Commit 48e3d668 authored by Philip P. Moltmann's avatar Philip P. Moltmann Committed by Greg Kroah-Hartman
Browse files

VMware balloon: Enable notification via VMCI 



Get notified immediately when a balloon target is set, instead of waiting for
up to one second.

The up-to 1 second gap could be long enough to cause swapping inside of the
VM that receives the VM.

Acked-by: default avatarAndy King <acking@vmware.com>
Signed-off-by: default avatarXavier Deguillard <xdeguillard@vmware.com>
Tested-by: default avatarSiva Sankar Reddy B <sankars@vmware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d7568c13

drivers/misc/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -414,7 +414,7 @@ config TI_DAC7512 


config VMWARE_BALLOON

	tristate "VMware Balloon Driver"

	depends on X86 && HYPERVISOR_GUEST

	depends on VMWARE_VMCI && X86 && HYPERVISOR_GUEST

	help

	  This is VMware physical memory management driver which acts

	  like a "balloon" that can be inflated to reclaim physical pages

drivers/misc/vmw_balloon.c

+96 −9
Original line number Diff line number Diff line 
/*

 * VMware Balloon driver.

 *

 * Copyright (C) 2000-2013, VMware, Inc. All Rights Reserved.

 * Copyright (C) 2000-2014, VMware, Inc. All Rights Reserved.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License as published by the
@@ -43,11 +43,13 @@ 
#include <linux/workqueue.h>

#include <linux/debugfs.h>

#include <linux/seq_file.h>

#include <linux/vmw_vmci_defs.h>

#include <linux/vmw_vmci_api.h>

#include <asm/hypervisor.h>



MODULE_AUTHOR("VMware, Inc.");

MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");

MODULE_VERSION("1.4.1.0-k");

MODULE_VERSION("1.5.0.0-k");

MODULE_ALIAS("dmi:*:svnVMware*:*");

MODULE_ALIAS("vmware_vmmemctl");

MODULE_LICENSE("GPL");
@@ -104,11 +106,13 @@ enum vmwballoon_capabilities { 
	VMW_BALLOON_BASIC_CMDS			= (1 << 1),

	VMW_BALLOON_BATCHED_CMDS		= (1 << 2),

	VMW_BALLOON_BATCHED_2M_CMDS		= (1 << 3),

	VMW_BALLOON_SIGNALLED_WAKEUP_CMD	= (1 << 4),

};



#define VMW_BALLOON_CAPABILITIES	(VMW_BALLOON_BASIC_CMDS \

					| VMW_BALLOON_BATCHED_CMDS \

					| VMW_BALLOON_BATCHED_2M_CMDS)

					| VMW_BALLOON_BATCHED_2M_CMDS \

					| VMW_BALLOON_SIGNALLED_WAKEUP_CMD)



#define VMW_BALLOON_2M_SHIFT		(9)

#define VMW_BALLOON_NUM_PAGE_SIZES	(2)
@@ -123,7 +127,9 @@ enum vmwballoon_capabilities { 
 * VMW_BALLOON_BATCHED_CMDS:

 *	BATCHED_LOCK and BATCHED_UNLOCK commands.

 * VMW BALLOON_BATCHED_2M_CMDS:

 *	BATCHED_2M_LOCK and BATCHED_2M_UNLOCK commands.

 *	BATCHED_2M_LOCK and BATCHED_2M_UNLOCK commands,

 * VMW VMW_BALLOON_SIGNALLED_WAKEUP_CMD:

 *	VMW_BALLOON_CMD_VMCI_DOORBELL_SET command.

 */

#define VMW_BALLOON_CMD_START			0

#define VMW_BALLOON_CMD_GET_TARGET		1
@@ -134,6 +140,7 @@ enum vmwballoon_capabilities { 
#define VMW_BALLOON_CMD_BATCHED_UNLOCK		7

#define VMW_BALLOON_CMD_BATCHED_2M_LOCK		8

#define VMW_BALLOON_CMD_BATCHED_2M_UNLOCK	9

#define VMW_BALLOON_CMD_VMCI_DOORBELL_SET	10





/* error codes */
@@ -214,6 +221,7 @@ static void vmballoon_batch_set_pa(struct vmballoon_batch_page *batch, int idx, 
#ifdef CONFIG_DEBUG_FS

struct vmballoon_stats {

	unsigned int timer;

	unsigned int doorbell;



	/* allocation statistics */

	unsigned int alloc[VMW_BALLOON_NUM_PAGE_SIZES];
@@ -235,6 +243,8 @@ struct vmballoon_stats { 
	unsigned int start_fail;

	unsigned int guest_type;

	unsigned int guest_type_fail;

	unsigned int doorbell_set;

	unsigned int doorbell_unset;

