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![Dmitry Torokhov](/assets/img/avatar_default.png)
Signed-off-by: Dmitry Torokhov <dtor@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
839 lines
21 KiB
C
839 lines
21 KiB
C
/*
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* VMware Balloon driver.
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*
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* Copyright (C) 2000-2010, VMware, Inc. All Rights Reserved.
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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 as published by the
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* Free Software Foundation; version 2 of the License and no later version.
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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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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Maintained by: Xavier Deguillard <xdeguillard@vmware.com>
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* Philip Moltmann <moltmann@vmware.com>
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*/
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/*
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* This is VMware physical memory management driver for Linux. The driver
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* acts like a "balloon" that can be inflated to reclaim physical pages by
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* reserving them in the guest and invalidating them in the monitor,
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* freeing up the underlying machine pages so they can be allocated to
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* other guests. The balloon can also be deflated to allow the guest to
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* use more physical memory. Higher level policies can control the sizes
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* of balloons in VMs in order to manage physical memory resources.
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*/
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//#define DEBUG
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/workqueue.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <asm/hypervisor.h>
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MODULE_AUTHOR("VMware, Inc.");
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MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
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MODULE_VERSION("1.2.1.3-k");
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MODULE_ALIAS("dmi:*:svnVMware*:*");
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MODULE_ALIAS("vmware_vmmemctl");
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MODULE_LICENSE("GPL");
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/*
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* Various constants controlling rate of inflaint/deflating balloon,
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* measured in pages.
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*/
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/*
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* Rate of allocating memory when there is no memory pressure
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* (driver performs non-sleeping allocations).
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*/
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#define VMW_BALLOON_NOSLEEP_ALLOC_MAX 16384U
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/*
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* Rates of memory allocaton when guest experiences memory pressure
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* (driver performs sleeping allocations).
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*/
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#define VMW_BALLOON_RATE_ALLOC_MIN 512U
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#define VMW_BALLOON_RATE_ALLOC_MAX 2048U
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#define VMW_BALLOON_RATE_ALLOC_INC 16U
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/*
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* Rates for releasing pages while deflating balloon.
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*/
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#define VMW_BALLOON_RATE_FREE_MIN 512U
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#define VMW_BALLOON_RATE_FREE_MAX 16384U
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#define VMW_BALLOON_RATE_FREE_INC 16U
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/*
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* When guest is under memory pressure, use a reduced page allocation
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* rate for next several cycles.
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*/
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#define VMW_BALLOON_SLOW_CYCLES 4
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/*
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* Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We don't
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* allow wait (__GFP_WAIT) for NOSLEEP page allocations. Use
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* __GFP_NOWARN, to suppress page allocation failure warnings.
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*/
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#define VMW_PAGE_ALLOC_NOSLEEP (__GFP_HIGHMEM|__GFP_NOWARN)
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/*
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* Use GFP_HIGHUSER when executing in a separate kernel thread
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* context and allocation can sleep. This is less stressful to
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* the guest memory system, since it allows the thread to block
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* while memory is reclaimed, and won't take pages from emergency
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* low-memory pools.
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*/
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#define VMW_PAGE_ALLOC_CANSLEEP (GFP_HIGHUSER)
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/* Maximum number of page allocations without yielding processor */
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#define VMW_BALLOON_YIELD_THRESHOLD 1024
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/* Maximum number of refused pages we accumulate during inflation cycle */
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#define VMW_BALLOON_MAX_REFUSED 16
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/*
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* Hypervisor communication port definitions.
