Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 1 | /****************************************************************************** |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 2 | * Xen balloon driver - enables returning/claiming memory to/from Xen. |
| 3 | * |
| 4 | * Copyright (c) 2003, B Dragovic |
| 5 | * Copyright (c) 2003-2004, M Williamson, K Fraser |
| 6 | * Copyright (c) 2005 Dan M. Smith, IBM Corporation |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 7 | * Copyright (c) 2010 Daniel Kiper |
| 8 | * |
| 9 | * Memory hotplug support was written by Daniel Kiper. Work on |
| 10 | * it was sponsored by Google under Google Summer of Code 2010 |
| 11 | * program. Jeremy Fitzhardinge from Citrix was the mentor for |
| 12 | * this project. |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 13 | * |
| 14 | * This program is free software; you can redistribute it and/or |
| 15 | * modify it under the terms of the GNU General Public License version 2 |
| 16 | * as published by the Free Software Foundation; or, when distributed |
| 17 | * separately from the Linux kernel or incorporated into other |
| 18 | * software packages, subject to the following license: |
| 19 | * |
| 20 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 21 | * of this source file (the "Software"), to deal in the Software without |
| 22 | * restriction, including without limitation the rights to use, copy, modify, |
| 23 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| 24 | * and to permit persons to whom the Software is furnished to do so, subject to |
| 25 | * the following conditions: |
| 26 | * |
| 27 | * The above copyright notice and this permission notice shall be included in |
| 28 | * all copies or substantial portions of the Software. |
| 29 | * |
| 30 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 31 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 32 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 33 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 34 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 35 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 36 | * IN THE SOFTWARE. |
| 37 | */ |
| 38 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 39 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
| 40 | |
Stefano Stabellini | cd9151e | 2013-08-04 15:39:40 +0100 | [diff] [blame] | 41 | #include <linux/cpu.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 42 | #include <linux/kernel.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 43 | #include <linux/sched.h> |
| 44 | #include <linux/errno.h> |
Paul Gortmaker | 72ee511 | 2011-07-03 16:20:57 -0400 | [diff] [blame] | 45 | #include <linux/module.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 46 | #include <linux/mm.h> |
| 47 | #include <linux/bootmem.h> |
| 48 | #include <linux/pagemap.h> |
| 49 | #include <linux/highmem.h> |
| 50 | #include <linux/mutex.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 51 | #include <linux/list.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 52 | #include <linux/gfp.h> |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 53 | #include <linux/notifier.h> |
| 54 | #include <linux/memory.h> |
| 55 | #include <linux/memory_hotplug.h> |
Stefano Stabellini | cd9151e | 2013-08-04 15:39:40 +0100 | [diff] [blame] | 56 | #include <linux/percpu-defs.h> |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 57 | #include <linux/slab.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 58 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 59 | #include <asm/page.h> |
| 60 | #include <asm/pgalloc.h> |
| 61 | #include <asm/pgtable.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 62 | #include <asm/tlb.h> |
| 63 | |
Jeremy Fitzhardinge | ecbf29c | 2008-12-16 12:37:07 -0800 | [diff] [blame] | 64 | #include <asm/xen/hypervisor.h> |
| 65 | #include <asm/xen/hypercall.h> |
Jeremy Fitzhardinge | 1ccbf53 | 2009-10-06 15:11:14 -0700 | [diff] [blame] | 66 | |
| 67 | #include <xen/xen.h> |
Jeremy Fitzhardinge | ecbf29c | 2008-12-16 12:37:07 -0800 | [diff] [blame] | 68 | #include <xen/interface/xen.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 69 | #include <xen/interface/memory.h> |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 70 | #include <xen/balloon.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 71 | #include <xen/features.h> |
| 72 | #include <xen/page.h> |
| 73 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 74 | /* |
| 75 | * balloon_process() state: |
