[PATCH 00/10] Drivers: hv: vmbus: Miscellaneous fixes

[PATCH 00/10] Drivers: hv: vmbus: Miscellaneous fixes

[kys]

From: K. Y. Srinivasan <kys@microsoft.com>

Miscellaneous fixes.

Stephen Hemminger (10):
  vmbus: only reschedule tasklet if time limit exceeded
  vmbus: use rcu for per-cpu channel list
  hyperv: fix warning about missing prototype
  vmbus: remove useless return's
  vmbus: remove unnecessary initialization
  vmbus: fix spelling errors
  hyperv: remove unnecessary return variable
  vmbus: make channel_message table constant
  vmbus: cleanup header file style
  vmbus: expose debug info for drivers

 arch/x86/hyperv/hv_init.c |    2 +-
 drivers/hv/channel.c      |   10 +++---
 drivers/hv/channel_mgmt.c |   55 +++++++++++++++++++------------------
 drivers/hv/connection.c   |   65 +++++++++++++++++++++++---------------------
 drivers/hv/hv_balloon.c   |    2 -
 drivers/hv/hv_fcopy.c     |    2 -
 drivers/hv/hv_kvp.c       |   12 +++-----
 drivers/hv/hv_snapshot.c  |    2 -
 drivers/hv/hyperv_vmbus.h |   29 ++++++--------------
 drivers/hv/ring_buffer.c  |   22 +++++---------
 drivers/hv/vmbus_drv.c    |   10 ++++---
 include/linux/hyperv.h    |   38 ++++++++++++++++++++-----
 12 files changed, 126 insertions(+), 123 deletions(-)

[PATCH 01/10] vmbus: only reschedule tasklet if time limit exceeded

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

The change to reschedule tasklet if more data arrives in ring buffer
can cause performance regression if host timing is such that the
next response happens in small window.

Go back to a modified version of the original looping behavior.
If the race occurs in a small time, then loop. But if the tasklet
has been running for a long interval due to flood, then reschedule
the tasklet to allow migration to ksoftirqd.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/connection.c |   65 ++++++++++++++++++++++++----------------------
 1 files changed, 34 insertions(+), 31 deletions(-)

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index a8366fe..fce27fb 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -296,44 +296,47 @@ struct vmbus_channel *relid2channel(u32 relid)
 
 /*
  * vmbus_on_event - Process a channel event notification
+ *
+ * For batched channels (default) optimize host to guest signaling
+ * by ensuring:
+ * 1. While reading the channel, we disable interrupts from host.
+ * 2. Ensure that we process all posted messages from the host
+ *    before returning from this callback.
+ * 3. Once we return, enable signaling from the host. Once this
+ *    state is set we check to see if additional packets are
+ *    available to read. In this case we repeat the process.
+ *    If this tasklet has been running for a long time
+ *    then reschedule ourselves.
  */
 void vmbus_on_event(unsigned long data)
 {
 	struct vmbus_channel *channel = (void *) data;
-	void (*callback_fn)(void *);
+	unsigned long time_limit = jiffies + 2;
 
-	/*
-	 * A channel once created is persistent even when there
-	 * is no driver handling the device. An unloading driver
-	 * sets the onchannel_callback to NULL on the same CPU
-	 * as where this interrupt is handled (in an interrupt context).
-	 * 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;
-
-	(*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:
-		 * 1. While reading the channel, we disable interrupts from
-		 *    host.
-		 * 2. Ensure that we process all posted messages from the host
-		 *    before returning from this callback.
-		 * 3. Once we return, enable signaling from the host. Once this
-		 *    state is set we check to see if additional packets are
-		 *    available to read. In this case we repeat the process.
+	do {
+		void (*callback_fn)(void *);
+
+		/* A channel once created is persistent even when
+		 * there is no driver handling the device. An
+		 * unloading driver sets the onchannel_callback to NULL.
 		 */
-		if (hv_end_read(&channel->inbound) != 0) {
-			hv_begin_read(&channel->inbound);
+		callback_fn = READ_ONCE(channel->onchannel_callback);
+		if (unlikely(callback_fn == NULL))
+			return;
 
-			tasklet_schedule(&channel->callback_event);
-		}
-	}
+		(*callback_fn)(channel->channel_callback_context);
+
+		if (channel->callback_mode != HV_CALL_BATCHED)
+			return;
+
+		if (likely(hv_end_read(&channel->inbound) == 0))
+			return;
+
+		hv_begin_read(&channel->inbound);
+	} while (likely(time_before(jiffies, time_limit)));
+
+	/* The time limit (2 jiffies) has been reached */
+	tasklet_schedule(&channel->callback_event);
 }
 
 /*
-- 
1.7.1

[PATCH 02/10] vmbus: use rcu for per-cpu channel list

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

The per-cpu channel list is now referred to in the interrupt
routine. This is mostly safe since the host will not normally generate
an interrupt when channel is being deleted but if it did then there
would be a use after free problem.

