[PATCH 0/3] Drivers: hv

[PATCH 0/3] Drivers: hv

[K. Y. Srinivasan]

The patch for the vmbus drivers properly cleans up the channel state on receipt
of the "offer rescind" message. The balloon driver patches permit the execution
of both "balloon up" operation as well as the "hot-add" operation in separate
execution contexts. This allows the balloon driver to be more responsive both
in terms of reporting pressure to the host as well as responding to the requests
from the host.

K. Y. Srinivasan (3):
  Drivers: hv: vmbus: Handle channel rescind message correctly
  Drivers: hv: balloon: Execute balloon inflation in a separate context
  Drivers: hv: balloon: Execute hot-add code in a separate context

 drivers/hv/channel_mgmt.c |   11 +++++++
 drivers/hv/hv_balloon.c   |   74 ++++++++++++++++++++++++++++-----------------
 2 files changed, 57 insertions(+), 28 deletions(-)

-- 
1.7.4.1

[PATCH 1/3] Drivers: hv: vmbus: Handle channel rescind message correctly

[K. Y. Srinivasan]

Properly cleanup the channel state on receipt of the "offer rescind" message.
Starting with ws2012, the host requires that the channel "relid" be properly
cleaned up when the offer is rescinded.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/hv/channel_mgmt.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 53a8600..7cb76fb 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -165,8 +165,19 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
 	struct vmbus_channel *channel = container_of(work,
 						     struct vmbus_channel,
 						     work);
+	unsigned long flags;
+	struct vmbus_channel_relid_released msg;
 
 	vmbus_device_unregister(channel->device_obj);
+	memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
+	msg.child_relid = channel->offermsg.child_relid;
+	msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
+	vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
+
+	spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+	list_del(&channel->listentry);
+	spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+	free_channel(channel);
 }
 
 void vmbus_free_channels(void)
-- 
1.7.4.1

[PATCH 2/3] Drivers: hv: balloon: Execute balloon inflation in a separate context

[K. Y. Srinivasan]

Execute the balloon inflation operation in a separate work context.
This allows us to decouple the pressure reporting activity from the
ballooning activity. Testing has shown that this decoupling makes the
guest more reponsive.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/hv/hv_balloon.c |   34 ++++++++++++++++++++++++----------
 1 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 3787321..860e176 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -412,6 +412,11 @@ struct dm_info_msg {
  * End protocol definitions.
  */
 
+struct balloon_state {
+	__u32 num_pages;
+	struct work_struct wrk;
+};
+
 static bool hot_add;
 static bool do_hot_add;
 /*
@@ -429,6 +434,7 @@ static atomic_t trans_id = ATOMIC_INIT(0);
 
 static int dm_ring_size = (5 * PAGE_SIZE);
 
+
 /*
  * Driver specific state.
  */
@@ -459,7 +465,12 @@ struct hv_dynmem_device {
 	unsigned int num_pages_ballooned;
 
 	/*
-	 * This thread handles both balloon/hot-add
+	 * State to manage the ballooning (up) operation.
+	 */
+	struct balloon_state balloon_wrk;
+
+	/*
+	 * This thread handles hot-add
 	 * requests from the host as well as notifying
 	 * the host with regards to memory pressure in
 	 * the guest.
@@ -657,9 +668,9 @@ static int  alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages,
 
 
 
-static void balloon_up(struct hv_dynmem_device *dm, struct dm_balloon *req)
+static void balloon_up(struct work_struct *dummy)
 {
-	int num_pages = req->num_pages;
+	int num_pages = dm_device.balloon_wrk.num_pages;
 	int num_ballooned = 0;
 	struct dm_balloon_response *bl_resp;
 	int alloc_unit;
@@ -684,14 +695,14 @@ static void balloon_up(struct hv_dynmem_device *dm, struct dm_balloon *req)
 
 
 		num_pages -= num_ballooned;
-		num_ballooned = alloc_balloon_pages(dm, num_pages,
+		num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
 						bl_resp, alloc_unit,
 						 &alloc_error);
 
 		if ((alloc_error) || (num_ballooned == num_pages)) {
 			bl_resp->more_pages = 0;
 			done = true;
-			dm->state = DM_INITIALIZED;
+			dm_device.state = DM_INITIALIZED;
 		}
 
