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> |
Ingo Molnar | 5b825c3 | 2017-02-02 17:54:15 +0100 | [diff] [blame] | 44 | #include <linux/cred.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 45 | #include <linux/errno.h> |
| 46 | #include <linux/mm.h> |
Mike Rapoport | 57c8a66 | 2018-10-30 15:09:49 -0700 | [diff] [blame] | 47 | #include <linux/memblock.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 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> |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 58 | #include <linux/sysctl.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 59 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 60 | #include <asm/page.h> |
| 61 | #include <asm/pgalloc.h> |
| 62 | #include <asm/pgtable.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 63 | #include <asm/tlb.h> |
| 64 | |
Jeremy Fitzhardinge | ecbf29c | 2008-12-16 12:37:07 -0800 | [diff] [blame] | 65 | #include <asm/xen/hypervisor.h> |
| 66 | #include <asm/xen/hypercall.h> |
Jeremy Fitzhardinge | 1ccbf53 | 2009-10-06 15:11:14 -0700 | [diff] [blame] | 67 | |
| 68 | #include <xen/xen.h> |
Jeremy Fitzhardinge | ecbf29c | 2008-12-16 12:37:07 -0800 | [diff] [blame] | 69 | #include <xen/interface/xen.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 70 | #include <xen/interface/memory.h> |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 71 | #include <xen/balloon.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 72 | #include <xen/features.h> |
| 73 | #include <xen/page.h> |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 74 | #include <xen/mem-reservation.h> |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 75 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 76 | static int xen_hotplug_unpopulated; |
| 77 | |
| 78 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
| 79 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 80 | static struct ctl_table balloon_table[] = { |
| 81 | { |
| 82 | .procname = "hotplug_unpopulated", |
| 83 | .data = &xen_hotplug_unpopulated, |
| 84 | .maxlen = sizeof(int), |
| 85 | .mode = 0644, |
| 86 | .proc_handler = proc_dointvec_minmax, |
Matteo Croce | eec4844 | 2019-07-18 15:58:50 -0700 | [diff] [blame] | 87 | .extra1 = SYSCTL_ZERO, |
| 88 | .extra2 = SYSCTL_ONE, |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 89 | }, |
| 90 | { } |
| 91 | }; |
| 92 | |
| 93 | static struct ctl_table balloon_root[] = { |
| 94 | { |
| 95 | .procname = "balloon", |
| 96 | .mode = 0555, |
| 97 | .child = balloon_table, |
| 98 | }, |
| 99 | { } |
| 100 | }; |
| 101 | |
| 102 | static struct ctl_table xen_root[] = { |
| 103 | { |
| 104 | .procname = "xen", |
| 105 | .mode = 0555, |
| 106 | .child = balloon_root, |
| 107 | }, |
| 108 | { } |
| 109 | }; |
| 110 | |
| 111 | #endif |
| 112 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 113 | /* |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 114 | * Use one extent per PAGE_SIZE to avoid to break down the page into |
| 115 | * multiple frame. |
| 116 | */ |
| 117 | #define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1) |
| 118 | |
| 119 | /* |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 120 | * balloon_process() state: |
| 121 | * |
| 122 | * BP_DONE: done or nothing to do, |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 123 | * BP_WAIT: wait to be rescheduled, |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 124 | * BP_EAGAIN: error, go to sleep, |
| 125 | * BP_ECANCELED: error, balloon operation canceled. |
| 126 | */ |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 127 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 128 | enum bp_state { |
| 129 | BP_DONE, |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 130 | BP_WAIT, |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 131 | BP_EAGAIN, |
| 132 | BP_ECANCELED |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 133 | }; |
| 134 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 135 | |
| 136 | static DEFINE_MUTEX(balloon_mutex); |
| 137 | |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 138 | struct balloon_stats balloon_stats; |
| 139 | EXPORT_SYMBOL_GPL(balloon_stats); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 140 | |
| 141 | /* We increase/decrease in batches which fit in a page */ |
Julien Grall | 3990dd2 | 2015-10-07 14:04:33 +0100 | [diff] [blame] | 142 | static xen_pfn_t frame_list[PAGE_SIZE / sizeof(xen_pfn_t)]; |
Stefano Stabellini | cd9151e | 2013-08-04 15:39:40 +0100 | [diff] [blame] | 143 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 144 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 145 | /* List of ballooned pages, threaded through the mem_map array. */ |