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*/
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#define VMW_BALLOON_HV_PORT 0x5670
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#define VMW_BALLOON_HV_MAGIC 0x456c6d6f
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#define VMW_BALLOON_PROTOCOL_VERSION 2
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#define VMW_BALLOON_GUEST_ID 1 /* Linux */
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#define VMW_BALLOON_CMD_START 0
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#define VMW_BALLOON_CMD_GET_TARGET 1
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#define VMW_BALLOON_CMD_LOCK 2
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#define VMW_BALLOON_CMD_UNLOCK 3
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#define VMW_BALLOON_CMD_GUEST_ID 4
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/* error codes */
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#define VMW_BALLOON_SUCCESS 0
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#define VMW_BALLOON_FAILURE -1
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#define VMW_BALLOON_ERROR_CMD_INVALID 1
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#define VMW_BALLOON_ERROR_PPN_INVALID 2
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#define VMW_BALLOON_ERROR_PPN_LOCKED 3
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#define VMW_BALLOON_ERROR_PPN_UNLOCKED 4
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#define VMW_BALLOON_ERROR_PPN_PINNED 5
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#define VMW_BALLOON_ERROR_PPN_NOTNEEDED 6
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#define VMW_BALLOON_ERROR_RESET 7
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#define VMW_BALLOON_ERROR_BUSY 8
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#define VMWARE_BALLOON_CMD(cmd, data, result) \
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({ \
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unsigned long __stat, __dummy1, __dummy2; \
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__asm__ __volatile__ ("inl %%dx" : \
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"=a"(__stat), \
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"=c"(__dummy1), \
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"=d"(__dummy2), \
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"=b"(result) : \
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"0"(VMW_BALLOON_HV_MAGIC), \
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"1"(VMW_BALLOON_CMD_##cmd), \
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"2"(VMW_BALLOON_HV_PORT), \
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"3"(data) : \
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"memory"); \
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result &= -1UL; \
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__stat & -1UL; \
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})
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#ifdef CONFIG_DEBUG_FS
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struct vmballoon_stats {
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unsigned int timer;
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/* allocation statistics */
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unsigned int alloc;
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unsigned int alloc_fail;
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unsigned int sleep_alloc;
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unsigned int sleep_alloc_fail;
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unsigned int refused_alloc;
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unsigned int refused_free;
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unsigned int free;
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/* monitor operations */
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unsigned int lock;
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unsigned int lock_fail;
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unsigned int unlock;
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unsigned int unlock_fail;
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unsigned int target;
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unsigned int target_fail;
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unsigned int start;
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unsigned int start_fail;
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unsigned int guest_type;
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unsigned int guest_type_fail;
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};
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#define STATS_INC(stat) (stat)++
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#else
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#define STATS_INC(stat)
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#endif
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struct vmballoon {
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/* list of reserved physical pages */
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struct list_head pages;
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/* transient list of non-balloonable pages */
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struct list_head refused_pages;
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unsigned int n_refused_pages;
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/* balloon size in pages */
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unsigned int size;
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unsigned int target;
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/* reset flag */
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bool reset_required;
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/* adjustment rates (pages per second) */
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unsigned int rate_alloc;
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unsigned int rate_free;
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/* slowdown page allocations for next few cycles */
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unsigned int slow_allocation_cycles;
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#ifdef CONFIG_DEBUG_FS
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/* statistics */
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struct vmballoon_stats stats;
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/* debugfs file exporting statistics */
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struct dentry *dbg_entry;
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#endif
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struct sysinfo sysinfo;
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struct delayed_work dwork;
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};
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static struct vmballoon balloon;
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/*
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* Send "start" command to the host, communicating supported version
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* of the protocol.
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*/
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static bool vmballoon_send_start(struct vmballoon *b)
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{
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unsigned long status, dummy;
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STATS_INC(b->stats.start);
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status = VMWARE_BALLOON_CMD(START, VMW_BALLOON_PROTOCOL_VERSION, dummy);
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if (status == VMW_BALLOON_SUCCESS)
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return true;
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pr_debug("%s - failed, hv returns %ld\n", __func__, status);
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STATS_INC(b->stats.start_fail);
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return false;
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}
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static bool vmballoon_check_status(struct vmballoon *b, unsigned long status)
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{
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switch (status) {
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case VMW_BALLOON_SUCCESS:
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return true;
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case VMW_BALLOON_ERROR_RESET:
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b->reset_required = true;
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/* fall through */
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default:
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return false;
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}
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}
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/*
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* Communicate guest type to the host so that it can adjust ballooning
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* algorithm to the one most appropriate for the guest. This command
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* is normally issued after sending "start" command and is part of
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* standard reset sequence.
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*/
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static bool vmballoon_send_guest_id(struct vmballoon *b)
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{
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unsigned long status, dummy;
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status = VMWARE_BALLOON_CMD(GUEST_ID, VMW_BALLOON_GUEST_ID, dummy);
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STATS_INC(b->stats.guest_type);
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if (vmballoon_check_status(b, status))
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return true;
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pr_debug("%s - failed, hv returns %ld\n", __func__, status);
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STATS_INC(b->stats.guest_type_fail);
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return false;
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}
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/*
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* Retrieve desired balloon size from the host.