 		/*
@@ -719,7 +730,7 @@ static void balloon_up(struct hv_dynmem_device *dm, struct dm_balloon *req)
 			pr_info("Balloon response failed\n");
 
 			for (i = 0; i < bl_resp->range_count; i++)
-				free_balloon_pages(dm,
+				free_balloon_pages(&dm_device,
 						 &bl_resp->range_array[i]);
 
 			done = true;
@@ -775,9 +786,6 @@ static int dm_thread_func(void *dm_dev)
 
 		scan_start = jiffies;
 		switch (dm->state) {
-		case DM_BALLOON_UP:
-			balloon_up(dm, (struct dm_balloon *)recv_buffer);
-			break;
 
 		case DM_HOT_ADD:
 			hot_add_req(dm, (struct dm_hot_add *)recv_buffer);
@@ -861,6 +869,7 @@ static void balloon_onchannelcallback(void *context)
 	struct dm_message *dm_msg;
 	struct dm_header *dm_hdr;
 	struct hv_dynmem_device *dm = hv_get_drvdata(dev);
+	struct dm_balloon *bal_msg;
 
 	memset(recv_buffer, 0, sizeof(recv_buffer));
 	vmbus_recvpacket(dev->channel, recv_buffer,
@@ -882,8 +891,12 @@ static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_BALLOON_REQUEST:
+			if (dm->state == DM_BALLOON_UP)
+				pr_warn("Currently ballooning\n");
+			bal_msg = (struct dm_balloon *)recv_buffer;
 			dm->state = DM_BALLOON_UP;
-			complete(&dm->config_event);
+			dm_device.balloon_wrk.num_pages = bal_msg->num_pages;
+			schedule_work(&dm_device.balloon_wrk.wrk);
 			break;
 
 		case DM_UNBALLOON_REQUEST:
@@ -937,6 +950,7 @@ static int balloon_probe(struct hv_device *dev,
 	dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
 	init_completion(&dm_device.host_event);
 	init_completion(&dm_device.config_event);
+	INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up);
 
 	dm_device.thread =
 		 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
-- 
1.7.4.1

[PATCH 3/3] Drivers: hv: balloon: Execute hot-add code in a separate context

[K. Y. Srinivasan]

Execute the hot-add operation in a separate work context.
This allows us to decouple the pressure reporting activity from the
"hot-add" activity.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/hv/hv_balloon.c |   40 ++++++++++++++++++++++------------------
 1 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 860e176..225a1fe 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -417,6 +417,11 @@ struct balloon_state {
 	struct work_struct wrk;
 };
 
+struct hot_add_wrk {
+	union dm_mem_page_range ha_page_range;
+	struct work_struct wrk;
+};
+
 static bool hot_add;
 static bool do_hot_add;
 /*
@@ -470,6 +475,11 @@ struct hv_dynmem_device {
 	struct balloon_state balloon_wrk;
 
 	/*
+	 * State to execute the "hot-add" operation.
+	 */
+	struct hot_add_wrk ha_wrk;
+
+	/*
 	 * This thread handles hot-add
 	 * requests from the host as well as notifying
 	 * the host with regards to memory pressure in
@@ -487,7 +497,7 @@ struct hv_dynmem_device {
 
 static struct hv_dynmem_device dm_device;
 
-static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg)
+static void hot_add_req(struct work_struct *dummy)
 {
 
 	struct dm_hot_add_response resp;
@@ -510,8 +520,8 @@ static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg)
 	resp.page_count = 0;
 	resp.result = 0;
 
-	dm->state = DM_INITIALIZED;
-	vmbus_sendpacket(dm->dev->channel, &resp,
+	dm_device.state = DM_INITIALIZED;
+	vmbus_sendpacket(dm_device.dev->channel, &resp,
 			sizeof(struct dm_hot_add_response),
 			(unsigned long)NULL,
 			VM_PKT_DATA_INBAND, 0);
@@ -772,7 +782,6 @@ static int dm_thread_func(void *dm_dev)
 {
 	struct hv_dynmem_device *dm = dm_dev;
 	int t;
-	unsigned long  scan_start;
 
 	while (!kthread_should_stop()) {
 		t = wait_for_completion_timeout(&dm_device.config_event, 1*HZ);
@@ -784,19 +793,6 @@ static int dm_thread_func(void *dm_dev)
 		if (t == 0)
 			post_status(dm);
 
