12 files changed, 760 insertions, 1116 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 5fb4c6d9209b..81a80c82f1bd 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -47,12 +47,8 @@ void vmbus_setevent(struct vmbus_channel *channel)
 	 * For channels marked as in "low latency" mode
 	 * bypass the monitor page mechanism.
 	 */
-	if ((channel->offermsg.monitor_allocated) &&
-	    (!channel->low_latency)) {
-		/* Each u32 represents 32 channels */
-		sync_set_bit(channel->offermsg.child_relid & 31,
-			(unsigned long *) vmbus_connection.send_int_page +
-			(channel->offermsg.child_relid >> 5));
+	if (channel->offermsg.monitor_allocated && !channel->low_latency) {
+		vmbus_send_interrupt(channel->offermsg.child_relid);
 
 		/* Get the child to parent monitor page */
 		monitorpage = vmbus_connection.monitor_pages[1];
@@ -157,6 +153,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	}
 
 	init_completion(&open_info->waitevent);
+	open_info->waiting_channel = newchannel;
 
 	open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 	open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
@@ -181,7 +178,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
 	ret = vmbus_post_msg(open_msg,
-			       sizeof(struct vmbus_channel_open_channel));
+			     sizeof(struct vmbus_channel_open_channel), true);
 
 	if (ret != 0) {
 		err = ret;
@@ -194,6 +191,11 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	list_del(&open_info->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
+	if (newchannel->rescind) {
+		err = -ENODEV;
+		goto error_free_gpadl;
+	}
+
 	if (open_info->response.open_result.status) {
 		err = -EAGAIN;
 		goto error_free_gpadl;
@@ -233,7 +235,7 @@ int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 	conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 	conn_msg.host_service_id = *shv_host_servie_id;
 
-	return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
+	return vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
 }
 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 
@@ -405,6 +407,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 		return ret;
 
 	init_completion(&msginfo->waitevent);
+	msginfo->waiting_channel = channel;
 
 	gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 	gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
@@ -419,7 +422,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
 	ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
-			       sizeof(*msginfo));
+			     sizeof(*msginfo), true);
 	if (ret != 0)
 		goto cleanup;
 
@@ -433,14 +436,19 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 		gpadl_body->gpadl = next_gpadl_handle;
 
 		ret = vmbus_post_msg(gpadl_body,
-				     submsginfo->msgsize -
-				     sizeof(*submsginfo));
+				     submsginfo->msgsize - sizeof(*submsginfo),
+				     true);
 		if (ret != 0)
 			goto cleanup;
 
 	}
 	wait_for_completion(&msginfo->waitevent);
 
+	if (channel->rescind) {
+		ret = -ENODEV;
+		goto cleanup;
+	}
+
 	/* At this point, we received the gpadl created msg */
 	*gpadl_handle = gpadlmsg->gpadl;
 
@@ -474,6 +482,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 		return -ENOMEM;
 
 	init_completion(&info->waitevent);
+	info->waiting_channel = channel;
 
 	msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 
@@ -485,14 +494,19 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 	list_add_tail(&info->msglistentry,
 		      &vmbus_connection.chn_msg_list);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-	ret = vmbus_post_msg(msg,
-			       sizeof(struct vmbus_channel_gpadl_teardown));
+	ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
+			     true);
 
 	if (ret)
 		goto post_msg_err;
 
 	wait_for_completion(&info->waitevent);
 
+	if (channel->rescind) {
+		ret = -ENODEV;
+		goto post_msg_err;
+	}
+
 post_msg_err:
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&info->msglistentry);
@@ -516,7 +530,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	int ret;
 
 	/*
-	 * process_chn_event(), running in the tasklet, can race
+	 * vmbus_on_event(), running in the tasklet, can race
 	 * with vmbus_close_internal() in the case of SMP guest, e.g., when
 	 * the former is accessing channel->inbound.ring_buffer, the latter
 	 * could be freeing the ring_buffer pages.
@@ -557,7 +571,8 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 	msg->child_relid = channel->offermsg.child_relid;
 