| 76 | * |
| 77 | * BP_DONE: done or nothing to do, |
| 78 | * BP_EAGAIN: error, go to sleep, |
| 79 | * BP_ECANCELED: error, balloon operation canceled. |
| 80 | */ |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 81 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 82 | enum bp_state { |
| 83 | BP_DONE, |
| 84 | BP_EAGAIN, |
| 85 | BP_ECANCELED |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 86 | }; |
| 87 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 88 | |
| 89 | static DEFINE_MUTEX(balloon_mutex); |
| 90 | |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 91 | struct balloon_stats balloon_stats; |
| 92 | EXPORT_SYMBOL_GPL(balloon_stats); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 93 | |
| 94 | /* We increase/decrease in batches which fit in a page */ |
Ian Campbell | 965c0aa | 2012-10-17 09:39:16 +0100 | [diff] [blame] | 95 | static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)]; |
Stefano Stabellini | cd9151e | 2013-08-04 15:39:40 +0100 | [diff] [blame] | 96 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 97 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 98 | /* List of ballooned pages, threaded through the mem_map array. */ |
| 99 | static LIST_HEAD(ballooned_pages); |
| 100 | |
| 101 | /* Main work function, always executed in process context. */ |
| 102 | static void balloon_process(struct work_struct *work); |
Daniel Kiper | 95170b2 | 2011-03-08 22:47:39 +0100 | [diff] [blame] | 103 | static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 104 | |
| 105 | /* When ballooning out (allocating memory to return to Xen) we don't really |
| 106 | want the kernel to try too hard since that can trigger the oom killer. */ |
| 107 | #define GFP_BALLOON \ |
| 108 | (GFP_HIGHUSER | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC) |
| 109 | |
| 110 | static void scrub_page(struct page *page) |
| 111 | { |
| 112 | #ifdef CONFIG_XEN_SCRUB_PAGES |
Jeremy Fitzhardinge | 26a3e99 | 2008-11-17 09:35:00 -0800 | [diff] [blame] | 113 | clear_highpage(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 114 | #endif |
| 115 | } |
| 116 | |
| 117 | /* balloon_append: add the given page to the balloon. */ |
Jeremy Fitzhardinge | 9be4d45 | 2010-08-31 15:01:16 -0700 | [diff] [blame] | 118 | static void __balloon_append(struct page *page) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 119 | { |
| 120 | /* Lowmem is re-populated first, so highmem pages go at list tail. */ |
| 121 | if (PageHighMem(page)) { |
| 122 | list_add_tail(&page->lru, &ballooned_pages); |
| 123 | balloon_stats.balloon_high++; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 124 | } else { |
| 125 | list_add(&page->lru, &ballooned_pages); |
| 126 | balloon_stats.balloon_low++; |
| 127 | } |
Jeremy Fitzhardinge | 9be4d45 | 2010-08-31 15:01:16 -0700 | [diff] [blame] | 128 | } |
Gianluca Guida | 3d65c94 | 2009-07-30 22:54:36 +0100 | [diff] [blame] | 129 | |
Jeremy Fitzhardinge | 9be4d45 | 2010-08-31 15:01:16 -0700 | [diff] [blame] | 130 | static void balloon_append(struct page *page) |
| 131 | { |
| 132 | __balloon_append(page); |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 133 | adjust_managed_page_count(page, -1); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 134 | } |
| 135 | |
| 136 | /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */ |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 137 | static struct page *balloon_retrieve(bool prefer_highmem) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 138 | { |
| 139 | struct page *page; |
| 140 | |
| 141 | if (list_empty(&ballooned_pages)) |
| 142 | return NULL; |
| 143 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 144 | if (prefer_highmem) |
| 145 | page = list_entry(ballooned_pages.prev, struct page, lru); |
| 146 | else |
| 147 | page = list_entry(ballooned_pages.next, struct page, lru); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 148 | list_del(&page->lru); |
| 149 | |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 150 | if (PageHighMem(page)) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 151 | balloon_stats.balloon_high--; |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 152 | else |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 153 | balloon_stats.balloon_low--; |
| 154 | |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 155 | adjust_managed_page_count(page, 1); |
Gianluca Guida | 3d65c94 | 2009-07-30 22:54:36 +0100 | [diff] [blame] | 156 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 157 | return page; |