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*/
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static bool vmballoon_send_get_target(struct vmballoon *b, u32 *new_target)
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{
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unsigned long status;
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unsigned long target;
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unsigned long limit;
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u32 limit32;
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/*
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* si_meminfo() is cheap. Moreover, we want to provide dynamic
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* max balloon size later. So let us call si_meminfo() every
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* iteration.
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*/
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si_meminfo(&b->sysinfo);
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limit = b->sysinfo.totalram;
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/* Ensure limit fits in 32-bits */
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limit32 = (u32)limit;
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if (limit != limit32)
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return false;
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/* update stats */
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STATS_INC(b->stats.target);
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status = VMWARE_BALLOON_CMD(GET_TARGET, limit, target);
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if (vmballoon_check_status(b, status)) {
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*new_target = target;
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return true;
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}
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pr_debug("%s - failed, hv returns %ld\n", __func__, status);
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STATS_INC(b->stats.target_fail);
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return false;
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}
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/*
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* Notify the host about allocated page so that host can use it without
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* fear that guest will need it. Host may reject some pages, we need to
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* check the return value and maybe submit a different page.
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*/
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static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
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unsigned int *hv_status)
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{
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unsigned long status, dummy;
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u32 pfn32;
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pfn32 = (u32)pfn;
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if (pfn32 != pfn)
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return -1;
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STATS_INC(b->stats.lock);
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*hv_status = status = VMWARE_BALLOON_CMD(LOCK, pfn, dummy);
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if (vmballoon_check_status(b, status))
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return 0;
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pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
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STATS_INC(b->stats.lock_fail);
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return 1;
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}
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/*
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* Notify the host that guest intends to release given page back into
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* the pool of available (to the guest) pages.
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*/
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static bool vmballoon_send_unlock_page(struct vmballoon *b, unsigned long pfn)
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{
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unsigned long status, dummy;
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u32 pfn32;
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pfn32 = (u32)pfn;
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if (pfn32 != pfn)
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return false;
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STATS_INC(b->stats.unlock);
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status = VMWARE_BALLOON_CMD(UNLOCK, pfn, dummy);
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if (vmballoon_check_status(b, status))
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return true;
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pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
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STATS_INC(b->stats.unlock_fail);
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return false;
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}
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/*
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* Quickly release all pages allocated for the balloon. This function is
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* called when host decides to "reset" balloon for one reason or another.
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* Unlike normal "deflate" we do not (shall not) notify host of the pages
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* being released.
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*/
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static void vmballoon_pop(struct vmballoon *b)
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{
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struct page *page, *next;
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unsigned int count = 0;
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list_for_each_entry_safe(page, next, &b->pages, lru) {
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list_del(&page->lru);
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__free_page(page);
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STATS_INC(b->stats.free);
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b->size--;
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if (++count >= b->rate_free) {
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count = 0;
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cond_resched();
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}
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}
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}
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/*
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* Perform standard reset sequence by popping the balloon (in case it
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* is not empty) and then restarting protocol. This operation normally
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* happens when host responds with VMW_BALLOON_ERROR_RESET to a command.
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*/
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static void vmballoon_reset(struct vmballoon *b)
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{
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/* free all pages, skipping monitor unlock */
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vmballoon_pop(b);
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if (vmballoon_send_start(b)) {
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b->reset_required = false;
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if (!vmballoon_send_guest_id(b))
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pr_err("failed to send guest ID to the host\n");
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}
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}
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/*
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* Allocate (or reserve) a page for the balloon and notify the host. If host
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* refuses the page put it on "refuse" list and allocate another one until host
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* is satisfied. "Refused" pages are released at the end of inflation cycle
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* (when we allocate b->rate_alloc pages).
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*/
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static int vmballoon_reserve_page(struct vmballoon *b, bool can_sleep)
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{
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struct page *page;
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gfp_t flags;
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unsigned int hv_status;
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int locked;
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flags = can_sleep ? VMW_PAGE_ALLOC_CANSLEEP : VMW_PAGE_ALLOC_NOSLEEP;
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do {
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if (!can_sleep)
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STATS_INC(b->stats.alloc);
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else
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STATS_INC(b->stats.sleep_alloc);
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page = alloc_page(flags);
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if (!page) {
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if (!can_sleep)
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STATS_INC(b->stats.alloc_fail);
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else
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STATS_INC(b->stats.sleep_alloc_fail);
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return -ENOMEM;
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}
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/* inform monitor */
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locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status);
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if (locked > 0) {
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STATS_INC(b->stats.refused_alloc);
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if (hv_status == VMW_BALLOON_ERROR_RESET ||
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hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED) {
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__free_page(page);
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return -EIO;
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}
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/*
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* Place page on the list of non-balloonable pages
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* and retry allocation, unless we already accumulated
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* too many of them, in which case take a breather.
