Release 4.12 drivers/hv/hv_balloon.c
  
  
  
/*
 * Copyright (c) 2012, Microsoft Corporation.
 *
 * Author:
 *   K. Y. Srinivasan <kys@microsoft.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/mman.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/completion.h>
#include <linux/memory_hotplug.h>
#include <linux/memory.h>
#include <linux/notifier.h>
#include <linux/percpu_counter.h>
#include <linux/hyperv.h>
/*
 * We begin with definitions supporting the Dynamic Memory protocol
 * with the host.
 *
 * Begin protocol definitions.
 */
/*
 * Protocol versions. The low word is the minor version, the high word the major
 * version.
 *
 * History:
 * Initial version 1.0
 * Changed to 0.1 on 2009/03/25
 * Changes to 0.2 on 2009/05/14
 * Changes to 0.3 on 2009/12/03
 * Changed to 1.0 on 2011/04/05
 */
#define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor)))
#define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16)
#define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff)
enum {
	
DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3),
	
DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0),
	
DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0),
	
DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
	
DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
	
DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3,
	
DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10
};
/*
 * Message Types
 */
enum dm_message_type {
	/*
         * Version 0.3
         */
	
DM_ERROR			= 0,
	
DM_VERSION_REQUEST		= 1,
	
DM_VERSION_RESPONSE		= 2,
	
DM_CAPABILITIES_REPORT		= 3,
	
DM_CAPABILITIES_RESPONSE	= 4,
	
DM_STATUS_REPORT		= 5,
	
DM_BALLOON_REQUEST		= 6,
	
DM_BALLOON_RESPONSE		= 7,
	
DM_UNBALLOON_REQUEST		= 8,
	
DM_UNBALLOON_RESPONSE		= 9,
	
DM_MEM_HOT_ADD_REQUEST		= 10,
	
DM_MEM_HOT_ADD_RESPONSE		= 11,
	
DM_VERSION_03_MAX		= 11,
	/*
         * Version 1.0.
         */
	
DM_INFO_MESSAGE			= 12,
	
DM_VERSION_1_MAX		= 12
};
/*
 * Structures defining the dynamic memory management
 * protocol.
 */
union dm_version {
	struct {
		
__u16 minor_version;
		
__u16 major_version;
	};
	
__u32 version;
} __packed;
union dm_caps {
	struct {
		
__u64 balloon:1;
		
__u64 hot_add:1;
		/*
                 * To support guests that may have alignment
                 * limitations on hot-add, the guest can specify
                 * its alignment requirements; a value of n
                 * represents an alignment of 2^n in mega bytes.
                 */
		
__u64 hot_add_alignment:4;
		
__u64 reservedz:58;
	
} cap_bits;
	
__u64 caps;
} __packed;
union dm_mem_page_range {
	struct  {
		/*
                 * The PFN number of the first page in the range.
                 * 40 bits is the architectural limit of a PFN
                 * number for AMD64.
                 */
		
__u64 start_page:40;
		/*
                 * The number of pages in the range.
                 */
		
__u64 page_cnt:24;
	
} finfo;
	
__u64  page_range;
} __packed;
/*
 * The header for all dynamic memory messages:
 *
 * type: Type of the message.
 * size: Size of the message in bytes; including the header.
 * trans_id: The guest is responsible for manufacturing this ID.
 */
struct dm_header {
	
__u16 type;
	
__u16 size;
	
__u32 trans_id;
} __packed;
/*
 * A generic message format for dynamic memory.
 * Specific message formats are defined later in the file.
 */
struct dm_message {
	
struct dm_header hdr;
	
__u8 data[]; /* enclosed message */
} __packed;
/*
 * Specific message types supporting the dynamic memory protocol.
 */
/*
 * Version negotiation message. Sent from the guest to the host.
 * The guest is free to try different versions until the host
 * accepts the version.
 *
 * dm_version: The protocol version requested.
 * is_last_attempt: If TRUE, this is the last version guest will request.
 * reservedz: Reserved field, set to zero.
 */
struct dm_version_request {
	
struct dm_header hdr;
	
union dm_version version;
	
__u32 is_last_attempt:1;
	
__u32 reservedz:31;
} __packed;
/*
 * Version response message; Host to Guest and indicates
 * if the host has accepted the version sent by the guest.
 *
 * is_accepted: If TRUE, host has accepted the version and the guest
 * should proceed to the next stage of the protocol. FALSE indicates that
 * guest should re-try with a different version.
 *
 * reservedz: Reserved field, set to zero.
 */
struct dm_version_response {
	
struct dm_header hdr;
	
__u64 is_accepted:1;
	
__u64 reservedz:63;
} __packed;
/*
 * Message reporting capabilities. This is sent from the guest to the
 * host.
 */
struct dm_capabilities {
	
struct dm_header hdr;
	
union dm_caps caps;
	
__u64 min_page_cnt;
	
__u64 max_page_number;
} __packed;
/*
 * Response to the capabilities message. This is sent from the host to the
 * guest. This message notifies if the host has accepted the guest's
 * capabilities. If the host has not accepted, the guest must shutdown
 * the service.
 *
 * is_accepted: Indicates if the host has accepted guest's capabilities.
 * reservedz: Must be 0.
 */
struct dm_capabilities_resp_msg {
	
struct dm_header hdr;
	
__u64 is_accepted:1;
	
__u64 reservedz:63;
} __packed;
/*
 * This message is used to report memory pressure from the guest.
 * This message is not part of any transaction and there is no
 * response to this message.
 *
 * num_avail: Available memory in pages.
 * num_committed: Committed memory in pages.
 * page_file_size: The accumulated size of all page files
 *                 in the system in pages.
 * zero_free: The nunber of zero and free pages.
 * page_file_writes: The writes to the page file in pages.
 * io_diff: An indicator of file cache efficiency or page file activity,
 *          calculated as File Cache Page Fault Count - Page Read Count.
 *          This value is in pages.
 *
 * Some of these metrics are Windows specific and fortunately
 * the algorithm on the host side that computes the guest memory
 * pressure only uses num_committed value.
 */
struct dm_status {
	
struct dm_header hdr;
	
__u64 num_avail;
	
__u64 num_committed;
	
__u64 page_file_size;
	
__u64 zero_free;
	
__u32 page_file_writes;
	
__u32 io_diff;
} __packed;
/*
 * Message to ask the guest to allocate memory - balloon up message.
 * This message is sent from the host to the guest. The guest may not be
 * able to allocate as much memory as requested.
 *
 * num_pages: number of pages to allocate.
 */
struct dm_balloon {
	
struct dm_header hdr;
	