| 158 | } |
| 159 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 160 | static struct page *balloon_next_page(struct page *page) |
| 161 | { |
| 162 | struct list_head *next = page->lru.next; |
| 163 | if (next == &ballooned_pages) |
| 164 | return NULL; |
| 165 | return list_entry(next, struct page, lru); |
| 166 | } |
| 167 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 168 | static enum bp_state update_schedule(enum bp_state state) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 169 | { |
Boris Ostrovsky | fd8b795 | 2014-10-07 17:00:07 -0400 | [diff] [blame] | 170 | if (state == BP_ECANCELED) |
| 171 | return BP_ECANCELED; |
| 172 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 173 | if (state == BP_DONE) { |
| 174 | balloon_stats.schedule_delay = 1; |
| 175 | balloon_stats.retry_count = 1; |
| 176 | return BP_DONE; |
| 177 | } |
| 178 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 179 | ++balloon_stats.retry_count; |
| 180 | |
| 181 | if (balloon_stats.max_retry_count != RETRY_UNLIMITED && |
| 182 | balloon_stats.retry_count > balloon_stats.max_retry_count) { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 183 | balloon_stats.schedule_delay = 1; |
| 184 | balloon_stats.retry_count = 1; |
| 185 | return BP_ECANCELED; |
| 186 | } |
| 187 | |
| 188 | balloon_stats.schedule_delay <<= 1; |
| 189 | |
| 190 | if (balloon_stats.schedule_delay > balloon_stats.max_schedule_delay) |
| 191 | balloon_stats.schedule_delay = balloon_stats.max_schedule_delay; |
| 192 | |
| 193 | return BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 194 | } |
| 195 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 196 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
| 197 | static long current_credit(void) |
| 198 | { |
| 199 | return balloon_stats.target_pages - balloon_stats.current_pages - |
| 200 | balloon_stats.hotplug_pages; |
| 201 | } |
| 202 | |
| 203 | static bool balloon_is_inflated(void) |
| 204 | { |
| 205 | if (balloon_stats.balloon_low || balloon_stats.balloon_high || |
| 206 | balloon_stats.balloon_hotplug) |
| 207 | return true; |
| 208 | else |
| 209 | return false; |
| 210 | } |
| 211 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 212 | static struct resource *additional_memory_resource(phys_addr_t size) |
| 213 | { |
| 214 | struct resource *res; |
| 215 | int ret; |
| 216 | |
| 217 | res = kzalloc(sizeof(*res), GFP_KERNEL); |
| 218 | if (!res) |
| 219 | return NULL; |
| 220 | |
| 221 | res->name = "System RAM"; |
| 222 | res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
| 223 | |
| 224 | ret = allocate_resource(&iomem_resource, res, |
| 225 | size, 0, -1, |
| 226 | PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); |
| 227 | if (ret < 0) { |
| 228 | pr_err("Cannot allocate new System RAM resource\n"); |
| 229 | kfree(res); |
| 230 | return NULL; |
| 231 | } |
| 232 | |
| 233 | return res; |
| 234 | } |
| 235 | |
| 236 | static void release_memory_resource(struct resource *resource) |
| 237 | { |
| 238 | if (!resource) |
| 239 | return; |
| 240 | |
| 241 | /* |
| 242 | * No need to reset region to identity mapped since we now |
| 243 | * know that no I/O can be in this region |
| 244 | */ |
| 245 | release_resource(resource); |
| 246 | kfree(resource); |
| 247 | } |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 248 | |
| 249 | static enum bp_state reserve_additional_memory(long credit) |
| 250 | { |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 251 | struct resource *resource; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 252 | int nid, rc; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 253 | unsigned long balloon_hotplug; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 254 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 255 | balloon_hotplug = round_up(credit, PAGES_PER_SECTION); |
| 256 | |
| 257 | resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE); |
| 258 | if (!resource) |
| 259 | goto err; |
| 260 | |
| 261 | nid = memory_add_physaddr_to_nid(resource->start); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 262 | |
Juergen Gross | 3c56b3a | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 263 | #ifdef CONFIG_XEN_HAVE_PVMMU |
| 264 | /* |
| 265 | * add_memory() will build page tables for the new memory so |
| 266 | * the p2m must contain invalid entries so the correct |
| 267 | * non-present PTEs will be written. |
| 268 | * |
| 269 | * If a failure occurs, the original (identity) p2m entries |