};



#define STATS_INC(stat) (stat)++
@@ -299,6 +309,8 @@ struct vmballoon { 
	struct sysinfo sysinfo;



	struct delayed_work dwork;



	struct vmci_handle vmci_doorbell;

};



static struct vmballoon balloon;
@@ -992,6 +1004,65 @@ static bool vmballoon_init_batching(struct vmballoon *b) 
	return true;

}



/*

 * Receive notification and resize balloon

 */

static void vmballoon_doorbell(void *client_data)

{

	struct vmballoon *b = client_data;



	STATS_INC(b->stats.doorbell);



	mod_delayed_work(system_freezable_wq, &b->dwork, 0);

}



/*

 * Clean up vmci doorbell

 */

static void vmballoon_vmci_cleanup(struct vmballoon *b)

{

	int error;



	VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, VMCI_INVALID_ID,

			VMCI_INVALID_ID, error);

	STATS_INC(b->stats.doorbell_unset);



	if (!vmci_handle_is_invalid(b->vmci_doorbell)) {

		vmci_doorbell_destroy(b->vmci_doorbell);

		b->vmci_doorbell = VMCI_INVALID_HANDLE;

	}

}



/*

 * Initialize vmci doorbell, to get notified as soon as balloon changes

 */

static int vmballoon_vmci_init(struct vmballoon *b)

{

	int error = 0;



	if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) != 0) {

		error = vmci_doorbell_create(&b->vmci_doorbell,

				VMCI_FLAG_DELAYED_CB,

				VMCI_PRIVILEGE_FLAG_RESTRICTED,

				vmballoon_doorbell, b);



		if (error == VMCI_SUCCESS) {

			VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET,

					b->vmci_doorbell.context,

					b->vmci_doorbell.resource, error);

			STATS_INC(b->stats.doorbell_set);

		}

	}



	if (error != 0) {

		vmballoon_vmci_cleanup(b);



		return -EIO;

	}



	return 0;

}



/*

 * Perform standard reset sequence by popping the balloon (in case it

 * is not  empty) and then restarting protocol. This operation normally
@@ -999,6 +1070,10 @@ static bool vmballoon_init_batching(struct vmballoon *b) 
 */

static void vmballoon_reset(struct vmballoon *b)

{

	int error;



	vmballoon_vmci_cleanup(b);



	/* free all pages, skipping monitor unlock */

	vmballoon_pop(b);
@@ -1024,6 +1099,11 @@ static void vmballoon_reset(struct vmballoon *b) 
	}



	b->reset_required = false;



	error = vmballoon_vmci_init(b);

	if (error)

		pr_err("failed to initialize vmci doorbell\n");



	if (!vmballoon_send_guest_id(b))

		pr_err("failed to send guest ID to the host\n");

}
@@ -1097,6 +1177,7 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset) 
	seq_printf(f,

		   "\n"

		   "timer:              %8u\n"

		   "doorbell:           %8u\n"

		   "start:              %8u (%4u failed)\n"

		   "guestType:          %8u (%4u failed)\n"

		   "2m-lock:            %8u (%4u failed)\n"
@@ -1112,8 +1193,11 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset) 
		   "err2mAlloc:         %8u\n"

		   "errAlloc:           %8u\n"

		   "err2mFree:          %8u\n"

		   "errFree:            %8u\n",

		   "errFree:            %8u\n"

		   "doorbellSet:        %8u\n"

		   "doorbellUnset:      %8u\n",

		   stats->timer,

		   stats->doorbell,

		   stats->start, stats->start_fail,

		   stats->guest_type, stats->guest_type_fail,

		   stats->lock[true],  stats->lock_fail[true],
@@ -1127,7 +1211,8 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset) 
		   stats->free[true],

		   stats->free[false],

		   stats->refused_alloc[true], stats->refused_alloc[false],

		   stats->refused_free[true], stats->refused_free[false]);

		   stats->refused_free[true], stats->refused_free[false],

		   stats->doorbell_set, stats->doorbell_unset);



	return 0;

}
@@ -1204,6 +1289,7 @@ static int __init vmballoon_init(void) 
	if (error)

		return error;



	balloon.vmci_doorbell = VMCI_INVALID_HANDLE;

	balloon.batch_page = NULL;

	balloon.page = NULL;

	balloon.reset_required = true;
@@ -1216,6 +1302,7 @@ module_init(vmballoon_init); 


static void __exit vmballoon_exit(void)

{

	vmballoon_vmci_cleanup(&balloon);

	cancel_delayed_work_sync(&balloon.dwork);



	vmballoon_debugfs_exit(&balloon);

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