/*
* 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/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_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN8
};
/*
* 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;
__u64 reservedz:62;
} 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