To solve, this use RCU protection on ther per-cpu list.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel_mgmt.c |    7 ++++---
 drivers/hv/vmbus_drv.c    |    6 +++++-
 include/linux/hyperv.h    |    7 +++++++
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f33465d..d2cfa3e 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -350,7 +350,8 @@ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
 static void free_channel(struct vmbus_channel *channel)
 {
 	tasklet_kill(&channel->callback_event);
-	kfree(channel);
+
+	kfree_rcu(channel, rcu);
 }
 
 static void percpu_channel_enq(void *arg)
@@ -359,14 +360,14 @@ static void percpu_channel_enq(void *arg)
 	struct hv_per_cpu_context *hv_cpu
 		= this_cpu_ptr(hv_context.cpu_context);
 
-	list_add_tail(&channel->percpu_list, &hv_cpu->chan_list);
+	list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list);
 }
 
 static void percpu_channel_deq(void *arg)
 {
 	struct vmbus_channel *channel = arg;
 
-	list_del(&channel->percpu_list);
+	list_del_rcu(&channel->percpu_list);
 }
 
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index f7f6b91..971ecb7 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -937,8 +937,10 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 		if (relid == 0)
 			continue;
 
+		rcu_read_lock();
+
 		/* Find channel based on relid */
-		list_for_each_entry(channel, &hv_cpu->chan_list, percpu_list) {
+		list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
 			if (channel->offermsg.child_relid != relid)
 				continue;
 
@@ -954,6 +956,8 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 				tasklet_schedule(&channel->callback_event);
 			}
 		}
+
+		rcu_read_unlock();
 	}
 }
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 62bbf3c..c4c7ae9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -845,6 +845,13 @@ struct vmbus_channel {
 	 * link up channels based on their CPU affinity.
 	 */
 	struct list_head percpu_list;
+
+	/*
+	 * Defer freeing channel until after all cpu's have
+	 * gone through grace period.
+	 */
+	struct rcu_head rcu;
+
 	/*
 	 * For performance critical channels (storage, networking
 	 * etc,), Hyper-V has a mechanism to enhance the throughput
-- 
1.7.1

[PATCH 03/10] hyperv: fix warning about missing prototype

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

Compiling with warnings enabled finds missing prototype for
hv_do_hypercall.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 arch/x86/hyperv/hv_init.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index db64baf..d4a5f82 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -25,7 +25,7 @@
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
 #include <linux/clockchips.h>
-
+#include <linux/hyperv.h>
 
 #ifdef CONFIG_X86_64
 
-- 
1.7.1

[PATCH 04/10] vmbus: remove useless return's

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

No need for empty return at end of void function

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/hv_balloon.c  |    2 --
 drivers/hv/hv_fcopy.c    |    2 --
 drivers/hv/hv_kvp.c      |    2 --
 drivers/hv/hv_snapshot.c |    2 --
 drivers/hv/ring_buffer.c |    2 --
 drivers/hv/vmbus_drv.c   |    2 --
 include/linux/hyperv.h   |    2 --
 7 files changed, 0 insertions(+), 14 deletions(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 5fd03e5..f5728de 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -722,8 +722,6 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,
 						    5*HZ);
 		post_status(&dm_device);
 	}
-
-	return;
 }
 
 static void hv_online_page(struct page *pg)
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
index 545cf43..778ad80 100644
--- a/drivers/hv/hv_fcopy.c
+++ b/drivers/hv/hv_fcopy.c
@@ -187,8 +187,6 @@ static void fcopy_send_data(struct work_struct *dummy)
 		}
 	}
 	kfree(smsg_out);
-
-	return;
 }
 