__u32 num_pages;
	
__u32 reservedz;
} __packed;
/*
 * Balloon response message; this message is sent from the guest
 * to the host in response to the balloon message.
 *
 * reservedz: Reserved; must be set to zero.
 * more_pages: If FALSE, this is the last message of the transaction.
 * if TRUE there will atleast one more message from the guest.
 *
 * range_count: The number of ranges in the range array.
 *
 * range_array: An array of page ranges returned to the host.
 *
 */
struct dm_balloon_response {
	
struct dm_header hdr;
	
__u32 reservedz;
	
__u32 more_pages:1;
	
__u32 range_count:31;
	
union dm_mem_page_range range_array[];
} __packed;
/*
 * Un-balloon message; this message is sent from the host
 * to the guest to give guest more memory.
 *
 * more_pages: If FALSE, this is the last message of the transaction.
 * if TRUE there will atleast one more message from the guest.
 *
 * reservedz: Reserved; must be set to zero.
 *
 * range_count: The number of ranges in the range array.
 *
 * range_array: An array of page ranges returned to the host.
 *
 */
struct dm_unballoon_request {
	
struct dm_header hdr;
	
__u32 more_pages:1;
	
__u32 reservedz:31;
	
__u32 range_count;
	
union dm_mem_page_range range_array[];
} __packed;
/*
 * Un-balloon response message; this message is sent from the guest
 * to the host in response to an unballoon request.
 *
 */
struct dm_unballoon_response {
	
struct dm_header hdr;
} __packed;
/*
 * Hot add request message. Message sent from the host to the guest.
 *
 * mem_range: Memory range to hot add.
 *
 * On Linux we currently don't support this since we cannot hot add
 * arbitrary granularity of memory.
 */
struct dm_hot_add {
	
struct dm_header hdr;
	
union dm_mem_page_range range;
} __packed;
/*
 * Hot add response message.
 * This message is sent by the guest to report the status of a hot add request.
 * If page_count is less than the requested page count, then the host should
 * assume all further hot add requests will fail, since this indicates that
 * the guest has hit an upper physical memory barrier.
 *
 * Hot adds may also fail due to low resources; in this case, the guest must
 * not complete this message until the hot add can succeed, and the host must
 * not send a new hot add request until the response is sent.
 * If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS
 * times it fails the request.
 *
 *
 * page_count: number of pages that were successfully hot added.
 *
 * result: result of the operation 1: success, 0: failure.
 *
 */
struct dm_hot_add_response {
	
struct dm_header hdr;
	
__u32 page_count;
	
__u32 result;
} __packed;
/*
 * Types of information sent from host to the guest.
 */
enum dm_info_type {
	
INFO_TYPE_MAX_PAGE_CNT = 0,
	
MAX_INFO_TYPE
};
/*
 * Header for the information message.
 */
struct dm_info_header {
	
enum dm_info_type type;
	
__u32 data_size;
} __packed;
/*
 * This message is sent from the host to the guest to pass
 * some relevant information (win8 addition).
 *
 * reserved: no used.
 * info_size: size of the information blob.
 * info: information blob.
 */
struct dm_info_msg {
	
struct dm_header hdr;
	
__u32 reserved;
	
__u32 info_size;
	
__u8  info[];
};
/*
 * End protocol definitions.
 */
/*
 * State to manage hot adding memory into the guest.
 * The range start_pfn : end_pfn specifies the range
 * that the host has asked us to hot add. The range
 * start_pfn : ha_end_pfn specifies the range that we have
 * currently hot added. We hot add in multiples of 128M
 * chunks; it is possible that we may not be able to bring
 * online all the pages in the region. The range
 * covered_start_pfn:covered_end_pfn defines the pages that can
 * be brough online.
 */
struct hv_hotadd_state {
	
struct list_head list;
	
unsigned long start_pfn;
	
unsigned long covered_start_pfn;
	
unsigned long covered_end_pfn;
	
unsigned long ha_end_pfn;
	
unsigned long end_pfn;
	/*
         * A list of gaps.
         */
	
struct list_head gap_list;
};
struct hv_hotadd_gap {
	
struct list_head list;
	
unsigned long start_pfn;
	
unsigned long end_pfn;
};
struct balloon_state {
	
__u32 num_pages;
	
struct work_struct wrk;
};
struct hot_add_wrk {
	
union dm_mem_page_range ha_page_range;
	
union dm_mem_page_range ha_region_range;
	
struct work_struct wrk;
};
static bool hot_add = true;
static bool do_hot_add;
/*
 * Delay reporting memory pressure by
 * the specified number of seconds.
 */
static uint pressure_report_delay = 45;
/*
 * The last time we posted a pressure report to host.
 */
static unsigned long last_post_time;
module_param(hot_add, bool, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add");
module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
static atomic_t trans_id = ATOMIC_INIT(0);
static int dm_ring_size = (5 * PAGE_SIZE);
/*
 * Driver specific state.
 */
enum hv_dm_state {
	
DM_INITIALIZING = 0,
	
DM_INITIALIZED,
	
DM_BALLOON_UP,
	
DM_BALLOON_DOWN,
	
DM_HOT_ADD,
	
DM_INIT_ERROR
};
static __u8 recv_buffer[PAGE_SIZE];
static __u8 *send_buffer;
#define PAGES_IN_2M	512
#define HA_CHUNK (32 * 1024)
struct hv_dynmem_device {
	
struct hv_device *dev;
	
enum hv_dm_state state;
	
struct completion host_event;
	
struct completion config_event;
	/*
         * Number of pages we have currently ballooned out.
         */
	
unsigned int num_pages_ballooned;
	
unsigned int num_pages_onlined;
	
unsigned int num_pages_added;
	/*
         * State to manage the ballooning (up) operation.
         */
	
struct balloon_state balloon_wrk;
	/*
         * State to execute the "hot-add" operation.
         */
	
struct hot_add_wrk ha_wrk;
	/*
         * This state tracks if the host has specified a hot-add
         * region.
         */
	
bool host_specified_ha_region;
	/*
         * State to synchronize hot-add.
         */
	
struct completion  ol_waitevent;
	
bool ha_waiting;
	/*
         * This thread handles hot-add
         * requests from the host as well as notifying
         * the host with regards to memory pressure in
         * the guest.
         */
	
struct task_struct *thread;
	/*
         * Protects ha_region_list, num_pages_onlined counter and individual
         * regions from ha_region_list.
         */
	
spinlock_t ha_lock;
	/*
         * A list of hot-add regions.
         */
	
struct list_head ha_region_list;
	/*
         * We start with the highest version we can support
         * and downgrade based on the host; we save here the
         * next version to try.
         */
	
