| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| K. Y. Srinivasan | 4264 | 62.24% | 21 | 24.71% |
| Vitaly Kuznetsov | 745 | 10.87% | 18 | 21.18% |
| Alexander Atanasov | 405 | 5.91% | 1 | 1.18% |
| Dexuan Cui | 371 | 5.42% | 4 | 4.71% |
| Sunil Muthuswamy | 321 | 4.69% | 1 | 1.18% |
| Shradha Gupta | 208 | 3.04% | 2 | 2.35% |
| Alex Ng | 194 | 2.83% | 8 | 9.41% |
| Boqun Feng | 89 | 1.30% | 3 | 3.53% |
| Michael Kelley | 71 | 1.04% | 2 | 2.35% |
| David Hildenbrand | 59 | 0.86% | 6 | 7.06% |
| Mitchell Levy | 36 | 0.53% | 1 | 1.18% |
| Arun K S | 27 | 0.39% | 3 | 3.53% |
| Himadri Pandya | 13 | 0.19% | 1 | 1.18% |
| Yanming Liu | 11 | 0.16% | 1 | 1.18% |
| Arjan van de Ven | 10 | 0.15% | 1 | 1.18% |
| JoonSoo Kim | 6 | 0.09% | 1 | 1.18% |
| Lan Tianyu | 6 | 0.09% | 1 | 1.18% |
| Aditya Nagesh | 4 | 0.06% | 1 | 1.18% |
| Thomas Gleixner | 2 | 0.03% | 1 | 1.18% |
| Wei Yongjun | 2 | 0.03% | 1 | 1.18% |
| Greg Kroah-Hartman | 2 | 0.03% | 2 | 2.35% |
| Lance Roy | 1 | 0.01% | 1 | 1.18% |
| Anssi Hannula | 1 | 0.01% | 1 | 1.18% |
| Olaf Hering | 1 | 0.01% | 1 | 1.18% |
| Dawei Li | 1 | 0.01% | 1 | 1.18% |
| Nicholas Mc Guire | 1 | 0.01% | 1 | 1.18% |
| Total | 6851 | 85 |
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2012, Microsoft Corporation. * * Author: * K. Y. Srinivasan <kys@microsoft.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/mman.h> #include <linux/debugfs.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/kthread.h> #include <linux/completion.h> #include <linux/count_zeros.h> #include <linux/memory_hotplug.h> #include <linux/memory.h> #include <linux/notifier.h> #include <linux/percpu_counter.h> #include <linux/page_reporting.h> #include <linux/sizes.h> #include <linux/hyperv.h> #include <asm/hyperv-tlfs.h> #include <asm/mshyperv.h> #define CREATE_TRACE_POINTS #include "hv_trace_balloon.h" /* * We begin with definitions supporting the Dynamic Memory protocol * with the host. * * Begin protocol definitions. */ /* * Protocol versions. The low word is the minor version, the high word the major * version. * * History: * Initial version 1.0 * Changed to 0.1 on 2009/03/25 * Changes to 0.2 on 2009/05/14 * Changes to 0.3 on 2009/12/03 * Changed to 1.0 on 2011/04/05 */ #define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor))) #define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16) #define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff) enum { DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3), DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0), DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0), DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1, DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2, DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3, DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10 }; /* * Message Types */ enum dm_message_type { /* * Version 0.3 */ DM_ERROR = 0, DM_VERSION_REQUEST = 1, DM_VERSION_RESPONSE = 2, DM_CAPABILITIES_REPORT = 3, DM_CAPABILITIES_RESPONSE = 4, DM_STATUS_REPORT = 5, DM_BALLOON_REQUEST = 6, DM_BALLOON_RESPONSE = 7, DM_UNBALLOON_REQUEST = 8, DM_UNBALLOON_RESPONSE = 9, DM_MEM_HOT_ADD_REQUEST = 10, DM_MEM_HOT_ADD_RESPONSE = 11, DM_VERSION_03_MAX = 11, /* * Version 1.0. */ DM_INFO_MESSAGE = 12, DM_VERSION_1_MAX = 12 }; /* * Structures defining the dynamic memory management * protocol. */ union dm_version { struct { __u16 minor_version; __u16 major_version; }; __u32 version; } __packed; union dm_caps { struct { __u64 balloon:1; __u64 hot_add:1; /* * To support guests that may have alignment * limitations on hot-add, the guest can specify * its alignment requirements; a value of n * represents an alignment of 2^n in mega bytes. */ __u64 hot_add_alignment:4; __u64 reservedz:58; } cap_bits; __u64 caps; } __packed; union dm_mem_page_range { struct { /* * The PFN number of the first page in the range. * 40 bits is the architectural limit of a PFN * number for AMD64. */ __u64 start_page:40; /* * The number of pages in the range. */ __u64 page_cnt:24; } finfo; __u64 page_range; } __packed; /* * The header for all dynamic memory messages: * * type: Type of the message. * size: Size of the message in bytes; including the header. * trans_id: The guest is responsible for manufacturing this ID. */ struct dm_header { __u16 type; __u16 size; __u32 trans_id; } __packed; /* * A generic message format for dynamic memory. * Specific message formats are defined later in the file. */ struct dm_message { struct dm_header hdr; __u8 data[]; /* enclosed message */ } __packed; /* * Specific message types supporting the dynamic memory protocol. */ /* * Version negotiation message. Sent from the guest to the host. * The guest is free to try different versions until the host * accepts the version. * * dm_version: The protocol version requested. * is_last_attempt: If TRUE, this is the last version guest will request. * reservedz: Reserved field, set to zero. */ struct dm_version_request { struct dm_header hdr; union dm_version version; __u32 is_last_attempt:1; __u32 reservedz:31; } __packed; /* * Version response message; Host to Guest and indicates * if the host has accepted the version sent by the guest. * * is_accepted: If TRUE, host has accepted the version and the guest * should proceed to the next stage of the protocol. FALSE indicates that * guest should re-try with a different version. * * reservedz: Reserved field, set to zero. */ struct dm_version_response { struct dm_header hdr; __u64 is_accepted:1; __u64 reservedz:63; } __packed; /* * Message reporting capabilities. This is sent from the guest to the * host. */ struct dm_capabilities { struct dm_header hdr; union dm_caps caps; __u64 min_page_cnt; __u64 max_page_number; } __packed; /* * Response to the capabilities message. This is sent from the host to the * guest. This message notifies if the host has accepted the guest's * capabilities. If the host has not accepted, the guest must shutdown * the service. * * is_accepted: Indicates if the host has accepted guest's capabilities. * reservedz: Must be 0. */ struct dm_capabilities_resp_msg { struct dm_header hdr; __u64 is_accepted:1; __u64 reservedz:63; } __packed; /* * This message is used to report memory pressure from the guest. * This message is not part of any transaction and there is no * response to this message. * * num_avail: Available memory in pages. * num_committed: Committed memory in pages. * page_file_size: The accumulated size of all page files * in the system in pages. * zero_free: The number of zero and free pages. * page_file_writes: The writes to the page file in pages. * io_diff: An indicator of file cache efficiency or page file activity, * calculated as File Cache Page Fault Count - Page Read Count. * This value is in pages. * * Some of these metrics are Windows specific and fortunately * the algorithm on the host side that computes the guest memory * pressure only uses num_committed value. */ struct dm_status { struct dm_header hdr; __u64 num_avail; __u64 num_committed; __u64 page_file_size; __u64 zero_free; __u32 page_file_writes; __u32 io_diff; } __packed; /* * Message to ask the guest to allocate memory - balloon up message. * This message is sent from the host to the guest. The guest may not be * able to allocate as much memory as requested. * * num_pages: number of pages to allocate. */ struct dm_balloon { struct dm_header hdr; __u32 num_pages; __u32 reservedz; } __packed; /* * Balloon response message; this message is sent from the guest * to the host in response to the balloon message. * * reservedz: Reserved; must be set to zero. * more_pages: If FALSE, this is the last message of the transaction. * if TRUE there will be at least one more message from the guest. * * range_count: The number of ranges in the range array. * * range_array: An array of page ranges returned to the host. * */ struct dm_balloon_response { struct dm_header hdr; __u32 reservedz; __u32 more_pages:1; __u32 range_count:31; union dm_mem_page_range range_array[]; } __packed; /* * Un-balloon message; this message is sent from the host * to the guest to give guest more memory. * * more_pages: If FALSE, this is the last message of the transaction. * if TRUE there will be at least one more message from the guest. * * reservedz: Reserved; must be set to zero. * * range_count: The number of ranges in the range array. * * range_array: An array of page ranges returned to the host. * */ struct dm_unballoon_request { struct dm_header hdr; __u32 more_pages:1; __u32 reservedz:31; __u32 range_count; union dm_mem_page_range range_array[]; } __packed; /* * Un-balloon response message; this message is sent from the guest * to the host in response to an unballoon request. * */ struct dm_unballoon_response { struct dm_header hdr; } __packed; /* * Hot add request message. Message sent from the host to the guest. * * mem_range: Memory range to hot add. * */ struct dm_hot_add { struct dm_header hdr; union dm_mem_page_range range; } __packed; /* * Hot add response message. * This message is sent by the guest to report the status of a hot add request. * If page_count is less than the requested page count, then the host should * assume all further hot add requests will fail, since this indicates that * the guest has hit an upper physical memory barrier. * * Hot adds may also fail due to low resources; in this case, the guest must * not complete this message until the hot add can succeed, and the host must * not send a new hot add request until the response is sent. * If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS * times it fails the request. * * * page_count: number of pages that were successfully hot added. * * result: result of the operation 1: success, 0: failure. * */ struct dm_hot_add_response { struct dm_header hdr; __u32 page_count; __u32 result; } __packed; /* * Types of information sent from host to the guest. */ enum dm_info_type { INFO_TYPE_MAX_PAGE_CNT = 0, MAX_INFO_TYPE }; /* * Header for the information message. */ struct dm_info_header { enum dm_info_type type; __u32 data_size; } __packed; /* * This message is sent from the host to the guest to pass * some relevant information (win8 addition). * * reserved: no used. * info_size: size of the information blob. * info: information blob. */ struct dm_info_msg { struct dm_header hdr; __u32 reserved; __u32 info_size; __u8 info[]; }; /* * End protocol definitions. */ /* * State to manage hot adding memory into the guest. * The range start_pfn : end_pfn specifies the range * that the host has asked us to hot add. The range * start_pfn : ha_end_pfn specifies the range that we have * currently hot added. We hot add in chunks equal to the * memory block size; it is possible that we may not be able * to bring online all the pages in the region. The range * covered_start_pfn:covered_end_pfn defines the pages that can * be brought online. */ struct hv_hotadd_state { struct list_head list; unsigned long start_pfn; unsigned long covered_start_pfn; unsigned long covered_end_pfn; unsigned long ha_end_pfn; unsigned long end_pfn; /* * A list of gaps. */ struct list_head gap_list; }; struct hv_hotadd_gap { struct list_head list; unsigned long start_pfn; unsigned long end_pfn; }; struct balloon_state { __u32 num_pages; struct work_struct wrk; }; struct hot_add_wrk { union dm_mem_page_range ha_page_range; union dm_mem_page_range ha_region_range; struct work_struct wrk; }; static bool allow_hibernation; static bool hot_add = true; static bool do_hot_add; /* * Delay reporting memory pressure by * the specified number of seconds. */ static uint pressure_report_delay = 45; extern unsigned int page_reporting_order; #define HV_MAX_FAILURES 2 /* * The last time we posted a pressure report to host. */ static unsigned long last_post_time; static int hv_hypercall_multi_failure; module_param(hot_add, bool, 0644); MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); module_param(pressure_report_delay, uint, 0644); MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure"); static atomic_t trans_id = ATOMIC_INIT(0); static int dm_ring_size = VMBUS_RING_SIZE(16 * 1024); /* * Driver specific state. */ enum hv_dm_state { DM_INITIALIZING = 0, DM_INITIALIZED, DM_BALLOON_UP, DM_BALLOON_DOWN, DM_HOT_ADD, DM_INIT_ERROR }; static __u8 recv_buffer[HV_HYP_PAGE_SIZE]; static __u8 balloon_up_send_buffer[HV_HYP_PAGE_SIZE]; static unsigned long ha_pages_in_chunk; #define HA_BYTES_IN_CHUNK (ha_pages_in_chunk << PAGE_SHIFT) #define PAGES_IN_2M (2 * 1024 * 1024 / PAGE_SIZE) struct hv_dynmem_device { struct hv_device *dev; enum hv_dm_state state; struct completion host_event; struct completion config_event; /* * Number of pages we have currently ballooned out. */ unsigned int num_pages_ballooned; unsigned int num_pages_onlined; unsigned int num_pages_added; /* * State to manage the ballooning (up) operation. */ struct balloon_state balloon_wrk; /* * State to execute the "hot-add" operation. */ struct hot_add_wrk ha_wrk; /* * This state tracks if the host has specified a hot-add * region. */ bool host_specified_ha_region; /* * State to synchronize hot-add. */ struct completion