| 146 | static LIST_HEAD(ballooned_pages); |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 147 | static DECLARE_WAIT_QUEUE_HEAD(balloon_wq); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 148 | |
| 149 | /* Main work function, always executed in process context. */ |
| 150 | static void balloon_process(struct work_struct *work); |
Daniel Kiper | 95170b2 | 2011-03-08 22:47:39 +0100 | [diff] [blame] | 151 | static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 152 | |
| 153 | /* When ballooning out (allocating memory to return to Xen) we don't really |
| 154 | want the kernel to try too hard since that can trigger the oom killer. */ |
| 155 | #define GFP_BALLOON \ |
| 156 | (GFP_HIGHUSER | __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC) |
| 157 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 158 | /* balloon_append: add the given page to the balloon. */ |
David Hildenbrand | dde3285 | 2019-10-01 11:01:50 +0200 | [diff] [blame] | 159 | static void balloon_append(struct page *page) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 160 | { |
David Hildenbrand | 59b52f1 | 2019-10-01 11:01:51 +0200 | [diff] [blame] | 161 | __SetPageOffline(page); |
| 162 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 163 | /* Lowmem is re-populated first, so highmem pages go at list tail. */ |
| 164 | if (PageHighMem(page)) { |
| 165 | list_add_tail(&page->lru, &ballooned_pages); |
| 166 | balloon_stats.balloon_high++; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 167 | } else { |
| 168 | list_add(&page->lru, &ballooned_pages); |
| 169 | balloon_stats.balloon_low++; |
| 170 | } |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 171 | wake_up(&balloon_wq); |
Jeremy Fitzhardinge | 9be4d45 | 2010-08-31 15:01:16 -0700 | [diff] [blame] | 172 | } |
Gianluca Guida | 3d65c94 | 2009-07-30 22:54:36 +0100 | [diff] [blame] | 173 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 174 | /* balloon_retrieve: rescue a page from the balloon, if it is not empty. */ |
David Vrabel | 81b286e | 2015-06-25 13:12:46 +0100 | [diff] [blame] | 175 | static struct page *balloon_retrieve(bool require_lowmem) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 176 | { |
| 177 | struct page *page; |
| 178 | |
| 179 | if (list_empty(&ballooned_pages)) |
| 180 | return NULL; |
| 181 | |
David Vrabel | 81b286e | 2015-06-25 13:12:46 +0100 | [diff] [blame] | 182 | page = list_entry(ballooned_pages.next, struct page, lru); |
| 183 | if (require_lowmem && PageHighMem(page)) |
| 184 | return NULL; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 185 | list_del(&page->lru); |
| 186 | |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 187 | if (PageHighMem(page)) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 188 | balloon_stats.balloon_high--; |
Jiang Liu | 3dcc057 | 2013-07-03 15:03:21 -0700 | [diff] [blame] | 189 | else |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 190 | balloon_stats.balloon_low--; |
| 191 | |
David Hildenbrand | 04ccbdc | 2019-10-01 11:01:52 +0200 | [diff] [blame] | 192 | __ClearPageOffline(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 193 | return page; |
| 194 | } |
| 195 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 196 | static struct page *balloon_next_page(struct page *page) |
| 197 | { |
| 198 | struct list_head *next = page->lru.next; |
| 199 | if (next == &ballooned_pages) |
| 200 | return NULL; |
| 201 | return list_entry(next, struct page, lru); |
| 202 | } |
| 203 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 204 | static enum bp_state update_schedule(enum bp_state state) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 205 | { |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 206 | if (state == BP_WAIT) |
| 207 | return BP_WAIT; |
| 208 | |
Boris Ostrovsky | fd8b795 | 2014-10-07 17:00:07 -0400 | [diff] [blame] | 209 | if (state == BP_ECANCELED) |
| 210 | return BP_ECANCELED; |
| 211 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 212 | if (state == BP_DONE) { |
| 213 | balloon_stats.schedule_delay = 1; |
| 214 | balloon_stats.retry_count = 1; |
| 215 | return BP_DONE; |
| 216 | } |
| 217 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 218 | ++balloon_stats.retry_count; |
| 219 | |
| 220 | if (balloon_stats.max_retry_count != RETRY_UNLIMITED && |
| 221 | balloon_stats.retry_count > balloon_stats.max_retry_count) { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 222 | balloon_stats.schedule_delay = 1; |
| 223 | balloon_stats.retry_count = 1; |
| 224 | return BP_ECANCELED; |
| 225 | } |
| 226 | |
| 227 | balloon_stats.schedule_delay <<= 1; |
| 228 | |
