| // 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/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/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 atleast 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 atleast 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 multiples of 128M |
| * chunks; 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 brough 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, (S_IRUGO | S_IWUSR)); |
| MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); |
| |
| module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR)); |
| 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]; |
| #define PAGES_IN_2M (2 * 1024 * 1024 / PAGE_SIZE) |
| #define HA_CHUNK (128 * 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 flags, pfn_count; |
| |
| switch (val) { |
| case MEM_ONLINE: |
| case MEM_CANCEL_ONLINE: |
| complete(&dm_device.ol_waitevent); |
| break; |
| |
| case MEM_OFFLINE: |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| 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; |
| } |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| 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; |
| } |
| if (PageOffline(pg)) |
| __ClearPageOffline(pg); |
| |
| /* 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; |
| unsigned long flags; |
| |
| for (i = 0; i < (size/HA_CHUNK); i++) { |
| start_pfn = start + (i * HA_CHUNK); |
| |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| has->ha_end_pfn += HA_CHUNK; |
| |
| if (total_pfn > HA_CHUNK) { |
| processed_pfn = HA_CHUNK; |
| total_pfn -= HA_CHUNK; |
| } else { |
| processed_pfn = total_pfn; |
| total_pfn = 0; |
| } |
| |
| has->covered_end_pfn += processed_pfn; |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| |
| 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_CHUNK << PAGE_SHIFT), 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; |
| } |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| has->ha_end_pfn -= HA_CHUNK; |
| has->covered_end_pfn -= processed_pfn; |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| 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 flags; |
| unsigned long pfn = page_to_pfn(pg); |
| |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| 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; |
| } |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| } |
| |
| 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, new_inc; |
| int ret = 0; |
| unsigned long flags; |
| |
| 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; |
| |
| /* |
| * 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) { |
| residual = (start_pfn + pfn_cnt - has->end_pfn); |
| /* |
| * Extend the region by multiples of HA_CHUNK. |
| */ |
| new_inc = (residual / HA_CHUNK) * HA_CHUNK; |
| if (residual % HA_CHUNK) |
| new_inc += HA_CHUNK; |
| |
| has->end_pfn += new_inc; |
| } |
| |
| ret = 1; |
| break; |
| } |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| |
| 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_CHUNK that fully covers the pages |
| * we have. |
| */ |
| size = (has->end_pfn - has->ha_end_pfn); |
| if (pfn_cnt <= size) { |
| size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK); |
| if (pfn_cnt % HA_CHUNK) |
| size += HA_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; |
| unsigned long flags; |
| |
| 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; |
| |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| list_add_tail(&ha_region->list, &dm_device.ha_region_list); |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| } |
| |
| 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)) { |
| unsigned long region_size; |
| unsigned long region_start; |
| |
| /* |
| * 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. |
| */ |
| region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK; |
| if (pfn_cnt % HA_CHUNK) |
| region_size += HA_CHUNK; |
| |
| region_start = (pg_start / HA_CHUNK) * HA_CHUNK; |
| |
| rg_start = region_start; |
| rg_sz = region_size; |
| } |
| |
| 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 = *(struct hv_memory_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 as it relates |
| * memory hot-add. Specify 128MB alignment. |
| */ |
| cap_msg.caps.cap_bits.hot_add_alignment = 7; |
| |
| /* |
| * 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 |
| do_hot_add = hot_add; |
| #else |
| 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 int 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; |
| unsigned long flags; |
| |
| 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 |
| } |
| |
| spin_lock_irqsave(&dm_device.ha_lock, flags); |
| 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); |
| } |
| spin_unlock_irqrestore(&dm_device.ha_lock, flags); |
| |
| return 0; |
| } |
| |
| 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"); |