ol_waitevent; /* * This thread handles hot-add * requests from the host as well as notifying * the host with regards to memory pressure in * the guest. */ struct task_struct *thread; /* * Protects ha_region_list, num_pages_onlined counter and individual * regions from ha_region_list. */ spinlock_t ha_lock; /* * A list of hot-add regions. */ struct list_head ha_region_list; /* * We start with the highest version we can support * and downgrade based on the host; we save here the * next version to try. */ __u32 next_version; /* * The negotiated version agreed by host. */ __u32 version; struct page_reporting_dev_info pr_dev_info; /* * Maximum number of pages that can be hot_add-ed */ __u64 max_dynamic_page_count; }; static struct hv_dynmem_device dm_device; static void post_status(struct hv_dynmem_device *dm); static void enable_page_reporting(void); static void disable_page_reporting(void); #ifdef CONFIG_MEMORY_HOTPLUG static inline bool has_pfn_is_backed(struct hv_hotadd_state *has, unsigned long pfn) { struct hv_hotadd_gap *gap; /* The page is not backed. */ if (pfn < has->covered_start_pfn || pfn >= has->covered_end_pfn) return false; /* Check for gaps. */ list_for_each_entry(gap, &has->gap_list, list) { if (pfn >= gap->start_pfn && pfn < gap->end_pfn) return false; } return true; } static unsigned long hv_page_offline_check(unsigned long start_pfn, unsigned long nr_pages) { unsigned long pfn = start_pfn, count = 0; struct hv_hotadd_state *has; bool found; while (pfn < start_pfn + nr_pages) { /* * Search for HAS which covers the pfn and when we find one * count how many consequitive PFNs are covered. */ found = false; list_for_each_entry(has, &dm_device.ha_region_list, list) { while ((pfn >= has->start_pfn) && (pfn < has->end_pfn) && (pfn < start_pfn + nr_pages)) { found = true; if (has_pfn_is_backed(has, pfn)) count++; pfn++; } } /* * This PFN is not in any HAS (e.g. we're offlining a region * which was present at boot), no need to account for it. Go * to the next one. */ if (!found) pfn++; } return count; } static int hv_memory_notifier(struct notifier_block *nb, unsigned long val, void *v) { struct memory_notify *mem = (struct memory_notify *)v; unsigned long pfn_count; switch (val) { case MEM_ONLINE: case MEM_CANCEL_ONLINE: complete(&dm_device.ol_waitevent); break; case MEM_OFFLINE: scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { pfn_count = hv_page_offline_check(mem->start_pfn, mem->nr_pages); if (pfn_count <= dm_device.num_pages_onlined) { dm_device.num_pages_onlined -= pfn_count; } else { /* * We're offlining more pages than we * managed to online. This is * unexpected. In any case don't let * num_pages_onlined wrap around zero. */ WARN_ON_ONCE(1); dm_device.num_pages_onlined = 0; } } break; case MEM_GOING_ONLINE: case MEM_GOING_OFFLINE: case MEM_CANCEL_OFFLINE: break; } return NOTIFY_OK; } static struct notifier_block hv_memory_nb = { .notifier_call = hv_memory_notifier, .priority = 0 }; /* Check if the particular page is backed and can be onlined and online it. */ static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg) { if (!has_pfn_is_backed(has, page_to_pfn(pg))) { if (!PageOffline(pg)) __SetPageOffline(pg); return; } else if (!PageOffline(pg)) return; /* This frame is currently backed; online the page. */ generic_online_page(pg, 0); lockdep_assert_held(&dm_device.ha_lock); dm_device.num_pages_onlined++; } static void hv_bring_pgs_online(struct hv_hotadd_state *has, unsigned long start_pfn, unsigned long size) { int i; pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn); for (i = 0; i < size; i++) hv_page_online_one(has, pfn_to_page(start_pfn + i)); } static void hv_mem_hot_add(unsigned long start, unsigned long size, unsigned long pfn_count, struct hv_hotadd_state *has) { int ret = 0; int i, nid; unsigned long start_pfn; unsigned long processed_pfn; unsigned long total_pfn = pfn_count; for (i = 0; i < (size/ha_pages_in_chunk); i++) { start_pfn = start + (i * ha_pages_in_chunk); scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { has->ha_end_pfn += ha_pages_in_chunk; processed_pfn = umin(total_pfn, ha_pages_in_chunk); total_pfn -= processed_pfn; has->covered_end_pfn += processed_pfn; } reinit_completion(&dm_device.ol_waitevent); nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); ret = add_memory(nid, PFN_PHYS((start_pfn)), HA_BYTES_IN_CHUNK, MHP_MERGE_RESOURCE); if (ret) { pr_err("hot_add memory failed error is %d\n", ret); if (ret == -EEXIST) { /* * This error indicates that the error * is not a transient failure. This is the * case where the guest's physical address map * precludes hot adding memory. Stop all further * memory hot-add. */ do_hot_add = false; } scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { has->ha_end_pfn -= ha_pages_in_chunk; has->covered_end_pfn -= processed_pfn; } break; } /* * Wait for memory to get onlined. If the kernel onlined the * memory when adding it, this will return directly. Otherwise, * it will wait for user space to online the memory. This helps * to avoid adding memory faster than it is getting onlined. As * adding succeeded, it is ok to proceed even if the memory was * not onlined in time. */ wait_for_completion_timeout(&dm_device.ol_waitevent, 5 * HZ); post_status(&dm_device); } } static void hv_online_page(struct page *pg, unsigned int order) { struct hv_hotadd_state *has; unsigned long pfn = page_to_pfn(pg); guard(spinlock_irqsave)(&dm_device.ha_lock); list_for_each_entry(has, &dm_device.ha_region_list, list) { /* The page belongs to a different HAS. */ if (pfn < has->start_pfn || (pfn + (1UL << order) > has->end_pfn)) continue; hv_bring_pgs_online(has, pfn, 1UL << order); break; } } static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) { struct hv_hotadd_state *has; struct hv_hotadd_gap *gap; unsigned long residual; int ret = 0; guard(spinlock_irqsave)(&dm_device.ha_lock); list_for_each_entry(has, &dm_device.ha_region_list, list) { /* * If the pfn range we are dealing with is not in the current * "hot add block", move on. */ if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn) continue; /* * If the current start pfn is not where the covered_end * is, create a gap and update covered_end_pfn. */ if (has->covered_end_pfn != start_pfn) { gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC); if (!gap) { ret = -ENOMEM; break; } INIT_LIST_HEAD(&gap->list); gap->start_pfn = has->covered_end_pfn; gap->end_pfn = start_pfn; list_add_tail(&gap->list, &has->gap_list); has->covered_end_pfn = start_pfn; } /* * If the current hot add-request extends beyond * our current limit; extend it. */ if ((start_pfn + pfn_cnt) > has->end_pfn) { /* Extend the region by multiples of ha_pages_in_chunk */ residual = (start_pfn + pfn_cnt - has->end_pfn); has->end_pfn += ALIGN(residual, ha_pages_in_chunk); } ret = 1; break; } return ret; } static unsigned long handle_pg_range(unsigned long pg_start, unsigned long pg_count) { unsigned long start_pfn = pg_start; unsigned long pfn_cnt = pg_count; unsigned long size; struct hv_hotadd_state *has; unsigned long pgs_ol = 0; unsigned long old_covered_state; unsigned long res = 0, flags; pr_debug("Hot adding %lu pages starting at pfn 0x%lx.