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*/
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list_add(&page->lru, &b->refused_pages);
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if (++b->n_refused_pages >= VMW_BALLOON_MAX_REFUSED)
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return -EIO;
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}
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} while (locked != 0);
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/* track allocated page */
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list_add(&page->lru, &b->pages);
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/* update balloon size */
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b->size++;
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return 0;
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}
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/*
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* Release the page allocated for the balloon. Note that we first notify
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* the host so it can make sure the page will be available for the guest
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* to use, if needed.
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*/
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static int vmballoon_release_page(struct vmballoon *b, struct page *page)
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{
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if (!vmballoon_send_unlock_page(b, page_to_pfn(page)))
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return -EIO;
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list_del(&page->lru);
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/* deallocate page */
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__free_page(page);
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STATS_INC(b->stats.free);
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/* update balloon size */
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b->size--;
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return 0;
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}
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|
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/*
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* Release pages that were allocated while attempting to inflate the
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* balloon but were refused by the host for one reason or another.
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*/
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static void vmballoon_release_refused_pages(struct vmballoon *b)
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{
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struct page *page, *next;
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list_for_each_entry_safe(page, next, &b->refused_pages, lru) {
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list_del(&page->lru);
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__free_page(page);
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STATS_INC(b->stats.refused_free);
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}
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b->n_refused_pages = 0;
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}
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|
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/*
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* Inflate the balloon towards its target size. Note that we try to limit
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* the rate of allocation to make sure we are not choking the rest of the
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* system.
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*/
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static void vmballoon_inflate(struct vmballoon *b)
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{
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unsigned int goal;
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unsigned int rate;
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unsigned int i;
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unsigned int allocations = 0;
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int error = 0;
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bool alloc_can_sleep = false;
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|
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pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);
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|
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/*
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* First try NOSLEEP page allocations to inflate balloon.
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*
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* If we do not throttle nosleep allocations, we can drain all
|
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* free pages in the guest quickly (if the balloon target is high).
|
|
* As a side-effect, draining free pages helps to inform (force)
|
|
* the guest to start swapping if balloon target is not met yet,
|
|
* which is a desired behavior. However, balloon driver can consume
|
|
* all available CPU cycles if too many pages are allocated in a
|
|
* second. Therefore, we throttle nosleep allocations even when
|
|
* the guest is not under memory pressure. OTOH, if we have already
|
|
* predicted that the guest is under memory pressure, then we
|
|
* slowdown page allocations considerably.
|
|
*/
|
|
|
|
goal = b->target - b->size;
|
|
/*
|
|
* Start with no sleep allocation rate which may be higher
|
|
* than sleeping allocation rate.
|
|
*/
|
|
rate = b->slow_allocation_cycles ?
|
|
b->rate_alloc : VMW_BALLOON_NOSLEEP_ALLOC_MAX;
|
|
|
|
pr_debug("%s - goal: %d, no-sleep rate: %d, sleep rate: %d\n",
|
|
__func__, goal, rate, b->rate_alloc);
|
|
|
|
for (i = 0; i < goal; i++) {
|
|
|
|
error = vmballoon_reserve_page(b, alloc_can_sleep);
|
|
if (error) {
|
|
if (error != -ENOMEM) {
|
|
/*
|
|
* Not a page allocation failure, stop this
|
|
* cycle. Maybe we'll get new target from
|
|
* the host soon.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
if (alloc_can_sleep) {
|
|
/*
|
|
* CANSLEEP page allocation failed, so guest
|
|
* is under severe memory pressure. Quickly
|
|
* decrease allocation rate.
|
|
*/
|
|
b->rate_alloc = max(b->rate_alloc / 2,
|
|
VMW_BALLOON_RATE_ALLOC_MIN);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* NOSLEEP page allocation failed, so the guest is
|
|
* under memory pressure. Let us slow down page
|
|
* allocations for next few cycles so that the guest
|
|
* gets out of memory pressure. Also, if we already
|
|
* allocated b->rate_alloc pages, let's pause,
|
|
* otherwise switch to sleeping allocations.