-	ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
+	ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel),
+			     true);
 
 	if (ret) {
 		pr_err("Close failed: close post msg return is %d\n", ret);
@@ -628,15 +643,14 @@ void vmbus_close(struct vmbus_channel *channel)
 EXPORT_SYMBOL_GPL(vmbus_close);
 
 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
-			   u32 bufferlen, u64 requestid,
-			   enum vmbus_packet_type type, u32 flags, bool kick_q)
+			 u32 bufferlen, u64 requestid,
+			 enum vmbus_packet_type type, u32 flags)
 {
 	struct vmpacket_descriptor desc;
 	u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 	u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
-	bool lock = channel->acquire_ring_lock;
 	int num_vecs = ((bufferlen != 0) ? 3 : 1);
 
 
@@ -655,9 +669,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, num_vecs,
-				   lock, kick_q);
-
+	return hv_ringbuffer_write(channel, bufferlist, num_vecs);
 }
 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 
@@ -680,7 +692,7 @@ int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 			   enum vmbus_packet_type type, u32 flags)
 {
 	return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
-				    type, flags, true);
+				    type, flags);
 }
 EXPORT_SYMBOL(vmbus_sendpacket);
 
@@ -692,11 +704,9 @@ EXPORT_SYMBOL(vmbus_sendpacket);
  * explicitly.
  */
 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
-				     struct hv_page_buffer pagebuffers[],
-				     u32 pagecount, void *buffer, u32 bufferlen,
-				     u64 requestid,
-				     u32 flags,
-				     bool kick_q)
+				    struct hv_page_buffer pagebuffers[],
+				    u32 pagecount, void *buffer, u32 bufferlen,
+				    u64 requestid, u32 flags)
 {
 	int i;
 	struct vmbus_channel_packet_page_buffer desc;
@@ -705,12 +715,10 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	u32 packetlen_aligned;
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
-	bool lock = channel->acquire_ring_lock;
 
 	if (pagecount > MAX_PAGE_BUFFER_COUNT)
 		return -EINVAL;
 
-
 	/*
 	 * Adjust the size down since vmbus_channel_packet_page_buffer is the
 	 * largest size we support
@@ -742,8 +750,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3,
-				   lock, kick_q);
+	return hv_ringbuffer_write(channel, bufferlist, 3);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 
@@ -757,9 +764,10 @@ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 				     u64 requestid)
 {
 	u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
+
 	return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
-					       buffer, bufferlen, requestid,
-					       flags, true);
+					       buffer, bufferlen,
+					       requestid, flags);
 
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
@@ -778,7 +786,6 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	u32 packetlen_aligned;
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
-	bool lock = channel->acquire_ring_lock;
 
 	packetlen = desc_size + bufferlen;
 	packetlen_aligned = ALIGN(packetlen, sizeof(u64));
@@ -798,8 +805,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3,
-				   lock, true);
+	return hv_ringbuffer_write(channel, bufferlist, 3);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 
@@ -817,7 +823,6 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	u32 packetlen_aligned;
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
-	bool lock = channel->acquire_ring_lock;
 	u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 					 multi_pagebuffer->len);
 
@@ -856,8 +861,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3,
-				   lock, true);
+	return hv_ringbuffer_write(channel, bufferlist, 3);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 26b419203f16..f33465d78a02 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -31,6 +31,7 @@
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/hyperv.h>
+#include <asm/mshyperv.h>
 
 #include "hyperv_vmbus.h"
 
@@ -147,6 +148,29 @@ static const struct {
 	{ HV_RDV_GUID	},
 };
 