\n", pg_count, pg_start); spin_lock_irqsave(&dm_device.ha_lock, flags); list_for_each_entry(has, &dm_device.ha_region_list, list) { /* * If the pfn range we are dealing with is not in the current * "hot add block", move on. */ if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn) continue; old_covered_state = has->covered_end_pfn; if (start_pfn < has->ha_end_pfn) { /* * This is the case where we are backing pages * in an already hot added region. Bring * these pages online first. */ pgs_ol = has->ha_end_pfn - start_pfn; if (pgs_ol > pfn_cnt) pgs_ol = pfn_cnt; has->covered_end_pfn += pgs_ol; pfn_cnt -= pgs_ol; /* * Check if the corresponding memory block is already * online. It is possible to observe struct pages still * being uninitialized here so check section instead. * In case the section is online we need to bring the * rest of pfns (which were not backed previously) * online too. */ if (start_pfn > has->start_pfn && online_section_nr(pfn_to_section_nr(start_pfn))) hv_bring_pgs_online(has, start_pfn, pgs_ol); } if (has->ha_end_pfn < has->end_pfn && pfn_cnt > 0) { /* * We have some residual hot add range * that needs to be hot added; hot add * it now. Hot add a multiple of * ha_pages_in_chunk that fully covers the pages * we have. */ size = (has->end_pfn - has->ha_end_pfn); if (pfn_cnt <= size) { size = ALIGN(pfn_cnt, ha_pages_in_chunk); } else { pfn_cnt = size; } spin_unlock_irqrestore(&dm_device.ha_lock, flags); hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has); spin_lock_irqsave(&dm_device.ha_lock, flags); } /* * If we managed to online any pages that were given to us, * we declare success. */ res = has->covered_end_pfn - old_covered_state; break; } spin_unlock_irqrestore(&dm_device.ha_lock, flags); return res; } static unsigned long process_hot_add(unsigned long pg_start, unsigned long pfn_cnt, unsigned long rg_start, unsigned long rg_size) { struct hv_hotadd_state *ha_region = NULL; int covered; if (pfn_cnt == 0) return 0; if (!dm_device.host_specified_ha_region) { covered = pfn_covered(pg_start, pfn_cnt); if (covered < 0) return 0; if (covered) goto do_pg_range; } /* * If the host has specified a hot-add range; deal with it first. */ if (rg_size != 0) { ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL); if (!ha_region) return 0; INIT_LIST_HEAD(&ha_region->list); INIT_LIST_HEAD(&ha_region->gap_list); ha_region->start_pfn = rg_start; ha_region->ha_end_pfn = rg_start; ha_region->covered_start_pfn = pg_start; ha_region->covered_end_pfn = pg_start; ha_region->end_pfn = rg_start + rg_size; scoped_guard(spinlock_irqsave, &dm_device.ha_lock) { list_add_tail(&ha_region->list, &dm_device.ha_region_list); } } do_pg_range: /* * Process the page range specified; bringing them * online if possible. */ return handle_pg_range(pg_start, pfn_cnt); } #endif static void hot_add_req(struct work_struct *dummy) { struct dm_hot_add_response resp; #ifdef CONFIG_MEMORY_HOTPLUG unsigned long pg_start, pfn_cnt; unsigned long rg_start, rg_sz; #endif struct hv_dynmem_device *dm = &dm_device; memset(&resp, 0, sizeof(struct dm_hot_add_response)); resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE; resp.hdr.size = sizeof(struct dm_hot_add_response); #ifdef CONFIG_MEMORY_HOTPLUG pg_start = dm->ha_wrk.ha_page_range.finfo.start_page; pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt; rg_start = dm->ha_wrk.ha_region_range.finfo.start_page; rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt; if (rg_start == 0 && !dm->host_specified_ha_region) { /* * The host has not specified the hot-add region. * Based on the hot-add page range being specified, * compute a hot-add region that can cover the pages * that need to be hot-added while ensuring the alignment * and size requirements of Linux as it relates to hot-add. */ rg_start = ALIGN_DOWN(pg_start, ha_pages_in_chunk); rg_sz = ALIGN(pfn_cnt, ha_pages_in_chunk); } if (do_hot_add) resp.page_count = process_hot_add(pg_start, pfn_cnt, rg_start, rg_sz); dm->num_pages_added += resp.page_count; #endif /* * The result field of the response structure has the * following semantics: * * 1. If all or some pages hot-added: Guest should return success. * * 2. If no pages could be hot-added: * * If the guest returns success, then the host * will not attempt any further hot-add operations. This * signifies a permanent failure. * * If the guest returns failure, then this failure will be * treated as a transient failure and the host may retry the * hot-add operation after some delay. */ if (resp.page_count > 0) resp.result = 1; else if (!do_hot_add) resp.result = 1; else resp.result = 0; if (!do_hot_add || resp.page_count == 0) { if (!allow_hibernation) pr_err("Memory hot add failed\n"); else pr_info("Ignore hot-add request!\n"); } dm->state = DM_INITIALIZED; resp.hdr.trans_id = atomic_inc_return(&trans_id); vmbus_sendpacket(dm->dev->channel, &resp, sizeof(struct dm_hot_add_response), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); } static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg) { struct dm_info_header *info_hdr; info_hdr = (struct dm_info_header *)msg->info; switch (info_hdr->type) { case INFO_TYPE_MAX_PAGE_CNT: if (info_hdr->data_size == sizeof(__u64)) { __u64 *max_page_count = (__u64 *)&info_hdr[1]; pr_info("Max. dynamic memory size: %llu MB\n", (*max_page_count) >> (20 - HV_HYP_PAGE_SHIFT)); dm->max_dynamic_page_count = *max_page_count; } break; default: pr_warn("Received Unknown type: %d\n", info_hdr->type); } } static unsigned long compute_balloon_floor(void) { unsigned long min_pages; unsigned long nr_pages = totalram_pages(); #define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) /* Simple continuous piecewiese linear function: * max MiB -> min MiB gradient * 0 0 * 16 16 * 32 24 * 128 72 (1/2) * 512 168 (1/4) * 2048 360 (1/8) * 8192 744 (1/16) * 32768 1512 (1/32) */ if (nr_pages < MB2PAGES(128)) min_pages = MB2PAGES(8) + (nr_pages >> 1); else if (nr_pages < MB2PAGES(512)) min_pages = MB2PAGES(40) + (nr_pages >> 2); else if (nr_pages < MB2PAGES(2048)) min_pages = MB2PAGES(104) + (nr_pages >> 3); else if (nr_pages < MB2PAGES(8192)) min_pages = MB2PAGES(232) + (nr_pages >> 4); else min_pages = MB2PAGES(488) + (nr_pages >> 5); #undef MB2PAGES return min_pages; } /* * Compute total committed memory pages */ static unsigned long get_pages_committed(struct hv_dynmem_device *dm) { return vm_memory_committed() + dm->num_pages_ballooned + (dm->num_pages_added > dm->num_pages_onlined ? dm->num_pages_added - dm->num_pages_onlined : 0) + compute_balloon_floor(); } /* * Post our status as it relates memory pressure to the * host. Host expects the guests to post this status * periodically at 1 second intervals. * * The metrics specified in this protocol are very Windows * specific and so we cook up numbers here to convey our memory * pressure. */ static void post_status(struct hv_dynmem_device *dm) { struct dm_status status; unsigned long now = jiffies; unsigned long last_post = last_post_time; unsigned long num_pages_avail, num_pages_committed; if (pressure_report_delay > 0) { --pressure_report_delay; return; } if (!time_after(now, (last_post_time + HZ))) return; memset(&status, 0, sizeof(struct dm_status)); status.hdr.type = DM_STATUS_REPORT; status.hdr.size = sizeof(struct dm_status); status.hdr.trans_id = atomic_inc_return(&trans_id); /* * The host expects the guest to report free and committed memory. * Furthermore, the host expects the pressure information to include * the ballooned out pages. For a given amount of memory that we are * managing we need to compute a floor below which we should not * balloon. Compute this and add it to the pressure report. * We also need to report all offline pages (num_pages_added - * num_pages_onlined) as committed to the host, otherwise it can try * asking us to balloon them out. */ num_pages_avail = si_mem_available(); num_pages_committed = get_pages_committed(dm); trace_balloon_status(num_pages_avail, num_pages_committed, vm_memory_committed(), dm->num_pages_ballooned, dm->num_pages_added, dm->num_pages_onlined); /* Convert numbers of pages into numbers of HV_HYP_PAGEs. */ status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE; status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE; /* * If our transaction ID is no longer current, just don't * send the status. This can happen if we were interrupted * after we picked our transaction ID. */ if (status.hdr.trans_id != atomic_read(&trans_id)) return; /* * If the last post time that we sampled has changed, * we have raced, don't post the status. */ if (last_post != last_post_time) return; last_post_time = jiffies; vmbus_sendpacket(dm->dev->channel, &status, sizeof(struct dm_status), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); } static void free_balloon_pages(struct hv_dynmem_device *dm, union dm_mem_page_range *range_array) { int num_pages = range_array->finfo.page_cnt; __u64 start_frame = range_array->finfo.start_page; struct page *pg; int i; for (i = 0; i < num_pages; i++) { pg = pfn_to_page(i + start_frame); __ClearPageOffline(pg); __free_page(pg); dm->num_pages_ballooned--; adjust_managed_page_count(pg, 1); } } static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm, unsigned int num_pages, struct dm_balloon_response *bl_resp, int alloc_unit) { unsigned int i, j; struct page *pg; for (i = 0; i < num_pages / alloc_unit; i++) { if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) > HV_HYP_PAGE_SIZE) return i * alloc_unit; /* * We execute this code in a thread context. Furthermore, * we don't want the kernel to try too hard. */ pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN, get_order(alloc_unit << PAGE_SHIFT)); if (!pg) return i * alloc_unit; dm->num_pages_ballooned += alloc_unit; /* * If we allocatted 2M pages; split them so we * can free them in any order we get. */ if (alloc_unit != 1) split_page(pg, get_order(alloc_unit << PAGE_SHIFT)); /* mark all pages offline */ for (j = 0; j < alloc_unit; j++) { __SetPageOffline(pg + j); adjust_managed_page_count(pg + j, -1); } bl_resp->range_count++; bl_resp->range_array[i].finfo.start_page = page_to_pfn(pg); bl_resp->range_array[i].finfo.page_cnt = alloc_unit; bl_resp->hdr.size += sizeof(union dm_mem_page_range); } return i * alloc_unit; } static void balloon_up(struct work_struct *dummy) { unsigned int num_pages = dm_device.balloon_wrk.num_pages; unsigned int num_ballooned = 0; struct dm_balloon_response *bl_resp; int alloc_unit; int ret; bool done = false; int i; long avail_pages; unsigned long floor; /* * We will attempt 2M allocations. However, if we fail to * allocate 2M chunks, we will go back to PAGE_SIZE allocations. */ alloc_unit = PAGES_IN_2M; avail_pages = si_mem_available(); floor = compute_balloon_floor(); /* Refuse to balloon below the floor. */ if (avail_pages < num_pages || avail_pages - num_pages < floor) { pr_info("Balloon request will be partially fulfilled. %s\n", avail_pages < num_pages ? "Not enough memory." : "Balloon floor reached."); num_pages = avail_pages > floor ? (avail_pages - floor) : 0; } while (!done) { memset(balloon_up_send_buffer, 0, HV_HYP_PAGE_SIZE); bl_resp = (struct dm_balloon_response *)balloon_up_send_buffer; bl_resp->hdr.type = DM_BALLOON_RESPONSE; bl_resp->hdr.size = sizeof(struct dm_balloon_response); bl_resp->more_pages = 1; num_pages -= num_ballooned; num_ballooned = alloc_balloon_pages(&dm_device, num_pages, bl_resp, alloc_unit); if (alloc_unit != 1 && num_ballooned == 0) { alloc_unit = 1; continue; } if (num_ballooned == 0 || num_ballooned == num_pages) { pr_debug("Ballooned %u out of %u requested pages.\n", num_pages, dm_device.balloon_wrk.num_pages); bl_resp->more_pages = 0; done = true; dm_device.state = DM_INITIALIZED; } /* * We are pushing a lot of data through the channel; * deal with transient failures caused because of the * lack of space in the ring buffer. */ do { bl_resp->hdr.trans_id = atomic_inc_return(&trans_id); ret = vmbus_sendpacket(dm_device.dev->channel, bl_resp, bl_resp->hdr.size, (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); if (ret == -EAGAIN) msleep(20); post_status(&dm_device); } while (ret == -EAGAIN); if (ret) { /* * Free up the memory we allocatted. */ pr_err("Balloon response failed\n"); for (i = 0; i < bl_resp->range_count; i++) free_balloon_pages(&dm_device, &bl_resp->range_array[i]); done = true; } } } static void balloon_down(struct hv_dynmem_device *dm, struct dm_unballoon_request *req) { union dm_mem_page_range *range_array = req->range_array; int range_count = req->range_count; struct dm_unballoon_response resp; int i; unsigned int prev_pages_ballooned = dm->num_pages_ballooned; for (i = 0; i < range_count; i++) { free_balloon_pages(dm, &range_array[i]); complete(&dm_device.config_event); } pr_debug("Freed %u ballooned pages.