| 270 | * are not restored since this region is now known not to |
| 271 | * conflict with any devices. |
| 272 | */ |
| 273 | if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
| 274 | unsigned long pfn, i; |
| 275 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 276 | pfn = PFN_DOWN(resource->start); |
Juergen Gross | 3c56b3a | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 277 | for (i = 0; i < balloon_hotplug; i++) { |
| 278 | if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { |
| 279 | pr_warn("set_phys_to_machine() failed, no memory added\n"); |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 280 | goto err; |
Juergen Gross | 3c56b3a | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 281 | } |
| 282 | } |
| 283 | } |
| 284 | #endif |
| 285 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 286 | rc = add_memory_resource(nid, resource); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 287 | if (rc) { |
David Vrabel | 3dcf636 | 2014-09-01 18:52:44 +0100 | [diff] [blame] | 288 | pr_warn("Cannot add additional memory (%i)\n", rc); |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 289 | goto err; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 290 | } |
| 291 | |
| 292 | balloon_hotplug -= credit; |
| 293 | |
| 294 | balloon_stats.hotplug_pages += credit; |
| 295 | balloon_stats.balloon_hotplug = balloon_hotplug; |
| 296 | |
| 297 | return BP_DONE; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame^] | 298 | err: |
| 299 | release_memory_resource(resource); |
| 300 | return BP_ECANCELED; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 301 | } |
| 302 | |
| 303 | static void xen_online_page(struct page *page) |
| 304 | { |
| 305 | __online_page_set_limits(page); |
| 306 | |
| 307 | mutex_lock(&balloon_mutex); |
| 308 | |
| 309 | __balloon_append(page); |
| 310 | |
| 311 | if (balloon_stats.hotplug_pages) |
| 312 | --balloon_stats.hotplug_pages; |
| 313 | else |
| 314 | --balloon_stats.balloon_hotplug; |
| 315 | |
| 316 | mutex_unlock(&balloon_mutex); |
| 317 | } |
| 318 | |
| 319 | static int xen_memory_notifier(struct notifier_block *nb, unsigned long val, void *v) |
| 320 | { |
| 321 | if (val == MEM_ONLINE) |
| 322 | schedule_delayed_work(&balloon_worker, 0); |
| 323 | |
| 324 | return NOTIFY_OK; |
| 325 | } |
| 326 | |
| 327 | static struct notifier_block xen_memory_nb = { |
| 328 | .notifier_call = xen_memory_notifier, |
| 329 | .priority = 0 |
| 330 | }; |
| 331 | #else |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 332 | static long current_credit(void) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 333 | { |
Ian Campbell | bc2c030 | 2009-06-05 11:58:37 +0100 | [diff] [blame] | 334 | unsigned long target = balloon_stats.target_pages; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 335 | |
| 336 | target = min(target, |
| 337 | balloon_stats.current_pages + |
| 338 | balloon_stats.balloon_low + |
| 339 | balloon_stats.balloon_high); |
| 340 | |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 341 | return target - balloon_stats.current_pages; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 342 | } |
| 343 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 344 | static bool balloon_is_inflated(void) |
| 345 | { |
| 346 | if (balloon_stats.balloon_low || balloon_stats.balloon_high) |
| 347 | return true; |
| 348 | else |
| 349 | return false; |
| 350 | } |
| 351 | |
| 352 | static enum bp_state reserve_additional_memory(long credit) |
| 353 | { |
| 354 | balloon_stats.target_pages = balloon_stats.current_pages; |
| 355 | return BP_DONE; |
| 356 | } |
| 357 | #endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */ |
| 358 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 359 | static enum bp_state increase_reservation(unsigned long nr_pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 360 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 361 | int rc; |
Jeremy Fitzhardinge | 2f70e0a | 2010-09-02 23:11:17 -0700 | [diff] [blame] | 362 | unsigned long pfn, i; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 363 | struct page *page; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 364 | struct xen_memory_reservation reservation = { |
| 365 | .address_bits = 0, |
| 366 | .extent_order = 0, |
| 367 | .domid = DOMID_SELF |
| 368 | }; |
| 369 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 370 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
| 371 | if (!balloon_stats.balloon_low && !balloon_stats.balloon_high) { |