 /*
diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index 15c7873..bc4a4da 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -484,8 +484,6 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 	}
 
 	kfree(message);
-
-	return;
 }
 
 /*
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 3847f19..3cb05f4 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -213,8 +213,6 @@ static void vss_send_op(void)
 	}
 
 	kfree(vss_msg);
-
-	return;
 }
 
 static void vss_handle_request(struct work_struct *dummy)
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 87799e8..d0ff5b4 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -73,8 +73,6 @@ static void hv_signal_on_write(u32 old_write, struct vmbus_channel *channel)
 	 */
 	if (old_write == READ_ONCE(rbi->ring_buffer->read_index))
 		vmbus_setevent(channel);
-
-	return;
 }
 
 /* Get the next write location for the specified ring buffer. */
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 971ecb7..9ddbf4d 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -785,8 +785,6 @@ static void vmbus_shutdown(struct device *child_device)
 
 	if (drv->shutdown)
 		drv->shutdown(dev);
-
-	return;
 }
 
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c4c7ae9..443788e 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1507,8 +1507,6 @@ static inline  void hv_signal_on_read(struct vmbus_channel *channel)
 	cached_write_sz = hv_get_cached_bytes_to_write(rbi);
 	if (cached_write_sz < pending_sz)
 		vmbus_setevent(channel);
-
-	return;
 }
 
 static inline void
-- 
1.7.1

[PATCH 05/10] vmbus: remove unnecessary initialization

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

Don't initialize variables that are then set a few lines later.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/ring_buffer.c |   13 +++++--------
 1 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index d0ff5b4..52d0556 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -265,14 +265,13 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count)
 {
-	int i = 0;
+	int i;
 	u32 bytes_avail_towrite;
-	u32 totalbytes_towrite = 0;
-
+	u32 totalbytes_towrite = sizeof(u64);
 	u32 next_write_location;
 	u32 old_write;
-	u64 prev_indices = 0;
-	unsigned long flags = 0;
+	u64 prev_indices;
+	unsigned long flags;
 	struct hv_ring_buffer_info *outring_info = &channel->outbound;
 
 	if (channel->rescind)
@@ -281,8 +280,6 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
 	for (i = 0; i < kv_count; i++)
 		totalbytes_towrite += kv_list[i].iov_len;
 
-	totalbytes_towrite += sizeof(u64);
-
 	spin_lock_irqsave(&outring_info->ring_lock, flags);
 
 	bytes_avail_towrite = hv_get_bytes_to_write(outring_info);
@@ -339,7 +336,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 		       u64 *requestid, bool raw)
 {
 	u32 bytes_avail_toread;
-	u32 next_read_location = 0;
+	u32 next_read_location;
 	u64 prev_indices = 0;
 	struct vmpacket_descriptor desc;
 	u32 offset;
-- 
1.7.1

[PATCH 06/10] vmbus: fix spelling errors

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

Several spelling errors in comments

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel.c |   10 +++++-----
 drivers/hv/hv_kvp.c  |   10 +++++-----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 81a80c8..deb8522 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -333,7 +333,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 			 * Gpadl is u32 and we are using a pointer which could
 			 * be 64-bit
 			 * This is governed by the guest/host protocol and
-			 * so the hypervisor gurantees that this is ok.
+			 * so the hypervisor guarantees that this is ok.
 			 */
 			for (i = 0; i < pfncurr; i++)
 				gpadl_body->pfn[i] = slow_virt_to_phys(
@@ -380,7 +380,7 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 }
 
 /*
- * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
+ * vmbus_establish_gpadl - Establish a GPADL for the specified buffer
  *
  * @channel: a channel
  * @kbuffer: from kmalloc or vmalloc
@@ -732,7 +732,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	/* Setup the descriptor */
 	desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 	desc.flags = flags;
-	desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
+	desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
 	desc.length8 = (u16)(packetlen_aligned >> 3);
 	desc.transactionid = requestid;
 	desc.rangecount = pagecount;
@@ -793,7 +793,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	/* Setup the descriptor */
 	desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 	desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
-	desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
+	desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */
 	desc->length8 = (u16)(packetlen_aligned >> 3);
 	desc->transactionid = requestid;
 	desc->rangecount = 1;
@@ -843,7 +843,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	/* Setup the descriptor */
 	desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 	desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
-	desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
+	desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
 	desc.length8 = (u16)(packetlen_aligned >> 3);
 	desc.transactionid = requestid;
 	desc.rangecount = 1;
diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index bc4a4da..646e0b3 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -69,7 +69,7 @@
  *
  * While the request/response protocol is guaranteed by the host, we further
  * ensure this by serializing packet processing in this driver - we do not
- * read additional packets from the VMBUs until the current packet is fully
+ * read additional packets from the VMBUS until the current packet is fully
  * handled.
  */
 