\n", prev_pages_ballooned - dm->num_pages_ballooned); if (req->more_pages == 1) return; memset(&resp, 0, sizeof(struct dm_unballoon_response)); resp.hdr.type = DM_UNBALLOON_RESPONSE; resp.hdr.trans_id = atomic_inc_return(&trans_id); resp.hdr.size = sizeof(struct dm_unballoon_response); vmbus_sendpacket(dm_device.dev->channel, &resp, sizeof(struct dm_unballoon_response), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); dm->state = DM_INITIALIZED; } static void balloon_onchannelcallback(void *context); static int dm_thread_func(void *dm_dev) { struct hv_dynmem_device *dm = dm_dev; while (!kthread_should_stop()) { wait_for_completion_interruptible_timeout(&dm_device.config_event, 1 * HZ); /* * The host expects us to post information on the memory * pressure every second. */ reinit_completion(&dm_device.config_event); post_status(dm); /* * disable free page reporting if multiple hypercall * failure flag set. It is not done in the page_reporting * callback context as that causes a deadlock between * page_reporting_process() and page_reporting_unregister() */ if (hv_hypercall_multi_failure >= HV_MAX_FAILURES) { pr_err("Multiple failures in cold memory discard hypercall, disabling page reporting\n"); disable_page_reporting(); /* Reset the flag after disabling reporting */ hv_hypercall_multi_failure = 0; } } return 0; } static void version_resp(struct hv_dynmem_device *dm, struct dm_version_response *vresp) { struct dm_version_request version_req; int ret; if (vresp->is_accepted) { /* * We are done; wakeup the * context waiting for version * negotiation. */ complete(&dm->host_event); return; } /* * If there are more versions to try, continue * with negotiations; if not * shutdown the service since we are not able * to negotiate a suitable version number * with the host. */ if (dm->next_version == 0) goto version_error; memset(&version_req, 0, sizeof(struct dm_version_request)); version_req.hdr.type = DM_VERSION_REQUEST; version_req.hdr.size = sizeof(struct dm_version_request); version_req.hdr.trans_id = atomic_inc_return(&trans_id); version_req.version.version = dm->next_version; dm->version = version_req.version.version; /* * Set the next version to try in case current version fails. * Win7 protocol ought to be the last one to try. */ switch (version_req.version.version) { case DYNMEM_PROTOCOL_VERSION_WIN8: dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7; version_req.is_last_attempt = 0; break; default: dm->next_version = 0; version_req.is_last_attempt = 1; } ret = vmbus_sendpacket(dm->dev->channel, &version_req, sizeof(struct dm_version_request), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); if (ret) goto version_error; return; version_error: dm->state = DM_INIT_ERROR; complete(&dm->host_event); } static void cap_resp(struct hv_dynmem_device *dm, struct dm_capabilities_resp_msg *cap_resp) { if (!cap_resp->is_accepted) { pr_err("Capabilities not accepted by host\n"); dm->state = DM_INIT_ERROR; } complete(&dm->host_event); } static void balloon_onchannelcallback(void *context) { struct hv_device *dev = context; u32 recvlen; u64 requestid; struct dm_message *dm_msg; struct dm_header *dm_hdr; struct hv_dynmem_device *dm = hv_get_drvdata(dev); struct dm_balloon *bal_msg; struct dm_hot_add *ha_msg; union dm_mem_page_range *ha_pg_range; union dm_mem_page_range *ha_region; memset(recv_buffer, 0, sizeof(recv_buffer)); vmbus_recvpacket(dev->channel, recv_buffer, HV_HYP_PAGE_SIZE, &recvlen, &requestid); if (recvlen > 0) { dm_msg = (struct dm_message *)recv_buffer; dm_hdr = &dm_msg->hdr; switch (dm_hdr->type) { case DM_VERSION_RESPONSE: version_resp(dm, (struct dm_version_response *)dm_msg); break; case DM_CAPABILITIES_RESPONSE: cap_resp(dm, (struct dm_capabilities_resp_msg *)dm_msg); break; case DM_BALLOON_REQUEST: if (allow_hibernation) { pr_info("Ignore balloon-up request!\n"); break; } if (dm->state == DM_BALLOON_UP) pr_warn("Currently ballooning\n"); bal_msg = (struct dm_balloon *)recv_buffer; dm->state = DM_BALLOON_UP; dm_device.balloon_wrk.num_pages = bal_msg->num_pages; schedule_work(&dm_device.balloon_wrk.wrk); break; case DM_UNBALLOON_REQUEST: if (allow_hibernation) { pr_info("Ignore balloon-down request!\n"); break; } dm->state = DM_BALLOON_DOWN; balloon_down(dm, (struct dm_unballoon_request *)recv_buffer); break; case DM_MEM_HOT_ADD_REQUEST: if (dm->state == DM_HOT_ADD) pr_warn("Currently hot-adding\n"); dm->state = DM_HOT_ADD; ha_msg = (struct dm_hot_add *)recv_buffer; if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) { /* * This is a normal hot-add request specifying * hot-add memory. */ dm->host_specified_ha_region = false; ha_pg_range = &ha_msg->range; dm->ha_wrk.ha_page_range = *ha_pg_range; dm->ha_wrk.ha_region_range.page_range = 0; } else { /* * Host is specifying that we first hot-add * a region and then partially populate this * region. */ dm->host_specified_ha_region = true; ha_pg_range = &ha_msg->range; ha_region = &ha_pg_range[1]; dm->ha_wrk.ha_page_range = *ha_pg_range; dm->ha_wrk.ha_region_range = *ha_region; } schedule_work(&dm_device.ha_wrk.wrk); break; case DM_INFO_MESSAGE: process_info(dm, (struct dm_info_msg *)dm_msg); break; default: pr_warn_ratelimited("Unhandled message: type: %d\n", dm_hdr->type); } } } #define HV_LARGE_REPORTING_ORDER 9 #define HV_LARGE_REPORTING_LEN (HV_HYP_PAGE_SIZE << \ HV_LARGE_REPORTING_ORDER) static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info, struct scatterlist *sgl, unsigned int nents) { unsigned long flags; struct hv_memory_hint *hint; int i, order; u64 status; struct scatterlist *sg; WARN_ON_ONCE(nents > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES); WARN_ON_ONCE(sgl->length < (HV_HYP_PAGE_SIZE << page_reporting_order)); local_irq_save(flags); hint = *this_cpu_ptr(hyperv_pcpu_input_arg); if (!hint) { local_irq_restore(flags); return -ENOSPC; } hint->type = HV_EXT_MEMORY_HEAT_HINT_TYPE_COLD_DISCARD; hint->reserved = 0; for_each_sg(sgl, sg, nents, i) { union hv_gpa_page_range *range; range = &hint->ranges[i]; range->address_space = 0; order = get_order(sg->length); /* * Hyper-V expects the additional_pages field in the units * of one of these 3 sizes, 4Kbytes, 2Mbytes or 1Gbytes. * This is dictated by the values of the fields page.largesize * and