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19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21#include <linux/kernel.h>
22#include <linux/jiffies.h>
23#include <linux/mman.h>
24#include <linux/delay.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/slab.h>
28#include <linux/kthread.h>
29#include <linux/completion.h>
30#include <linux/memory_hotplug.h>
31#include <linux/memory.h>
32#include <linux/notifier.h>
33#include <linux/percpu_counter.h>
34
35#include <linux/hyperv.h>
36
37#define CREATE_TRACE_POINTS
38#include "hv_trace_balloon.h"
39
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60
61#define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor)))
62#define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16)
63#define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff)
64
65enum {
66 DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3),
67 DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0),
68 DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0),
69
70 DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
71 DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
72 DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3,
73
74 DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10
75};
76
77
78
79
80
81
82
83enum dm_message_type {
84
85
86
87 DM_ERROR = 0,
88 DM_VERSION_REQUEST = 1,
89 DM_VERSION_RESPONSE = 2,
90 DM_CAPABILITIES_REPORT = 3,
91 DM_CAPABILITIES_RESPONSE = 4,
92 DM_STATUS_REPORT = 5,
93 DM_BALLOON_REQUEST = 6,
94 DM_BALLOON_RESPONSE = 7,
95 DM_UNBALLOON_REQUEST = 8,
96 DM_UNBALLOON_RESPONSE = 9,
97 DM_MEM_HOT_ADD_REQUEST = 10,
98 DM_MEM_HOT_ADD_RESPONSE = 11,
99 DM_VERSION_03_MAX = 11,
100
101
102
103 DM_INFO_MESSAGE = 12,
104 DM_VERSION_1_MAX = 12
105};
106
107
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110
111
112
113union dm_version {
114 struct {
115 __u16 minor_version;
116 __u16 major_version;
117 };
118 __u32 version;
119} __packed;
120
121
122union dm_caps {
123 struct {
124 __u64 balloon:1;
125 __u64 hot_add:1;
126
127
128
129
130
131
132 __u64 hot_add_alignment:4;
133 __u64 reservedz:58;
134 } cap_bits;
135 __u64 caps;
136} __packed;
137
138union dm_mem_page_range {
139 struct {
140
141
142
143
144
145 __u64 start_page:40;
146
147
148
149 __u64 page_cnt:24;
150 } finfo;
151 __u64 page_range;
152} __packed;
153
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162
163
164struct dm_header {
165 __u16 type;
166 __u16 size;
167 __u32 trans_id;
168} __packed;
169
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173
174
175struct dm_message {
176 struct dm_header hdr;
177 __u8 data[];
178} __packed;
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194
195struct dm_version_request {
196 struct dm_header hdr;
197 union dm_version version;
198 __u32 is_last_attempt:1;
199 __u32 reservedz:31;
200} __packed;
201
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212
213struct dm_version_response {
214 struct dm_header hdr;
215 __u64 is_accepted:1;
216 __u64 reservedz:63;
217} __packed;
218
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222
223
224struct dm_capabilities {
225 struct dm_header hdr;
226 union dm_caps caps;
227 __u64 min_page_cnt;
228 __u64 max_page_number;
229} __packed;
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240
241struct dm_capabilities_resp_msg {
242 struct dm_header hdr;
243 __u64 is_accepted:1;
244 __u64 reservedz:63;
245} __packed;
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267struct dm_status {
268 struct dm_header hdr;
269 __u64 num_avail;
270 __u64 num_committed;
271 __u64 page_file_size;
272 __u64 zero_free;
273 __u32 page_file_writes;
274 __u32 io_diff;
275} __packed;
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285
286struct dm_balloon {
287 struct dm_header hdr;
288 __u32 num_pages;
289 __u32 reservedz;
290} __packed;
291
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306
307struct dm_balloon_response {
308 struct dm_header hdr;
309 __u32 reservedz;
310 __u32 more_pages:1;
311 __u32 range_count:31;
312 union dm_mem_page_range range_array[];
313} __packed;
314
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329
330struct dm_unballoon_request {
331 struct dm_header hdr;
332 __u32 more_pages:1;
333 __u32 reservedz:31;
334 __u32 range_count;
335 union dm_mem_page_range range_array[];
336} __packed;
337
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342
343
344struct dm_unballoon_response {
345 struct dm_header hdr;
346} __packed;
347
