qemu/include/exec/memory.h
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   1/*
   2 * Physical memory management API
   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.  See
  10 * the COPYING file in the top-level directory.
  11 *
  12 */
  13
  14#ifndef MEMORY_H
  15#define MEMORY_H
  16
  17#ifndef CONFIG_USER_ONLY
  18
  19#include "exec/cpu-common.h"
  20#include "exec/hwaddr.h"
  21#include "exec/memattrs.h"
  22#include "exec/memop.h"
  23#include "exec/ramlist.h"
  24#include "qemu/bswap.h"
  25#include "qemu/queue.h"
  26#include "qemu/int128.h"
  27#include "qemu/notify.h"
  28#include "qom/object.h"
  29#include "qemu/rcu.h"
  30
  31#define RAM_ADDR_INVALID (~(ram_addr_t)0)
  32
  33#define MAX_PHYS_ADDR_SPACE_BITS 62
  34#define MAX_PHYS_ADDR            (((hwaddr)1 << MAX_PHYS_ADDR_SPACE_BITS) - 1)
  35
  36#define TYPE_MEMORY_REGION "qemu:memory-region"
  37#define MEMORY_REGION(obj) \
  38        OBJECT_CHECK(MemoryRegion, (obj), TYPE_MEMORY_REGION)
  39
  40#define TYPE_IOMMU_MEMORY_REGION "qemu:iommu-memory-region"
  41#define IOMMU_MEMORY_REGION(obj) \
  42        OBJECT_CHECK(IOMMUMemoryRegion, (obj), TYPE_IOMMU_MEMORY_REGION)
  43#define IOMMU_MEMORY_REGION_CLASS(klass) \
  44        OBJECT_CLASS_CHECK(IOMMUMemoryRegionClass, (klass), \
  45                         TYPE_IOMMU_MEMORY_REGION)
  46#define IOMMU_MEMORY_REGION_GET_CLASS(obj) \
  47        OBJECT_GET_CLASS(IOMMUMemoryRegionClass, (obj), \
  48                         TYPE_IOMMU_MEMORY_REGION)
  49
  50extern bool global_dirty_log;
  51
  52typedef struct MemoryRegionOps MemoryRegionOps;
  53
  54struct ReservedRegion {
  55    hwaddr low;
  56    hwaddr high;
  57    unsigned type;
  58};
  59
  60typedef struct IOMMUTLBEntry IOMMUTLBEntry;
  61
  62/* See address_space_translate: bit 0 is read, bit 1 is write.  */
  63typedef enum {
  64    IOMMU_NONE = 0,
  65    IOMMU_RO   = 1,
  66    IOMMU_WO   = 2,
  67    IOMMU_RW   = 3,
  68} IOMMUAccessFlags;
  69
  70#define IOMMU_ACCESS_FLAG(r, w) (((r) ? IOMMU_RO : 0) | ((w) ? IOMMU_WO : 0))
  71
  72struct IOMMUTLBEntry {
  73    AddressSpace    *target_as;
  74    hwaddr           iova;
  75    hwaddr           translated_addr;
  76    hwaddr           addr_mask;  /* 0xfff = 4k translation */
  77    IOMMUAccessFlags perm;
  78};
  79
  80/*
  81 * Bitmap for different IOMMUNotifier capabilities. Each notifier can
  82 * register with one or multiple IOMMU Notifier capability bit(s).
  83 */
  84typedef enum {
  85    IOMMU_NOTIFIER_NONE = 0,
  86    /* Notify cache invalidations */
  87    IOMMU_NOTIFIER_UNMAP = 0x1,
  88    /* Notify entry changes (newly created entries) */
  89    IOMMU_NOTIFIER_MAP = 0x2,
  90} IOMMUNotifierFlag;
  91
  92#define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP)
  93
  94struct IOMMUNotifier;
  95typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier,
  96                            IOMMUTLBEntry *data);
  97
  98struct IOMMUNotifier {
  99    IOMMUNotify notify;
 100    IOMMUNotifierFlag notifier_flags;
 101    /* Notify for address space range start <= addr <= end */
 102    hwaddr start;
 103    hwaddr end;
 104    int iommu_idx;
 105    QLIST_ENTRY(IOMMUNotifier) node;
 106};
 107typedef struct IOMMUNotifier IOMMUNotifier;
 108
 109/* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
 110#define RAM_PREALLOC   (1 << 0)
 111
 112/* RAM is mmap-ed with MAP_SHARED */
 113#define RAM_SHARED     (1 << 1)
 114
 115/* Only a portion of RAM (used_length) is actually used, and migrated.
 116 * This used_length size can change across reboots.