__u32 next_version;
	/*
         * The negotiated version agreed by host.
         */
	
__u32 version;
};
static struct hv_dynmem_device dm_device;
static void post_status(struct hv_dynmem_device *dm);
#ifdef CONFIG_MEMORY_HOTPLUG
static int hv_memory_notifier(struct notifier_block *nb, unsigned long val,
			      void *v)
{
	struct memory_notify *mem = (struct memory_notify *)v;
	unsigned long flags;
	switch (val) {
	case MEM_ONLINE:
		spin_lock_irqsave(&dm_device.ha_lock, flags);
		dm_device.num_pages_onlined += mem->nr_pages;
		spin_unlock_irqrestore(&dm_device.ha_lock, flags);
		/* Fall through */
	case MEM_CANCEL_ONLINE:
		if (dm_device.ha_waiting) {
			dm_device.ha_waiting = false;
			complete(&dm_device.ol_waitevent);
		}
		break;
	case MEM_OFFLINE:
		spin_lock_irqsave(&dm_device.ha_lock, flags);
		dm_device.num_pages_onlined -= mem->nr_pages;
		spin_unlock_irqrestore(&dm_device.ha_lock, flags);
		break;
	case MEM_GOING_ONLINE:
	case MEM_GOING_OFFLINE:
	case MEM_CANCEL_OFFLINE:
		break;
	}
	return NOTIFY_OK;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Vitaly Kuznetsov | 78 | 54.17% | 5 | 83.33% | 
| K. Y. Srinivasan | 66 | 45.83% | 1 | 16.67% | 
| Total | 144 | 100.00% | 6 | 100.00% | 
static struct notifier_block hv_memory_nb = {
	.notifier_call = hv_memory_notifier,
	.priority = 0
};
/* Check if the particular page is backed and can be onlined and online it. */
static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
{
	unsigned long cur_start_pgp;
	unsigned long cur_end_pgp;
	struct hv_hotadd_gap *gap;
	cur_start_pgp = (unsigned long)pfn_to_page(has->covered_start_pfn);
	cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn);
	/* The page is not backed. */
	if (((unsigned long)pg < cur_start_pgp) ||
	    ((unsigned long)pg >= cur_end_pgp))
		return;
	/* Check for gaps. */
	list_for_each_entry(gap, &has->gap_list, list) {
		cur_start_pgp = (unsigned long)
			pfn_to_page(gap->start_pfn);
		cur_end_pgp = (unsigned long)
			pfn_to_page(gap->end_pfn);
		if (((unsigned long)pg >= cur_start_pgp) &&
		    ((unsigned long)pg < cur_end_pgp)) {
			return;
		}
	}
	/* This frame is currently backed; online the page. */
	__online_page_set_limits(pg);
	__online_page_increment_counters(pg);
	__online_page_free(pg);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Vitaly Kuznetsov | 157 | 100.00% | 1 | 100.00% | 
| Total | 157 | 100.00% | 1 | 100.00% | 
static void hv_bring_pgs_online(struct hv_hotadd_state *has,
				unsigned long start_pfn, unsigned long size)
{
	int i;
	pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn);
	for (i = 0; i < size; i++)
		hv_page_online_one(has, pfn_to_page(start_pfn + i));
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 37 | 66.07% | 1 | 25.00% | 
| Alex Ng | 9 | 16.07% | 1 | 25.00% | 
| Vitaly Kuznetsov | 9 | 16.07% | 1 | 25.00% | 
| Wei Yongjun | 1 | 1.79% | 1 | 25.00% | 
| Total | 56 | 100.00% | 4 | 100.00% | 
static void hv_mem_hot_add(unsigned long start, unsigned long size,
				unsigned long pfn_count,
				struct hv_hotadd_state *has)
{
	int ret = 0;
	int i, nid;
	unsigned long start_pfn;
	unsigned long processed_pfn;
	unsigned long total_pfn = pfn_count;
	unsigned long flags;
	for (i = 0; i < (size/HA_CHUNK); i++) {
		start_pfn = start + (i * HA_CHUNK);
		spin_lock_irqsave(&dm_device.ha_lock, flags);
		has->ha_end_pfn +=  HA_CHUNK;
		if (total_pfn > HA_CHUNK) {
			processed_pfn = HA_CHUNK;
			total_pfn -= HA_CHUNK;
		} else {
			processed_pfn = total_pfn;
			total_pfn = 0;
		}
		has->covered_end_pfn +=  processed_pfn;
		spin_unlock_irqrestore(&dm_device.ha_lock, flags);
		init_completion(&dm_device.ol_waitevent);
		dm_device.ha_waiting = !memhp_auto_online;
		nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
		ret = add_memory(nid, PFN_PHYS((start_pfn)),
				(HA_CHUNK << PAGE_SHIFT));
		if (ret) {
			pr_warn("hot_add memory failed error is %d\n", ret);
			if (ret == -EEXIST) {
				/*
                                 * This error indicates that the error
                                 * is not a transient failure. This is the
                                 * case where the guest's physical address map
                                 * precludes hot adding memory. Stop all further
                                 * memory hot-add.
                                 */
				do_hot_add = false;
			}
			spin_lock_irqsave(&dm_device.ha_lock, flags);
			has->ha_end_pfn -= HA_CHUNK;
			has->covered_end_pfn -=  processed_pfn;
			spin_unlock_irqrestore(&dm_device.ha_lock, flags);
			break;
		}
		/*
                 * Wait for the memory block to be onlined when memory onlining
                 * is done outside of kernel (memhp_auto_online). Since the hot
                 * add has succeeded, it is ok to proceed even if the pages in
                 * the hot added region have not been "onlined" within the
                 * allowed time.
                 */
		if (dm_device.ha_waiting)
			wait_for_completion_timeout(&dm_device.ol_waitevent,
						    5*HZ);
		post_status(&dm_device);
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 215 | 79.93% | 4 | 50.00% | 
| Vitaly Kuznetsov | 53 | 19.70% | 3 | 37.50% | 
| Alex Ng | 1 | 0.37% | 1 | 12.50% | 
| Total | 269 | 100.00% | 8 | 100.00% | 
static void hv_online_page(struct page *pg)
{
	struct hv_hotadd_state *has;
	unsigned long cur_start_pgp;
	unsigned long cur_end_pgp;
	unsigned long flags;
	spin_lock_irqsave(&dm_device.ha_lock, flags);
	list_for_each_entry(has, &dm_device.ha_region_list, list) {
		cur_start_pgp = (unsigned long)
			pfn_to_page(has->start_pfn);
		cur_end_pgp = (unsigned long)pfn_to_page(has->end_pfn);
		/* The page belongs to a different HAS. */
		if (((unsigned long)pg < cur_start_pgp) ||
		    ((unsigned long)pg >= cur_end_pgp))
			continue;
		hv_page_online_one(has, pg);
		break;
	}
	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 79 | 68.10% | 1 | 33.33% | 
| Vitaly Kuznetsov | 37 | 31.90% | 2 | 66.67% | 
| Total | 116 | 100.00% | 3 | 100.00% | 
static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