+/*
+ * The rescinded channel may be blocked waiting for a response from the host;
+ * take care of that.
+ */
+static void vmbus_rescind_cleanup(struct vmbus_channel *channel)
+{
+	struct vmbus_channel_msginfo *msginfo;
+	unsigned long flags;
+
+
+	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+
+	list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
+				msglistentry) {
+
+		if (msginfo->waiting_channel == channel) {
+			complete(&msginfo->waitevent);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+}
+
 static bool is_unsupported_vmbus_devs(const uuid_le *guid)
 {
 	int i;
@@ -180,33 +204,34 @@ static u16 hv_get_dev_type(const struct vmbus_channel *channel)
  * @buf: Raw buffer channel data
  *
  * @icmsghdrp is of type &struct icmsg_hdr.
- * @negop is of type &struct icmsg_negotiate.
  * Set up and fill in default negotiate response message.
  *
- * The fw_version specifies the  framework version that
- * we can support and srv_version specifies the service
- * version we can support.
+ * The fw_version and fw_vercnt specifies the framework version that
+ * we can support.
+ *
+ * The srv_version and srv_vercnt specifies the service
+ * versions we can support.
+ *
+ * Versions are given in decreasing order.
+ *
+ * nego_fw_version and nego_srv_version store the selected protocol versions.
  *
  * Mainly used by Hyper-V drivers.
  */
 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
-				struct icmsg_negotiate *negop, u8 *buf,
-				int fw_version, int srv_version)
+				u8 *buf, const int *fw_version, int fw_vercnt,
+				const int *srv_version, int srv_vercnt,
+				int *nego_fw_version, int *nego_srv_version)
 {
 	int icframe_major, icframe_minor;
 	int icmsg_major, icmsg_minor;
 	int fw_major, fw_minor;
 	int srv_major, srv_minor;
-	int i;
+	int i, j;
 	bool found_match = false;
+	struct icmsg_negotiate *negop;
 
 	icmsghdrp->icmsgsize = 0x10;
-	fw_major = (fw_version >> 16);
-	fw_minor = (fw_version & 0xFFFF);
-
-	srv_major = (srv_version >> 16);
-	srv_minor = (srv_version & 0xFFFF);
-
 	negop = (struct icmsg_negotiate *)&buf[
 		sizeof(struct vmbuspipe_hdr) +
 		sizeof(struct icmsg_hdr)];
@@ -222,13 +247,22 @@ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
 	 * support.
 	 */
 
-	for (i = 0; i < negop->icframe_vercnt; i++) {
-		if ((negop->icversion_data[i].major == fw_major) &&
-		   (negop->icversion_data[i].minor == fw_minor)) {
-			icframe_major = negop->icversion_data[i].major;
-			icframe_minor = negop->icversion_data[i].minor;
-			found_match = true;
+	for (i = 0; i < fw_vercnt; i++) {
+		fw_major = (fw_version[i] >> 16);
+		fw_minor = (fw_version[i] & 0xFFFF);
+
+		for (j = 0; j < negop->icframe_vercnt; j++) {
+			if ((negop->icversion_data[j].major == fw_major) &&
+			    (negop->icversion_data[j].minor == fw_minor)) {
+				icframe_major = negop->icversion_data[j].major;
+				icframe_minor = negop->icversion_data[j].minor;
+				found_match = true;
+				break;
+			}
 		}
+
+		if (found_match)
+			break;
 	}
 
 	if (!found_match)
@@ -236,14 +270,26 @@ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
 
 	found_match = false;
 
-	for (i = negop->icframe_vercnt;
-		 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
-		if ((negop->icversion_data[i].major == srv_major) &&
-		   (negop->icversion_data[i].minor == srv_minor)) {
-			icmsg_major = negop->icversion_data[i].major;
-			icmsg_minor = negop->icversion_data[i].minor;
-			found_match = true;
+	for (i = 0; i < srv_vercnt; i++) {
+		srv_major = (srv_version[i] >> 16);
+		srv_minor = (srv_version[i] & 0xFFFF);
+
+		for (j = negop->icframe_vercnt;
+			(j < negop->icframe_vercnt + negop->icmsg_vercnt);
+			j++) {
+
+			if ((negop->icversion_data[j].major == srv_major) &&
+				(negop->icversion_data[j].minor == srv_minor)) {
+
+				icmsg_major = negop->icversion_data[j].major;
+				icmsg_minor = negop->icversion_data[j].minor;
+				found_match = true;
+				break;
+			}
 		}
+
+		if (found_match)
+			break;
 	}
 