| 372 | nr_pages = min(nr_pages, balloon_stats.balloon_hotplug); |
| 373 | balloon_stats.hotplug_pages += nr_pages; |
| 374 | balloon_stats.balloon_hotplug -= nr_pages; |
| 375 | return BP_DONE; |
| 376 | } |
| 377 | #endif |
| 378 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 379 | if (nr_pages > ARRAY_SIZE(frame_list)) |
| 380 | nr_pages = ARRAY_SIZE(frame_list); |
| 381 | |
Jie Liu | 9346c2a | 2013-11-13 20:59:58 +0800 | [diff] [blame] | 382 | page = list_first_entry_or_null(&ballooned_pages, struct page, lru); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 383 | for (i = 0; i < nr_pages; i++) { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 384 | if (!page) { |
| 385 | nr_pages = i; |
| 386 | break; |
| 387 | } |
Joe Perches | a419aef | 2009-08-18 11:18:35 -0700 | [diff] [blame] | 388 | frame_list[i] = page_to_pfn(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 389 | page = balloon_next_page(page); |
| 390 | } |
| 391 | |
Isaku Yamahata | a90971e | 2008-05-26 23:31:14 +0100 | [diff] [blame] | 392 | set_xen_guest_handle(reservation.extent_start, frame_list); |
Jeremy Fitzhardinge | fde28e8 | 2008-07-24 16:28:00 -0700 | [diff] [blame] | 393 | reservation.nr_extents = nr_pages; |
| 394 | rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); |
Konrad Rzeszutek Wilk | 40095de | 2011-03-14 11:42:40 -0400 | [diff] [blame] | 395 | if (rc <= 0) |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 396 | return BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 397 | |
Ian Campbell | bc2c030 | 2009-06-05 11:58:37 +0100 | [diff] [blame] | 398 | for (i = 0; i < rc; i++) { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 399 | page = balloon_retrieve(false); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 400 | BUG_ON(page == NULL); |
| 401 | |
| 402 | pfn = page_to_pfn(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 403 | |
Ian Campbell | c2374bf | 2012-10-03 12:17:50 +0100 | [diff] [blame] | 404 | #ifdef CONFIG_XEN_HAVE_PVMMU |
Stefano Stabellini | c1d15f5 | 2013-12-11 16:58:42 +0000 | [diff] [blame] | 405 | if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
| 406 | set_phys_to_machine(pfn, frame_list[i]); |
| 407 | |
| 408 | /* Link back into the page tables if not highmem. */ |
| 409 | if (!PageHighMem(page)) { |
| 410 | int ret; |
| 411 | ret = HYPERVISOR_update_va_mapping( |
| 412 | (unsigned long)__va(pfn << PAGE_SHIFT), |
| 413 | mfn_pte(frame_list[i], PAGE_KERNEL), |
| 414 | 0); |
| 415 | BUG_ON(ret); |
| 416 | } |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 417 | } |
Ian Campbell | c2374bf | 2012-10-03 12:17:50 +0100 | [diff] [blame] | 418 | #endif |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 419 | |
| 420 | /* Relinquish the page back to the allocator. */ |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 421 | __free_reserved_page(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 422 | } |
| 423 | |
Ian Campbell | bc2c030 | 2009-06-05 11:58:37 +0100 | [diff] [blame] | 424 | balloon_stats.current_pages += rc; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 425 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 426 | return BP_DONE; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 427 | } |
| 428 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 429 | static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 430 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 431 | enum bp_state state = BP_DONE; |
Jeremy Fitzhardinge | 2f70e0a | 2010-09-02 23:11:17 -0700 | [diff] [blame] | 432 | unsigned long pfn, i; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 433 | struct page *page; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 434 | int ret; |
| 435 | struct xen_memory_reservation reservation = { |
| 436 | .address_bits = 0, |
| 437 | .extent_order = 0, |
| 438 | .domid = DOMID_SELF |
| 439 | }; |
| 440 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 441 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
| 442 | if (balloon_stats.hotplug_pages) { |
| 443 | nr_pages = min(nr_pages, balloon_stats.hotplug_pages); |
| 444 | balloon_stats.hotplug_pages -= nr_pages; |
| 445 | balloon_stats.balloon_hotplug += nr_pages; |
| 446 | return BP_DONE; |
| 447 | } |
| 448 | #endif |
| 449 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 450 | if (nr_pages > ARRAY_SIZE(frame_list)) |
| 451 | nr_pages = ARRAY_SIZE(frame_list); |
| 452 | |
| 453 | for (i = 0; i < nr_pages; i++) { |
