1094 строки
25 KiB
C
1094 строки
25 KiB
C
/*
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* Copyright (c) 2012, Microsoft Corporation.
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*
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* Author:
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* K. Y. Srinivasan <kys@microsoft.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/mman.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/kthread.h>
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#include <linux/completion.h>
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#include <linux/memory_hotplug.h>
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#include <linux/memory.h>
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#include <linux/notifier.h>
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#include <linux/percpu_counter.h>
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#include <linux/hyperv.h>
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/*
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* We begin with definitions supporting the Dynamic Memory protocol
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* with the host.
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*
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* Begin protocol definitions.
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*/
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/*
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* Protocol versions. The low word is the minor version, the high word the major
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* version.
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*
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* History:
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* Initial version 1.0
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* Changed to 0.1 on 2009/03/25
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* Changes to 0.2 on 2009/05/14
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* Changes to 0.3 on 2009/12/03
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* Changed to 1.0 on 2011/04/05
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*/
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#define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor)))
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#define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16)
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#define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff)
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enum {
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DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3),
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DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0),
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DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
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DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
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DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN8
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};
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/*
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* Message Types
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*/
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enum dm_message_type {
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/*
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* Version 0.3
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*/
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DM_ERROR = 0,
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DM_VERSION_REQUEST = 1,
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DM_VERSION_RESPONSE = 2,
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DM_CAPABILITIES_REPORT = 3,
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DM_CAPABILITIES_RESPONSE = 4,
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DM_STATUS_REPORT = 5,
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DM_BALLOON_REQUEST = 6,
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DM_BALLOON_RESPONSE = 7,
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DM_UNBALLOON_REQUEST = 8,
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DM_UNBALLOON_RESPONSE = 9,
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DM_MEM_HOT_ADD_REQUEST = 10,
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DM_MEM_HOT_ADD_RESPONSE = 11,
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DM_VERSION_03_MAX = 11,
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/*
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* Version 1.0.
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*/
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DM_INFO_MESSAGE = 12,
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DM_VERSION_1_MAX = 12
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};
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/*
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* Structures defining the dynamic memory management
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* protocol.
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*/
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union dm_version {
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struct {
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__u16 minor_version;
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__u16 major_version;
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};
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__u32 version;
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} __packed;
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union dm_caps {
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struct {
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__u64 balloon:1;
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__u64 hot_add:1;
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__u64 reservedz:62;
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} cap_bits;
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__u64 caps;
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} __packed;
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union dm_mem_page_range {
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struct {
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/*
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* The PFN number of the first page in the range.
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* 40 bits is the architectural limit of a PFN
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* number for AMD64.
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*/
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__u64 start_page:40;
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/*
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* The number of pages in the range.
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*/
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__u64 page_cnt:24;
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} finfo;
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__u64 page_range;
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} __packed;
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/*
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* The header for all dynamic memory messages:
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*
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* type: Type of the message.
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* size: Size of the message in bytes; including the header.
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* trans_id: The guest is responsible for manufacturing this ID.
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*/
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struct dm_header {
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__u16 type;
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__u16 size;
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__u32 trans_id;
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} __packed;
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/*
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* A generic message format for dynamic memory.
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* Specific message formats are defined later in the file.
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*/
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struct dm_message {
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struct dm_header hdr;
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__u8 data[]; /* enclosed message */
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} __packed;
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/*
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* Specific message types supporting the dynamic memory protocol.
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*/
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/*
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* Version negotiation message. Sent from the guest to the host.
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* The guest is free to try different versions until the host
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* accepts the version.
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*
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* dm_version: The protocol version requested.
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* is_last_attempt: If TRUE, this is the last version guest will request.
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* reservedz: Reserved field, set to zero.
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*/
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struct dm_version_request {
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struct dm_header hdr;
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union dm_version version;
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__u32 is_last_attempt:1;
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__u32 reservedz:31;
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} __packed;
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/*
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* Version response message; Host to Guest and indicates
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* if the host has accepted the version sent by the guest.
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*
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* is_accepted: If TRUE, host has accepted the version and the guest
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* should proceed to the next stage of the protocol. FALSE indicates that
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* guest should re-try with a different version.
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*
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* reservedz: Reserved field, set to zero.
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*/
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struct dm_version_response {
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struct dm_header hdr;
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__u64 is_accepted:1;
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__u64 reservedz:63;
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} __packed;
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/*
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* Message reporting capabilities. This is sent from the guest to the
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* host.
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*/
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struct dm_capabilities {
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struct dm_header hdr;
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union dm_caps caps;
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__u64 min_page_cnt;
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__u64 max_page_number;
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} __packed;
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/*
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* Response to the capabilities message. This is sent from the host to the
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* guest. This message notifies if the host has accepted the guest's
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* capabilities. If the host has not accepted, the guest must shutdown
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* the service.