 	/*
@@ -260,6 +306,12 @@ fw_error:
 		negop->icmsg_vercnt = 1;
 	}
 
+	if (nego_fw_version)
+		*nego_fw_version = (icframe_major << 16) | icframe_minor;
+
+	if (nego_srv_version)
+		*nego_srv_version = (icmsg_major << 16) | icmsg_minor;
+
 	negop->icversion_data[0].major = icframe_major;
 	negop->icversion_data[0].minor = icframe_minor;
 	negop->icversion_data[1].major = icmsg_major;
@@ -280,13 +332,15 @@ static struct vmbus_channel *alloc_channel(void)
 	if (!channel)
 		return NULL;
 
-	channel->acquire_ring_lock = true;
 	spin_lock_init(&channel->inbound_lock);
 	spin_lock_init(&channel->lock);
 
 	INIT_LIST_HEAD(&channel->sc_list);
 	INIT_LIST_HEAD(&channel->percpu_list);
 
+	tasklet_init(&channel->callback_event,
+		     vmbus_on_event, (unsigned long)channel);
+
 	return channel;
 }
 
@@ -295,15 +349,17 @@ static struct vmbus_channel *alloc_channel(void)
  */
 static void free_channel(struct vmbus_channel *channel)
 {
+	tasklet_kill(&channel->callback_event);
 	kfree(channel);
 }
 
 static void percpu_channel_enq(void *arg)
 {
 	struct vmbus_channel *channel = arg;
-	int cpu = smp_processor_id();
+	struct hv_per_cpu_context *hv_cpu
+		= this_cpu_ptr(hv_context.cpu_context);
 
-	list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]);
+	list_add_tail(&channel->percpu_list, &hv_cpu->chan_list);
 }
 
 static void percpu_channel_deq(void *arg)
@@ -321,24 +377,21 @@ static void vmbus_release_relid(u32 relid)
 	memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
 	msg.child_relid = relid;
 	msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
-	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
+	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released),
+		       true);
 }
 
 void hv_event_tasklet_disable(struct vmbus_channel *channel)
 {
-	struct tasklet_struct *tasklet;
-	tasklet = hv_context.event_dpc[channel->target_cpu];
-	tasklet_disable(tasklet);
+	tasklet_disable(&channel->callback_event);
 }
 
 void hv_event_tasklet_enable(struct vmbus_channel *channel)
 {
-	struct tasklet_struct *tasklet;
-	tasklet = hv_context.event_dpc[channel->target_cpu];
-	tasklet_enable(tasklet);
+	tasklet_enable(&channel->callback_event);
 
 	/* In case there is any pending event */
-	tasklet_schedule(tasklet);
+	tasklet_schedule(&channel->callback_event);
 }
 
 void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
@@ -673,9 +726,12 @@ static void vmbus_wait_for_unload(void)
 			break;
 
 		for_each_online_cpu(cpu) {
-			page_addr = hv_context.synic_message_page[cpu];
-			msg = (struct hv_message *)page_addr +
-				VMBUS_MESSAGE_SINT;
+			struct hv_per_cpu_context *hv_cpu
+				= per_cpu_ptr(hv_context.cpu_context, cpu);
+
+			page_addr = hv_cpu->synic_message_page;
+			msg = (struct hv_message *)page_addr
+				+ VMBUS_MESSAGE_SINT;
 