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357
358struct dm_hot_add {
359 struct dm_header hdr;
360 union dm_mem_page_range range;
361} __packed;
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383struct dm_hot_add_response {
384 struct dm_header hdr;
385 __u32 page_count;
386 __u32 result;
387} __packed;
388
389
390
391
392
393enum dm_info_type {
394 INFO_TYPE_MAX_PAGE_CNT = 0,
395 MAX_INFO_TYPE
396};
397
398
399
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401
402
403struct dm_info_header {
404 enum dm_info_type type;
405 __u32 data_size;
406} __packed;
407
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416
417struct dm_info_msg {
418 struct dm_header hdr;
419 __u32 reserved;
420 __u32 info_size;
421 __u8 info[];
422};
423
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439
440struct hv_hotadd_state {
441 struct list_head list;
442 unsigned long start_pfn;
443 unsigned long covered_start_pfn;
444 unsigned long covered_end_pfn;
445 unsigned long ha_end_pfn;
446 unsigned long end_pfn;
447
448
449
450 struct list_head gap_list;
451};
452
453struct hv_hotadd_gap {
454 struct list_head list;
455 unsigned long start_pfn;
456 unsigned long end_pfn;
457};
458
459struct balloon_state {
460 __u32 num_pages;
461 struct work_struct wrk;
462};
463
464struct hot_add_wrk {
465 union dm_mem_page_range ha_page_range;
466 union dm_mem_page_range ha_region_range;
467 struct work_struct wrk;
468};
469
470static bool hot_add = true;
471static bool do_hot_add;
472
473
474
475
476static uint pressure_report_delay = 45;
477
478
479
480
481static unsigned long last_post_time;
482
483module_param(hot_add, bool, (S_IRUGO | S_IWUSR));
484MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add");
485
486module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
487MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
488static atomic_t trans_id = ATOMIC_INIT(0);
489
490static int dm_ring_size = (5 * PAGE_SIZE);
491
492
493
494
495
496enum hv_dm_state {
497 DM_INITIALIZING = 0,
498 DM_INITIALIZED,
499 DM_BALLOON_UP,
500 DM_BALLOON_DOWN,
501 DM_HOT_ADD,
502 DM_INIT_ERROR
503};
504
505
506static __u8 recv_buffer[PAGE_SIZE];
507static __u8 *send_buffer;
508#define PAGES_IN_2M 512
509#define HA_CHUNK (32 * 1024)
510
511struct hv_dynmem_device {
512 struct hv_device *dev;
513 enum hv_dm_state state;
514 struct completion host_event;
515 struct completion config_event;
516
517
518
519
520 unsigned int num_pages_ballooned;
521 unsigned int num_pages_onlined;
522 unsigned int num_pages_added;
523
524
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526
527 struct balloon_state balloon_wrk;
528
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530
531
532 struct hot_add_wrk ha_wrk;
533
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537
538 bool host_specified_ha_region;
539
540
541
542
543 struct completion ol_waitevent;
544 bool ha_waiting;
545
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548
549
550
551 struct task_struct *thread;
552
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556
557 spinlock_t ha_lock;
558
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561
562 struct list_head ha_region_list;
563
564
565
566
567
568
569 __u32 next_version;
570
571
572
573
574 __u32 version;
575};
576
577static struct hv_dynmem_device dm_device;
578
579static void post_status(struct hv_dynmem_device *dm);
580
581#ifdef CONFIG_MEMORY_HOTPLUG
582static inline bool has_pfn_is_backed(struct hv_hotadd_state *has,
583 unsigned long pfn)
584{
585 struct hv_hotadd_gap *gap;
586
587
588 if ((pfn < has->covered_start_pfn) || (pfn >= has->covered_end_pfn))
589 return false;
590
591
592 list_for_each_entry(gap, &has->gap_list, list) {
593 if ((pfn >= gap->start_pfn) && (pfn < gap->end_pfn))
594 return false;
595 }
596
597 return true;
598}
599
600static unsigned long hv_page_offline_check(unsigned long start_pfn,
601 unsigned long nr_pages)
602{
603 unsigned long pfn = start_pfn, count = 0;
604 struct hv_hotadd_state *has;
605 bool found;
606
607 while (pfn < start_pfn + nr_pages) {
608
609
610
611
612 found = false;
613 list_for_each_entry(has, &dm_device.ha_region_list, list) {
614 while ((pfn >= has->start_pfn) &&
615 (pfn < has->end_pfn) &&
616 (pfn < start_pfn + nr_pages)) {
617 found = true;
618 if (has_pfn_is_backed(has, pfn))
619 count++;
620 pfn++;
621 }
622 }
623
624
625
626
627
628
629 if (!found)
630 pfn++;
631 }
632
633 return count;
634}
635
636static int hv_memory_notifier(struct notifier_block *nb, unsigned long val,