Lisa Nguyen | fce9268 | 2013-05-15 22:59:40 -0700 | [diff] [blame] | 454 | page = alloc_page(gfp); |
| 455 | if (page == NULL) { |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 456 | nr_pages = i; |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 457 | state = BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 458 | break; |
| 459 | } |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 460 | scrub_page(page); |
Dan Magenheimer | 1058a75 | 2009-01-22 14:36:08 -0800 | [diff] [blame] | 461 | |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 462 | frame_list[i] = page_to_pfn(page); |
| 463 | } |
| 464 | |
| 465 | /* |
| 466 | * Ensure that ballooned highmem pages don't have kmaps. |
| 467 | * |
| 468 | * Do this before changing the p2m as kmap_flush_unused() |
| 469 | * reads PTEs to obtain pages (and hence needs the original |
| 470 | * p2m entry). |
| 471 | */ |
| 472 | kmap_flush_unused(); |
| 473 | |
| 474 | /* Update direct mapping, invalidate P2M, and add to balloon. */ |
| 475 | for (i = 0; i < nr_pages; i++) { |
| 476 | pfn = frame_list[i]; |
Julien Grall | 0df4f26 | 2015-08-07 17:34:37 +0100 | [diff] [blame] | 477 | frame_list[i] = pfn_to_gfn(pfn); |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 478 | page = pfn_to_page(pfn); |
| 479 | |
Stefano Stabellini | c1d15f5 | 2013-12-11 16:58:42 +0000 | [diff] [blame] | 480 | #ifdef CONFIG_XEN_HAVE_PVMMU |
Wei Liu | 04660bb | 2013-08-27 16:17:25 +0100 | [diff] [blame] | 481 | if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
Stefano Stabellini | c1d15f5 | 2013-12-11 16:58:42 +0000 | [diff] [blame] | 482 | if (!PageHighMem(page)) { |
| 483 | ret = HYPERVISOR_update_va_mapping( |
| 484 | (unsigned long)__va(pfn << PAGE_SHIFT), |
David Vrabel | 0bb599f | 2015-01-05 17:06:01 +0000 | [diff] [blame] | 485 | __pte_ma(0), 0); |
Stefano Stabellini | c1d15f5 | 2013-12-11 16:58:42 +0000 | [diff] [blame] | 486 | BUG_ON(ret); |
David Vrabel | fb9a0c4 | 2014-06-27 10:42:03 +0100 | [diff] [blame] | 487 | } |
| 488 | __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); |
Wei Liu | 04660bb | 2013-08-27 16:17:25 +0100 | [diff] [blame] | 489 | } |
Stefano Stabellini | c1d15f5 | 2013-12-11 16:58:42 +0000 | [diff] [blame] | 490 | #endif |
David Vrabel | 24f6937 | 2013-09-19 17:14:53 +0100 | [diff] [blame] | 491 | |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 492 | balloon_append(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 493 | } |
| 494 | |
David Vrabel | 24f6937 | 2013-09-19 17:14:53 +0100 | [diff] [blame] | 495 | flush_tlb_all(); |
David Vrabel | 2bad07c | 2013-09-11 17:45:44 +0000 | [diff] [blame] | 496 | |
Isaku Yamahata | a90971e | 2008-05-26 23:31:14 +0100 | [diff] [blame] | 497 | set_xen_guest_handle(reservation.extent_start, frame_list); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 498 | reservation.nr_extents = nr_pages; |
| 499 | ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); |
| 500 | BUG_ON(ret != nr_pages); |
| 501 | |
| 502 | balloon_stats.current_pages -= nr_pages; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 503 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 504 | return state; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 505 | } |
| 506 | |
| 507 | /* |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 508 | * As this is a work item it is guaranteed to run as a single instance only. |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 509 | * We may of course race updates of the target counts (which are protected |
| 510 | * by the balloon lock), or with changes to the Xen hard limit, but we will |
| 511 | * recover from these in time. |
| 512 | */ |
| 513 | static void balloon_process(struct work_struct *work) |
| 514 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 515 | enum bp_state state = BP_DONE; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 516 | long credit; |
| 517 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 518 | |
| 519 | do { |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 520 | mutex_lock(&balloon_mutex); |
| 521 | |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 522 | credit = current_credit(); |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 523 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 524 | if (credit > 0) { |
| 525 | if (balloon_is_inflated()) |
| 526 | state = increase_reservation(credit); |
| 527 | else |
| 528 | state = reserve_additional_memory(credit); |