 			message_type = READ_ONCE(msg->header.message_type);
 			if (message_type == HVMSG_NONE)
@@ -699,7 +755,10 @@ static void vmbus_wait_for_unload(void)
 	 * messages after we reconnect.
 	 */
 	for_each_online_cpu(cpu) {
-		page_addr = hv_context.synic_message_page[cpu];
+		struct hv_per_cpu_context *hv_cpu
+			= per_cpu_ptr(hv_context.cpu_context, cpu);
+
+		page_addr = hv_cpu->synic_message_page;
 		msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 		msg->header.message_type = HVMSG_NONE;
 	}
@@ -728,7 +787,8 @@ void vmbus_initiate_unload(bool crash)
 	init_completion(&vmbus_connection.unload_event);
 	memset(&hdr, 0, sizeof(struct vmbus_channel_message_header));
 	hdr.msgtype = CHANNELMSG_UNLOAD;
-	vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header));
+	vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header),
+		       !crash);
 
 	/*
 	 * vmbus_initiate_unload() is also called on crash and the crash can be
@@ -759,13 +819,6 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 	}
 
 	/*
-	 * By default we setup state to enable batched
-	 * reading. A specific service can choose to
-	 * disable this prior to opening the channel.
-	 */
-	newchannel->batched_reading = true;
-
-	/*
 	 * Setup state for signalling the host.
 	 */
 	newchannel->sig_event = (struct hv_input_signal_event *)
@@ -823,6 +876,8 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 	channel->rescind = true;
 	spin_unlock_irqrestore(&channel->lock, flags);
 
+	vmbus_rescind_cleanup(channel);
+
 	if (channel->device_obj) {
 		if (channel->chn_rescind_callback) {
 			channel->chn_rescind_callback(channel);
@@ -1116,8 +1171,8 @@ int vmbus_request_offers(void)
 	msg->msgtype = CHANNELMSG_REQUESTOFFERS;
 
 
-	ret = vmbus_post_msg(msg,
-			       sizeof(struct vmbus_channel_message_header));
+	ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header),
+			     true);
 	if (ret != 0) {
 		pr_err("Unable to request offers - %d\n", ret);
 
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6ce8b874e833..a8366fec1458 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -93,12 +93,10 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	 * all the CPUs. This is needed for kexec to work correctly where
 	 * the CPU attempting to connect may not be CPU 0.
 	 */
-	if (version >= VERSION_WIN8_1) {
-		msg->target_vcpu = hv_context.vp_index[get_cpu()];
-		put_cpu();
-	} else {
+	if (version >= VERSION_WIN8_1)
+		msg->target_vcpu = hv_context.vp_index[smp_processor_id()];
+	else
 		msg->target_vcpu = 0;
-	}
 
 	/*
 	 * Add to list before we send the request since we may
@@ -111,7 +109,8 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
 	ret = vmbus_post_msg(msg,
-			       sizeof(struct vmbus_channel_initiate_contact));
+			     sizeof(struct vmbus_channel_initiate_contact),
+			     true);
 	if (ret != 0) {
 		spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 		list_del(&msginfo->msglistentry);
@@ -220,11 +219,8 @@ int vmbus_connect(void)
 		goto cleanup;
 
 	vmbus_proto_version = version;
-	pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n",
-		    host_info_eax, host_info_ebx >> 16,
-		    host_info_ebx & 0xFFFF, host_info_ecx,
-		    host_info_edx >> 24, host_info_edx & 0xFFFFFF,
-		    version >> 16, version & 0xFFFF);
+	pr_info("Vmbus version:%d.%d\n",
+		version >> 16, version & 0xFFFF);
 
 	kfree(msginfo);
 	return 0;
@@ -264,29 +260,6 @@ void vmbus_disconnect(void)
 }
 
 /*
- * Map the given relid to the corresponding channel based on the
- * per-cpu list of channels that have been affinitized to this CPU.
- * This will be used in the channel callback path as we can do this
- * mapping in a lock-free fashion.
- */
-static struct vmbus_channel *pcpu_relid2channel(u32 relid)
-{
-	struct vmbus_channel *channel;
-	struct vmbus_channel *found_channel  = NULL;
-	int cpu = smp_processor_id();
-	struct list_head *pcpu_head = &hv_context.percpu_list[cpu];
-
-	list_for_each_entry(channel, pcpu_head, percpu_list) {
-		if (channel->offermsg.child_relid == relid) {
-			found_channel = channel;
-			break;
-		}
-	}
-
-	return found_channel;
-}
-
-/*
  * relid2channel - Get the channel object given its
  * child relative id (ie channel id)
  */
@@ -322,23 +295,12 @@ struct vmbus_channel *relid2channel(u32 relid)
 }
 