637 void *v)
638{
639 struct memory_notify *mem = (struct memory_notify *)v;
640 unsigned long flags, pfn_count;
641
642 switch (val) {
643 case MEM_ONLINE:
644 case MEM_CANCEL_ONLINE:
645 if (dm_device.ha_waiting) {
646 dm_device.ha_waiting = false;
647 complete(&dm_device.ol_waitevent);
648 }
649 break;
650
651 case MEM_OFFLINE:
652 spin_lock_irqsave(&dm_device.ha_lock, flags);
653 pfn_count = hv_page_offline_check(mem->start_pfn,
654 mem->nr_pages);
655 if (pfn_count <= dm_device.num_pages_onlined) {
656 dm_device.num_pages_onlined -= pfn_count;
657 } else {
658
659
660
661
662
663 WARN_ON_ONCE(1);
664 dm_device.num_pages_onlined = 0;
665 }
666 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
667 break;
668 case MEM_GOING_ONLINE:
669 case MEM_GOING_OFFLINE:
670 case MEM_CANCEL_OFFLINE:
671 break;
672 }
673 return NOTIFY_OK;
674}
675
676static struct notifier_block hv_memory_nb = {
677 .notifier_call = hv_memory_notifier,
678 .priority = 0
679};
680
681
682static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
683{
684 if (!has_pfn_is_backed(has, page_to_pfn(pg)))
685 return;
686
687
688 __online_page_set_limits(pg);
689 __online_page_increment_counters(pg);
690 __online_page_free(pg);
691
692 WARN_ON_ONCE(!spin_is_locked(&dm_device.ha_lock));
693 dm_device.num_pages_onlined++;
694}
695
696static void hv_bring_pgs_online(struct hv_hotadd_state *has,
697 unsigned long start_pfn, unsigned long size)
698{
699 int i;
700
701 pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn);
702 for (i = 0; i < size; i++)
703 hv_page_online_one(has, pfn_to_page(start_pfn + i));
704}
705
706static void hv_mem_hot_add(unsigned long start, unsigned long size,
707 unsigned long pfn_count,
708 struct hv_hotadd_state *has)
709{
710 int ret = 0;
711 int i, nid;
712 unsigned long start_pfn;
713 unsigned long processed_pfn;
714 unsigned long total_pfn = pfn_count;
715 unsigned long flags;
716
717 for (i = 0; i < (size/HA_CHUNK); i++) {
718 start_pfn = start + (i * HA_CHUNK);
719
720 spin_lock_irqsave(&dm_device.ha_lock, flags);
721 has->ha_end_pfn += HA_CHUNK;
722
723 if (total_pfn > HA_CHUNK) {
724 processed_pfn = HA_CHUNK;
725 total_pfn -= HA_CHUNK;
726 } else {
727 processed_pfn = total_pfn;
728 total_pfn = 0;
729 }
730
731 has->covered_end_pfn += processed_pfn;
732 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
733
734 init_completion(&dm_device.ol_waitevent);
735 dm_device.ha_waiting = !memhp_auto_online;
736
737 nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
738 ret = add_memory(nid, PFN_PHYS((start_pfn)),
739 (HA_CHUNK << PAGE_SHIFT));
740
741 if (ret) {
742 pr_err("hot_add memory failed error is %d\n", ret);
743 if (ret == -EEXIST) {
744
745
746
747
748
749
750
751 do_hot_add = false;
752 }
753 spin_lock_irqsave(&dm_device.ha_lock, flags);
754 has->ha_end_pfn -= HA_CHUNK;
755 has->covered_end_pfn -= processed_pfn;
756 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
757 break;
758 }
759
760
761
762
763
764
765
766
767 if (dm_device.ha_waiting)
768 wait_for_completion_timeout(&dm_device.ol_waitevent,
769 5*HZ);
770 post_status(&dm_device);
771 }
772}
773
774static void hv_online_page(struct page *pg)
775{
776 struct hv_hotadd_state *has;
777 unsigned long flags;
778 unsigned long pfn = page_to_pfn(pg);
779
780 spin_lock_irqsave(&dm_device.ha_lock, flags);
781 list_for_each_entry(has, &dm_device.ha_region_list, list) {
782
783 if ((pfn < has->start_pfn) || (pfn >= has->end_pfn))
784 continue;
785
786 hv_page_online_one(has, pg);
787 break;
788 }
789 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
790}
791
792static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
793{
794 struct hv_hotadd_state *has;
795 struct hv_hotadd_gap *gap;
796 unsigned long residual, new_inc;
797 int ret = 0;
798 unsigned long flags;
799
800 spin_lock_irqsave(&dm_device.ha_lock, flags);
801 list_for_each_entry(has, &dm_device.ha_region_list, list) {
802
803
804
805
806 if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
807 continue;
808
809
810
811
812
813 if (has->covered_end_pfn != start_pfn) {
814 gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC);
815 if (!gap) {
816 ret = -ENOMEM;
817 break;
818 }
819
820 INIT_LIST_HEAD(&gap->list);
821 gap->start_pfn = has->covered_end_pfn;
822 gap->end_pfn = start_pfn;
823 list_add_tail(&gap->list, &has->gap_list);
824
825 has->covered_end_pfn = start_pfn;
826 }
827
828
829
830
831
832 if ((start_pfn + pfn_cnt) > has->end_pfn) {