-		scan_start = jiffies;
-		switch (dm->state) {
-
-		case DM_HOT_ADD:
-			hot_add_req(dm, (struct dm_hot_add *)recv_buffer);
-			break;
-		default:
-			break;
-		}
-
-		if (!time_in_range(jiffies, scan_start, scan_start + HZ))
-			post_status(dm);
-
 	}
 
 	return 0;
@@ -870,6 +866,8 @@ static void balloon_onchannelcallback(void *context)
 	struct dm_header *dm_hdr;
 	struct hv_dynmem_device *dm = hv_get_drvdata(dev);
 	struct dm_balloon *bal_msg;
+	struct dm_hot_add *ha_msg;
+	union dm_mem_page_range *ha_pg_range;
 
 	memset(recv_buffer, 0, sizeof(recv_buffer));
 	vmbus_recvpacket(dev->channel, recv_buffer,
@@ -906,8 +904,13 @@ static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_MEM_HOT_ADD_REQUEST:
+			if (dm->state == DM_HOT_ADD)
+				pr_warn("Currently hot-adding\n");
 			dm->state = DM_HOT_ADD;
-			complete(&dm->config_event);
+			ha_msg = (struct dm_hot_add *)recv_buffer;
+			ha_pg_range = &ha_msg->range;
+			dm_device.ha_wrk.ha_page_range = *ha_pg_range;
+			schedule_work(&dm_device.ha_wrk.wrk);
 			break;
 
 		case DM_INFO_MESSAGE:
@@ -951,6 +954,7 @@ static int balloon_probe(struct hv_device *dev,
 	init_completion(&dm_device.host_event);
 	init_completion(&dm_device.config_event);
 	INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up);
+	INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req);
 
 	dm_device.thread =
 		 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
-- 
1.7.4.1

RE: [PATCH 0/3] Drivers: hv

[KY Srinivasan]

> -----Original Message-----
> From: K. Y. Srinivasan [mailto:kys@microsoft.com]
> Sent: Sunday, February 17, 2013 4:31 PM
> To: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com
> Cc: KY Srinivasan
> Subject: [PATCH 0/3] Drivers: hv
> 
> The patch for the vmbus drivers properly cleans up the channel state on receipt
> of the "offer rescind" message. The balloon driver patches permit the execution
> of both "balloon up" operation as well as the "hot-add" operation in separate
> execution contexts. This allows the balloon driver to be more responsive both
> in terms of reporting pressure to the host as well as responding to the requests
> from the host.
> 
> K. Y. Srinivasan (3):
>   Drivers: hv: vmbus: Handle channel rescind message correctly
>   Drivers: hv: balloon: Execute balloon inflation in a separate context
>   Drivers: hv: balloon: Execute hot-add code in a separate context
> 
>  drivers/hv/channel_mgmt.c |   11 +++++++
>  drivers/hv/hv_balloon.c   |   74 ++++++++++++++++++++++++++++----------------
> -
>  2 files changed, 57 insertions(+), 28 deletions(-)

Greg,

I had sent these patches a couple of weeks ago. Should I resend these.

Regards,

K. Y
> 
> --
> 1.7.4.1
> 
> 

RE: [PATCH 0/3] Drivers: hv

[KY Srinivasan]

> -----Original Message-----
> From: K. Y. Srinivasan [mailto:kys@microsoft.com]
> Sent: Sunday, February 17, 2013 4:31 PM
> To: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> jasowang@redhat.com
> Cc: KY Srinivasan
> Subject: [PATCH 0/3] Drivers: hv
> 
> The patch for the vmbus drivers properly cleans up the channel state on receipt
> of the "offer rescind" message. The balloon driver patches permit the execution
> of both "balloon up" operation as well as the "hot-add" operation in separate
> execution contexts. This allows the balloon driver to be more responsive both
> in terms of reporting pressure to the host as well as responding to the requests
> from the host.
> 
> K. Y. Srinivasan (3):
>   Drivers: hv: vmbus: Handle channel rescind message correctly
>   Drivers: hv: balloon: Execute balloon inflation in a separate context
>   Drivers: hv: balloon: Execute hot-add code in a separate context
> 
>  drivers/hv/channel_mgmt.c |   11 +++++++
>  drivers/hv/hv_balloon.c   |   74 ++++++++++++++++++++++++++++----------------
> -
>  2 files changed, 57 insertions(+), 28 deletions(-)
> 
> --
> 1.7.4.1

Greg,

Please drop this set; I will resend these with some fixes.

Regards,

K. Y
> 
>