 /*
- * process_chn_event - Process a channel event notification
+ * vmbus_on_event - Process a channel event notification
  */
-static void process_chn_event(u32 relid)
+void vmbus_on_event(unsigned long data)
 {
-	struct vmbus_channel *channel;
-	void *arg;
-	bool read_state;
-	u32 bytes_to_read;
-
-	/*
-	 * Find the channel based on this relid and invokes the
-	 * channel callback to process the event
-	 */
-	channel = pcpu_relid2channel(relid);
-
-	if (!channel)
-		return;
+	struct vmbus_channel *channel = (void *) data;
+	void (*callback_fn)(void *);
 
 	/*
 	 * A channel once created is persistent even when there
@@ -348,10 +310,13 @@ static void process_chn_event(u32 relid)
 	 * Thus, checking and invoking the driver specific callback takes
 	 * care of orderly unloading of the driver.
 	 */
+	callback_fn = READ_ONCE(channel->onchannel_callback);
+	if (unlikely(callback_fn == NULL))
+		return;
 
-	if (channel->onchannel_callback != NULL) {
-		arg = channel->channel_callback_context;
-		read_state = channel->batched_reading;
+	(*callback_fn)(channel->channel_callback_context);
+
+	if (channel->callback_mode == HV_CALL_BATCHED) {
 		/*
 		 * This callback reads the messages sent by the host.
 		 * We can optimize host to guest signaling by ensuring:
@@ -363,71 +328,10 @@ static void process_chn_event(u32 relid)
 		 *    state is set we check to see if additional packets are
 		 *    available to read. In this case we repeat the process.
 		 */
+		if (hv_end_read(&channel->inbound) != 0) {
+			hv_begin_read(&channel->inbound);
 
-		do {
-			if (read_state)
-				hv_begin_read(&channel->inbound);
-			channel->onchannel_callback(arg);
-			if (read_state)
-				bytes_to_read = hv_end_read(&channel->inbound);
-			else
-				bytes_to_read = 0;
-		} while (read_state && (bytes_to_read != 0));
-	}
-}
-
-/*
- * vmbus_on_event - Handler for events
- */
-void vmbus_on_event(unsigned long data)
-{
-	u32 dword;
-	u32 maxdword;
-	int bit;
-	u32 relid;
-	u32 *recv_int_page = NULL;
-	void *page_addr;
-	int cpu = smp_processor_id();
-	union hv_synic_event_flags *event;
-
-	if (vmbus_proto_version < VERSION_WIN8) {
-		maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
-		recv_int_page = vmbus_connection.recv_int_page;
-	} else {
-		/*
-		 * When the host is win8 and beyond, the event page
-		 * can be directly checked to get the id of the channel
-		 * that has the interrupt pending.
-		 */
-		maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
-		page_addr = hv_context.synic_event_page[cpu];
-		event = (union hv_synic_event_flags *)page_addr +
-						 VMBUS_MESSAGE_SINT;
-		recv_int_page = event->flags32;
-	}
-
-
-
-	/* Check events */
-	if (!recv_int_page)
-		return;
-	for (dword = 0; dword < maxdword; dword++) {
-		if (!recv_int_page[dword])
-			continue;
-		for (bit = 0; bit < 32; bit++) {
-			if (sync_test_and_clear_bit(bit,
-				(unsigned long *)&recv_int_page[dword])) {
-				relid = (dword << 5) + bit;
-
-				if (relid == 0)
-					/*
-					 * Special case - vmbus
-					 * channel protocol msg
-					 */
-					continue;
-
-				process_chn_event(relid);
-			}
+			tasklet_schedule(&channel->callback_event);
 		}
 	}
 }
@@ -435,7 +339,7 @@ void vmbus_on_event(unsigned long data)
 /*
  * vmbus_post_msg - Send a msg on the vmbus's message connection
  */
-int vmbus_post_msg(void *buffer, size_t buflen)
+int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
 {
 	union hv_connection_id conn_id;
 	int ret = 0;
@@ -450,7 +354,7 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 	 * insufficient resources. Retry the operation a couple of
 	 * times before giving up.
 	 */
-	while (retries < 20) {
+	while (retries < 100) {
 		ret = hv_post_message(conn_id, 1, buffer, buflen);
 