{
	struct hv_hotadd_state *has;
	struct hv_hotadd_gap *gap;
	unsigned long residual, new_inc;
	int ret = 0;
	unsigned long flags;
	spin_lock_irqsave(&dm_device.ha_lock, flags);
	list_for_each_entry(has, &dm_device.ha_region_list, list) {
		/*
                 * If the pfn range we are dealing with is not in the current
                 * "hot add block", move on.
                 */
		if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
			continue;
		/*
                 * If the current start pfn is not where the covered_end
                 * is, create a gap and update covered_end_pfn.
                 */
		if (has->covered_end_pfn != start_pfn) {
			gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC);
			if (!gap) {
				ret = -ENOMEM;
				break;
			}
			INIT_LIST_HEAD(&gap->list);
			gap->start_pfn = has->covered_end_pfn;
			gap->end_pfn = start_pfn;
			list_add_tail(&gap->list, &has->gap_list);
			has->covered_end_pfn = start_pfn;
		}
		/*
                 * If the current hot add-request extends beyond
                 * our current limit; extend it.
                 */
		if ((start_pfn + pfn_cnt) > has->end_pfn) {
			residual = (start_pfn + pfn_cnt - has->end_pfn);
			/*
                         * Extend the region by multiples of HA_CHUNK.
                         */
			new_inc = (residual / HA_CHUNK) * HA_CHUNK;
			if (residual % HA_CHUNK)
				new_inc += HA_CHUNK;
			has->end_pfn += new_inc;
		}
		ret = 1;
		break;
	}
	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
	return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Vitaly Kuznetsov | 124 | 55.11% | 3 | 75.00% | 
| K. Y. Srinivasan | 101 | 44.89% | 1 | 25.00% | 
| Total | 225 | 100.00% | 4 | 100.00% | 
static unsigned long handle_pg_range(unsigned long pg_start,
					unsigned long pg_count)
{
	unsigned long start_pfn = pg_start;
	unsigned long pfn_cnt = pg_count;
	unsigned long size;
	struct hv_hotadd_state *has;
	unsigned long pgs_ol = 0;
	unsigned long old_covered_state;
	unsigned long res = 0, flags;
	pr_debug("Hot adding %lu pages starting at pfn 0x%lx.\n", pg_count,
		pg_start);
	spin_lock_irqsave(&dm_device.ha_lock, flags);
	list_for_each_entry(has, &dm_device.ha_region_list, list) {
		/*
                 * If the pfn range we are dealing with is not in the current
                 * "hot add block", move on.
                 */
		if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
			continue;
		old_covered_state = has->covered_end_pfn;
		if (start_pfn < has->ha_end_pfn) {
			/*
                         * This is the case where we are backing pages
                         * in an already hot added region. Bring
                         * these pages online first.
                         */
			pgs_ol = has->ha_end_pfn - start_pfn;
			if (pgs_ol > pfn_cnt)
				pgs_ol = pfn_cnt;
			has->covered_end_pfn +=  pgs_ol;
			pfn_cnt -= pgs_ol;
			/*
                         * Check if the corresponding memory block is already
                         * online by checking its last previously backed page.
                         * In case it is we need to bring rest (which was not
                         * backed previously) online too.
                         */
			if (start_pfn > has->start_pfn &&
			    !PageReserved(pfn_to_page(start_pfn - 1)))
				hv_bring_pgs_online(has, start_pfn, pgs_ol);
		}
		if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) {
			/*
                         * We have some residual hot add range
                         * that needs to be hot added; hot add
                         * it now. Hot add a multiple of
                         * of HA_CHUNK that fully covers the pages
                         * we have.
                         */
			size = (has->end_pfn - has->ha_end_pfn);
			if (pfn_cnt <= size) {
				size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK);
				if (pfn_cnt % HA_CHUNK)
					size += HA_CHUNK;
			} else {
				pfn_cnt = size;
			}
			spin_unlock_irqrestore(&dm_device.ha_lock, flags);
			hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has);
			spin_lock_irqsave(&dm_device.ha_lock, flags);
		}
		/*
                 * If we managed to online any pages that were given to us,
                 * we declare success.
                 */
		res = has->covered_end_pfn - old_covered_state;
		break;
	}
	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
	return res;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 200 | 66.89% | 1 | 16.67% | 
| Vitaly Kuznetsov | 90 | 30.10% | 4 | 66.67% | 
| Alex Ng | 9 | 3.01% | 1 | 16.67% | 
| Total | 299 | 100.00% | 6 | 100.00% | 
static unsigned long process_hot_add(unsigned long pg_start,
					unsigned long pfn_cnt,
					unsigned long rg_start,
					unsigned long rg_size)
{
	struct hv_hotadd_state *ha_region = NULL;
	int covered;
	unsigned long flags;
	if (pfn_cnt == 0)
		return 0;
	if (!dm_device.host_specified_ha_region) {
		covered = pfn_covered(pg_start, pfn_cnt);
		if (covered < 0)
			return 0;
		if (covered)
			goto do_pg_range;
	}
	/*
         * If the host has specified a hot-add range; deal with it first.
         */
	if (rg_size != 0) {
		ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL);
		if (!ha_region)
			return 0;
		INIT_LIST_HEAD(&ha_region->list);
		INIT_LIST_HEAD(&ha_region->gap_list);
		ha_region->start_pfn = rg_start;
		ha_region->ha_end_pfn = rg_start;
		ha_region->covered_start_pfn = pg_start;
		ha_region->covered_end_pfn = pg_start;
		ha_region->end_pfn = rg_start + rg_size;
		spin_lock_irqsave(&dm_device.ha_lock, flags);
		list_add_tail(&ha_region->list, &dm_device.ha_region_list);
		spin_unlock_irqrestore(&dm_device.ha_lock, flags);
	}
do_pg_range:
	/*
         * Process the page range specified; bringing them
         * online if possible.
         */
	return handle_pg_range(pg_start, pfn_cnt);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 131 | 64.85% | 1 | 25.00% | 
| Vitaly Kuznetsov | 71 | 35.15% | 3 | 75.00% | 
| Total | 202 | 100.00% | 4 | 100.00% | 
#endif
static void hot_add_req(struct work_struct *dummy)