 117 */
 118#define RAM_RESIZEABLE (1 << 2)
 119
 120/* UFFDIO_ZEROPAGE is available on this RAMBlock to atomically
 121 * zero the page and wake waiting processes.
 122 * (Set during postcopy)
 123 */
 124#define RAM_UF_ZEROPAGE (1 << 3)
 125
 126/* RAM can be migrated */
 127#define RAM_MIGRATABLE (1 << 4)
 128
 129/* RAM is a persistent kind memory */
 130#define RAM_PMEM (1 << 5)
 131
 132static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
 133                                       IOMMUNotifierFlag flags,
 134                                       hwaddr start, hwaddr end,
 135                                       int iommu_idx)
 136{
 137    n->notify = fn;
 138    n->notifier_flags = flags;
 139    n->start = start;
 140    n->end = end;
 141    n->iommu_idx = iommu_idx;
 142}
 143
 144/*
 145 * Memory region callbacks
 146 */
 147struct MemoryRegionOps {
 148    /* Read from the memory region. @addr is relative to @mr; @size is
 149     * in bytes. */
 150    uint64_t (*read)(void *opaque,
 151                     hwaddr addr,
 152                     unsigned size);
 153    /* Write to the memory region. @addr is relative to @mr; @size is
 154     * in bytes. */
 155    void (*write)(void *opaque,
 156                  hwaddr addr,
 157                  uint64_t data,
 158                  unsigned size);
 159
 160    MemTxResult (*read_with_attrs)(void *opaque,
 161                                   hwaddr addr,
 162                                   uint64_t *data,
 163                                   unsigned size,
 164                                   MemTxAttrs attrs);
 165    MemTxResult (*write_with_attrs)(void *opaque,
 166                                    hwaddr addr,
 167                                    uint64_t data,
 168                                    unsigned size,
 169                                    MemTxAttrs attrs);
 170
 171    enum device_endian endianness;
 172    /* Guest-visible constraints: */
 173    struct {
 174        /* If nonzero, specify bounds on access sizes beyond which a machine
 175         * check is thrown.
 176         */
 177        unsigned min_access_size;
 178        unsigned max_access_size;
 179        /* If true, unaligned accesses are supported.  Otherwise unaligned
 180         * accesses throw machine checks.
 181         */
 182         bool unaligned;
 183        /*
 184         * If present, and returns #false, the transaction is not accepted
 185         * by the device (and results in machine dependent behaviour such
 186         * as a machine check exception).
 187         */
 188        bool (*accepts)(void *opaque, hwaddr addr,
 189                        unsigned size, bool is_write,
 190                        MemTxAttrs attrs);
 191    } valid;
 192    /* Internal implementation constraints: */
 193    struct {
 194        /* If nonzero, specifies the minimum size implemented.  Smaller sizes
 195         * will be rounded upwards and a partial result will be returned.
 196         */
 197        unsigned min_access_size;
 198        /* If nonzero, specifies the maximum size implemented.  Larger sizes
 199         * will be done as a series of accesses with smaller sizes.
 200         */
 201        unsigned max_access_size;
 202        /* If true, unaligned accesses are supported.  Otherwise all accesses
 203         * are converted to (possibly multiple) naturally aligned accesses.
 204         */
 205        bool unaligned;
 206    } impl;
 207};
 208
 209typedef struct MemoryRegionClass {
 210    /* private */
 211    ObjectClass parent_class;
 212} MemoryRegionClass;
 213
 214
 215enum IOMMUMemoryRegionAttr {
 216    IOMMU_ATTR_SPAPR_TCE_FD
 217};
 218
 219/**
 220 * IOMMUMemoryRegionClass:
 221 *
 222 * All IOMMU implementations need to subclass TYPE_IOMMU_MEMORY_REGION
 223 * and provide an implementation of at least the @translate method here
 224 * to handle requests to the memory region. Other methods are optional.
 225 *
 226 * The IOMMU implementation must use the IOMMU notifier infrastructure
 227 * to report whenever mappings are changed, by calling
 228 * memory_region_notify_iommu() (or, if necessary, by calling
 229 * memory_region_notify_one() for each registered notifier).
 230 *
 231 * Conceptually an IOMMU provides a mapping from input address
 232 * to an output TLB entry. If the IOMMU is aware of memory transaction
 233 * attributes and the output TLB entry depends on the transaction
 234 * attributes, we represent this using IOMMU indexes. Each index
 235 * selects a particular translation table that the IOMMU has:
 236 *   @attrs_to_index returns the IOMMU index for a set of transaction attributes
 237 *   @translate takes an input address and an IOMMU index
 238 * and the mapping returned can only depend on the input address and the
 239 * IOMMU index.