 		switch (ret) {
@@ -473,8 +377,14 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 		}
 
 		retries++;
-		udelay(usec);
-		if (usec < 2048)
+		if (can_sleep && usec > 1000)
+			msleep(usec / 1000);
+		else if (usec < MAX_UDELAY_MS * 1000)
+			udelay(usec);
+		else
+			mdelay(usec / 1000);
+
+		if (usec < 256000)
 			usec *= 2;
 	}
 	return ret;
@@ -487,12 +397,8 @@ void vmbus_set_event(struct vmbus_channel *channel)
 {
 	u32 child_relid = channel->offermsg.child_relid;
 
-	if (!channel->is_dedicated_interrupt) {
-		/* Each u32 represents 32 channels */
-		sync_set_bit(child_relid & 31,
-			(unsigned long *)vmbus_connection.send_int_page +
-			(child_relid >> 5));
-	}
+	if (!channel->is_dedicated_interrupt)
+		vmbus_send_interrupt(child_relid);
 
 	hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
 }
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index b44b32f21e61..665a64f1611e 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -36,7 +36,6 @@
 /* The one and only */
 struct hv_context hv_context = {
 	.synic_initialized	= false,
-	.hypercall_page		= NULL,
 };
 
 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
@@ -44,276 +43,20 @@ struct hv_context hv_context = {
 #define HV_MIN_DELTA_TICKS 1
 
