_msg->seq_num += 1;
+		} else {
+			icmsghdrp->status = HV_E_FAIL;
+			pr_err_ratelimited("Heartbeat request received. Invalid msg type: %d\n",
+					   icmsghdrp->icmsgtype);
 		}
 
 		icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
 			| ICMSGHDRFLAG_RESPONSE;
 
 		vmbus_sendpacket(channel, hbeat_txf_buf,
-				       recvlen, requestid,
-				       VM_PKT_DATA_INBAND, 0);
+				 recvlen, requestid,
+				 VM_PKT_DATA_INBAND, 0);
 	}
 }
 
+#define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
+#define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
+
 static int util_probe(struct hv_device *dev,
 			const struct hv_vmbus_device_id *dev_id)
 {
@@ -279,15 +586,14 @@ static int util_probe(struct hv_device *dev,
 		(struct hv_util_service *)dev_id->driver_data;
 	int ret;
 
-	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
+	srv->recv_buffer = kmalloc_array(4, HV_HYP_PAGE_SIZE, GFP_KERNEL);
 	if (!srv->recv_buffer)
 		return -ENOMEM;
+	srv->channel = dev->channel;
 	if (srv->util_init) {
 		ret = srv->util_init(srv);
-		if (ret) {
-			ret = -ENODEV;
+		if (ret)
 			goto error1;
-		}
 	}
 
 	/*
@@ -297,15 +603,23 @@ static int util_probe(struct hv_device *dev,
 	 * Turn off batched reading for all util drivers before we open the
 	 * channel.
 	 */
+	set_channel_read_mode(dev->channel, HV_CALL_DIRECT);
 
-	set_channel_read_state(dev->channel, false);
+	hv_set_drvdata(dev, srv);
 
-	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
-			srv->util_cb, dev->channel);
+	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
+			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
+			 dev->channel);
 	if (ret)
 		goto error;
 
-	hv_set_drvdata(dev, srv);
+	if (srv->util_init_transport) {
+		ret = srv->util_init_transport();
+		if (ret) {
+			vmbus_close(dev->channel);
+			goto error;
+		}
+	}
 	return 0;
 
 error:
@@ -316,18 +630,54 @@ error1:
 	return ret;
 }
 
-static int util_remove(struct hv_device *dev)
+static void 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();
+	vmbus_close(dev->channel);
 	kfree(srv->recv_buffer);
+}
+
+/*
+ * When we're in util_suspend(), all the userspace processes have been frozen
+ * (refer to hibernate() -> freeze_processes()). The userspace is thawed only
+ * after the whole resume procedure, including util_resume(), finishes.
+ */
+static int util_suspend(struct hv_device *dev)
+{
+	struct hv_util_service *srv = hv_get_drvdata(dev);
+	int ret = 0;
+
+	if (srv->util_pre_suspend) {
+		ret = srv->util_pre_suspend();
+		if (ret)
+			return ret;
+	}
+
+	vmbus_close(dev->channel);
 
 	return 0;
 }
 
+static int util_resume(struct hv_device *dev)
+{
+	struct hv_util_service *srv = hv_get_drvdata(dev);
+	int ret = 0;
+
+	if (srv->util_pre_resume) {
+		ret = srv->util_pre_resume();
+		if (ret)
+			return ret;
+	}
+
+	ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
+			 HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
+			 dev->channel);
+	return ret;
+}
+
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Shutdown guid */
 	{ HV_SHUTDOWN_GUID,
@@ -356,12 +706,94 @@ MODULE_DEVICE_TABLE(vmbus, id_table);
 
 /* The one and only one */
 static  struct hv_driver util_drv = {
-	.name = "hv_util",
+	.name = "hv_utils",
 	.id_table = id_table,
 	.probe =  util_probe,
 	.remove =  util_remove,
+	.suspend = util_suspend,
+	.resume =  util_resume,
+	.driver = {
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+static int hv_ptp_enable(struct ptp_clock_info *info,
+			 struct ptp_clock_request *request, int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static int hv_ptp_settime(struct ptp_clock_info *p, const struct timespec64 *ts)
+{
+	return -EOPNOTSUPP;
+}
+
+static int hv_ptp_adjfine(struct ptp_clock_info *ptp, long delta)
+{
+	return -EOPNOTSUPP;
+}
+static int hv_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	return -EOPNOTSUPP;
+}
+
+static int hv_ptp_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
+{
+	return hv_get_adj_host_time(ts);
+}
+
+static struct ptp_clock_info ptp_hyperv_info = {
+	.name		= "hyperv",
+	.enable         = hv_ptp_enable,
+	.adjtime        = hv_ptp_adjtime,
+	.adjfine        = hv_ptp_adjfine,
+	.gettime64      = hv_ptp_gettime,
+	.settime64      = hv_ptp_settime,
+	.owner		= THIS_MODULE,
 };
 
+static struct ptp_clock *hv_ptp_clock;
+
+static int hv_timesync_init(struct hv_util_service *srv)
+{
+	spin_lock_init(&host_ts.lock);
+
+	INIT_WORK(&adj_time_work, hv_set_host_time);
+
+	/*
+	 * ptp_clock_register() returns NULL when CONFIG_PTP_1588_CLOCK is
+	 * disabled but the driver is still useful without the PTP device
+	 * as it still handles the ICTIMESYNCFLAG_SYNC case.
+	 */
+	hv_ptp_clock = ptp_clock_register(&ptp_hyperv_info, NULL);
+	if (IS_ERR_OR_NULL(hv_ptp_clock)) {
+		pr_err("cannot register PTP clock: %d\n",
+		       PTR_ERR_OR_ZERO(hv_ptp_clock));
+		hv_ptp_clock = NULL;
+	}
+
+	return 0;
+}
+
+static void hv_timesync_cancel_work(void)
+{
+	cancel_work_sync(&adj_time_work);
+}
+
+static int hv_timesync_pre_suspend(void)
+{
+	hv_timesync_cancel_work();
+	return 0;
+}
+
+static void hv_timesync_deinit(void)
+{
+	if (hv_ptp_clock)
+		ptp_clock_unregister(hv_ptp_clock);
+
+	hv_timesync_cancel_work();
+}
+
 static int __init init_hyperv_utils(void)
 {
 	pr_info("Registering HyperV Utility Driver\n");
@@ -380,5 +812,4 @@ module_init(init_hyperv_utils);
 module_exit(exit_hyperv_utils);
 
 MODULE_DESCRIPTION("Hyper-V Utilities");
-MODULE_VERSION(HV_DRV_VERSION);
 MODULE_LICENSE("GPL");