| 229 | if (balloon_stats.schedule_delay > balloon_stats.max_schedule_delay) |
| 230 | balloon_stats.schedule_delay = balloon_stats.max_schedule_delay; |
| 231 | |
| 232 | return BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 233 | } |
| 234 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 235 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
Ross Lagerwall | 842775f | 2016-05-10 10:27:54 +0100 | [diff] [blame] | 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 | } |
| 248 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 249 | static struct resource *additional_memory_resource(phys_addr_t size) |
| 250 | { |
Igor Druzhinin | 1236641 | 2018-11-27 20:58:21 +0000 | [diff] [blame] | 251 | struct resource *res; |
| 252 | int ret; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 253 | |
| 254 | res = kzalloc(sizeof(*res), GFP_KERNEL); |
| 255 | if (!res) |
| 256 | return NULL; |
| 257 | |
| 258 | res->name = "System RAM"; |
Toshi Kani | 782b866 | 2016-01-26 21:57:24 +0100 | [diff] [blame] | 259 | res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 260 | |
Igor Druzhinin | 1236641 | 2018-11-27 20:58:21 +0000 | [diff] [blame] | 261 | ret = allocate_resource(&iomem_resource, res, |
| 262 | size, 0, -1, |
| 263 | PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL); |
| 264 | if (ret < 0) { |
| 265 | pr_err("Cannot allocate new System RAM resource\n"); |
| 266 | kfree(res); |
| 267 | return NULL; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 268 | } |
| 269 | |
Ross Lagerwall | dfd74a1 | 2016-03-17 16:52:00 +0000 | [diff] [blame] | 270 | #ifdef CONFIG_SPARSEMEM |
| 271 | { |
| 272 | unsigned long limit = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT); |
| 273 | unsigned long pfn = res->start >> PAGE_SHIFT; |
| 274 | |
| 275 | if (pfn > limit) { |
| 276 | pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n", |
| 277 | pfn, limit); |
| 278 | release_memory_resource(res); |
| 279 | return NULL; |
| 280 | } |
| 281 | } |
| 282 | #endif |
| 283 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 284 | return res; |
| 285 | } |
| 286 | |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 287 | static enum bp_state reserve_additional_memory(void) |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 288 | { |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 289 | long credit; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 290 | struct resource *resource; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 291 | int nid, rc; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 292 | unsigned long balloon_hotplug; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 293 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 294 | credit = balloon_stats.target_pages + balloon_stats.target_unpopulated |
| 295 | - balloon_stats.total_pages; |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 296 | |
| 297 | /* |
| 298 | * Already hotplugged enough pages? Wait for them to be |
| 299 | * onlined. |
| 300 | */ |
| 301 | if (credit <= 0) |
| 302 | return BP_WAIT; |
| 303 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 304 | balloon_hotplug = round_up(credit, PAGES_PER_SECTION); |
| 305 | |
| 306 | resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE); |
| 307 | if (!resource) |
| 308 | goto err; |
| 309 | |
| 310 | nid = memory_add_physaddr_to_nid(resource->start); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 311 | |
Juergen Gross | 3c56b3a1 | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 312 | #ifdef CONFIG_XEN_HAVE_PVMMU |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 313 | /* |
| 314 | * We don't support PV MMU when Linux and Xen is using |
| 315 | * different page granularity. |
| 316 | */ |
| 317 | BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); |
| 318 | |
Juergen Gross | 3c56b3a1 | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 319 | /* |
| 320 | * add_memory() will build page tables for the new memory so |
| 321 | * the p2m must contain invalid entries so the correct |
| 322 | * non-present PTEs will be written. |
| 323 | * |
| 324 | * If a failure occurs, the original (identity) p2m entries |
| 325 | * are not restored since this region is now known not to |
| 326 | * conflict with any devices. |
| 327 | */ |
| 328 | if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
| 329 | unsigned long pfn, i; |
| 330 | |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 331 | pfn = PFN_DOWN(resource->start); |
Juergen Gross | 3c56b3a1 | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 332 | for (i = 0; i < balloon_hotplug; i++) { |
| 333 | if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) { |