 240 *
 241 * Most IOMMUs don't care about the transaction attributes and support
 242 * only a single IOMMU index. A more complex IOMMU might have one index
 243 * for secure transactions and one for non-secure transactions.
 244 */
 245typedef struct IOMMUMemoryRegionClass {
 246    /* private */
 247    MemoryRegionClass parent_class;
 248
 249    /*
 250     * Return a TLB entry that contains a given address.
 251     *
 252     * The IOMMUAccessFlags indicated via @flag are optional and may
 253     * be specified as IOMMU_NONE to indicate that the caller needs
 254     * the full translation information for both reads and writes. If
 255     * the access flags are specified then the IOMMU implementation
 256     * may use this as an optimization, to stop doing a page table
 257     * walk as soon as it knows that the requested permissions are not
 258     * allowed. If IOMMU_NONE is passed then the IOMMU must do the
 259     * full page table walk and report the permissions in the returned
 260     * IOMMUTLBEntry. (Note that this implies that an IOMMU may not
 261     * return different mappings for reads and writes.)
 262     *
 263     * The returned information remains valid while the caller is
 264     * holding the big QEMU lock or is inside an RCU critical section;
 265     * if the caller wishes to cache the mapping beyond that it must
 266     * register an IOMMU notifier so it can invalidate its cached
 267     * information when the IOMMU mapping changes.
 268     *
 269     * @iommu: the IOMMUMemoryRegion
 270     * @hwaddr: address to be translated within the memory region
 271     * @flag: requested access permissions
 272     * @iommu_idx: IOMMU index for the translation
 273     */
 274    IOMMUTLBEntry (*translate)(IOMMUMemoryRegion *iommu, hwaddr addr,
 275                               IOMMUAccessFlags flag, int iommu_idx);
 276    /* Returns minimum supported page size in bytes.
 277     * If this method is not provided then the minimum is assumed to
 278     * be TARGET_PAGE_SIZE.
 279     *
 280     * @iommu: the IOMMUMemoryRegion
 281     */
 282    uint64_t (*get_min_page_size)(IOMMUMemoryRegion *iommu);
 283    /* Called when IOMMU Notifier flag changes (ie when the set of
 284     * events which IOMMU users are requesting notification for changes).
 285     * Optional method -- need not be provided if the IOMMU does not
 286     * need to know exactly which events must be notified.
 287     *
 288     * @iommu: the IOMMUMemoryRegion
 289     * @old_flags: events which previously needed to be notified
 290     * @new_flags: events which now need to be notified
 291     *
 292     * Returns 0 on success, or a negative errno; in particular
 293     * returns -EINVAL if the new flag bitmap is not supported by the
 294     * IOMMU memory region. In case of failure, the error object
 295     * must be created
 296     */
 297    int (*notify_flag_changed)(IOMMUMemoryRegion *iommu,
 298                               IOMMUNotifierFlag old_flags,
 299                               IOMMUNotifierFlag new_flags,
 300                               Error **errp);
 301    /* Called to handle memory_region_iommu_replay().
 302     *
 303     * The default implementation of memory_region_iommu_replay() is to
 304     * call the IOMMU translate method for every page in the address space
 305     * with flag == IOMMU_NONE and then call the notifier if translate
 306     * returns a valid mapping. If this method is implemented then it
 307     * overrides the default behaviour, and must provide the full semantics
 308     * of memory_region_iommu_replay(), by calling @notifier for every
 309     * translation present in the IOMMU.
 310     *
 311     * Optional method -- an IOMMU only needs to provide this method
 312     * if the default is inefficient or produces undesirable side effects.
 313     *
 314     * Note: this is not related to record-and-replay functionality.
 315     */
 316    void (*replay)(IOMMUMemoryRegion *iommu, IOMMUNotifier *notifier);
 317
 318    /* Get IOMMU misc attributes. This is an optional method that
 319     * can be used to allow users of the IOMMU to get implementation-specific
 320     * information. The IOMMU implements this method to handle calls
 321     * by IOMMU users to memory_region_iommu_get_attr() by filling in
 322     * the arbitrary data pointer for any IOMMUMemoryRegionAttr values that
 323     * the IOMMU supports. If the method is unimplemented then
 324     * memory_region_iommu_get_attr() will always return -EINVAL.
 325     *
 326     * @iommu: the IOMMUMemoryRegion
 327     * @attr: attribute being queried
 328     * @data: memory to fill in with the attribute data
 329     *
 330     * Returns 0 on success, or a negative errno; in particular
 331     * returns -EINVAL for unrecognized or unimplemented attribute types.