{
	struct dm_hot_add_response resp;
#ifdef CONFIG_MEMORY_HOTPLUG
	unsigned long pg_start, pfn_cnt;
	unsigned long rg_start, rg_sz;
#endif
	struct hv_dynmem_device *dm = &dm_device;
	memset(&resp, 0, sizeof(struct dm_hot_add_response));
	resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE;
	resp.hdr.size = sizeof(struct dm_hot_add_response);
#ifdef CONFIG_MEMORY_HOTPLUG
	pg_start = dm->ha_wrk.ha_page_range.finfo.start_page;
	pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt;
	rg_start = dm->ha_wrk.ha_region_range.finfo.start_page;
	rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt;
	if ((rg_start == 0) && (!dm->host_specified_ha_region)) {
		unsigned long region_size;
		unsigned long region_start;
		/*
                 * The host has not specified the hot-add region.
                 * Based on the hot-add page range being specified,
                 * compute a hot-add region that can cover the pages
                 * that need to be hot-added while ensuring the alignment
                 * and size requirements of Linux as it relates to hot-add.
                 */
		region_start = pg_start;
		region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
		if (pfn_cnt % HA_CHUNK)
			region_size += HA_CHUNK;
		region_start = (pg_start / HA_CHUNK) * HA_CHUNK;
		rg_start = region_start;
		rg_sz = region_size;
	}
	if (do_hot_add)
		resp.page_count = process_hot_add(pg_start, pfn_cnt,
						rg_start, rg_sz);
	dm->num_pages_added += resp.page_count;
#endif
	/*
         * The result field of the response structure has the
         * following semantics:
         *
         * 1. If all or some pages hot-added: Guest should return success.
         *
         * 2. If no pages could be hot-added:
         *
         * If the guest returns success, then the host
         * will not attempt any further hot-add operations. This
         * signifies a permanent failure.
         *
         * If the guest returns failure, then this failure will be
         * treated as a transient failure and the host may retry the
         * hot-add operation after some delay.
         */
	if (resp.page_count > 0)
		resp.result = 1;
	else if (!do_hot_add)
		resp.result = 1;
	else
		resp.result = 0;
	if (!do_hot_add || (resp.page_count == 0))
		pr_info("Memory hot add failed\n");
	dm->state = DM_INITIALIZED;
	resp.hdr.trans_id = atomic_inc_return(&trans_id);
	vmbus_sendpacket(dm->dev->channel, &resp,
			sizeof(struct dm_hot_add_response),
			(unsigned long)NULL,
			VM_PKT_DATA_INBAND, 0);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 312 | 97.50% | 5 | 83.33% | 
| Vitaly Kuznetsov | 8 | 2.50% | 1 | 16.67% | 
| Total | 320 | 100.00% | 6 | 100.00% | 
static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
{
	struct dm_info_header *info_hdr;
	info_hdr = (struct dm_info_header *)msg->info;
	switch (info_hdr->type) {
	case INFO_TYPE_MAX_PAGE_CNT:
		if (info_hdr->data_size == sizeof(__u64)) {
			__u64 *max_page_count = (__u64 *)&info_hdr[1];
			pr_info("INFO_TYPE_MAX_PAGE_CNT = %llu\n",
				*max_page_count);
		}
		break;
	default:
		pr_info("Received Unknown type: %d\n", info_hdr->type);
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 61 | 68.54% | 2 | 66.67% | 
| Alex Ng | 28 | 31.46% | 1 | 33.33% | 
| Total | 89 | 100.00% | 3 | 100.00% | 
static unsigned long compute_balloon_floor(void)
{
	unsigned long min_pages;
#define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT))
	/* Simple continuous piecewiese linear function:
         *  max MiB -> min MiB  gradient
         *       0         0
         *      16        16
         *      32        24
         *     128        72    (1/2)
         *     512       168    (1/4)
         *    2048       360    (1/8)
         *    8192       744    (1/16)
         *   32768      1512    (1/32)
         */
	if (totalram_pages < MB2PAGES(128))
		min_pages = MB2PAGES(8) + (totalram_pages >> 1);
	else if (totalram_pages < MB2PAGES(512))
		min_pages = MB2PAGES(40) + (totalram_pages >> 2);
	else if (totalram_pages < MB2PAGES(2048))
		min_pages = MB2PAGES(104) + (totalram_pages >> 3);
	else if (totalram_pages < MB2PAGES(8192))
		min_pages = MB2PAGES(232) + (totalram_pages >> 4);
	else
		min_pages = MB2PAGES(488) + (totalram_pages >> 5);
#undef MB2PAGES
	return min_pages;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 128 | 96.97% | 2 | 50.00% | 
| Vitaly Kuznetsov | 3 | 2.27% | 1 | 25.00% | 
| Wei Yongjun | 1 | 0.76% | 1 | 25.00% | 
| Total | 132 | 100.00% | 4 | 100.00% | 
/*
 * Post our status as it relates memory pressure to the
 * host. Host expects the guests to post this status
 * periodically at 1 second intervals.
 *
 * The metrics specified in this protocol are very Windows
 * specific and so we cook up numbers here to convey our memory
 * pressure.
 */
static void post_status(struct hv_dynmem_device *dm)
{
	struct dm_status status;
	unsigned long now = jiffies;
	unsigned long last_post = last_post_time;
	if (pressure_report_delay > 0) {
		--pressure_report_delay;
		return;
	}
	if (!time_after(now, (last_post_time + HZ)))
		return;
	memset(&status, 0, sizeof(struct dm_status));
	status.hdr.type = DM_STATUS_REPORT;
	status.hdr.size = sizeof(struct dm_status);
	status.hdr.trans_id = atomic_inc_return(&trans_id);
	/*
         * The host expects the guest to report free and committed memory.
         * Furthermore, the host expects the pressure information to include
         * the ballooned out pages. For a given amount of memory that we are
         * managing we need to compute a floor below which we should not
         * balloon. Compute this and add it to the pressure report.
         * We also need to report all offline pages (num_pages_added -
         * num_pages_onlined) as committed to the host, otherwise it can try
         * asking us to balloon them out.
         */
	status.num_avail = si_mem_available();
	status.num_committed = vm_memory_committed() +
		dm->num_pages_ballooned +
		(dm->num_pages_added > dm->num_pages_onlined ?