@@ -398,7 +398,7 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 	 * the max lengths specified. We will however, reserve room
 	 * for the string terminating character - in the utf16s_utf8s()
 	 * function we limit the size of the buffer where the converted
-	 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to gaurantee
+	 * string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
 	 * that the strings can be properly terminated!
 	 */
 
@@ -532,7 +532,7 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
 	 */
 	if (error) {
 		/*
-		 * Something failed or we have timedout;
+		 * Something failed or we have timed out;
 		 * terminate the current host-side iteration.
 		 */
 		goto response_done;
@@ -606,8 +606,8 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
  * This callback is invoked when we get a KVP message from the host.
  * The host ensures that only one KVP transaction can be active at a time.
  * KVP implementation in Linux needs to forward the key to a user-mde
- * component to retrive the corresponding value. Consequently, we cannot
- * respond to the host in the conext of this callback. Since the host
+ * component to retrieve the corresponding value. Consequently, we cannot
+ * respond to the host in the context of this callback. Since the host
  * guarantees that at most only one transaction can be active at a time,
  * we stash away the transaction state in a set of global variables.
  */
-- 
1.7.1

[PATCH 07/10] hyperv: remove unnecessary return variable

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

hv_ringbuffer_read cleanup.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/ring_buffer.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 52d0556..8a24974 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -341,13 +341,11 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 	struct vmpacket_descriptor desc;
 	u32 offset;
 	u32 packetlen;
-	int ret = 0;
 	struct hv_ring_buffer_info *inring_info = &channel->inbound;
 
 	if (buflen <= 0)
 		return -EINVAL;
 
-
 	*buffer_actual_len = 0;
 	*requestid = 0;
 
@@ -358,7 +356,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 		 * No error is set when there is even no header, drivers are
 		 * supposed to analyze buffer_actual_len.
 		 */
-		return ret;
+		return 0;
 	}
 
 	init_cached_read_index(channel);
@@ -403,5 +401,5 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 
 	hv_signal_on_read(channel);
 
-	return ret;
+	return 0;
 }
-- 
1.7.1

[PATCH 08/10] vmbus: make channel_message table constant

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

This table is immutable and should be const.
Cleanup indentation and whitespace for this as well.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/channel_mgmt.c |   48 ++++++++++++++++++++++----------------------
 drivers/hv/hyperv_vmbus.h |    2 +-
 drivers/hv/vmbus_drv.c    |    2 +-
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index d2cfa3e..e8f52c0 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -1098,30 +1098,30 @@ static void vmbus_onversion_response(
 }
 
