1 /* 2 * Declarations for cpu physical memory functions 3 * 4 * Copyright 2011 Red Hat, Inc. and/or its affiliates 5 * 6 * Authors: 7 * Avi Kivity <avi@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or 10 * later. See the COPYING file in the top-level directory. 11 * 12 */ 13 14 /* 15 * This header is for use by exec.c and memory.c ONLY. Do not include it. 16 * The functions declared here will be removed soon. 17 */ 18 19 #ifndef SYSTEM_RAMBLOCK_H 20 #define SYSTEM_RAMBLOCK_H 21 22 #include "exec/cpu-common.h" 23 #include "qemu/rcu.h" 24 #include "exec/ramlist.h" 25 26 struct RAMBlock { 27 struct rcu_head rcu; 28 struct MemoryRegion *mr; 29 uint8_t *host; 30 uint8_t *colo_cache; /* For colo, VM's ram cache */ 31 ram_addr_t offset; 32 ram_addr_t used_length; 33 ram_addr_t max_length; 34 void (*resized)(const char*, uint64_t length, void *host); 35 uint32_t flags; 36 /* Protected by the BQL. */ 37 char idstr[256]; 38 /* RCU-enabled, writes protected by the ramlist lock */ 39 QLIST_ENTRY(RAMBlock) next; 40 QLIST_HEAD(, RAMBlockNotifier) ramblock_notifiers; 41 Error *cpr_blocker; 42 int fd; 43 uint64_t fd_offset; 44 int guest_memfd; 45 size_t page_size; 46 /* dirty bitmap used during migration */ 47 unsigned long *bmap; 48 49 /* 50 * Below fields are only used by mapped-ram migration 51 */ 52 /* bitmap of pages present in the migration file */ 53 unsigned long *file_bmap; 54 /* 55 * offset in the file pages belonging to this ramblock are saved, 56 * used only during migration to a file. 57 */ 58 off_t bitmap_offset; 59 uint64_t pages_offset; 60 61 /* Bitmap of already received pages. Only used on destination side. */ 62 unsigned long *receivedmap; 63 64 /* 65 * bitmap to track already cleared dirty bitmap. When the bit is 66 * set, it means the corresponding memory chunk needs a log-clear. 67 * Set this up to non-NULL to enable the capability to postpone 68 * and split clearing of dirty bitmap on the remote node (e.g., 69 * KVM). The bitmap will be set only when doing global sync. 70 * 71 * It is only used during src side of ram migration, and it is 72 * protected by the global ram_state.bitmap_mutex. 73 * 74 * NOTE: this bitmap is different comparing to the other bitmaps 75 * in that one bit can represent multiple guest pages (which is 76 * decided by the `clear_bmap_shift' variable below). On 77 * destination side, this should always be NULL, and the variable 78 * `clear_bmap_shift' is meaningless. 79 */ 80 unsigned long *clear_bmap; 81 uint8_t clear_bmap_shift; 82 83 /* 84 * RAM block length that corresponds to the used_length on the migration 85 * source (after RAM block sizes were synchronized). Especially, after 86 * starting to run the guest, used_length and postcopy_length can differ. 87 * Used to register/unregister uffd handlers and as the size of the received 88 * bitmap. Receiving any page beyond this length will bail out, as it 89 * could not have been valid on the source. 90 */ 91 ram_addr_t postcopy_length; 92 }; 93 94 #endif 95