page_size. * This code however, only uses 4Kbytes and 2Mbytes units * and not 1Gbytes unit. */ /* page reporting for pages 2MB or higher */ if (order >= HV_LARGE_REPORTING_ORDER) { range->page.largepage = 1; range->page_size = HV_GPA_PAGE_RANGE_PAGE_SIZE_2MB; range->base_large_pfn = page_to_hvpfn( sg_page(sg)) >> HV_LARGE_REPORTING_ORDER; range->page.additional_pages = (sg->length / HV_LARGE_REPORTING_LEN) - 1; } else { /* Page reporting for pages below 2MB */ range->page.basepfn = page_to_hvpfn(sg_page(sg)); range->page.largepage = false; range->page.additional_pages = (sg->length / HV_HYP_PAGE_SIZE) - 1; } } status = hv_do_rep_hypercall(HV_EXT_CALL_MEMORY_HEAT_HINT, nents, 0, hint, NULL); local_irq_restore(flags); if (!hv_result_success(status)) { pr_err("Cold memory discard hypercall failed with status %llx\n", status); if (hv_hypercall_multi_failure > 0) hv_hypercall_multi_failure++; if (hv_result(status) == HV_STATUS_INVALID_PARAMETER) { pr_err("Underlying Hyper-V does not support order less than 9. Hypercall failed\n"); pr_err("Defaulting to page_reporting_order %d\n", pageblock_order); page_reporting_order = pageblock_order; hv_hypercall_multi_failure++; return -EINVAL; } return -EINVAL; } return 0; } static void enable_page_reporting(void) { int ret; if (!hv_query_ext_cap(HV_EXT_CAPABILITY_MEMORY_COLD_DISCARD_HINT)) { pr_debug("Cold memory discard hint not supported by Hyper-V\n"); return; } BUILD_BUG_ON(PAGE_REPORTING_CAPACITY > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES); dm_device.pr_dev_info.report = hv_free_page_report; /* * We let the page_reporting_order parameter decide the order * in the page_reporting code */ dm_device.pr_dev_info.order = 0; ret = page_reporting_register(&dm_device.pr_dev_info); if (ret < 0) { dm_device.pr_dev_info.report = NULL; pr_err("Failed to enable cold memory discard: %d\n", ret); } else { pr_info("Cold memory discard hint enabled with order %d\n", page_reporting_order); } } static void disable_page_reporting(void) { if (dm_device.pr_dev_info.report) { page_reporting_unregister(&dm_device.pr_dev_info); dm_device.pr_dev_info.report = NULL; } } static int ballooning_enabled(void) { /* * Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE), * since currently it's unclear to us whether an unballoon request can * make sure all page ranges are guest page size aligned. */ if (PAGE_SIZE != HV_HYP_PAGE_SIZE) { pr_info("Ballooning disabled because page size is not 4096 bytes\n"); return 0; } return 1; } static int hot_add_enabled(void) { /* * Disable hot add on ARM64, because we currently rely on * memory_add_physaddr_to_nid() to get a node id of a hot add range, * however ARM64's memory_add_physaddr_to_nid() always return 0 and * DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for * add_memory(). */ if (IS_ENABLED(CONFIG_ARM64)) { pr_info("Memory hot add disabled on ARM64\n"); return 0; } return 1; } static int balloon_connect_vsp(struct hv_device *dev) { struct dm_version_request version_req; struct dm_capabilities cap_msg; unsigned long t; int ret; /* * max_pkt_size should be large enough for one vmbus packet header plus * our receive buffer size. Hyper-V sends messages up to * HV_HYP_PAGE_SIZE bytes long on balloon channel. */ dev->channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2; ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0, balloon_onchannelcallback, dev); if (ret) return ret; /* * Initiate the hand shake with the host and negotiate * a version that the host can support. We start with the * highest version number and go down if the host cannot * support it. */ memset(&version_req, 0, sizeof(struct dm_version_request)); version_req.hdr.type = DM_VERSION_REQUEST; version_req.hdr.size = sizeof(struct dm_version_request); version_req.hdr.trans_id = atomic_inc_return(&trans_id); version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10; version_req.is_last_attempt = 0; dm_device.version = version_req.version.version; ret = vmbus_sendpacket(dev->channel, &version_req, sizeof(struct dm_version_request), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); if (ret) goto out; t = wait_for_completion_timeout(&dm_device.host_event, 5 * HZ); if (t == 0) { ret = -ETIMEDOUT; goto out; } /* * If we could not negotiate a compatible version with the host * fail the probe function. */ if (dm_device.state == DM_INIT_ERROR) { ret = -EPROTO; goto out; } pr_info("Using Dynamic Memory protocol version %u.%u\n", DYNMEM_MAJOR_VERSION(dm_device.version), DYNMEM_MINOR_VERSION(dm_device.version)); /* * Now submit our capabilities to the host. */ memset(&cap_msg, 0, sizeof(struct dm_capabilities)); cap_msg.hdr.type = DM_CAPABILITIES_REPORT; cap_msg.hdr.size = sizeof(struct dm_capabilities); cap_msg.hdr.trans_id = atomic_inc_return(&trans_id); /* * When hibernation (i.e. virtual ACPI S4 state) is enabled, the host * currently still requires the bits to be set, so we have to add code * to fail the host's hot-add and balloon up/down requests, if any. */ cap_msg.caps.cap_bits.balloon = ballooning_enabled(); cap_msg.caps.cap_bits.hot_add = hot_add_enabled(); /* * Specify our alignment requirements for memory hot-add. The value is * the log base 2 of the number of megabytes in a chunk. For example, * with 256 MiB chunks, the value is 8. The number of MiB in a chunk * must be a power of 2. */ cap_msg.caps.cap_bits.hot_add_alignment = ilog2(HA_BYTES_IN_CHUNK / SZ_1M); /* * Currently the host does not use these * values and we set them to what is done in the * Windows driver. */ cap_msg.min_page_cnt = 0; cap_msg.max_page_number = -1; ret = vmbus_sendpacket(dev->channel, &cap_msg, sizeof(struct dm_capabilities), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); if (ret) goto out; t = wait_for_completion_timeout(&dm_device.host_event, 5 * HZ); if (t == 0) { ret = -ETIMEDOUT; goto out; } /* * If the host does not like our capabilities, * fail the probe function. */ if (dm_device.state == DM_INIT_ERROR) { ret = -EPROTO; goto out; } return 0; out: vmbus_close(dev->channel); return ret; } /* * DEBUGFS Interface */ #ifdef CONFIG_DEBUG_FS /** * hv_balloon_debug_show - shows statistics of balloon operations. * @f: pointer to the &struct seq_file. * @offset: ignored. * * Provides the statistics that can be accessed in hv-balloon in the debugfs. * * Return: zero on success or an error code. */ static int hv_balloon_debug_show(struct seq_file *f, void *offset) { struct hv_dynmem_device *dm = f->private; char *sname; seq_printf(f, "%-22s: %u.