| 334 | pr_warn("set_phys_to_machine() failed, no memory added\n"); |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 335 | goto err; |
Juergen Gross | 3c56b3a1 | 2015-03-20 13:55:39 +0100 | [diff] [blame] | 336 | } |
| 337 | } |
| 338 | } |
| 339 | #endif |
| 340 | |
Vitaly Kuznetsov | 703fc13 | 2016-03-15 14:56:52 -0700 | [diff] [blame] | 341 | /* |
| 342 | * add_memory_resource() will call online_pages() which in its turn |
| 343 | * will call xen_online_page() callback causing deadlock if we don't |
| 344 | * release balloon_mutex here. Unlocking here is safe because the |
| 345 | * callers drop the mutex before trying again. |
| 346 | */ |
| 347 | mutex_unlock(&balloon_mutex); |
David Hildenbrand | 8df1d0e | 2018-10-30 15:10:24 -0700 | [diff] [blame] | 348 | /* add_memory_resource() requires the device_hotplug lock */ |
| 349 | lock_device_hotplug(); |
David Hildenbrand | f29d8e9c0 | 2018-12-28 00:35:36 -0800 | [diff] [blame] | 350 | rc = add_memory_resource(nid, resource); |
David Hildenbrand | 8df1d0e | 2018-10-30 15:10:24 -0700 | [diff] [blame] | 351 | unlock_device_hotplug(); |
Vitaly Kuznetsov | 703fc13 | 2016-03-15 14:56:52 -0700 | [diff] [blame] | 352 | mutex_lock(&balloon_mutex); |
| 353 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 354 | if (rc) { |
David Vrabel | 3dcf636 | 2014-09-01 18:52:44 +0100 | [diff] [blame] | 355 | pr_warn("Cannot add additional memory (%i)\n", rc); |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 356 | goto err; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 357 | } |
| 358 | |
David Vrabel | de5a77d | 2015-06-25 12:08:20 +0100 | [diff] [blame] | 359 | balloon_stats.total_pages += balloon_hotplug; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 360 | |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 361 | return BP_WAIT; |
David Vrabel | 55b3da9 | 2015-06-24 15:58:42 +0100 | [diff] [blame] | 362 | err: |
| 363 | release_memory_resource(resource); |
| 364 | return BP_ECANCELED; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 365 | } |
| 366 | |
Arun KS | a9cd410 | 2019-03-05 15:42:14 -0800 | [diff] [blame] | 367 | static void xen_online_page(struct page *page, unsigned int order) |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 368 | { |
Arun KS | a9cd410 | 2019-03-05 15:42:14 -0800 | [diff] [blame] | 369 | unsigned long i, size = (1 << order); |
| 370 | unsigned long start_pfn = page_to_pfn(page); |
| 371 | struct page *p; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 372 | |
Arun KS | a9cd410 | 2019-03-05 15:42:14 -0800 | [diff] [blame] | 373 | pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 374 | mutex_lock(&balloon_mutex); |
Arun KS | a9cd410 | 2019-03-05 15:42:14 -0800 | [diff] [blame] | 375 | for (i = 0; i < size; i++) { |
| 376 | p = pfn_to_page(start_pfn + i); |
| 377 | __online_page_set_limits(p); |
David Hildenbrand | dde3285 | 2019-10-01 11:01:50 +0200 | [diff] [blame] | 378 | balloon_append(p); |
Arun KS | a9cd410 | 2019-03-05 15:42:14 -0800 | [diff] [blame] | 379 | } |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 380 | mutex_unlock(&balloon_mutex); |
| 381 | } |
| 382 | |
| 383 | static int xen_memory_notifier(struct notifier_block *nb, unsigned long val, void *v) |
| 384 | { |
| 385 | if (val == MEM_ONLINE) |
| 386 | schedule_delayed_work(&balloon_worker, 0); |
| 387 | |
| 388 | return NOTIFY_OK; |
| 389 | } |
| 390 | |
| 391 | static struct notifier_block xen_memory_nb = { |
| 392 | .notifier_call = xen_memory_notifier, |
| 393 | .priority = 0 |
| 394 | }; |
| 395 | #else |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 396 | static enum bp_state reserve_additional_memory(void) |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 397 | { |
| 398 | balloon_stats.target_pages = balloon_stats.current_pages; |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 399 | return BP_ECANCELED; |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 400 | } |
| 401 | #endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */ |
| 402 | |
David Vrabel | de5a77d | 2015-06-25 12:08:20 +0100 | [diff] [blame] | 403 | static long current_credit(void) |
| 404 | { |
| 405 | return balloon_stats.target_pages - balloon_stats.current_pages; |
| 406 | } |
| 407 | |
| 408 | static bool balloon_is_inflated(void) |
| 409 | { |
| 410 | return balloon_stats.balloon_low || balloon_stats.balloon_high; |
| 411 | } |
| 412 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 413 | static enum bp_state increase_reservation(unsigned long nr_pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 414 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 415 | int rc; |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 416 | unsigned long i; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 417 | struct page *page; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 418 | |