 /* Channel message dispatch table */
-struct vmbus_channel_message_table_entry
-	channel_message_table[CHANNELMSG_COUNT] = {
-	{CHANNELMSG_INVALID,			0, NULL},
-	{CHANNELMSG_OFFERCHANNEL,		0, vmbus_onoffer},
-	{CHANNELMSG_RESCIND_CHANNELOFFER,	0, vmbus_onoffer_rescind},
-	{CHANNELMSG_REQUESTOFFERS,		0, NULL},
-	{CHANNELMSG_ALLOFFERS_DELIVERED,	1, vmbus_onoffers_delivered},
-	{CHANNELMSG_OPENCHANNEL,		0, NULL},
-	{CHANNELMSG_OPENCHANNEL_RESULT,		1, vmbus_onopen_result},
-	{CHANNELMSG_CLOSECHANNEL,		0, NULL},
-	{CHANNELMSG_GPADL_HEADER,		0, NULL},
-	{CHANNELMSG_GPADL_BODY,			0, NULL},
-	{CHANNELMSG_GPADL_CREATED,		1, vmbus_ongpadl_created},
-	{CHANNELMSG_GPADL_TEARDOWN,		0, NULL},
-	{CHANNELMSG_GPADL_TORNDOWN,		1, vmbus_ongpadl_torndown},
-	{CHANNELMSG_RELID_RELEASED,		0, NULL},
-	{CHANNELMSG_INITIATE_CONTACT,		0, NULL},
-	{CHANNELMSG_VERSION_RESPONSE,		1, vmbus_onversion_response},
-	{CHANNELMSG_UNLOAD,			0, NULL},
-	{CHANNELMSG_UNLOAD_RESPONSE,		1, vmbus_unload_response},
-	{CHANNELMSG_18,				0, NULL},
-	{CHANNELMSG_19,				0, NULL},
-	{CHANNELMSG_20,				0, NULL},
-	{CHANNELMSG_TL_CONNECT_REQUEST,		0, NULL},
+const struct vmbus_channel_message_table_entry
+channel_message_table[CHANNELMSG_COUNT] = {
+	{ CHANNELMSG_INVALID,			0, NULL },
+	{ CHANNELMSG_OFFERCHANNEL,		0, vmbus_onoffer },
+	{ CHANNELMSG_RESCIND_CHANNELOFFER,	0, vmbus_onoffer_rescind },
+	{ CHANNELMSG_REQUESTOFFERS,		0, NULL },
+	{ CHANNELMSG_ALLOFFERS_DELIVERED,	1, vmbus_onoffers_delivered },
+	{ CHANNELMSG_OPENCHANNEL,		0, NULL },
+	{ CHANNELMSG_OPENCHANNEL_RESULT,	1, vmbus_onopen_result },
+	{ CHANNELMSG_CLOSECHANNEL,		0, NULL },
+	{ CHANNELMSG_GPADL_HEADER,		0, NULL },
+	{ CHANNELMSG_GPADL_BODY,		0, NULL },
+	{ CHANNELMSG_GPADL_CREATED,		1, vmbus_ongpadl_created },
+	{ CHANNELMSG_GPADL_TEARDOWN,		0, NULL },
+	{ CHANNELMSG_GPADL_TORNDOWN,		1, vmbus_ongpadl_torndown },
+	{ CHANNELMSG_RELID_RELEASED,		0, NULL },
+	{ CHANNELMSG_INITIATE_CONTACT,		0, NULL },
+	{ CHANNELMSG_VERSION_RESPONSE,		1, vmbus_onversion_response },
+	{ CHANNELMSG_UNLOAD,			0, NULL },
+	{ CHANNELMSG_UNLOAD_RESPONSE,		1, vmbus_unload_response },
+	{ CHANNELMSG_18,			0, NULL },
+	{ CHANNELMSG_19,			0, NULL },
+	{ CHANNELMSG_20,			0, NULL },
+	{ CHANNELMSG_TL_CONNECT_REQUEST,	0, NULL },
 };
 
 /*
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 884f83b..b552c3a 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -376,7 +376,7 @@ struct vmbus_channel_message_table_entry {
 	void (*message_handler)(struct vmbus_channel_message_header *msg);
 };
 
-extern struct vmbus_channel_message_table_entry
+extern const struct vmbus_channel_message_table_entry
 	channel_message_table[CHANNELMSG_COUNT];
 
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 9ddbf4d..7fe8ef3 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -851,7 +851,7 @@ void vmbus_on_msg_dpc(unsigned long data)
 	struct hv_message *msg = (struct hv_message *)page_addr +
 				  VMBUS_MESSAGE_SINT;
 	struct vmbus_channel_message_header *hdr;
-	struct vmbus_channel_message_table_entry *entry;
+	const struct vmbus_channel_message_table_entry *entry;
 	struct onmessage_work_context *ctx;
 	u32 message_type = msg->header.message_type;
 
-- 
1.7.1

[PATCH 09/10] vmbus: cleanup header file style

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

Minor changes to align hyper-v vmbus include files with current
linux kernel style.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/hyperv_vmbus.h |   16 ++++++++--------
 include/linux/hyperv.h    |   12 ++++++------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index b552c3a..a69b52d 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -218,8 +218,8 @@ struct hv_per_cpu_context {
 
 struct hv_context {
 	/* We only support running on top of Hyper-V
-	* So at this point this really can only contain the Hyper-V ID
-	*/
+	 * So at this point this really can only contain the Hyper-V ID
+	 */
 	u64 guestid;
 
 	void *tsc_page;
@@ -403,17 +403,17 @@ struct hv_device *vmbus_device_create(const uuid_le *type,
 void vmbus_on_event(unsigned long data);
 void vmbus_on_msg_dpc(unsigned long data);
 
-int hv_kvp_init(struct hv_util_service *);
+int hv_kvp_init(struct hv_util_service *srv);
 void hv_kvp_deinit(void);
-void hv_kvp_onchannelcallback(void *);
+void hv_kvp_onchannelcallback(void *context);
 
-int hv_vss_init(struct hv_util_service *);
+int hv_vss_init(struct hv_util_service *srv);
 void hv_vss_deinit(void);
-void hv_vss_onchannelcallback(void *);
+void hv_vss_onchannelcallback(void *context);
 