 /*
- * query_hypervisor_info - Get version info of the windows hypervisor
- */
-unsigned int host_info_eax;
-unsigned int host_info_ebx;
-unsigned int host_info_ecx;
-unsigned int host_info_edx;
-
-static int query_hypervisor_info(void)
-{
-	unsigned int eax;
-	unsigned int ebx;
-	unsigned int ecx;
-	unsigned int edx;
-	unsigned int max_leaf;
-	unsigned int op;
-
-	/*
-	* Its assumed that this is called after confirming that Viridian
-	* is present. Query id and revision.
-	*/
-	eax = 0;
-	ebx = 0;
-	ecx = 0;
-	edx = 0;
-	op = HVCPUID_VENDOR_MAXFUNCTION;
-	cpuid(op, &eax, &ebx, &ecx, &edx);
-
-	max_leaf = eax;
-
-	if (max_leaf >= HVCPUID_VERSION) {
-		eax = 0;
-		ebx = 0;
-		ecx = 0;
-		edx = 0;
-		op = HVCPUID_VERSION;
-		cpuid(op, &eax, &ebx, &ecx, &edx);
-		host_info_eax = eax;
-		host_info_ebx = ebx;
-		host_info_ecx = ecx;
-		host_info_edx = edx;
-	}
-	return max_leaf;
-}
-
-/*
- * hv_do_hypercall- Invoke the specified hypercall
- */
-u64 hv_do_hypercall(u64 control, void *input, void *output)
-{
-	u64 input_address = (input) ? virt_to_phys(input) : 0;
-	u64 output_address = (output) ? virt_to_phys(output) : 0;
-	void *hypercall_page = hv_context.hypercall_page;
-#ifdef CONFIG_X86_64
-	u64 hv_status = 0;
-
-	if (!hypercall_page)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
-	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
-			     "c" (control), "d" (input_address),
-			     "m" (hypercall_page));
-
-	return hv_status;
-
-#else
-
-	u32 control_hi = control >> 32;
-	u32 control_lo = control & 0xFFFFFFFF;
-	u32 hv_status_hi = 1;
-	u32 hv_status_lo = 1;
-	u32 input_address_hi = input_address >> 32;
-	u32 input_address_lo = input_address & 0xFFFFFFFF;
-	u32 output_address_hi = output_address >> 32;
-	u32 output_address_lo = output_address & 0xFFFFFFFF;
-
-	if (!hypercall_page)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
-			      "=a"(hv_status_lo) : "d" (control_hi),
-			      "a" (control_lo), "b" (input_address_hi),
-			      "c" (input_address_lo), "D"(output_address_hi),
-			      "S"(output_address_lo), "m" (hypercall_page));
-
-	return hv_status_lo | ((u64)hv_status_hi << 32);
-#endif /* !x86_64 */
-}
-EXPORT_SYMBOL_GPL(hv_do_hypercall);
-
-#ifdef CONFIG_X86_64
-static u64 read_hv_clock_tsc(struct clocksource *arg)
-{
-	u64 current_tick;
-	struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
-
-	if (tsc_pg->tsc_sequence != 0) {
-		/*
-		 * Use the tsc page to compute the value.
-		 */
-
-		while (1) {
-			u64 tmp;
-			u32 sequence = tsc_pg->tsc_sequence;
-			u64 cur_tsc;
-			u64 scale = tsc_pg->tsc_scale;
-			s64 offset = tsc_pg->tsc_offset;
-
-			rdtscll(cur_tsc);
-			/* current_tick = ((cur_tsc *scale) >> 64) + offset */
-			asm("mulq %3"
-				: "=d" (current_tick), "=a" (tmp)
-				: "a" (cur_tsc), "r" (scale));
-
-			current_tick += offset;
-			if (tsc_pg->tsc_sequence == sequence)
-				return current_tick;
-
-			if (tsc_pg->tsc_sequence != 0)
-				continue;
-			/*
-			 * Fallback using MSR method.
-			 */
-			break;
-		}
-	}
-	rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
-	return current_tick;
-}
-
-static struct clocksource hyperv_cs_tsc = {
-		.name           = "hyperv_clocksource_tsc_page",
-		.rating         = 425,
-		.read           = read_hv_clock_tsc,
-		.mask           = CLOCKSOURCE_MASK(64),
-		.flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-#endif
-
-
-/*
  * hv_init - Main initialization routine.
  *
  * This routine must be called before any other routines in here are called
  */
 int hv_init(void)
 {
-	int max_leaf;
-	union hv_x64_msr_hypercall_contents hypercall_msr;
-	void *virtaddr = NULL;
-
-	memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
-	memset(hv_context.synic_message_page, 0,
-	       sizeof(void *) * NR_CPUS);
-	memset(hv_context.post_msg_page, 0,
-	       sizeof(void *) * NR_CPUS);
-	memset(hv_context.vp_index, 0,
-	       sizeof(int) * NR_CPUS);
-	memset(hv_context.event_dpc, 0,
-	       sizeof(void *) * NR_CPUS);
-	memset(hv_context.msg_dpc, 0,
-	       sizeof(void *) * NR_CPUS);
-	memset(hv_context.clk_evt, 0,
-	       sizeof(void *) * NR_CPUS);
-
-	max_leaf = query_hypervisor_info();
+	if (!hv_is_hypercall_page_setup())
+		return -ENOTSUPP;
 
-	/*
-	 * Write our OS ID.
-	 */
-	hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
-	wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
-
-	/* See if the hypercall page is already set */
-	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
-
-	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
-
-	if (!virtaddr)
-		goto cleanup;
-
-	hypercall_msr.enable = 1;
-
-	hypercall_msr.guest_physical_ad