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*
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* is_accepted: Indicates if the host has accepted guest's capabilities.
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* reservedz: Must be 0.
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*/
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struct dm_capabilities_resp_msg {
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struct dm_header hdr;
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__u64 is_accepted:1;
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__u64 reservedz:63;
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} __packed;
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/*
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* This message is used to report memory pressure from the guest.
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* This message is not part of any transaction and there is no
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* response to this message.
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*
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* num_avail: Available memory in pages.
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* num_committed: Committed memory in pages.
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* page_file_size: The accumulated size of all page files
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* in the system in pages.
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* zero_free: The nunber of zero and free pages.
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* page_file_writes: The writes to the page file in pages.
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* io_diff: An indicator of file cache efficiency or page file activity,
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* calculated as File Cache Page Fault Count - Page Read Count.
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* This value is in pages.
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*
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* Some of these metrics are Windows specific and fortunately
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* the algorithm on the host side that computes the guest memory
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* pressure only uses num_committed value.
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*/
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struct dm_status {
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struct dm_header hdr;
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__u64 num_avail;
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__u64 num_committed;
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__u64 page_file_size;
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__u64 zero_free;
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__u32 page_file_writes;
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__u32 io_diff;
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} __packed;
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/*
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* Message to ask the guest to allocate memory - balloon up message.
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* This message is sent from the host to the guest. The guest may not be
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* able to allocate as much memory as requested.
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*
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* num_pages: number of pages to allocate.
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*/
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struct dm_balloon {
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struct dm_header hdr;
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__u32 num_pages;
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__u32 reservedz;
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} __packed;
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/*
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* Balloon response message; this message is sent from the guest
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* to the host in response to the balloon message.
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*
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* reservedz: Reserved; must be set to zero.
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* more_pages: If FALSE, this is the last message of the transaction.
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* if TRUE there will atleast one more message from the guest.
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*
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* range_count: The number of ranges in the range array.
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*
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* range_array: An array of page ranges returned to the host.
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*
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*/
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struct dm_balloon_response {
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struct dm_header hdr;
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__u32 reservedz;
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__u32 more_pages:1;
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__u32 range_count:31;
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union dm_mem_page_range range_array[];
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} __packed;
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/*
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* Un-balloon message; this message is sent from the host
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* to the guest to give guest more memory.
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*
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* more_pages: If FALSE, this is the last message of the transaction.
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* if TRUE there will atleast one more message from the guest.
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*
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* reservedz: Reserved; must be set to zero.
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*
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* range_count: The number of ranges in the range array.
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*
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* range_array: An array of page ranges returned to the host.
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*
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*/
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struct dm_unballoon_request {
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struct dm_header hdr;
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__u32 more_pages:1;
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__u32 reservedz:31;
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__u32 range_count;
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union dm_mem_page_range range_array[];
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} __packed;
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/*
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* Un-balloon response message; this message is sent from the guest
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* to the host in response to an unballoon request.
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*
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*/
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struct dm_unballoon_response {
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struct dm_header hdr;
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} __packed;
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/*
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* Hot add request message. Message sent from the host to the guest.
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*
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* mem_range: Memory range to hot add.
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*
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* On Linux we currently don't support this since we cannot hot add
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* arbitrary granularity of memory.
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*/
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struct dm_hot_add {
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struct dm_header hdr;
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union dm_mem_page_range range;
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} __packed;
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/*
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* Hot add response message.
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* This message is sent by the guest to report the status of a hot add request.
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* If page_count is less than the requested page count, then the host should
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* assume all further hot add requests will fail, since this indicates that
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* the guest has hit an upper physical memory barrier.
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*
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* Hot adds may also fail due to low resources; in this case, the guest must
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* not complete this message until the hot add can succeed, and the host must
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* not send a new hot add request until the response is sent.
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* If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS
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* times it fails the request.
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*
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*
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* page_count: number of pages that were successfully hot added.
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*
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* result: result of the operation 1: success, 0: failure.
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*
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*/
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struct dm_hot_add_response {
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struct dm_header hdr;
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__u32 page_count;
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__u32 result;
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} __packed;
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/*
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* Types of information sent from host to the guest.
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*/
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enum dm_info_type {
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INFO_TYPE_MAX_PAGE_CNT = 0,
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MAX_INFO_TYPE
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};
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/*
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* Header for the information message.
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*/
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struct dm_info_header {
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enum dm_info_type type;
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__u32 data_size;
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} __packed;
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/*
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* This message is sent from the host to the guest to pass
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* some relevant information (win8 addition).
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*
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* reserved: no used.
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* info_size: size of the information blob.
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* info: information blob.
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*/
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struct dm_info_msg {
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struct dm_header hdr;
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__u32 reserved;
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__u32 info_size;
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__u8 info[];
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};
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/*
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* End protocol definitions.