833 residual = (start_pfn + pfn_cnt - has->end_pfn);
834
835
836
837 new_inc = (residual / HA_CHUNK) * HA_CHUNK;
838 if (residual % HA_CHUNK)
839 new_inc += HA_CHUNK;
840
841 has->end_pfn += new_inc;
842 }
843
844 ret = 1;
845 break;
846 }
847 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
848
849 return ret;
850}
851
852static unsigned long handle_pg_range(unsigned long pg_start,
853 unsigned long pg_count)
854{
855 unsigned long start_pfn = pg_start;
856 unsigned long pfn_cnt = pg_count;
857 unsigned long size;
858 struct hv_hotadd_state *has;
859 unsigned long pgs_ol = 0;
860 unsigned long old_covered_state;
861 unsigned long res = 0, flags;
862
863 pr_debug("Hot adding %lu pages starting at pfn 0x%lx.\n", pg_count,
864 pg_start);
865
866 spin_lock_irqsave(&dm_device.ha_lock, flags);
867 list_for_each_entry(has, &dm_device.ha_region_list, list) {
868
869
870
871
872 if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn)
873 continue;
874
875 old_covered_state = has->covered_end_pfn;
876
877 if (start_pfn < has->ha_end_pfn) {
878
879
880
881
882
883 pgs_ol = has->ha_end_pfn - start_pfn;
884 if (pgs_ol > pfn_cnt)
885 pgs_ol = pfn_cnt;
886
887 has->covered_end_pfn += pgs_ol;
888 pfn_cnt -= pgs_ol;
889
890
891
892
893
894
895 if (start_pfn > has->start_pfn &&
896 !PageReserved(pfn_to_page(start_pfn - 1)))
897 hv_bring_pgs_online(has, start_pfn, pgs_ol);
898
899 }
900
901 if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) {
902
903
904
905
906
907
908
909 size = (has->end_pfn - has->ha_end_pfn);
910 if (pfn_cnt <= size) {
911 size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK);
912 if (pfn_cnt % HA_CHUNK)
913 size += HA_CHUNK;
914 } else {
915 pfn_cnt = size;
916 }
917 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
918 hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has);
919 spin_lock_irqsave(&dm_device.ha_lock, flags);
920 }
921
922
923
924
925 res = has->covered_end_pfn - old_covered_state;
926 break;
927 }
928 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
929
930 return res;
931}
932
933static unsigned long process_hot_add(unsigned long pg_start,
934 unsigned long pfn_cnt,
935 unsigned long rg_start,
936 unsigned long rg_size)
937{
938 struct hv_hotadd_state *ha_region = NULL;
939 int covered;
940 unsigned long flags;
941
942 if (pfn_cnt == 0)
943 return 0;
944
945 if (!dm_device.host_specified_ha_region) {
946 covered = pfn_covered(pg_start, pfn_cnt);
947 if (covered < 0)
948 return 0;
949
950 if (covered)
951 goto do_pg_range;
952 }
953
954
955
956
957
958 if (rg_size != 0) {
959 ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL);
960 if (!ha_region)
961 return 0;
962
963 INIT_LIST_HEAD(&ha_region->list);
964 INIT_LIST_HEAD(&ha_region->gap_list);
965
966 ha_region->start_pfn = rg_start;
967 ha_region->ha_end_pfn = rg_start;
968 ha_region->covered_start_pfn = pg_start;
969 ha_region->covered_end_pfn = pg_start;
970 ha_region->end_pfn = rg_start + rg_size;
971
972 spin_lock_irqsave(&dm_device.ha_lock, flags);
973 list_add_tail(&ha_region->list, &dm_device.ha_region_list);
974 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
975 }
976
977do_pg_range:
978
979
980
981
982 return handle_pg_range(pg_start, pfn_cnt);
983}
984
985#endif
986
987static void hot_add_req(struct work_struct *dummy)
988{
989 struct dm_hot_add_response resp;
990#ifdef CONFIG_MEMORY_HOTPLUG
991 unsigned long pg_start, pfn_cnt;
992 unsigned long rg_start, rg_sz;
993#endif
994 struct hv_dynmem_device *dm = &dm_device;
995
996 memset(&resp, 0, sizeof(struct dm_hot_add_response));
997 resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE;
998 resp.hdr.size = sizeof(struct dm_hot_add_response);
999
1000#ifdef CONFIG_MEMORY_HOTPLUG
1001 pg_start = dm->ha_wrk.ha_page_range.finfo.start_page;
1002 pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt;
1003
1004 rg_start = dm->ha_wrk.ha_region_range.finfo.start_page;
1005 rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt;
1006
1007 if ((rg_start == 0) && (!dm->host_specified_ha_region)) {
1008 unsigned long region_size;
1009 unsigned long region_start;
1010
1011
1012
1013
1014
1015
1016
1017
1018 region_start = pg_start;
1019 region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
1020 if (pfn_cnt % HA_CHUNK)
1021 region_size += HA_CHUNK;
1022
1023 region_start = (pg_start / HA_CHUNK) * HA_CHUNK;
1024
1025 rg_start = region_start;
1026 rg_sz = region_size;
1027 }
1028
1029 if (do_hot_add)
1030 resp.page_count = process_hot_add(pg_start, pfn_cnt,