| 419 | if (nr_pages > ARRAY_SIZE(frame_list)) |
| 420 | nr_pages = ARRAY_SIZE(frame_list); |
| 421 | |
Jie Liu | 9346c2a | 2013-11-13 20:59:58 +0800 | [diff] [blame] | 422 | page = list_first_entry_or_null(&ballooned_pages, struct page, lru); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 423 | for (i = 0; i < nr_pages; i++) { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 424 | if (!page) { |
| 425 | nr_pages = i; |
| 426 | break; |
| 427 | } |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 428 | |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 429 | frame_list[i] = page_to_xen_pfn(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 430 | page = balloon_next_page(page); |
| 431 | } |
| 432 | |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 433 | rc = xenmem_reservation_increase(nr_pages, frame_list); |
Konrad Rzeszutek Wilk | 40095de | 2011-03-14 11:42:40 -0400 | [diff] [blame] | 434 | if (rc <= 0) |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 435 | return BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 436 | |
Ian Campbell | bc2c030 | 2009-06-05 11:58:37 +0100 | [diff] [blame] | 437 | for (i = 0; i < rc; i++) { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 438 | page = balloon_retrieve(false); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 439 | BUG_ON(page == NULL); |
| 440 | |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 441 | xenmem_reservation_va_mapping_update(1, &page, &frame_list[i]); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 442 | |
| 443 | /* Relinquish the page back to the allocator. */ |
Ross Lagerwall | 709613a | 2016-12-09 17:10:22 +0000 | [diff] [blame] | 444 | free_reserved_page(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 445 | } |
| 446 | |
Ian Campbell | bc2c030 | 2009-06-05 11:58:37 +0100 | [diff] [blame] | 447 | balloon_stats.current_pages += rc; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 448 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 449 | return BP_DONE; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 450 | } |
| 451 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 452 | 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] | 453 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 454 | enum bp_state state = BP_DONE; |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 455 | unsigned long i; |
| 456 | struct page *page, *tmp; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 457 | int ret; |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 458 | LIST_HEAD(pages); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 459 | |
| 460 | if (nr_pages > ARRAY_SIZE(frame_list)) |
| 461 | nr_pages = ARRAY_SIZE(frame_list); |
| 462 | |
| 463 | for (i = 0; i < nr_pages; i++) { |
Lisa Nguyen | fce9268 | 2013-05-15 22:59:40 -0700 | [diff] [blame] | 464 | page = alloc_page(gfp); |
| 465 | if (page == NULL) { |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 466 | nr_pages = i; |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 467 | state = BP_EAGAIN; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 468 | break; |
| 469 | } |
Ross Lagerwall | 709613a | 2016-12-09 17:10:22 +0000 | [diff] [blame] | 470 | adjust_managed_page_count(page, -1); |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 471 | xenmem_reservation_scrub_page(page); |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 472 | list_add(&page->lru, &pages); |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Ensure that ballooned highmem pages don't have kmaps. |
| 477 | * |
| 478 | * Do this before changing the p2m as kmap_flush_unused() |
| 479 | * reads PTEs to obtain pages (and hence needs the original |
| 480 | * p2m entry). |
| 481 | */ |
| 482 | kmap_flush_unused(); |
| 483 | |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 484 | /* |
| 485 | * Setup the frame, update direct mapping, invalidate P2M, |
| 486 | * and add to balloon. |
| 487 | */ |
| 488 | i = 0; |
| 489 | list_for_each_entry_safe(page, tmp, &pages, lru) { |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 490 | frame_list[i++] = xen_page_to_gfn(page); |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 491 | |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 492 | xenmem_reservation_va_mapping_reset(1, &page); |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 493 | |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 494 | list_del(&page->lru); |
David Vrabel | 24f6937 | 2013-09-19 17:14:53 +0100 | [diff] [blame] | 495 | |