 332     */
 333    int (*get_attr)(IOMMUMemoryRegion *iommu, enum IOMMUMemoryRegionAttr attr,
 334                    void *data);
 335
 336    /* Return the IOMMU index to use for a given set of transaction attributes.
 337     *
 338     * Optional method: if an IOMMU only supports a single IOMMU index then
 339     * the default implementation of memory_region_iommu_attrs_to_index()
 340     * will return 0.
 341     *
 342     * The indexes supported by an IOMMU must be contiguous, starting at 0.
 343     *
 344     * @iommu: the IOMMUMemoryRegion
 345     * @attrs: memory transaction attributes
 346     */
 347    int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs);
 348
 349    /* Return the number of IOMMU indexes this IOMMU supports.
 350     *
 351     * Optional method: if this method is not provided, then
 352     * memory_region_iommu_num_indexes() will return 1, indicating that
 353     * only a single IOMMU index is supported.
 354     *
 355     * @iommu: the IOMMUMemoryRegion
 356     */
 357    int (*num_indexes)(IOMMUMemoryRegion *iommu);
 358} IOMMUMemoryRegionClass;
 359
 360typedef struct CoalescedMemoryRange CoalescedMemoryRange;
 361typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
 362
 363/** MemoryRegion:
 364 *
 365 * A struct representing a memory region.
 366 */
 367struct MemoryRegion {
 368    Object parent_obj;
 369
 370    /* private: */
 371
 372    /* The following fields should fit in a cache line */
 373    bool romd_mode;
 374    bool ram;
 375    bool subpage;
 376    bool readonly; /* For RAM regions */
 377    bool nonvolatile;
 378    bool rom_device;
 379    bool flush_coalesced_mmio;
 380    bool global_locking;
 381    uint8_t dirty_log_mask;
 382    bool is_iommu;
 383    RAMBlock *ram_block;
 384    Object *owner;
 385
 386    const MemoryRegionOps *ops;
 387    void *opaque;
 388    MemoryRegion *container;
 389    Int128 size;
 390    hwaddr addr;
 391    void (*destructor)(MemoryRegion *mr);
 392    uint64_t align;
 393    bool terminates;
 394    bool ram_device;
 395    bool enabled;
 396    bool warning_printed; /* For reservations */
 397    uint8_t vga_logging_count;
 398    MemoryRegion *alias;
 399    hwaddr alias_offset;
 400    int32_t priority;
 401    QTAILQ_HEAD(, MemoryRegion) subregions;
 402    QTAILQ_ENTRY(MemoryRegion) subregions_link;
 403    QTAILQ_HEAD(, CoalescedMemoryRange) coalesced;
 404    const char *name;
 405    unsigned ioeventfd_nb;
 406    MemoryRegionIoeventfd *ioeventfds;
 407};
 408
 409struct IOMMUMemoryRegion {
 410    MemoryRegion parent_obj;
 411
 412    QLIST_HEAD(, IOMMUNotifier) iommu_notify;
 413    IOMMUNotifierFlag iommu_notify_flags;
 414};
 415
 416#define IOMMU_NOTIFIER_FOREACH(n, mr) \
 417    QLIST_FOREACH((n), &(mr)->iommu_notify, node)
 418
 419/**
 420 * MemoryListener: callbacks structure for updates to the physical memory map
 421 *
 422 * Allows a component to adjust to changes in the guest-visible memory map.
 423 * Use with memory_listener_register() and memory_listener_unregister().
 424 */
 425struct MemoryListener {
 426    /**
 427     * @begin:
 428     *
 429     * Called at the beginning of an address space update transaction.
 430     * Followed by calls to #MemoryListener.region_add(),
 431     * #MemoryListener.region_del(), #MemoryListener.region_nop(),
 432     * #MemoryListener.log_start() and #MemoryListener.log_stop() in
 433     * increasing address order.
 434     *
 435     * @listener: The #MemoryListener.
 436     */
 437    void (*begin)(MemoryListener *listener);
 438
 439    /**
 440     * @commit:
 441     *
 442     * Called at the end of an address space update transaction,
 443     * after the last call to #MemoryListener.region_add(),
 444     * #MemoryListener.region_del() or #MemoryListener.region_nop(),
 445     * #MemoryListener.log_start() and #MemoryListener.log_stop().
 446     *
 447     * @listener: The #MemoryListener.
 448     */
 449    void (*commit)(MemoryListener *listener);
 450
 451    /**
 452     * @region_add:
 453     *
 454     * Called during an address space update transaction,
 455     * for a section of the address space that is new in this address space
 456     * space since the last transaction.