| 529 | } |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 530 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 531 | if (credit < 0) |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 532 | state = decrease_reservation(-credit, GFP_BALLOON); |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 533 | |
| 534 | state = update_schedule(state); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 535 | |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 536 | mutex_unlock(&balloon_mutex); |
| 537 | |
| 538 | cond_resched(); |
| 539 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 540 | } while (credit && state == BP_DONE); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 541 | |
| 542 | /* Schedule more work if there is some still to be done. */ |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 543 | if (state == BP_EAGAIN) |
| 544 | schedule_delayed_work(&balloon_worker, balloon_stats.schedule_delay * HZ); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 545 | } |
| 546 | |
| 547 | /* Resets the Xen limit, sets new target, and kicks off processing. */ |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 548 | void balloon_set_new_target(unsigned long target) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 549 | { |
| 550 | /* No need for lock. Not read-modify-write updates. */ |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 551 | balloon_stats.target_pages = target; |
Daniel Kiper | 95170b2 | 2011-03-08 22:47:39 +0100 | [diff] [blame] | 552 | schedule_delayed_work(&balloon_worker, 0); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 553 | } |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 554 | EXPORT_SYMBOL_GPL(balloon_set_new_target); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 555 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 556 | /** |
| 557 | * alloc_xenballooned_pages - get pages that have been ballooned out |
| 558 | * @nr_pages: Number of pages to get |
| 559 | * @pages: pages returned |
Daniel De Graaf | 72e9cf2 | 2011-10-19 17:59:37 -0400 | [diff] [blame] | 560 | * @highmem: allow highmem pages |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 561 | * @return 0 on success, error otherwise |
| 562 | */ |
Stefano Stabellini | 693394b | 2011-09-29 11:57:55 +0100 | [diff] [blame] | 563 | int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 564 | { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 565 | int pgno = 0; |
Ruslan Pisarev | e882dc9 | 2011-07-26 14:15:59 +0300 | [diff] [blame] | 566 | struct page *page; |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 567 | mutex_lock(&balloon_mutex); |
| 568 | while (pgno < nr_pages) { |
Stefano Stabellini | 693394b | 2011-09-29 11:57:55 +0100 | [diff] [blame] | 569 | page = balloon_retrieve(highmem); |
Daniel De Graaf | 72e9cf2 | 2011-10-19 17:59:37 -0400 | [diff] [blame] | 570 | if (page && (highmem || !PageHighMem(page))) { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 571 | pages[pgno++] = page; |
| 572 | } else { |
| 573 | enum bp_state st; |
Stefano Stabellini | 693394b | 2011-09-29 11:57:55 +0100 | [diff] [blame] | 574 | if (page) |
| 575 | balloon_append(page); |
| 576 | st = decrease_reservation(nr_pages - pgno, |
| 577 | highmem ? GFP_HIGHUSER : GFP_USER); |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 578 | if (st != BP_DONE) |
| 579 | goto out_undo; |
| 580 | } |
| 581 | } |
| 582 | mutex_unlock(&balloon_mutex); |
| 583 | return 0; |
| 584 | out_undo: |
| 585 | while (pgno) |
| 586 | balloon_append(pages[--pgno]); |
| 587 | /* Free the memory back to the kernel soon */ |
| 588 | schedule_delayed_work(&balloon_worker, 0); |
| 589 | mutex_unlock(&balloon_mutex); |
| 590 | return -ENOMEM; |
| 591 | } |
| 592 | EXPORT_SYMBOL(alloc_xenballooned_pages); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 593 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 594 | /** |
| 595 | * free_xenballooned_pages - return pages retrieved with get_ballooned_pages |
| 596 | * @nr_pages: Number of pages |
| 597 | * @pages: pages to return |
| 598 | */ |
Ruslan Pisarev | e882dc9 | 2011-07-26 14:15:59 +0300 | [diff] [blame] | 599 | void free_xenballooned_pages(int nr_pages, struct page **pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 600 | { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 601 | int i; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 602 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 603 | mutex_lock(&balloon_mutex); |
| 604 | |
| 605 | for (i = 0; i < nr_pages; i++) { |
| 606 | if (pages[i]) |