1031 rg_start, rg_sz);
1032
1033 dm->num_pages_added += resp.page_count;
1034#endif
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051 if (resp.page_count > 0)
1052 resp.result = 1;
1053 else if (!do_hot_add)
1054 resp.result = 1;
1055 else
1056 resp.result = 0;
1057
1058 if (!do_hot_add || (resp.page_count == 0))
1059 pr_err("Memory hot add failed\n");
1060
1061 dm->state = DM_INITIALIZED;
1062 resp.hdr.trans_id = atomic_inc_return(&trans_id);
1063 vmbus_sendpacket(dm->dev->channel, &resp,
1064 sizeof(struct dm_hot_add_response),
1065 (unsigned long)NULL,
1066 VM_PKT_DATA_INBAND, 0);
1067}
1068
1069static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
1070{
1071 struct dm_info_header *info_hdr;
1072
1073 info_hdr = (struct dm_info_header *)msg->info;
1074
1075 switch (info_hdr->type) {
1076 case INFO_TYPE_MAX_PAGE_CNT:
1077 if (info_hdr->data_size == sizeof(__u64)) {
1078 __u64 *max_page_count = (__u64 *)&info_hdr[1];
1079
1080 pr_info("Max. dynamic memory size: %llu MB\n",
1081 (*max_page_count) >> (20 - PAGE_SHIFT));
1082 }
1083
1084 break;
1085 default:
1086 pr_warn("Received Unknown type: %d\n", info_hdr->type);
1087 }
1088}
1089
1090static unsigned long compute_balloon_floor(void)
1091{
1092 unsigned long min_pages;
1093#define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT))
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105 if (totalram_pages < MB2PAGES(128))
1106 min_pages = MB2PAGES(8) + (totalram_pages >> 1);
1107 else if (totalram_pages < MB2PAGES(512))
1108 min_pages = MB2PAGES(40) + (totalram_pages >> 2);
1109 else if (totalram_pages < MB2PAGES(2048))
1110 min_pages = MB2PAGES(104) + (totalram_pages >> 3);
1111 else if (totalram_pages < MB2PAGES(8192))
1112 min_pages = MB2PAGES(232) + (totalram_pages >> 4);
1113 else
1114 min_pages = MB2PAGES(488) + (totalram_pages >> 5);
1115#undef MB2PAGES
1116 return min_pages;
1117}
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129static void post_status(struct hv_dynmem_device *dm)
1130{
1131 struct dm_status status;
1132 unsigned long now = jiffies;
1133 unsigned long last_post = last_post_time;
1134
1135 if (pressure_report_delay > 0) {
1136 --pressure_report_delay;
1137 return;
1138 }
1139
1140 if (!time_after(now, (last_post_time + HZ)))
1141 return;
1142
1143 memset(&status, 0, sizeof(struct dm_status));
1144 status.hdr.type = DM_STATUS_REPORT;
1145 status.hdr.size = sizeof(struct dm_status);
1146 status.hdr.trans_id = atomic_inc_return(&trans_id);
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158 status.num_avail = si_mem_available();
1159 status.num_committed = vm_memory_committed() +
1160 dm->num_pages_ballooned +
1161 (dm->num_pages_added > dm->num_pages_onlined ?
1162 dm->num_pages_added - dm->num_pages_onlined : 0) +
1163 compute_balloon_floor();
1164
1165 trace_balloon_status(status.num_avail, status.num_committed,
1166 vm_memory_committed(), dm->num_pages_ballooned,
1167 dm->num_pages_added, dm->num_pages_onlined);
1168
1169
1170
1171
1172
1173 if (status.hdr.trans_id != atomic_read(&trans_id))
1174 return;
1175
1176
1177
1178
1179
1180 if (last_post != last_post_time)
1181 return;
1182
1183 last_post_time = jiffies;
1184 vmbus_sendpacket(dm->dev->channel, &status,
1185 sizeof(struct dm_status),
1186 (unsigned long)NULL,
1187 VM_PKT_DATA_INBAND, 0);
1188
1189}
1190
1191static void free_balloon_pages(struct hv_dynmem_device *dm,
1192 union dm_mem_page_range *range_array)
1193{
1194 int num_pages = range_array->finfo.page_cnt;
1195 __u64 start_frame = range_array->finfo.start_page;
1196 struct page *pg;
1197 int i;
1198
1199 for (i = 0; i < num_pages; i++) {
1200 pg = pfn_to_page(i + start_frame);
1201 __free_page(pg);
1202 dm->num_pages_ballooned--;
1203 }
1204}
1205
1206
1207
1208static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
1209 unsigned int num_pages,
1210 struct dm_balloon_response *bl_resp,
1211 int alloc_unit)
1212{
1213 unsigned int i = 0;
1214 struct page *pg;
1215
1216 if (num_pages < alloc_unit)
1217 return 0;
1218
1219 for (i = 0; (i * alloc_unit) < num_pages; i++) {
1220 if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) >
1221 PAGE_SIZE)
1222 return i * alloc_unit;
1223
1224
1225
1226
1227
1228 pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY |
1229 __GFP_NOMEMALLOC | __GFP_NOWARN,
1230 get_order(alloc_unit << PAGE_SHIFT));
1231
1232 if (!pg)
1233 return i * alloc_unit;
1234
1235 dm->num_pages_ballooned += alloc_unit;
1236
1237
1238
1239
1240
1241