Wei Liu | 09ed3d5 | 2014-03-15 16:11:47 +0000 | [diff] [blame] | 496 | balloon_append(page); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 497 | } |
| 498 | |
David Vrabel | 24f6937 | 2013-09-19 17:14:53 +0100 | [diff] [blame] | 499 | flush_tlb_all(); |
David Vrabel | 2bad07c | 2013-09-11 17:45:44 +0000 | [diff] [blame] | 500 | |
Oleksandr Andrushchenko | ae4c51a | 2018-07-20 12:01:44 +0300 | [diff] [blame] | 501 | ret = xenmem_reservation_decrease(nr_pages, frame_list); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 502 | BUG_ON(ret != nr_pages); |
| 503 | |
| 504 | balloon_stats.current_pages -= nr_pages; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 505 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 506 | return state; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 507 | } |
| 508 | |
| 509 | /* |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 510 | * 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] | 511 | * We may of course race updates of the target counts (which are protected |
| 512 | * by the balloon lock), or with changes to the Xen hard limit, but we will |
| 513 | * recover from these in time. |
| 514 | */ |
| 515 | static void balloon_process(struct work_struct *work) |
| 516 | { |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 517 | enum bp_state state = BP_DONE; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 518 | long credit; |
| 519 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 520 | |
| 521 | do { |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 522 | mutex_lock(&balloon_mutex); |
| 523 | |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 524 | credit = current_credit(); |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 525 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 526 | if (credit > 0) { |
| 527 | if (balloon_is_inflated()) |
| 528 | state = increase_reservation(credit); |
| 529 | else |
David Vrabel | b2ac6aa | 2015-06-25 12:10:28 +0100 | [diff] [blame] | 530 | state = reserve_additional_memory(); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 531 | } |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 532 | |
Juergen Gross | a1078e8 | 2019-06-19 11:00:56 +0200 | [diff] [blame] | 533 | if (credit < 0) { |
| 534 | long n_pages; |
| 535 | |
| 536 | n_pages = min(-credit, si_mem_available()); |
| 537 | state = decrease_reservation(n_pages, GFP_BALLOON); |
| 538 | if (state == BP_DONE && n_pages != -credit && |
| 539 | n_pages < totalreserve_pages) |
| 540 | state = BP_EAGAIN; |
| 541 | } |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 542 | |
| 543 | state = update_schedule(state); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 544 | |
Juergen Gross | 929423f | 2015-07-20 13:49:39 +0200 | [diff] [blame] | 545 | mutex_unlock(&balloon_mutex); |
| 546 | |
| 547 | cond_resched(); |
| 548 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 549 | } while (credit && state == BP_DONE); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 550 | |
| 551 | /* Schedule more work if there is some still to be done. */ |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 552 | if (state == BP_EAGAIN) |
| 553 | schedule_delayed_work(&balloon_worker, balloon_stats.schedule_delay * HZ); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 554 | } |
| 555 | |
| 556 | /* Resets the Xen limit, sets new target, and kicks off processing. */ |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 557 | void balloon_set_new_target(unsigned long target) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 558 | { |
| 559 | /* No need for lock. Not read-modify-write updates. */ |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 560 | balloon_stats.target_pages = target; |
Daniel Kiper | 95170b2 | 2011-03-08 22:47:39 +0100 | [diff] [blame] | 561 | schedule_delayed_work(&balloon_worker, 0); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 562 | } |
Daniel De Graaf | 803eb04 | 2011-03-14 11:29:37 -0400 | [diff] [blame] | 563 | EXPORT_SYMBOL_GPL(balloon_set_new_target); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 564 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 565 | static int add_ballooned_pages(int nr_pages) |
| 566 | { |
| 567 | enum bp_state st; |
| 568 | |
| 569 | if (xen_hotplug_unpopulated) { |
| 570 | st = reserve_additional_memory(); |
| 571 | if (st != BP_ECANCELED) { |
| 572 | mutex_unlock(&balloon_mutex); |
| 573 | wait_event(balloon_wq, |
| 574 | !list_empty(&ballooned_pages)); |
| 575 | mutex_lock(&balloon_mutex); |
| 576 | return 0; |
| 577 | } |
| 578 | } |
| 579 | |
Juergen Gross | a1078e8 | 2019-06-19 11:00:56 +0200 | [diff] [blame] | 580 | if (si_mem_available() < nr_pages) |