		 dm->num_pages_added - dm->num_pages_onlined : 0) +
		compute_balloon_floor();
	/*
         * If our transaction ID is no longer current, just don't
         * send the status. This can happen if we were interrupted
         * after we picked our transaction ID.
         */
	if (status.hdr.trans_id != atomic_read(&trans_id))
		return;
	/*
         * If the last post time that we sampled has changed,
         * we have raced, don't post the status.
         */
	if (last_post != last_post_time)
		return;
	last_post_time = jiffies;
	vmbus_sendpacket(dm->dev->channel, &status,
				sizeof(struct dm_status),
				(unsigned long)NULL,
				VM_PKT_DATA_INBAND, 0);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 175 | 88.38% | 6 | 75.00% | 
| Vitaly Kuznetsov | 21 | 10.61% | 1 | 12.50% | 
| Alex Ng | 2 | 1.01% | 1 | 12.50% | 
| Total | 198 | 100.00% | 8 | 100.00% | 
static void free_balloon_pages(struct hv_dynmem_device *dm,
			 union dm_mem_page_range *range_array)
{
	int num_pages = range_array->finfo.page_cnt;
	__u64 start_frame = range_array->finfo.start_page;
	struct page *pg;
	int i;
	for (i = 0; i < num_pages; i++) {
		pg = pfn_to_page(i + start_frame);
		__free_page(pg);
		dm->num_pages_ballooned--;
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 75 | 98.68% | 1 | 50.00% | 
| Greg Kroah-Hartman | 1 | 1.32% | 1 | 50.00% | 
| Total | 76 | 100.00% | 2 | 100.00% | 
static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
					unsigned int num_pages,
					struct dm_balloon_response *bl_resp,
					int alloc_unit)
{
	unsigned int i = 0;
	struct page *pg;
	if (num_pages < alloc_unit)
		return 0;
	for (i = 0; (i * alloc_unit) < num_pages; i++) {
		if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) >
			PAGE_SIZE)
			return i * alloc_unit;
		/*
                 * We execute this code in a thread context. Furthermore,
                 * we don't want the kernel to try too hard.
                 */
		pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY |
				__GFP_NOMEMALLOC | __GFP_NOWARN,
				get_order(alloc_unit << PAGE_SHIFT));
		if (!pg)
			return i * alloc_unit;
		dm->num_pages_ballooned += alloc_unit;
		/*
                 * If we allocatted 2M pages; split them so we
                 * can free them in any order we get.
                 */
		if (alloc_unit != 1)
			split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
		bl_resp->range_count++;
		bl_resp->range_array[i].finfo.start_page =
			page_to_pfn(pg);
		bl_resp->range_array[i].finfo.page_cnt = alloc_unit;
		bl_resp->hdr.size += sizeof(union dm_mem_page_range);
	}
	return num_pages;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 186 | 98.41% | 2 | 66.67% | 
| Vitaly Kuznetsov | 3 | 1.59% | 1 | 33.33% | 
| Total | 189 | 100.00% | 3 | 100.00% | 
static void balloon_up(struct work_struct *dummy)
{
	unsigned int num_pages = dm_device.balloon_wrk.num_pages;
	unsigned int num_ballooned = 0;
	struct dm_balloon_response *bl_resp;
	int alloc_unit;
	int ret;
	bool done = false;
	int i;
	long avail_pages;
	unsigned long floor;
	/* The host balloons pages in 2M granularity. */
	WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0);
	/*
         * We will attempt 2M allocations. However, if we fail to
         * allocate 2M chunks, we will go back to 4k allocations.
         */
	alloc_unit = 512;
	avail_pages = si_mem_available();
	floor = compute_balloon_floor();
	/* Refuse to balloon below the floor, keep the 2M granularity. */
	if (avail_pages < num_pages || avail_pages - num_pages < floor) {
		pr_warn("Balloon request will be partially fulfilled. %s\n",
			avail_pages < num_pages ? "Not enough memory." :
			"Balloon floor reached.");
		num_pages = avail_pages > floor ? (avail_pages - floor) : 0;
		num_pages -= num_pages % PAGES_IN_2M;
	}
	while (!done) {
		bl_resp = (struct dm_balloon_response *)send_buffer;
		memset(send_buffer, 0, PAGE_SIZE);
		bl_resp->hdr.type = DM_BALLOON_RESPONSE;
		bl_resp->hdr.size = sizeof(struct dm_balloon_response);
		bl_resp->more_pages = 1;
		num_pages -= num_ballooned;
		num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
						    bl_resp, alloc_unit);
		if (alloc_unit != 1 && num_ballooned == 0) {
			alloc_unit = 1;
			continue;
		}
		if (num_ballooned == 0 || num_ballooned == num_pages) {
			pr_debug("Ballooned %u out of %u requested pages.\n",
				num_pages, dm_device.balloon_wrk.num_pages);
			bl_resp->more_pages = 0;
			done = true;
			dm_device.state = DM_INITIALIZED;
		}
		/*
                 * We are pushing a lot of data through the channel;
                 * deal with transient failures caused because of the
                 * lack of space in the ring buffer.
                 */
		do {
			bl_resp->hdr.trans_id = atomic_inc_return(&trans_id);
			ret = vmbus_sendpacket(dm_device.dev->channel,
						bl_resp,
						bl_resp->hdr.size,
						(unsigned long)NULL,
						VM_PKT_DATA_INBAND, 0);
			if (ret == -EAGAIN)
				msleep(20);
			post_status(&dm_device);
		} while (ret == -EAGAIN);
		if (ret) {
			/*
                         * Free up the memory we allocatted.
                         */
			pr_info("Balloon response failed\n");
			for (i = 0; i < bl_resp->range_count; i++)
				free_balloon_pages(&dm_device,
						 &bl_resp->range_array[i]);
			done = true;
		}
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 272 | 73.71% | 5 | 41.67% | 
| Vitaly Kuznetsov | 46 | 12.47% | 4 | 33.33% | 
| Alex Ng | 36 | 9.76% | 2 | 16.67% | 
| Dexuan Cui | 15 | 4.07% | 1 | 8.33% | 
| Total | 369 | 100.00% | 12 | 100.00% | 
static void balloon_down(struct hv_dynmem_device *dm,
			struct dm_unballoon_request *req)
{
	union dm_mem_page_range *range_array = req->range_array;
	int range_count = req->range_count;
	struct dm_unballoon_response resp;
	int i;
	unsigned int prev_pages_ballooned = dm->num_pages_ballooned;
	for (i = 0; i < range_count; i++) {
		free_balloon_pages(dm, &range_array[i]);
		complete(&dm_device.config_event);
	}
	pr_debug("Freed %u ballooned pages.\n",
		prev_pages_ballooned - dm->num_pages_ballooned);
	if (req->more_pages == 1)