1242 if (alloc_unit != 1)
1243 split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
1244
1245 bl_resp->range_count++;
1246 bl_resp->range_array[i].finfo.start_page =
1247 page_to_pfn(pg);
1248 bl_resp->range_array[i].finfo.page_cnt = alloc_unit;
1249 bl_resp->hdr.size += sizeof(union dm_mem_page_range);
1250
1251 }
1252
1253 return num_pages;
1254}
1255
1256static void balloon_up(struct work_struct *dummy)
1257{
1258 unsigned int num_pages = dm_device.balloon_wrk.num_pages;
1259 unsigned int num_ballooned = 0;
1260 struct dm_balloon_response *bl_resp;
1261 int alloc_unit;
1262 int ret;
1263 bool done = false;
1264 int i;
1265 long avail_pages;
1266 unsigned long floor;
1267
1268
1269 WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0);
1270
1271
1272
1273
1274
1275 alloc_unit = 512;
1276
1277 avail_pages = si_mem_available();
1278 floor = compute_balloon_floor();
1279
1280
1281 if (avail_pages < num_pages || avail_pages - num_pages < floor) {
1282 pr_warn("Balloon request will be partially fulfilled. %s\n",
1283 avail_pages < num_pages ? "Not enough memory." :
1284 "Balloon floor reached.");
1285
1286 num_pages = avail_pages > floor ? (avail_pages - floor) : 0;
1287 num_pages -= num_pages % PAGES_IN_2M;
1288 }
1289
1290 while (!done) {
1291 bl_resp = (struct dm_balloon_response *)send_buffer;
1292 memset(send_buffer, 0, PAGE_SIZE);
1293 bl_resp->hdr.type = DM_BALLOON_RESPONSE;
1294 bl_resp->hdr.size = sizeof(struct dm_balloon_response);
1295 bl_resp->more_pages = 1;
1296
1297 num_pages -= num_ballooned;
1298 num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
1299 bl_resp, alloc_unit);
1300
1301 if (alloc_unit != 1 && num_ballooned == 0) {
1302 alloc_unit = 1;
1303 continue;
1304 }
1305
1306 if (num_ballooned == 0 || num_ballooned == num_pages) {
1307 pr_debug("Ballooned %u out of %u requested pages.\n",
1308 num_pages, dm_device.balloon_wrk.num_pages);
1309
1310 bl_resp->more_pages = 0;
1311 done = true;
1312 dm_device.state = DM_INITIALIZED;
1313 }
1314
1315
1316
1317
1318
1319
1320
1321 do {
1322 bl_resp->hdr.trans_id = atomic_inc_return(&trans_id);
1323 ret = vmbus_sendpacket(dm_device.dev->channel,
1324 bl_resp,
1325 bl_resp->hdr.size,
1326 (unsigned long)NULL,
1327 VM_PKT_DATA_INBAND, 0);
1328
1329 if (ret == -EAGAIN)
1330 msleep(20);
1331 post_status(&dm_device);
1332 } while (ret == -EAGAIN);
1333
1334 if (ret) {
1335
1336
1337
1338 pr_err("Balloon response failed\n");
1339
1340 for (i = 0; i < bl_resp->range_count; i++)
1341 free_balloon_pages(&dm_device,
1342 &bl_resp->range_array[i]);
1343
1344 done = true;
1345 }
1346 }
1347
1348}
1349
1350static void balloon_down(struct hv_dynmem_device *dm,
1351 struct dm_unballoon_request *req)
1352{
1353 union dm_mem_page_range *range_array = req->range_array;
1354 int range_count = req->range_count;
1355 struct dm_unballoon_response resp;
1356 int i;
1357 unsigned int prev_pages_ballooned = dm->num_pages_ballooned;
1358
1359 for (i = 0; i < range_count; i++) {
1360 free_balloon_pages(dm, &range_array[i]);
1361 complete(&dm_device.config_event);
1362 }
1363
1364 pr_debug("Freed %u ballooned pages.\n",
1365 prev_pages_ballooned - dm->num_pages_ballooned);
1366
1367 if (req->more_pages == 1)
1368 return;
1369
1370 memset(&resp, 0, sizeof(struct dm_unballoon_response));
1371 resp.hdr.type = DM_UNBALLOON_RESPONSE;
1372 resp.hdr.trans_id = atomic_inc_return(&trans_id);
1373 resp.hdr.size = sizeof(struct dm_unballoon_response);
1374
1375 vmbus_sendpacket(dm_device.dev->channel, &resp,
1376 sizeof(struct dm_unballoon_response),
1377 (unsigned long)NULL,
1378 VM_PKT_DATA_INBAND, 0);
1379
1380 dm->state = DM_INITIALIZED;
1381}
1382
1383static void balloon_onchannelcallback(void *context);
1384
1385static int dm_thread_func(void *dm_dev)
1386{
1387 struct hv_dynmem_device *dm = dm_dev;
1388
1389 while (!kthread_should_stop()) {
1390 wait_for_completion_interruptible_timeout(
1391 &dm_device.config_event, 1*HZ);
1392
1393
1394
1395
1396 reinit_completion(&dm_device.config_event);
1397 post_status(dm);
1398 }
1399
1400 return 0;
1401}
1402
1403
1404static void version_resp(struct hv_dynmem_device *dm,
1405 struct dm_version_response *vresp)
1406{
1407 struct dm_version_request version_req;
1408 int ret;
1409
1410 if (vresp->is_accepted) {
1411
1412
1413
1414
1415
1416 complete(&dm->host_event);
1417 return;
1418 }
1419
1420
1421
1422
1423
1424
1425
1426 if (dm->next_version == 0)
1427 goto version_error;
1428
1429 memset(&version_req, 0, sizeof(struct dm_version_request));