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*/
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static bool hot_add;
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static bool do_hot_add;
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/*
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* Delay reporting memory pressure by
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* the specified number of seconds.
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*/
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static uint pressure_report_delay = 30;
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module_param(hot_add, bool, (S_IRUGO | S_IWUSR));
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MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add");
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module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
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MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
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static atomic_t trans_id = ATOMIC_INIT(0);
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static int dm_ring_size = (5 * PAGE_SIZE);
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/*
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* Driver specific state.
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*/
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enum hv_dm_state {
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DM_INITIALIZING = 0,
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DM_INITIALIZED,
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DM_BALLOON_UP,
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DM_BALLOON_DOWN,
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DM_HOT_ADD,
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DM_INIT_ERROR
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};
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static __u8 recv_buffer[PAGE_SIZE];
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static __u8 *send_buffer;
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#define PAGES_IN_2M 512
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struct hv_dynmem_device {
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struct hv_device *dev;
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enum hv_dm_state state;
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struct completion host_event;
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struct completion config_event;
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/*
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* Number of pages we have currently ballooned out.
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*/
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unsigned int num_pages_ballooned;
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/*
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* This thread handles both balloon/hot-add
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* requests from the host as well as notifying
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* the host with regards to memory pressure in
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* the guest.
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*/
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struct task_struct *thread;
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/*
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* We start with the highest version we can support
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* and downgrade based on the host; we save here the
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* next version to try.
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*/
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__u32 next_version;
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};
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static struct hv_dynmem_device dm_device;
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static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg)
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{
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struct dm_hot_add_response resp;
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if (do_hot_add) {
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pr_info("Memory hot add not supported\n");
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/*
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* Currently we do not support hot add.
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* Just fail the request.
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*/
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}
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memset(&resp, 0, sizeof(struct dm_hot_add_response));
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resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE;
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resp.hdr.size = sizeof(struct dm_hot_add_response);
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resp.hdr.trans_id = atomic_inc_return(&trans_id);
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resp.page_count = 0;
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resp.result = 0;
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dm->state = DM_INITIALIZED;
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vmbus_sendpacket(dm->dev->channel, &resp,
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sizeof(struct dm_hot_add_response),
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(unsigned long)NULL,
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VM_PKT_DATA_INBAND, 0);
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}
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static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
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{
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struct dm_info_header *info_hdr;
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info_hdr = (struct dm_info_header *)msg->info;
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switch (info_hdr->type) {
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case INFO_TYPE_MAX_PAGE_CNT:
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pr_info("Received INFO_TYPE_MAX_PAGE_CNT\n");
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pr_info("Data Size is %d\n", info_hdr->data_size);
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break;
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default:
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pr_info("Received Unknown type: %d\n", info_hdr->type);
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}
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}
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unsigned long compute_balloon_floor(void)
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{
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unsigned long min_pages;
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#define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT))
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/* Simple continuous piecewiese linear function:
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* max MiB -> min MiB gradient
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* 0 0
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* 16 16
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* 32 24
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* 128 72 (1/2)
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* 512 168 (1/4)
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* 2048 360 (1/8)
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* 8192 552 (1/32)
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* 32768 1320
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* 131072 4392
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*/
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if (totalram_pages < MB2PAGES(128))
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min_pages = MB2PAGES(8) + (totalram_pages >> 1);
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else if (totalram_pages < MB2PAGES(512))
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min_pages = MB2PAGES(40) + (totalram_pages >> 2);
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else if (totalram_pages < MB2PAGES(2048))
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min_pages = MB2PAGES(104) + (totalram_pages >> 3);
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else
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min_pages = MB2PAGES(296) + (totalram_pages >> 5);
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#undef MB2PAGES
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return min_pages;
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}
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/*
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* Post our status as it relates memory pressure to the
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* host. Host expects the guests to post this status
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* periodically at 1 second intervals.
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*
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* The metrics specified in this protocol are very Windows
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* specific and so we cook up numbers here to convey our memory
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* pressure.
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*/
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static void post_status(struct hv_dynmem_device *dm)
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{
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struct dm_status status;
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struct sysinfo val;
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if (pressure_report_delay > 0) {
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--pressure_report_delay;
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return;
|
|
}
|
|
si_meminfo(&val);
|
|
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 memory.
|
|
* Further, 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.