 457     *
 458     * @listener: The #MemoryListener.
 459     * @section: The new #MemoryRegionSection.
 460     */
 461    void (*region_add)(MemoryListener *listener, MemoryRegionSection *section);
 462
 463    /**
 464     * @region_del:
 465     *
 466     * Called during an address space update transaction,
 467     * for a section of the address space that has disappeared in the address
 468     * space since the last transaction.
 469     *
 470     * @listener: The #MemoryListener.
 471     * @section: The old #MemoryRegionSection.
 472     */
 473    void (*region_del)(MemoryListener *listener, MemoryRegionSection *section);
 474
 475    /**
 476     * @region_nop:
 477     *
 478     * Called during an address space update transaction,
 479     * for a section of the address space that is in the same place in the address
 480     * space as in the last transaction.
 481     *
 482     * @listener: The #MemoryListener.
 483     * @section: The #MemoryRegionSection.
 484     */
 485    void (*region_nop)(MemoryListener *listener, MemoryRegionSection *section);
 486
 487    /**
 488     * @log_start:
 489     *
 490     * Called during an address space update transaction, after
 491     * one of #MemoryListener.region_add(),#MemoryListener.region_del() or
 492     * #MemoryListener.region_nop(), if dirty memory logging clients have
 493     * become active since the last transaction.
 494     *
 495     * @listener: The #MemoryListener.
 496     * @section: The #MemoryRegionSection.
 497     * @old: A bitmap of dirty memory logging clients that were active in
 498     * the previous transaction.
 499     * @new: A bitmap of dirty memory logging clients that are active in
 500     * the current transaction.
 501     */
 502    void (*log_start)(MemoryListener *listener, MemoryRegionSection *section,
 503                      int old, int new);
 504
 505    /**
 506     * @log_stop:
 507     *
 508     * Called during an address space update transaction, after
 509     * one of #MemoryListener.region_add(), #MemoryListener.region_del() or
 510     * #MemoryListener.region_nop() and possibly after
 511     * #MemoryListener.log_start(), if dirty memory logging clients have
 512     * become inactive since the last transaction.
 513     *
 514     * @listener: The #MemoryListener.
 515     * @section: The #MemoryRegionSection.
 516     * @old: A bitmap of dirty memory logging clients that were active in
 517     * the previous transaction.
 518     * @new: A bitmap of dirty memory logging clients that are active in
 519     * the current transaction.
 520     */
 521    void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section,
 522                     int old, int new);
 523
 524    /**
 525     * @log_sync:
 526     *
 527     * Called by memory_region_snapshot_and_clear_dirty() and
 528     * memory_global_dirty_log_sync(), before accessing QEMU's "official"
 529     * copy of the dirty memory bitmap for a #MemoryRegionSection.
 530     *
 531     * @listener: The #MemoryListener.
 532     * @section: The #MemoryRegionSection.
 533     */
 534    void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
 535
 536    /**
 537     * @log_clear:
 538     *
 539     * Called before reading the dirty memory bitmap for a
 540     * #MemoryRegionSection.
 541     *
 542     * @listener: The #MemoryListener.
 543     * @section: The #MemoryRegionSection.
 544     */
 545    void (*log_clear)(MemoryListener *listener, MemoryRegionSection *section);
 546
 547    /**
 548     * @log_global_start:
 549     *
 550     * Called by memory_global_dirty_log_start(), which
 551     * enables the %DIRTY_LOG_MIGRATION client on all memory regions in
 552     * the address space.  #MemoryListener.log_global_start() is also
 553     * called when a #MemoryListener is added, if global dirty logging is
 554     * active at that time.
 555     *
 556     * @listener: The #MemoryListener.
 557     */
 558    void (*log_global_start)(MemoryListener *listener);
 559
 560    /**
 561     * @log_global_stop:
 562     *
 563     * Called by memory_global_dirty_log_stop(), which
 564     * disables the %DIRTY_LOG_MIGRATION client on all memory regions in
 565     * the address space.
 566     *
 567     * @listener: The #MemoryListener.
 568     */
 569    void (*log_global_stop)(MemoryListener *listener);
 570
 571    /**
 572     * @log_global_after_sync:
 573     *
 574     * Called after reading the dirty memory bitmap
 575     * for any #MemoryRegionSection.
 576     *
 577     * @listener: The #MemoryListener.
 578     */
 579    void (*log_global_after_sync)(MemoryListener *listener);
 580
 581    /**
 582     * @eventfd_add:
 583     *
 584     * Called during an address space update transaction,
 585     * for a section of the address space that has had a new ioeventfd
 586     * registration since the last transaction.
 587     *
 588     * @listener: The #MemoryListener.