1430 version_req.hdr.type = DM_VERSION_REQUEST;
1431 version_req.hdr.size = sizeof(struct dm_version_request);
1432 version_req.hdr.trans_id = atomic_inc_return(&trans_id);
1433 version_req.version.version = dm->next_version;
1434 dm->version = version_req.version.version;
1435
1436
1437
1438
1439
1440 switch (version_req.version.version) {
1441 case DYNMEM_PROTOCOL_VERSION_WIN8:
1442 dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
1443 version_req.is_last_attempt = 0;
1444 break;
1445 default:
1446 dm->next_version = 0;
1447 version_req.is_last_attempt = 1;
1448 }
1449
1450 ret = vmbus_sendpacket(dm->dev->channel, &version_req,
1451 sizeof(struct dm_version_request),
1452 (unsigned long)NULL,
1453 VM_PKT_DATA_INBAND, 0);
1454
1455 if (ret)
1456 goto version_error;
1457
1458 return;
1459
1460version_error:
1461 dm->state = DM_INIT_ERROR;
1462 complete(&dm->host_event);
1463}
1464
1465static void cap_resp(struct hv_dynmem_device *dm,
1466 struct dm_capabilities_resp_msg *cap_resp)
1467{
1468 if (!cap_resp->is_accepted) {
1469 pr_err("Capabilities not accepted by host\n");
1470 dm->state = DM_INIT_ERROR;
1471 }
1472 complete(&dm->host_event);
1473}
1474
1475static void balloon_onchannelcallback(void *context)
1476{
1477 struct hv_device *dev = context;
1478 u32 recvlen;
1479 u64 requestid;
1480 struct dm_message *dm_msg;
1481 struct dm_header *dm_hdr;
1482 struct hv_dynmem_device *dm = hv_get_drvdata(dev);
1483 struct dm_balloon *bal_msg;
1484 struct dm_hot_add *ha_msg;
1485 union dm_mem_page_range *ha_pg_range;
1486 union dm_mem_page_range *ha_region;
1487
1488 memset(recv_buffer, 0, sizeof(recv_buffer));
1489 vmbus_recvpacket(dev->channel, recv_buffer,
1490 PAGE_SIZE, &recvlen, &requestid);
1491
1492 if (recvlen > 0) {
1493 dm_msg = (struct dm_message *)recv_buffer;
1494 dm_hdr = &dm_msg->hdr;
1495
1496 switch (dm_hdr->type) {
1497 case DM_VERSION_RESPONSE:
1498 version_resp(dm,
1499 (struct dm_version_response *)dm_msg);
1500 break;
1501
1502 case DM_CAPABILITIES_RESPONSE:
1503 cap_resp(dm,
1504 (struct dm_capabilities_resp_msg *)dm_msg);
1505 break;
1506
1507 case DM_BALLOON_REQUEST:
1508 if (dm->state == DM_BALLOON_UP)
1509 pr_warn("Currently ballooning\n");
1510 bal_msg = (struct dm_balloon *)recv_buffer;
1511 dm->state = DM_BALLOON_UP;
1512 dm_device.balloon_wrk.num_pages = bal_msg->num_pages;
1513 schedule_work(&dm_device.balloon_wrk.wrk);
1514 break;
1515
1516 case DM_UNBALLOON_REQUEST:
1517 dm->state = DM_BALLOON_DOWN;
1518 balloon_down(dm,
1519 (struct dm_unballoon_request *)recv_buffer);
1520 break;
1521
1522 case DM_MEM_HOT_ADD_REQUEST:
1523 if (dm->state == DM_HOT_ADD)
1524 pr_warn("Currently hot-adding\n");
1525 dm->state = DM_HOT_ADD;
1526 ha_msg = (struct dm_hot_add *)recv_buffer;
1527 if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) {
1528
1529
1530
1531
1532 dm->host_specified_ha_region = false;
1533 ha_pg_range = &ha_msg->range;
1534 dm->ha_wrk.ha_page_range = *ha_pg_range;
1535 dm->ha_wrk.ha_region_range.page_range = 0;
1536 } else {
1537
1538
1539
1540
1541
1542 dm->host_specified_ha_region = true;
1543 ha_pg_range = &ha_msg->range;
1544 ha_region = &ha_pg_range[1];
1545 dm->ha_wrk.ha_page_range = *ha_pg_range;
1546 dm->ha_wrk.ha_region_range = *ha_region;
1547 }
1548 schedule_work(&dm_device.ha_wrk.wrk);
1549 break;
1550
1551 case DM_INFO_MESSAGE:
1552 process_info(dm, (struct dm_info_msg *)dm_msg);
1553 break;
1554
1555 default:
1556 pr_warn("Unhandled message: type: %d\n", dm_hdr->type);
1557
1558 }
1559 }
1560
1561}
1562
1563static int balloon_probe(struct hv_device *dev,
1564 const struct hv_vmbus_device_id *dev_id)
1565{
1566 int ret;
1567 unsigned long t;
1568 struct dm_version_request version_req;
1569 struct dm_capabilities cap_msg;
1570
1571#ifdef CONFIG_MEMORY_HOTPLUG
1572 do_hot_add = hot_add;
1573#else
1574 do_hot_add = false;
1575#endif
1576
1577
1578
1579
1580
1581 send_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
1582 if (!send_buffer)
1583 return -ENOMEM;
1584
1585 ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0,
1586 balloon_onchannelcallback, dev);
1587
1588 if (ret)
1589 goto probe_error0;
1590
1591 dm_device.dev = dev;
1592 dm_device.state = DM_INITIALIZING;
1593 dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8;
1594 init_completion(&dm_device.host_event);
1595 init_completion(&dm_device.config_event);
1596 INIT_LIST_HEAD(&dm_device.ha_region_list);
1597 spin_lock_init(&dm_device.ha_lock);