| 607 | balloon_append(pages[i]); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 608 | } |
| 609 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 610 | /* The balloon may be too large now. Shrink it if needed. */ |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 611 | if (current_credit()) |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 612 | schedule_delayed_work(&balloon_worker, 0); |
| 613 | |
| 614 | mutex_unlock(&balloon_mutex); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 615 | } |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 616 | EXPORT_SYMBOL(free_xenballooned_pages); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 617 | |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 618 | static void __init balloon_add_region(unsigned long start_pfn, |
| 619 | unsigned long pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 620 | { |
Daniel Kiper | 4dfe22f | 2011-03-28 11:33:18 +0200 | [diff] [blame] | 621 | unsigned long pfn, extra_pfn_end; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 622 | struct page *page; |
| 623 | |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 624 | /* |
| 625 | * If the amount of usable memory has been limited (e.g., with |
| 626 | * the 'mem' command line parameter), don't add pages beyond |
| 627 | * this limit. |
| 628 | */ |
| 629 | extra_pfn_end = min(max_pfn, start_pfn + pages); |
| 630 | |
| 631 | for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) { |
| 632 | page = pfn_to_page(pfn); |
| 633 | /* totalram_pages and totalhigh_pages do not |
| 634 | include the boot-time balloon extension, so |
| 635 | don't subtract from it. */ |
| 636 | __balloon_append(page); |
| 637 | } |
| 638 | } |
| 639 | |
| 640 | static int __init balloon_init(void) |
| 641 | { |
David Vrabel | 0bb599f | 2015-01-05 17:06:01 +0000 | [diff] [blame] | 642 | int i; |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 643 | |
Stefano Stabellini | 53d5522 | 2010-12-02 17:55:05 +0000 | [diff] [blame] | 644 | if (!xen_domain()) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 645 | return -ENODEV; |
| 646 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 647 | pr_info("Initialising balloon driver\n"); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 648 | |
David Vrabel | aa24411 | 2011-09-28 17:46:32 +0100 | [diff] [blame] | 649 | balloon_stats.current_pages = xen_pv_domain() |
| 650 | ? min(xen_start_info->nr_pages - xen_released_pages, max_pfn) |
Boris Ostrovsky | c275a57 | 2013-11-06 15:37:40 -0500 | [diff] [blame] | 651 | : get_num_physpages(); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 652 | balloon_stats.target_pages = balloon_stats.current_pages; |
| 653 | balloon_stats.balloon_low = 0; |
| 654 | balloon_stats.balloon_high = 0; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 655 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 656 | balloon_stats.schedule_delay = 1; |
| 657 | balloon_stats.max_schedule_delay = 32; |
| 658 | balloon_stats.retry_count = 1; |
Konrad Rzeszutek Wilk | 40095de | 2011-03-14 11:42:40 -0400 | [diff] [blame] | 659 | balloon_stats.max_retry_count = RETRY_UNLIMITED; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 660 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 661 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
| 662 | balloon_stats.hotplug_pages = 0; |
| 663 | balloon_stats.balloon_hotplug = 0; |
| 664 | |
| 665 | set_online_page_callback(&xen_online_page); |
| 666 | register_memory_notifier(&xen_memory_nb); |
| 667 | #endif |
| 668 | |
Jeremy Fitzhardinge | 2a4c92f | 2010-12-02 15:30:06 -0800 | [diff] [blame] | 669 | /* |
David Vrabel | b1cbf9b | 2011-09-28 17:46:33 +0100 | [diff] [blame] | 670 | * Initialize the balloon with pages from the extra memory |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 671 | * regions (see arch/x86/xen/setup.c). |
Jeremy Fitzhardinge | 2a4c92f | 2010-12-02 15:30:06 -0800 | [diff] [blame] | 672 | */ |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 673 | for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) |
Juergen Gross | 626d750 | 2015-09-04 14:05:51 +0200 | [diff] [blame] | 674 | if (xen_extra_mem[i].n_pfns) |
| 675 | balloon_add_region(xen_extra_mem[i].start_pfn, |
| 676 | xen_extra_mem[i].n_pfns); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 677 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 678 | return 0; |
| 679 | } |
| 680 | |
| 681 | subsys_initcall(balloon_init); |
| 682 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 683 | MODULE_LICENSE("GPL"); |