 589     * @section: The new #MemoryRegionSection.
 590     * @match_data: The @match_data parameter for the new ioeventfd.
 591     * @data: The @data parameter for the new ioeventfd.
 592     * @e: The #EventNotifier parameter for the new ioeventfd.
 593     */
 594    void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
 595                        bool match_data, uint64_t data, EventNotifier *e);
 596
 597    /**
 598     * @eventfd_del:
 599     *
 600     * Called during an address space update transaction,
 601     * for a section of the address space that has dropped an ioeventfd
 602     * registration since the last transaction.
 603     *
 604     * @listener: The #MemoryListener.
 605     * @section: The new #MemoryRegionSection.
 606     * @match_data: The @match_data parameter for the dropped ioeventfd.
 607     * @data: The @data parameter for the dropped ioeventfd.
 608     * @e: The #EventNotifier parameter for the dropped ioeventfd.
 609     */
 610    void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
 611                        bool match_data, uint64_t data, EventNotifier *e);
 612
 613    /**
 614     * @coalesced_io_add:
 615     *
 616     * Called during an address space update transaction,
 617     * for a section of the address space that has had a new coalesced
 618     * MMIO range registration since the last transaction.
 619     *
 620     * @listener: The #MemoryListener.
 621     * @section: The new #MemoryRegionSection.
 622     * @addr: The starting address for the coalesced MMIO range.
 623     * @len: The length of the coalesced MMIO range.
 624     */
 625    void (*coalesced_io_add)(MemoryListener *listener, MemoryRegionSection *section,
 626                               hwaddr addr, hwaddr len);
 627
 628    /**
 629     * @coalesced_io_del:
 630     *
 631     * Called during an address space update transaction,
 632     * for a section of the address space that has dropped a coalesced
 633     * MMIO range since the last transaction.
 634     *
 635     * @listener: The #MemoryListener.
 636     * @section: The new #MemoryRegionSection.
 637     * @addr: The starting address for the coalesced MMIO range.
 638     * @len: The length of the coalesced MMIO range.
 639     */
 640    void (*coalesced_io_del)(MemoryListener *listener, MemoryRegionSection *section,
 641                               hwaddr addr, hwaddr len);
 642    /**
 643     * @priority:
 644     *
 645     * Govern the order in which memory listeners are invoked. Lower priorities
 646     * are invoked earlier for "add" or "start" callbacks, and later for "delete"
 647     * or "stop" callbacks.
 648     */
 649    unsigned priority;
 650
 651    /* private: */
 652    AddressSpace *address_space;
 653    QTAILQ_ENTRY(MemoryListener) link;
 654    QTAILQ_ENTRY(MemoryListener) link_as;
 655};
 656
 657/**
 658 * AddressSpace: describes a mapping of addresses to #MemoryRegion objects
 659 */
 660struct AddressSpace {
 661    /* private: */
 662    struct rcu_head rcu;
 663    char *name;
 664    MemoryRegion *root;
 665
 666    /* Accessed via RCU.  */
 667    struct FlatView *current_map;
 668
 669    int ioeventfd_nb;
 670    struct MemoryRegionIoeventfd *ioeventfds;
 671    QTAILQ_HEAD(, MemoryListener) listeners;
 672    QTAILQ_ENTRY(AddressSpace) address_spaces_link;
 673};
 674
 675typedef struct AddressSpaceDispatch AddressSpaceDispatch;
 676typedef struct FlatRange FlatRange;
 677
 678/* Flattened global view of current active memory hierarchy.  Kept in sorted
 679 * order.
 680 */
 681struct FlatView {
 682    struct rcu_head rcu;
 683    unsigned ref;
 684    FlatRange *ranges;
 685    unsigned nr;
 686    unsigned nr_allocated;
 687    struct AddressSpaceDispatch *dispatch;
 688    MemoryRegion *root;
 689};
 690
 691static inline FlatView *address_space_to_flatview(AddressSpace *as)
 692{
 693    return atomic_rcu_read(&as->current_map);
 694}
 695
 696
 697/**
 698 * MemoryRegionSection: describes a fragment of a #MemoryRegion
 699 *
 700 * @mr: the region, or %NULL if empty
 701 * @fv: the flat view of the address space the region is mapped in
 702 * @offset_within_region: the beginning of the section, relative to @mr's start
 703 * @size: the size of the section; will not exceed @mr's boundaries
 704 * @offset_within_address_space: the address of the first byte of the section
 705 *     relative to the region's address space
 706 * @readonly: writes to this section are ignored
 707 * @nonvolatile: this section is non-volatile
 708 */
 709struct MemoryRegionSection {
 710    Int128 size;
 711    MemoryRegion *mr;
 712    FlatView *fv;
 713    hwaddr offset_within_region;
 714    hwaddr offset_within_address_space;
 715    bool readonly;
 716    bool nonvolatile;
 717};
 718
 719static inline bool MemoryRegionSection_eq(MemoryRegionSection *a,
 720                                          MemoryRegionSection *b)
 721{
 722    return a->mr == b->mr &&
 723           a->fv == b->fv &&
 724           a->offset_within_region == b->offset_within_region &&
 725           a->offset_within_address_space == b->offset_within_address_space &&
 726           int128_eq(a->size, b->size) &&
 727           a->readonly == b->readonly &&
 728           a->nonvolatile == b->nonvolatile;
 729}
 730
 731/**
 732 * memory_region_init: Initialize a memory region
 733 *
 734 * The region typically acts as a container for other memory regions.  Use
 735 * memory_region_add_subregion() to add subregions.