1598 INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up);
1599 INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req);
1600 dm_device.host_specified_ha_region = false;
1601
1602 dm_device.thread =
1603 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
1604 if (IS_ERR(dm_device.thread)) {
1605 ret = PTR_ERR(dm_device.thread);
1606 goto probe_error1;
1607 }
1608
1609#ifdef CONFIG_MEMORY_HOTPLUG
1610 set_online_page_callback(&hv_online_page);
1611 register_memory_notifier(&hv_memory_nb);
1612#endif
1613
1614 hv_set_drvdata(dev, &dm_device);
1615
1616
1617
1618
1619
1620
1621 memset(&version_req, 0, sizeof(struct dm_version_request));
1622 version_req.hdr.type = DM_VERSION_REQUEST;
1623 version_req.hdr.size = sizeof(struct dm_version_request);
1624 version_req.hdr.trans_id = atomic_inc_return(&trans_id);
1625 version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10;
1626 version_req.is_last_attempt = 0;
1627 dm_device.version = version_req.version.version;
1628
1629 ret = vmbus_sendpacket(dev->channel, &version_req,
1630 sizeof(struct dm_version_request),
1631 (unsigned long)NULL,
1632 VM_PKT_DATA_INBAND, 0);
1633 if (ret)
1634 goto probe_error2;
1635
1636 t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
1637 if (t == 0) {
1638 ret = -ETIMEDOUT;
1639 goto probe_error2;
1640 }
1641
1642
1643
1644
1645
1646 if (dm_device.state == DM_INIT_ERROR) {
1647 ret = -ETIMEDOUT;
1648 goto probe_error2;
1649 }
1650
1651 pr_info("Using Dynamic Memory protocol version %u.%u\n",
1652 DYNMEM_MAJOR_VERSION(dm_device.version),
1653 DYNMEM_MINOR_VERSION(dm_device.version));
1654
1655
1656
1657
1658 memset(&cap_msg, 0, sizeof(struct dm_capabilities));
1659 cap_msg.hdr.type = DM_CAPABILITIES_REPORT;
1660 cap_msg.hdr.size = sizeof(struct dm_capabilities);
1661 cap_msg.hdr.trans_id = atomic_inc_return(&trans_id);
1662
1663 cap_msg.caps.cap_bits.balloon = 1;
1664 cap_msg.caps.cap_bits.hot_add = 1;
1665
1666
1667
1668
1669
1670 cap_msg.caps.cap_bits.hot_add_alignment = 7;
1671
1672
1673
1674
1675
1676
1677 cap_msg.min_page_cnt = 0;
1678 cap_msg.max_page_number = -1;
1679
1680 ret = vmbus_sendpacket(dev->channel, &cap_msg,
1681 sizeof(struct dm_capabilities),
1682 (unsigned long)NULL,
1683 VM_PKT_DATA_INBAND, 0);
1684 if (ret)
1685 goto probe_error2;
1686
1687 t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ);
1688 if (t == 0) {
1689 ret = -ETIMEDOUT;
1690 goto probe_error2;
1691 }
1692
1693
1694
1695
1696
1697 if (dm_device.state == DM_INIT_ERROR) {
1698 ret = -ETIMEDOUT;
1699 goto probe_error2;
1700 }
1701
1702 dm_device.state = DM_INITIALIZED;
1703 last_post_time = jiffies;
1704
1705 return 0;
1706
1707probe_error2:
1708#ifdef CONFIG_MEMORY_HOTPLUG
1709 restore_online_page_callback(&hv_online_page);
1710#endif
1711 kthread_stop(dm_device.thread);
1712
1713probe_error1:
1714 vmbus_close(dev->channel);
1715probe_error0:
1716 kfree(send_buffer);
1717 return ret;
1718}
1719
1720static int balloon_remove(struct hv_device *dev)
1721{
1722 struct hv_dynmem_device *dm = hv_get_drvdata(dev);
1723 struct hv_hotadd_state *has, *tmp;
1724 struct hv_hotadd_gap *gap, *tmp_gap;
1725 unsigned long flags;
1726
1727 if (dm->num_pages_ballooned != 0)
1728 pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned);
1729
1730 cancel_work_sync(&dm->balloon_wrk.wrk);
1731 cancel_work_sync(&dm->ha_wrk.wrk);
1732
1733 vmbus_close(dev->channel);
1734 kthread_stop(dm->thread);
1735 kfree(send_buffer);
1736#ifdef CONFIG_MEMORY_HOTPLUG
1737 restore_online_page_callback(&hv_online_page);
1738 unregister_memory_notifier(&hv_memory_nb);
1739#endif
1740 spin_lock_irqsave(&dm_device.ha_lock, flags);
1741 list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) {
1742 list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
1743 list_del(&gap->list);
1744 kfree(gap);
1745 }
1746 list_del(&has->list);
1747 kfree(has);
1748 }
1749 spin_unlock_irqrestore(&dm_device.ha_lock, flags);
1750
1751 return 0;
1752}
1753
1754static const struct hv_vmbus_device_id id_table[] = {
1755
1756
1757 { HV_DM_GUID, },
1758 { },
1759};
1760
1761MODULE_DEVICE_TABLE(vmbus, id_table);
1762
1763static struct hv_driver balloon_drv = {
1764 .name = "hv_balloon",
1765 .id_table = id_table,
1766 .probe = balloon_probe,
1767 .remove = balloon_remove,
1768};
1769
1770static int __init init_balloon_drv(void)
1771{
1772
1773 return vmbus_driver_register(&balloon_drv);
1774}
1775
1776module_init(init_balloon_drv);
1777
1778MODULE_DESCRIPTION("Hyper-V Balloon");
1779MODULE_LICENSE("GPL");
1780