%u\n", "host_version", DYNMEM_MAJOR_VERSION(dm->version), DYNMEM_MINOR_VERSION(dm->version)); seq_printf(f, "%-22s:", "capabilities"); if (ballooning_enabled()) seq_puts(f, " enabled"); if (hot_add_enabled()) seq_puts(f, " hot_add"); seq_puts(f, "\n"); seq_printf(f, "%-22s: %u", "state", dm->state); switch (dm->state) { case DM_INITIALIZING: sname = "Initializing"; break; case DM_INITIALIZED: sname = "Initialized"; break; case DM_BALLOON_UP: sname = "Balloon Up"; break; case DM_BALLOON_DOWN: sname = "Balloon Down"; break; case DM_HOT_ADD: sname = "Hot Add"; break; case DM_INIT_ERROR: sname = "Error"; break; default: sname = "Unknown"; } seq_printf(f, " (%s)\n", sname); /* HV Page Size */ seq_printf(f, "%-22s: %ld\n", "page_size", HV_HYP_PAGE_SIZE); /* Pages added with hot_add */ seq_printf(f, "%-22s: %u\n", "pages_added", dm->num_pages_added); /* pages that are "onlined"/used from pages_added */ seq_printf(f, "%-22s: %u\n", "pages_onlined", dm->num_pages_onlined); /* pages we have given back to host */ seq_printf(f, "%-22s: %u\n", "pages_ballooned", dm->num_pages_ballooned); seq_printf(f, "%-22s: %lu\n", "total_pages_committed", get_pages_committed(dm)); seq_printf(f, "%-22s: %llu\n", "max_dynamic_page_count", dm->max_dynamic_page_count); return 0; } DEFINE_SHOW_ATTRIBUTE(hv_balloon_debug); static void hv_balloon_debugfs_init(struct hv_dynmem_device *b) { debugfs_create_file("hv-balloon", 0444, NULL, b, &hv_balloon_debug_fops); } static void hv_balloon_debugfs_exit(struct hv_dynmem_device *b) { debugfs_lookup_and_remove("hv-balloon", NULL); } #else static inline void hv_balloon_debugfs_init(struct hv_dynmem_device *b) { } static inline void hv_balloon_debugfs_exit(struct hv_dynmem_device *b) { } #endif /* CONFIG_DEBUG_FS */ static int balloon_probe(struct hv_device *dev, const struct hv_vmbus_device_id *dev_id) { int ret; allow_hibernation = hv_is_hibernation_supported(); if (allow_hibernation) hot_add = false; #ifdef CONFIG_MEMORY_HOTPLUG /* * Hot-add must operate in chunks that are of size equal to the * memory block size because that's what the core add_memory() * interface requires. The Hyper-V interface requires that the memory * block size be a power of 2, which is guaranteed by the check in * memory_dev_init(). */ ha_pages_in_chunk = memory_block_size_bytes() / PAGE_SIZE; do_hot_add = hot_add; #else /* * Without MEMORY_HOTPLUG, the guest returns a failure status for all * hot add requests from Hyper-V, and the chunk size is used only to * specify alignment to Hyper-V as required by the host/guest protocol. * Somewhat arbitrarily, use 128 MiB. */ ha_pages_in_chunk = SZ_128M / PAGE_SIZE; do_hot_add = false; #endif dm_device.dev = dev; dm_device.state = DM_INITIALIZING; dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8; init_completion(&dm_device.host_event); init_completion(&dm_device.config_event); INIT_LIST_HEAD(&dm_device.ha_region_list); spin_lock_init(&dm_device.ha_lock); INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up); INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req); dm_device.host_specified_ha_region = false; #ifdef CONFIG_MEMORY_HOTPLUG set_online_page_callback(&hv_online_page); init_completion(&dm_device.ol_waitevent); register_memory_notifier(&hv_memory_nb); #endif hv_set_drvdata(dev, &dm_device); ret = balloon_connect_vsp(dev); if (ret != 0) goto connect_error; enable_page_reporting(); dm_device.state = DM_INITIALIZED; dm_device.thread = kthread_run(dm_thread_func, &dm_device, "hv_balloon"); if (IS_ERR(dm_device.thread)) { ret = PTR_ERR(dm_device.thread); goto probe_error; } hv_balloon_debugfs_init(&dm_device); return 0; probe_error: dm_device.state = DM_INIT_ERROR; dm_device.thread = NULL; disable_page_reporting(); vmbus_close(dev->channel); connect_error: #ifdef CONFIG_MEMORY_HOTPLUG unregister_memory_notifier(&hv_memory_nb); restore_online_page_callback(&hv_online_page); #endif return ret; } static void balloon_remove(struct hv_device *dev) { struct hv_dynmem_device *dm = hv_get_drvdata(dev); struct hv_hotadd_state *has, *tmp; struct hv_hotadd_gap *gap, *tmp_gap; if (dm->num_pages_ballooned != 0) pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned); hv_balloon_debugfs_exit(dm); cancel_work_sync(&dm->balloon_wrk.wrk); cancel_work_sync(&dm->ha_wrk.wrk); kthread_stop(dm->thread); /* * This is to handle the case when balloon_resume() * call has failed and some cleanup has been done as * a part of the error handling. */ if (dm_device.state != DM_INIT_ERROR) { disable_page_reporting(); vmbus_close(dev->channel); #ifdef CONFIG_MEMORY_HOTPLUG unregister_memory_notifier(&hv_memory_nb); restore_online_page_callback(&hv_online_page); #endif } guard(spinlock_irqsave)(&dm_device.ha_lock); list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) { list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) { list_del(&gap->list); kfree(gap); } list_del(&has->list); kfree(has); } } static int balloon_suspend(struct hv_device *hv_dev) { struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev); tasklet_disable(&hv_dev->channel->callback_event); cancel_work_sync(&dm->balloon_wrk.wrk); cancel_work_sync(&dm->ha_wrk.wrk); if (dm->thread) { kthread_stop(dm->thread); dm->thread = NULL; vmbus_close(hv_dev->channel); } tasklet_enable(&hv_dev->channel->callback_event); return 0; } static int balloon_resume(struct hv_device *dev) { int ret; dm_device.state = DM_INITIALIZING; ret = balloon_connect_vsp(dev); if (ret != 0) goto out; dm_device.thread = kthread_run(dm_thread_func, &dm_device, "hv_balloon"); if (IS_ERR(dm_device.thread)) { ret = PTR_ERR(dm_device.thread); dm_device.thread = NULL; goto close_channel; } dm_device.state = DM_INITIALIZED; return 0; close_channel: vmbus_close(dev->channel); out: dm_device.state = DM_INIT_ERROR; disable_page_reporting(); #ifdef CONFIG_MEMORY_HOTPLUG unregister_memory_notifier(&hv_memory_nb); restore_online_page_callback(&hv_online_page); #endif return ret; } static const struct hv_vmbus_device_id id_table[] = { /* Dynamic Memory Class ID */ /* 525074DC-8985-46e2-8057-A307DC18A502 */ { HV_DM_GUID, }, { }, }; MODULE_DEVICE_TABLE(vmbus, id_table); static struct hv_driver balloon_drv = { .name = "hv_balloon", .id_table = id_table, .probe = balloon_probe, .remove = balloon_remove, .suspend = balloon_suspend, .resume = balloon_resume, .driver = { .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, }; static int __init init_balloon_drv(void) { return vmbus_driver_register(&balloon_drv); } module_init(init_balloon_drv); MODULE_DESCRIPTION("Hyper-V Balloon"); MODULE_LICENSE("GPL");
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