 736 *
 737 * @mr: the #MemoryRegion to be initialized
 738 * @owner: the object that tracks the region's reference count
 739 * @name: used for debugging; not visible to the user or ABI
 740 * @size: size of the region; any subregions beyond this size will be clipped
 741 */
 742void memory_region_init(MemoryRegion *mr,
 743                        struct Object *owner,
 744                        const char *name,
 745                        uint64_t size);
 746
 747/**
 748 * memory_region_ref: Add 1 to a memory region's reference count
 749 *
 750 * Whenever memory regions are accessed outside the BQL, they need to be
 751 * preserved against hot-unplug.  MemoryRegions actually do not have their
 752 * own reference count; they piggyback on a QOM object, their "owner".
 753 * This function adds a reference to the owner.
 754 *
 755 * All MemoryRegions must have an owner if they can disappear, even if the
 756 * device they belong to operates exclusively under the BQL.  This is because
 757 * the region could be returned at any time by memory_region_find, and this
 758 * is usually under guest control.
 759 *
 760 * @mr: the #MemoryRegion
 761 */
 762void memory_region_ref(MemoryRegion *mr);
 763
 764/**
 765 * memory_region_unref: Remove 1 to a memory region's reference count
 766 *
 767 * Whenever memory regions are accessed outside the BQL, they need to be
 768 * preserved against hot-unplug.  MemoryRegions actually do not have their
 769 * own reference count; they piggyback on a QOM object, their "owner".
 770 * This function removes a reference to the owner and possibly destroys it.
 771 *
 772 * @mr: the #MemoryRegion
 773 */
 774void memory_region_unref(MemoryRegion *mr);
 775
 776/**
 777 * memory_region_init_io: Initialize an I/O memory region.
 778 *
 779 * Accesses into the region will cause the callbacks in @ops to be called.
 780 * if @size is nonzero, subregions will be clipped to @size.
 781 *
 782 * @mr: the #MemoryRegion to be initialized.
 783 * @owner: the object that tracks the region's reference count
 784 * @ops: a structure containing read and write callbacks to be used when
 785 *       I/O is performed on the region.
 786 * @opaque: passed to the read and write callbacks of the @ops structure.
 787 * @name: used for debugging; not visible to the user or ABI
 788 * @size: size of the region.
 789 */
 790void memory_region_init_io(MemoryRegion *mr,
 791                           struct Object *owner,
 792                           const MemoryRegionOps *ops,
 793                           void *opaque,
 794                           const char *name,
 795                           uint64_t size);
 796
 797/**
 798 * memory_region_init_ram_nomigrate:  Initialize RAM memory region.  Accesses
 799 *                                    into the region will modify memory
 800 *                                    directly.
 801 *
 802 * @mr: the #MemoryRegion to be initialized.
 803 * @owner: the object that tracks the region's reference count
 804 * @name: Region name, becomes part of RAMBlock name used in migration stream
 805 *        must be unique within any device
 806 * @size: size of the region.
 807 * @errp: pointer to Error*, to store an error if it happens.
 808 *
 809 * Note that this function does not do anything to cause the data in the
 810 * RAM memory region to be migrated; that is the responsibility of the caller.
 811 */
 812void memory_region_init_ram_nomigrate(MemoryRegion *mr,
 813                                      struct Object *owner,
 814                                      const char *name,
 815                                      uint64_t size,
 816                                      Error **errp);
 817
 818/**
 819 * memory_region_init_ram_shared_nomigrate:  Initialize RAM memory region.
 820 *                                           Accesses into the region will
 821 *                                           modify memory directly.
 822 *
 823 * @mr: the #MemoryRegion to be initialized.