|
|
*/
|
|
b->slow_allocation_cycles = VMW_BALLOON_SLOW_CYCLES;
|
|
|
|
if (i >= b->rate_alloc)
|
|
break;
|
|
|
|
alloc_can_sleep = true;
|
|
/* Lower rate for sleeping allocations. */
|
|
rate = b->rate_alloc;
|
|
}
|
|
|
|
if (++allocations > VMW_BALLOON_YIELD_THRESHOLD) {
|
|
cond_resched();
|
|
allocations = 0;
|
|
}
|
|
|
|
if (i >= rate) {
|
|
/* We allocated enough pages, let's take a break. */
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We reached our goal without failures so try increasing
|
|
* allocation rate.
|
|
*/
|
|
if (error == 0 && i >= b->rate_alloc) {
|
|
unsigned int mult = i / b->rate_alloc;
|
|
|
|
b->rate_alloc =
|
|
min(b->rate_alloc + mult * VMW_BALLOON_RATE_ALLOC_INC,
|
|
VMW_BALLOON_RATE_ALLOC_MAX);
|
|
}
|
|
|
|
vmballoon_release_refused_pages(b);
|
|
}
|
|
|
|
/*
|
|
* Decrease the size of the balloon allowing guest to use more memory.
|
|
*/
|
|
static void vmballoon_deflate(struct vmballoon *b)
|
|
{
|
|
struct page *page, *next;
|
|
unsigned int i = 0;
|
|
unsigned int goal;
|
|
int error;
|
|
|
|
pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);
|
|
|
|
/* limit deallocation rate */
|
|
goal = min(b->size - b->target, b->rate_free);
|
|
|
|
pr_debug("%s - goal: %d, rate: %d\n", __func__, goal, b->rate_free);
|
|
|
|
/* free pages to reach target */
|
|
list_for_each_entry_safe(page, next, &b->pages, lru) {
|
|
error = vmballoon_release_page(b, page);
|
|
if (error) {
|
|
/* quickly decrease rate in case of error */
|
|
b->rate_free = max(b->rate_free / 2,
|
|
VMW_BALLOON_RATE_FREE_MIN);
|
|
return;
|
|
}
|
|
|
|
if (++i >= goal)
|
|
break;
|
|
}
|
|
|
|
/* slowly increase rate if there were no errors */
|
|
b->rate_free = min(b->rate_free + VMW_BALLOON_RATE_FREE_INC,
|
|
VMW_BALLOON_RATE_FREE_MAX);
|
|
}
|
|
|
|
/*
|
|
* Balloon work function: reset protocol, if needed, get the new size and
|
|
* adjust balloon as needed. Repeat in 1 sec.
|
|
*/
|
|
static void vmballoon_work(struct work_struct *work)
|
|
{
|
|
struct delayed_work *dwork = to_delayed_work(work);
|
|
struct vmballoon *b = container_of(dwork, struct vmballoon, dwork);
|
|
unsigned int target;
|
|
|
|
STATS_INC(b->stats.timer);
|
|
|
|
if (b->reset_required)
|
|
vmballoon_reset(b);
|
|
|
|
if (b->slow_allocation_cycles > 0)
|
|
b->slow_allocation_cycles--;
|
|
|
|
if (vmballoon_send_get_target(b, &target)) {
|
|
/* update target, adjust size */
|
|
b->target = target;
|
|
|
|
if (b->size < target)
|
|
vmballoon_inflate(b);
|
|
else if (b->size > target)
|
|
vmballoon_deflate(b);
|
|
}
|
|
|
|
/*
|
|
* We are using a freezable workqueue so that balloon operations are
|
|
* stopped while the system transitions to/from sleep/hibernation.