|
|
*/
|
|
status.num_avail = val.freeram;
|
|
status.num_committed = vm_memory_committed() +
|
|
dm->num_pages_ballooned +
|
|
compute_balloon_floor();
|
|
|
|
vmbus_sendpacket(dm->dev->channel, &status,
|
|
sizeof(struct dm_status),
|
|
(unsigned long)NULL,
|
|
VM_PKT_DATA_INBAND, 0);
|
|
|
|
}
|
|
|
|
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--;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
static int alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages,
|
|
struct dm_balloon_response *bl_resp, int alloc_unit,
|
|
bool *alloc_error)
|
|
{
|
|
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) {
|
|
*alloc_error = true;
|
|
return i * alloc_unit;
|
|
}
|
|
|
|
|
|
dm->num_pages_ballooned += alloc_unit;
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
|
|
static void balloon_up(struct hv_dynmem_device *dm, struct dm_balloon *req)
|
|
{
|
|
int num_pages = req->num_pages;
|
|
int num_ballooned = 0;
|
|
struct dm_balloon_response *bl_resp;
|
|
int alloc_unit;
|
|
int ret;
|
|
bool alloc_error = false;
|
|
bool done = false;
|
|
int i;
|
|
|
|
|
|
/*
|
|
* Currently, we only support 4k allocations.
|
|
*/
|
|
alloc_unit = 1;
|
|
|
|
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.trans_id = atomic_inc_return(&trans_id);
|
|
bl_resp->hdr.size = sizeof(struct dm_balloon_response);
|
|
bl_resp->more_pages = 1;
|
|
|
|
|
|
num_pages -= num_ballooned;
|
|
num_ballooned = alloc_balloon_pages(dm, 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;
|
|
}
|
|
|
|
/*
|
|
* 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 {
|
|
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);
|
|
|
|
} 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,
|
|
&bl_resp->range_array[i]);
|
|
|
|
done = true;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
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;
|
|
|
|
for (i = 0; i < range_count; i++)
|
|
free_balloon_pages(dm, &range_array[i]);
|
|
|
|
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;
|
|
}
|
|
|
|
static void balloon_onchannelcallback(void *context);
|
|
|
|
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);
|
|
/*
|
|
* The host expects us to post information on the memory
|
|
* pressure every second.
|
|
*/
|
|
|
|
if (t == 0)
|
|
post_status(dm);
|
|
|
|
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);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (!time_in_range(jiffies, scan_start, scan_start + HZ))
|
|
post_status(dm);
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
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;
|
|
|
|
dm->next_version = 0;
|
|
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_WIN7;
|
|
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);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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);
|
|
|
|
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:
|
|
dm->state = DM_BALLOON_UP;
|
|
complete(&dm->config_event);
|
|
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:
|
|
dm->state = DM_HOT_ADD;
|
|
complete(&dm->config_event);
|
|
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);
|
|
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
static int balloon_probe(struct hv_device *dev,
|
|
const struct hv_vmbus_device_id *dev_id)
|
|
{
|
|
int ret, t;
|
|
struct dm_version_request version_req;
|
|
struct dm_capabilities cap_msg;
|
|
|
|
do_hot_add = hot_add;
|
|
|
|
/*
|
|
* 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_WIN7;
|
|
init_completion(&dm_device.host_event);
|
|
init_completion(&dm_device.config_event);
|
|
|
|
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;
|
|
}
|
|
|
|
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_WIN8;
|
|
version_req.is_last_attempt = 0;
|
|
|
|
ret = vmbus_sendpacket(dev->channel, &version_req,
|
|
sizeof(struct dm_version_request),
|
|
(unsigned long)NULL,
|
|
VM_PKT_DATA_INBAND,
|
|
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
|
|
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;
|
|
}
|
|
/*
|
|
* 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;
|
|
/*
|
|
* While we currently don't support hot-add,
|
|
* we still advertise this capability since the
|
|
* host requires that guests partcipating in the
|
|
* dynamic memory protocol support hot add.
|
|
*/
|
|
cap_msg.caps.cap_bits.hot_add = 1;
|
|
|
|
/*
|
|
* 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,
|
|
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
|
|
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:
|
|
kthread_stop(dm_device.thread);
|
|
|
|
probe_error1:
|
|
vmbus_close(dev->channel);
|
|
probe_error0:
|
|
kfree(send_buffer);
|
|
return ret;
|
|
}
|
|
|
|
static int balloon_remove(struct hv_device *dev)
|
|
{
|
|
struct hv_dynmem_device *dm = hv_get_drvdata(dev);
|
|
|
|
if (dm->num_pages_ballooned != 0)
|
|
pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned);
|
|
|
|
vmbus_close(dev->channel);
|
|
kthread_stop(dm->thread);
|
|
kfree(send_buffer);
|
|
|
|
return 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static void exit_balloon_drv(void)
|
|
{
|
|
|
|
vmbus_driver_unregister(&balloon_drv);
|
|
}
|
|
|
|
module_init(init_balloon_drv);
|
|
module_exit(exit_balloon_drv);
|
|
|
|
MODULE_DESCRIPTION("Hyper-V Balloon");
|
|
MODULE_VERSION(HV_DRV_VERSION);
|
|
MODULE_LICENSE("GPL");
|