		return;
	memset(&resp, 0, sizeof(struct dm_unballoon_response));
	resp.hdr.type = DM_UNBALLOON_RESPONSE;
	resp.hdr.trans_id = atomic_inc_return(&trans_id);
	resp.hdr.size = sizeof(struct dm_unballoon_response);
	vmbus_sendpacket(dm_device.dev->channel, &resp,
				sizeof(struct dm_unballoon_response),
				(unsigned long)NULL,
				VM_PKT_DATA_INBAND, 0);
	dm->state = DM_INITIALIZED;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 162 | 89.50% | 3 | 75.00% | 
| Alex Ng | 19 | 10.50% | 1 | 25.00% | 
| Total | 181 | 100.00% | 4 | 100.00% | 
static void balloon_onchannelcallback(void *context);
static int dm_thread_func(void *dm_dev)
{
	struct hv_dynmem_device *dm = dm_dev;
	while (!kthread_should_stop()) {
		wait_for_completion_interruptible_timeout(
						&dm_device.config_event, 1*HZ);
		/*
                 * The host expects us to post information on the memory
                 * pressure every second.
                 */
		reinit_completion(&dm_device.config_event);
		post_status(dm);
	}
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 54 | 100.00% | 3 | 100.00% | 
| Total | 54 | 100.00% | 3 | 100.00% | 
static void version_resp(struct hv_dynmem_device *dm,
			struct dm_version_response *vresp)
{
	struct dm_version_request version_req;
	int ret;
	if (vresp->is_accepted) {
		/*
                 * We are done; wakeup the
                 * context waiting for version
                 * negotiation.
                 */
		complete(&dm->host_event);
		return;
	}
	/*
         * If there are more versions to try, continue
         * with negotiations; if not
         * shutdown the service since we are not able
         * to negotiate a suitable version number
         * with the host.
         */
	if (dm->next_version == 0)
		goto version_error;
	memset(&version_req, 0, sizeof(struct dm_version_request));
	version_req.hdr.type = DM_VERSION_REQUEST;
	version_req.hdr.size = sizeof(struct dm_version_request);
	version_req.hdr.trans_id = atomic_inc_return(&trans_id);
	version_req.version.version = dm->next_version;
	dm->version = version_req.version.version;
	/*
         * Set the next version to try in case current version fails.
         * Win7 protocol ought to be the last one to try.
         */
	switch (version_req.version.version) {
	case DYNMEM_PROTOCOL_VERSION_WIN8:
		dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
		version_req.is_last_attempt = 0;
		break;
	default:
		dm->next_version = 0;
		version_req.is_last_attempt = 1;
	}
	ret = vmbus_sendpacket(dm->dev->channel, &version_req,
				sizeof(struct dm_version_request),
				(unsigned long)NULL,
				VM_PKT_DATA_INBAND, 0);
	if (ret)
		goto version_error;
	return;
version_error:
	dm->state = DM_INIT_ERROR;
	complete(&dm->host_event);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 167 | 78.40% | 1 | 33.33% | 
| Alex Ng | 46 | 21.60% | 2 | 66.67% | 
| Total | 213 | 100.00% | 3 | 100.00% | 
static void cap_resp(struct hv_dynmem_device *dm,
			struct dm_capabilities_resp_msg *cap_resp)
{
	if (!cap_resp->is_accepted) {
		pr_info("Capabilities not accepted by host\n");
		dm->state = DM_INIT_ERROR;
	}
	complete(&dm->host_event);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 44 | 100.00% | 1 | 100.00% | 
| Total | 44 | 100.00% | 1 | 100.00% | 
static void balloon_onchannelcallback(void *context)
{
	struct hv_device *dev = context;
	u32 recvlen;
	u64 requestid;
	struct dm_message *dm_msg;
	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;
	union dm_mem_page_range *ha_region;
	memset(recv_buffer, 0, sizeof(recv_buffer));
	vmbus_recvpacket(dev->channel, recv_buffer,
			 PAGE_SIZE, &recvlen, &requestid);
	if (recvlen > 0) {
		dm_msg = (struct dm_message *)recv_buffer;
		dm_hdr = &dm_msg->hdr;
		switch (dm_hdr->type) {
		case DM_VERSION_RESPONSE:
			version_resp(dm,
				 (struct dm_version_response *)dm_msg);
			break;
		case DM_CAPABILITIES_RESPONSE:
			cap_resp(dm,
				 (struct dm_capabilities_resp_msg *)dm_msg);
			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;
			dm_device.balloon_wrk.num_pages = bal_msg->num_pages;
			schedule_work(&dm_device.balloon_wrk.wrk);
			break;
		case DM_UNBALLOON_REQUEST:
			dm->state = DM_BALLOON_DOWN;
			balloon_down(dm,
				 (struct dm_unballoon_request *)recv_buffer);
			break;
		case DM_MEM_HOT_ADD_REQUEST:
			if (dm->state == DM_HOT_ADD)
				pr_warn("Currently hot-adding\n");
			dm->state = DM_HOT_ADD;
			ha_msg = (struct dm_hot_add *)recv_buffer;
			if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) {
				/*
                                 * This is a normal hot-add request specifying
                                 * hot-add memory.
                                 */
				dm->host_specified_ha_region = false;
				ha_pg_range = &ha_msg->range;
				dm->ha_wrk.ha_page_range = *ha_pg_range;
				dm->ha_wrk.ha_region_range.page_range = 0;
			} else {
				/*
                                 * Host is specifying that we first hot-add
                                 * a region and then partially populate this
                                 * region.
                                 */
				dm->host_specified_ha_region = true;
				ha_pg_range = &ha_msg->range;
				ha_region = &ha_pg_range[1];
				dm->ha_wrk.ha_page_range = *ha_pg_range;
				dm->ha_wrk.ha_region_range = *ha_region;
			}
			schedule_work(&dm_device.ha_wrk.wrk);
			break;
		case DM_INFO_MESSAGE:
			process_info(dm, (struct dm_info_msg *)dm_msg);
			break;
		default:
			pr_err("Unhandled message: type: %d\n", dm_hdr->type);
		}
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 384 | 98.46% | 4 | 80.00% | 
| Vitaly Kuznetsov | 6 | 1.54% | 1 | 20.00% | 
| Total | 390 | 100.00% | 5 | 100.00% | 
static int balloon_probe(struct hv_device *dev,
			const struct hv_vmbus_device_id *dev_id)
{
	int ret;
	unsigned long t;
	struct dm_version_request version_req;
	struct dm_capabilities cap_msg;
#ifdef CONFIG_MEMORY_HOTPLUG
	do_hot_add = hot_add;
#else
	do_hot_add = false;
#endif
	/*
         * First allocate a send buffer.
         */