| 581 | return -ENOMEM; |
| 582 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 583 | st = decrease_reservation(nr_pages, GFP_USER); |
| 584 | if (st != BP_DONE) |
| 585 | return -ENOMEM; |
| 586 | |
| 587 | return 0; |
| 588 | } |
| 589 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 590 | /** |
| 591 | * alloc_xenballooned_pages - get pages that have been ballooned out |
| 592 | * @nr_pages: Number of pages to get |
| 593 | * @pages: pages returned |
| 594 | * @return 0 on success, error otherwise |
| 595 | */ |
David Vrabel | 81b286e | 2015-06-25 13:12:46 +0100 | [diff] [blame] | 596 | int alloc_xenballooned_pages(int nr_pages, struct page **pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 597 | { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 598 | int pgno = 0; |
Ruslan Pisarev | e882dc9 | 2011-07-26 14:15:59 +0300 | [diff] [blame] | 599 | struct page *page; |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 600 | int ret; |
| 601 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 602 | mutex_lock(&balloon_mutex); |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 603 | |
| 604 | balloon_stats.target_unpopulated += nr_pages; |
| 605 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 606 | while (pgno < nr_pages) { |
David Vrabel | 81b286e | 2015-06-25 13:12:46 +0100 | [diff] [blame] | 607 | page = balloon_retrieve(true); |
| 608 | if (page) { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 609 | pages[pgno++] = page; |
David Vrabel | 4a69c90 | 2015-07-22 14:50:37 +0100 | [diff] [blame] | 610 | #ifdef CONFIG_XEN_HAVE_PVMMU |
Julien Grall | 30756c6 | 2015-05-04 15:39:08 +0100 | [diff] [blame] | 611 | /* |
| 612 | * We don't support PV MMU when Linux and Xen is using |
| 613 | * different page granularity. |
| 614 | */ |
| 615 | BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); |
| 616 | |
Boris Ostrovsky | b194da2 | 2017-08-23 18:27:04 -0400 | [diff] [blame] | 617 | if (!xen_feature(XENFEAT_auto_translated_physmap)) { |
| 618 | ret = xen_alloc_p2m_entry(page_to_pfn(page)); |
| 619 | if (ret < 0) |
| 620 | goto out_undo; |
| 621 | } |
David Vrabel | 4a69c90 | 2015-07-22 14:50:37 +0100 | [diff] [blame] | 622 | #endif |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 623 | } else { |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 624 | ret = add_ballooned_pages(nr_pages - pgno); |
| 625 | if (ret < 0) |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 626 | goto out_undo; |
| 627 | } |
| 628 | } |
| 629 | mutex_unlock(&balloon_mutex); |
| 630 | return 0; |
| 631 | out_undo: |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 632 | mutex_unlock(&balloon_mutex); |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 633 | free_xenballooned_pages(pgno, pages); |
| 634 | return ret; |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 635 | } |
| 636 | EXPORT_SYMBOL(alloc_xenballooned_pages); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 637 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 638 | /** |
| 639 | * free_xenballooned_pages - return pages retrieved with get_ballooned_pages |
| 640 | * @nr_pages: Number of pages |
| 641 | * @pages: pages to return |
| 642 | */ |
Ruslan Pisarev | e882dc9 | 2011-07-26 14:15:59 +0300 | [diff] [blame] | 643 | void free_xenballooned_pages(int nr_pages, struct page **pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 644 | { |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 645 | int i; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 646 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 647 | mutex_lock(&balloon_mutex); |
| 648 | |
| 649 | for (i = 0; i < nr_pages; i++) { |
David Hildenbrand | 59b52f1 | 2019-10-01 11:01:51 +0200 | [diff] [blame] | 650 | if (pages[i]) |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 651 | balloon_append(pages[i]); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 652 | } |
| 653 | |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 654 | balloon_stats.target_unpopulated -= nr_pages; |
| 655 | |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 656 | /* The balloon may be too large now. Shrink it if needed. */ |
Daniel Kiper | 83be7e5 | 2011-03-28 11:34:10 +0200 | [diff] [blame] | 657 | if (current_credit()) |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 658 | schedule_delayed_work(&balloon_worker, 0); |
| 659 | |
| 660 | mutex_unlock(&balloon_mutex); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 661 | } |
Konrad Rzeszutek Wilk | b6f3067 | 2011-03-15 10:23:57 -0400 | [diff] [blame] | 662 | EXPORT_SYMBOL(free_xenballooned_pages); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 663 | |