|
|
*/
|
|
queue_delayed_work(system_freezable_wq,
|
|
dwork, round_jiffies_relative(HZ));
|
|
}
|
|
|
|
/*
|
|
* DEBUGFS Interface
|
|
*/
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
static int vmballoon_debug_show(struct seq_file *f, void *offset)
|
|
{
|
|
struct vmballoon *b = f->private;
|
|
struct vmballoon_stats *stats = &b->stats;
|
|
|
|
/* format size info */
|
|
seq_printf(f,
|
|
"target: %8d pages\n"
|
|
"current: %8d pages\n",
|
|
b->target, b->size);
|
|
|
|
/* format rate info */
|
|
seq_printf(f,
|
|
"rateNoSleepAlloc: %8d pages/sec\n"
|
|
"rateSleepAlloc: %8d pages/sec\n"
|
|
"rateFree: %8d pages/sec\n",
|
|
VMW_BALLOON_NOSLEEP_ALLOC_MAX,
|
|
b->rate_alloc, b->rate_free);
|
|
|
|
seq_printf(f,
|
|
"\n"
|
|
"timer: %8u\n"
|
|
"start: %8u (%4u failed)\n"
|
|
"guestType: %8u (%4u failed)\n"
|
|
"lock: %8u (%4u failed)\n"
|
|
"unlock: %8u (%4u failed)\n"
|
|
"target: %8u (%4u failed)\n"
|
|
"primNoSleepAlloc: %8u (%4u failed)\n"
|
|
"primCanSleepAlloc: %8u (%4u failed)\n"
|
|
"primFree: %8u\n"
|
|
"errAlloc: %8u\n"
|
|
"errFree: %8u\n",
|
|
stats->timer,
|
|
stats->start, stats->start_fail,
|
|
stats->guest_type, stats->guest_type_fail,
|
|
stats->lock, stats->lock_fail,
|
|
stats->unlock, stats->unlock_fail,
|
|
stats->target, stats->target_fail,
|
|
stats->alloc, stats->alloc_fail,
|
|
stats->sleep_alloc, stats->sleep_alloc_fail,
|
|
stats->free,
|
|
stats->refused_alloc, stats->refused_free);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int vmballoon_debug_open(struct inode *inode, struct file *file)
|
|
{
|
|
return single_open(file, vmballoon_debug_show, inode->i_private);
|
|
}
|
|
|
|
static const struct file_operations vmballoon_debug_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = vmballoon_debug_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
};
|
|
|
|
static int __init vmballoon_debugfs_init(struct vmballoon *b)
|
|
{
|
|
int error;
|
|
|
|
b->dbg_entry = debugfs_create_file("vmmemctl", S_IRUGO, NULL, b,
|
|
&vmballoon_debug_fops);
|
|
if (IS_ERR(b->dbg_entry)) {
|
|
error = PTR_ERR(b->dbg_entry);
|
|
pr_err("failed to create debugfs entry, error: %d\n", error);
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit vmballoon_debugfs_exit(struct vmballoon *b)
|
|
{
|
|
debugfs_remove(b->dbg_entry);
|
|
}
|
|
|
|
#else
|
|
|
|
static inline int vmballoon_debugfs_init(struct vmballoon *b)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void vmballoon_debugfs_exit(struct vmballoon *b)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_DEBUG_FS */
|
|
|
|
static int __init vmballoon_init(void)
|
|
{
|
|
int error;
|
|
|
|
/*
|
|
* Check if we are running on VMware's hypervisor and bail out
|
|
* if we are not.
|
|
*/
|
|
if (x86_hyper != &x86_hyper_vmware)
|
|
return -ENODEV;
|
|
|
|
INIT_LIST_HEAD(&balloon.pages);
|
|
INIT_LIST_HEAD(&balloon.refused_pages);
|
|
|
|
/* initialize rates */
|
|
balloon.rate_alloc = VMW_BALLOON_RATE_ALLOC_MAX;
|
|
balloon.rate_free = VMW_BALLOON_RATE_FREE_MAX;
|
|
|
|
INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work);
|
|
|
|
/*
|
|
* Start balloon.
|
|
*/
|
|
if (!vmballoon_send_start(&balloon)) {
|
|
pr_err("failed to send start command to the host\n");
|
|
return -EIO;
|
|
}
|
|
|
|
if (!vmballoon_send_guest_id(&balloon)) {
|
|
pr_err("failed to send guest ID to the host\n");
|
|
return -EIO;
|
|
}
|
|
|
|
error = vmballoon_debugfs_init(&balloon);
|
|
if (error)
|
|
return error;
|
|
|
|
queue_delayed_work(system_freezable_wq, &balloon.dwork, 0);
|
|
|
|
return 0;
|
|
}
|
|
module_init(vmballoon_init);
|
|
|
|
static void __exit vmballoon_exit(void)
|
|
{
|
|
cancel_delayed_work_sync(&balloon.dwork);
|
|
|
|
vmballoon_debugfs_exit(&balloon);
|
|
|
|
/*
|
|
* Deallocate all reserved memory, and reset connection with monitor.
|
|
* Reset connection before deallocating memory to avoid potential for
|
|
* additional spurious resets from guest touching deallocated pages.
|
|
*/
|
|
vmballoon_send_start(&balloon);
|
|
vmballoon_pop(&balloon);
|
|
}
|
|
module_exit(vmballoon_exit);
|