	send_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!send_buffer)
		return -ENOMEM;
	ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0,
			balloon_onchannelcallback, dev);
	if (ret)
		goto probe_error0;
	dm_device.dev = dev;
	dm_device.state = DM_INITIALIZING;
	dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8;
	init_completion(&dm_device.host_event);
	init_completion(&dm_device.config_event);
	INIT_LIST_HEAD(&dm_device.ha_region_list);
	spin_lock_init(&dm_device.ha_lock);
	INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up);
	INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req);
	dm_device.host_specified_ha_region = false;
	dm_device.thread =
		 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
	if (IS_ERR(dm_device.thread)) {
		ret = PTR_ERR(dm_device.thread);
		goto probe_error1;
	}
#ifdef CONFIG_MEMORY_HOTPLUG
	set_online_page_callback(&hv_online_page);
	register_memory_notifier(&hv_memory_nb);
#endif
	hv_set_drvdata(dev, &dm_device);
	/*
         * Initiate the hand shake with the host and negotiate
         * a version that the host can support. We start with the
         * highest version number and go down if the host cannot
         * support it.
         */
	memset(&version_req, 0, sizeof(struct dm_version_request));
	version_req.hdr.type = DM_VERSION_REQUEST;
	version_req.hdr.size = sizeof(struct dm_version_request);
	version_req.hdr.trans_id = atomic_inc_return(&trans_id);
	version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10;
	version_req.is_last_attempt = 0;
	dm_device.version = version_req.version.version;
	ret = vmbus_sendpacket(dev->channel, &version_req,
				sizeof(struct dm_version_request),
				(unsigned long)NULL,
				VM_PKT_DATA_INBAND, 0);
	if (ret)
		goto probe_error2;
	t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
	if (t == 0) {
		ret = -ETIMEDOUT;
		goto probe_error2;
	}
	/*
         * If we could not negotiate a compatible version with the host
         * fail the probe function.
         */
	if (dm_device.state == DM_INIT_ERROR) {
		ret = -ETIMEDOUT;
		goto probe_error2;
	}
	pr_info("Using Dynamic Memory protocol version %u.%u\n",
		DYNMEM_MAJOR_VERSION(dm_device.version),
		DYNMEM_MINOR_VERSION(dm_device.version));
	/*
         * Now submit our capabilities to the host.
         */
	memset(&cap_msg, 0, sizeof(struct dm_capabilities));
	cap_msg.hdr.type = DM_CAPABILITIES_REPORT;
	cap_msg.hdr.size = sizeof(struct dm_capabilities);
	cap_msg.hdr.trans_id = atomic_inc_return(&trans_id);
	cap_msg.caps.cap_bits.balloon = 1;
	cap_msg.caps.cap_bits.hot_add = 1;
	/*
         * Specify our alignment requirements as it relates
         * memory hot-add. Specify 128MB alignment.
         */
	cap_msg.caps.cap_bits.hot_add_alignment = 7;
	/*
         * Currently the host does not use these
         * values and we set them to what is done in the
         * Windows driver.
         */
	cap_msg.min_page_cnt = 0;
	cap_msg.max_page_number = -1;
	ret = vmbus_sendpacket(dev->channel, &cap_msg,
				sizeof(struct dm_capabilities),
				(unsigned long)NULL,
				VM_PKT_DATA_INBAND, 0);
	if (ret)
		goto probe_error2;
	t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
	if (t == 0) {
		ret = -ETIMEDOUT;
		goto probe_error2;
	}
	/*
         * If the host does not like our capabilities,
         * fail the probe function.
         */
	if (dm_device.state == DM_INIT_ERROR) {
		ret = -ETIMEDOUT;
		goto probe_error2;
	}
	dm_device.state = DM_INITIALIZED;
	return 0;
probe_error2:
#ifdef CONFIG_MEMORY_HOTPLUG
	restore_online_page_callback(&hv_online_page);
#endif
	kthread_stop(dm_device.thread);
probe_error1:
	vmbus_close(dev->channel);
probe_error0:
	kfree(send_buffer);
	return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 587 | 92.59% | 8 | 61.54% | 
| Alex Ng | 42 | 6.62% | 3 | 23.08% | 
| Nicholas Mc Guire | 3 | 0.47% | 1 | 7.69% | 
| Vitaly Kuznetsov | 2 | 0.32% | 1 | 7.69% | 
| Total | 634 | 100.00% | 13 | 100.00% | 
static int balloon_remove(struct hv_device *dev)
{
	struct hv_dynmem_device *dm = hv_get_drvdata(dev);
	struct hv_hotadd_state *has, *tmp;
	struct hv_hotadd_gap *gap, *tmp_gap;
	unsigned long flags;
	if (dm->num_pages_ballooned != 0)
		pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned);
	cancel_work_sync(&dm->balloon_wrk.wrk);
	cancel_work_sync(&dm->ha_wrk.wrk);
	vmbus_close(dev->channel);
	kthread_stop(dm->thread);
	kfree(send_buffer);
#ifdef CONFIG_MEMORY_HOTPLUG
	restore_online_page_callback(&hv_online_page);
	unregister_memory_notifier(&hv_memory_nb);
#endif
	spin_lock_irqsave(&dm_device.ha_lock, flags);
	list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) {
		list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
			list_del(&gap->list);
			kfree(gap);
		}
		list_del(&has->list);
		kfree(has);
	}
	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 125 | 66.84% | 6 | 75.00% | 
| Vitaly Kuznetsov | 62 | 33.16% | 2 | 25.00% | 
| Total | 187 | 100.00% | 8 | 100.00% | 
static const struct hv_vmbus_device_id id_table[] = {
	/* Dynamic Memory Class ID */
	/* 525074DC-8985-46e2-8057-A307DC18A502 */
	{ HV_DM_GUID, },
	{ },
};
MODULE_DEVICE_TABLE(vmbus, id_table);
static  struct hv_driver balloon_drv = {
	.name = "hv_balloon",
	.id_table = id_table,
	.probe =  balloon_probe,
	.remove =  balloon_remove,
};
static int __init init_balloon_drv(void)
{
	return vmbus_driver_register(&balloon_drv);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 16 | 100.00% | 1 | 100.00% | 
| Total | 16 | 100.00% | 1 | 100.00% | 
module_init(init_balloon_drv);
MODULE_DESCRIPTION("Hyper-V Balloon");
MODULE_LICENSE("GPL");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| K. Y. Srinivasan | 4499 | 81.22% | 21 | 44.68% | 
| Vitaly Kuznetsov | 809 | 14.61% | 17 | 36.17% | 
| Alex Ng | 210 | 3.79% | 5 | 10.64% | 
| Dexuan Cui | 15 | 0.27% | 1 | 2.13% | 
| Nicholas Mc Guire | 3 | 0.05% | 1 | 2.13% | 
| Wei Yongjun | 2 | 0.04% | 1 | 2.13% | 
| Greg Kroah-Hartman | 1 | 0.02% | 1 | 2.13% | 
| Total | 5539 | 100.00% | 47 | 100.00% | 
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.