Vitaly Kuznetsov | 4fee9ad | 2017-03-14 18:35:53 +0100 | [diff] [blame] | 664 | #ifdef CONFIG_XEN_PV |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 665 | static void __init balloon_add_region(unsigned long start_pfn, |
| 666 | unsigned long pages) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 667 | { |
Daniel Kiper | 4dfe22f | 2011-03-28 11:33:18 +0200 | [diff] [blame] | 668 | unsigned long pfn, extra_pfn_end; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 669 | |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 670 | /* |
| 671 | * If the amount of usable memory has been limited (e.g., with |
| 672 | * the 'mem' command line parameter), don't add pages beyond |
| 673 | * this limit. |
| 674 | */ |
| 675 | extra_pfn_end = min(max_pfn, start_pfn + pages); |
| 676 | |
| 677 | for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) { |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 678 | /* totalram_pages and totalhigh_pages do not |
| 679 | include the boot-time balloon extension, so |
| 680 | don't subtract from it. */ |
David Hildenbrand | 59b52f1 | 2019-10-01 11:01:51 +0200 | [diff] [blame] | 681 | balloon_append(pfn_to_page(pfn)); |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 682 | } |
David Vrabel | de5a77d | 2015-06-25 12:08:20 +0100 | [diff] [blame] | 683 | |
| 684 | balloon_stats.total_pages += extra_pfn_end - start_pfn; |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 685 | } |
Vitaly Kuznetsov | 4fee9ad | 2017-03-14 18:35:53 +0100 | [diff] [blame] | 686 | #endif |
David Vrabel | 8b5d44a | 2011-09-28 17:46:34 +0100 | [diff] [blame] | 687 | |
| 688 | static int __init balloon_init(void) |
| 689 | { |
Stefano Stabellini | 53d5522 | 2010-12-02 17:55:05 +0000 | [diff] [blame] | 690 | if (!xen_domain()) |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 691 | return -ENODEV; |
| 692 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 693 | pr_info("Initialising balloon driver\n"); |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 694 | |
Vitaly Kuznetsov | 4fee9ad | 2017-03-14 18:35:53 +0100 | [diff] [blame] | 695 | #ifdef CONFIG_XEN_PV |
David Vrabel | aa24411 | 2011-09-28 17:46:32 +0100 | [diff] [blame] | 696 | balloon_stats.current_pages = xen_pv_domain() |
| 697 | ? min(xen_start_info->nr_pages - xen_released_pages, max_pfn) |
Boris Ostrovsky | c275a57 | 2013-11-06 15:37:40 -0500 | [diff] [blame] | 698 | : get_num_physpages(); |
Vitaly Kuznetsov | 4fee9ad | 2017-03-14 18:35:53 +0100 | [diff] [blame] | 699 | #else |
| 700 | balloon_stats.current_pages = get_num_physpages(); |
| 701 | #endif |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 702 | balloon_stats.target_pages = balloon_stats.current_pages; |
| 703 | balloon_stats.balloon_low = 0; |
| 704 | balloon_stats.balloon_high = 0; |
David Vrabel | de5a77d | 2015-06-25 12:08:20 +0100 | [diff] [blame] | 705 | balloon_stats.total_pages = balloon_stats.current_pages; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 706 | |
Daniel Kiper | 95d2ac4 | 2011-03-08 22:48:24 +0100 | [diff] [blame] | 707 | balloon_stats.schedule_delay = 1; |
| 708 | balloon_stats.max_schedule_delay = 32; |
| 709 | balloon_stats.retry_count = 1; |
Juergen Gross | a1078e8 | 2019-06-19 11:00:56 +0200 | [diff] [blame] | 710 | balloon_stats.max_retry_count = 4; |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 711 | |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 712 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 713 | set_online_page_callback(&xen_online_page); |
| 714 | register_memory_notifier(&xen_memory_nb); |
David Vrabel | 1cf6a6c | 2015-06-25 16:29:18 +0100 | [diff] [blame] | 715 | register_sysctl_table(xen_root); |
Daniel Kiper | 080e2be | 2011-07-25 17:12:06 -0700 | [diff] [blame] | 716 | #endif |
| 717 | |
Vitaly Kuznetsov | 4fee9ad | 2017-03-14 18:35:53 +0100 | [diff] [blame] | 718 | #ifdef CONFIG_XEN_PV |
| 719 | { |
| 720 | int i; |
| 721 | |
| 722 | /* |
| 723 | * Initialize the balloon with pages from the extra memory |
| 724 | * regions (see arch/x86/xen/setup.c). |
| 725 | */ |
| 726 | for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) |
| 727 | if (xen_extra_mem[i].n_pfns) |
| 728 | balloon_add_region(xen_extra_mem[i].start_pfn, |
| 729 | xen_extra_mem[i].n_pfns); |
| 730 | } |
| 731 | #endif |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 732 | |
Juergen Gross | 96edd61 | 2017-07-10 10:10:45 +0200 | [diff] [blame] | 733 | /* Init the xen-balloon driver. */ |
| 734 | xen_balloon_init(); |
| 735 | |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 736 | return 0; |
| 737 | } |
Jeremy Fitzhardinge | 1775826 | 2008-04-02 10:54:13 -0700 | [diff] [blame] | 738 | subsys_initcall(balloon_init); |