-int hv_fcopy_init(struct hv_util_service *);
+int hv_fcopy_init(struct hv_util_service *srv);
 void hv_fcopy_deinit(void);
-void hv_fcopy_onchannelcallback(void *);
+void hv_fcopy_onchannelcallback(void *context);
 void vmbus_initiate_unload(bool crash);
 
 static inline void hv_poll_channel(struct vmbus_channel *channel,
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 443788e..9d5df04 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -524,10 +524,10 @@ struct vmbus_channel_open_channel {
 	u32 target_vp;
 
 	/*
-	* The upstream ring buffer begins at offset zero in the memory
-	* described by RingBufferGpadlHandle. The downstream ring buffer
-	* follows it at this offset (in pages).
-	*/
+	 * The upstream ring buffer begins at offset zero in the memory
+	 * described by RingBufferGpadlHandle. The downstream ring buffer
+	 * follows it at this offset (in pages).
+	 */
 	u32 downstream_ringbuffer_pageoffset;
 
 	/* User-specific data to be passed along to the server endpoint. */
@@ -1013,7 +1013,7 @@ extern int vmbus_open(struct vmbus_channel *channel,
 			    u32 recv_ringbuffersize,
 			    void *userdata,
 			    u32 userdatalen,
-			    void(*onchannel_callback)(void *context),
+			    void (*onchannel_callback)(void *context),
 			    void *context);
 
 extern void vmbus_close(struct vmbus_channel *channel);
@@ -1428,7 +1428,7 @@ struct hyperv_service_callback {
 	char *log_msg;
 	uuid_le data;
 	struct vmbus_channel *channel;
-	void (*callback) (void *context);
+	void (*callback)(void *context);
 };
 
 #define MAX_SRV_VER	0x7ffffff
-- 
1.7.1

[PATCH 10/10] vmbus: expose debug info for drivers

[kys]

From: Stephen Hemminger <stephen@networkplumber.org>

Allow driver to get debug information about state of the ring.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 drivers/hv/hyperv_vmbus.h |   11 -----------
 drivers/hv/ring_buffer.c  |    1 +
 include/linux/hyperv.h    |   17 +++++++++++++++++
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index a69b52d..6113e91 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -248,14 +248,6 @@ struct hv_context {
 
 extern struct hv_context hv_context;
 
-struct hv_ring_buffer_debug_info {
-	u32 current_interrupt_mask;
-	u32 current_read_index;
-	u32 current_write_index;
-	u32 bytes_avail_toread;
-	u32 bytes_avail_towrite;
-};
-
 /* Hv Interface */
 
 extern int hv_init(void);
@@ -289,9 +281,6 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 		       void *buffer, u32 buflen, u32 *buffer_actual_len,
 		       u64 *requestid, bool raw);
 
-void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
-				 struct hv_ring_buffer_debug_info *debug_info);
-
 /*
  * Maximum channels is determined by the size of the interrupt page
  * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 8a24974..cfacca5 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -206,6 +206,7 @@ void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
 			ring_info->ring_buffer->interrupt_mask;
 	}
 }
+EXPORT_SYMBOL_GPL(hv_ringbuffer_get_debuginfo);
 
 /* Initialize the ring buffer. */
 int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 9d5df04..1f97f93 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -491,6 +491,12 @@ struct vmbus_channel_rescind_offer {
 	u32 child_relid;
 } __packed;
 
+static inline u32
+hv_ringbuffer_pending_size(const struct hv_ring_buffer_info *rbi)
+{
+	return rbi->ring_buffer->pending_send_sz;
+}
+
 /*
  * Request Offer -- no parameters, SynIC message contains the partition ID
  * Set Snoop -- no parameters, SynIC message contains the partition ID
@@ -1155,6 +1161,17 @@ static inline void hv_set_drvdata(struct hv_device *dev, void *data)
 	return dev_get_drvdata(&dev->device);
 }
 
+struct hv_ring_buffer_debug_info {
+	u32 current_interrupt_mask;
+	u32 current_read_index;
+	u32 current_write_index;
+	u32 bytes_avail_toread;
+	u32 bytes_avail_towrite;
+};
+
+void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+			    struct hv_ring_buffer_debug_info *debug_info);
+
 /* Vmbus interface */
 #define vmbus_driver_register(driver)	\
 	__vmbus_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
-- 
1.7.1