 824 * @owner: the object that tracks the region's reference count
 825 * @name: Region name, becomes part of RAMBlock name used in migration stream
 826 *        must be unique within any device
 827 * @size: size of the region.
 828 * @share: allow remapping RAM to different addresses
 829 * @errp: pointer to Error*, to store an error if it happens.
 830 *
 831 * Note that this function is similar to memory_region_init_ram_nomigrate.
 832 * The only difference is part of the RAM region can be remapped.
 833 */
 834void memory_region_init_ram_shared_nomigrate(MemoryRegion *mr,
 835                                             struct Object *owner,
 836                                             const char *name,
 837                                             uint64_t size,
 838                                             bool share,
 839                                             Error **errp);
 840
 841/**
 842 * memory_region_init_resizeable_ram:  Initialize memory region with resizeable
 843 *                                     RAM.  Accesses into the region will
 844 *                                     modify memory directly.  Only an initial
 845 *                                     portion of this RAM is actually used.
 846 *                                     The used size can change across reboots.
 847 *
 848 * @mr: the #MemoryRegion to be initialized.
 849 * @owner: the object that tracks the region's reference count
 850 * @name: Region name, becomes part of RAMBlock name used in migration stream
 851 *        must be unique within any device
 852 * @size: used size of the region.
 853 * @max_size: max size of the region.
 854 * @resized: callback to notify owner about used size change.
 855 * @errp: pointer to Error*, to store an error if it happens.
 856 *
 857 * Note that this function does not do anything to cause the data in the
 858 * RAM memory region to be migrated; that is the responsibility of the caller.
 859 */
 860void memory_region_init_resizeable_ram(MemoryRegion *mr,
 861                                       struct Object *owner,
 862                                       const char *name,
 863                                       uint64_t size,
 864                                       uint64_t max_size,
 865                                       void (*resized)(const char*,
 866                                                       uint64_t length,
 867                                                       void *host),
 868                                       Error **errp);
 869#ifdef CONFIG_POSIX
 870
 871/**
 872 * memory_region_init_ram_from_file:  Initialize RAM memory region with a
 873 *                                    mmap-ed backend.
 874 *
 875 * @mr: the #MemoryRegion to be initialized.
 876 * @owner: the object that tracks the region's reference count
 877 * @name: Region name, becomes part of RAMBlock name used in migration stream
 878 *        must be unique within any device
 879 * @size: size of the region.
 880 * @align: alignment of the region base address; if 0, the default alignment
 881 *         (getpagesize()) will be used.
 882 * @ram_flags: Memory region features:
 883 *             - RAM_SHARED: memory must be mmaped with the MAP_SHARED flag
 884 *             - RAM_PMEM: the memory is persistent memory
 885 *             Other bits are ignored now.
 886 * @path: the path in which to allocate the RAM.
 887 * @errp: pointer to Error*, to store an error if it happens.
 888 *
 889 * Note that this function does not do anything to cause the data in the
 890 * RAM memory region to be migrated; that is the responsibility of the caller.
 891 */
 892void memory_region_init_ram_from_file(MemoryRegion *mr,
 893                                      struct Object *owner,
 894                                      const char *name,
 895                                      uint64_t size,
 896                                      uint64_t align,
 897                                      uint32_t ram_flags,
 898                                      const char *path,
 899                                      Error **errp);
 900
 901/**
 902 * memory_region_init_ram_from_fd:  Initialize RAM memory region with a
 903 *                                  mmap-ed backend.
 904 *
 905 * @mr: the #MemoryRegion to be initialized.
 906 * @owner: the object that tracks the region's reference count
 907 * @name: the name of the region.
 908 * @size: size of the region.
 909 * @share: %true if memory must be mmaped with the MAP_SHARED flag
 910 * @fd: the fd to mmap.
 911 * @errp: pointer to Error*, to store an error if it happens.
 912 *
 913 * Note that this function does not do anything to cause the data in the
 914 * RAM memory region to be migrated; that is the responsibility of the caller.
 915 */
 916void memory_region_init_ram_from_fd(MemoryRegion *mr,
 917                                    struct Object *owner,
 918                                    const char *name,
 919                                    uint64_t size,
 920                                    bool share,
 921                                    int fd,
 922                                    Error **errp);
 923#endif
 924
 925/**
 926 * memory_region_init_ram_ptr:  Initialize RAM memory region from a
 927 *                              user-provided pointer.  Accesses into the
 928 *                              region will modify memory directly.
 929 *
 930 * @mr: the #MemoryRegion to be initialized.
 931 * @owner: the object that tracks the region's reference count
 932 * @name: Region name, becomes part of RAMBlock name used in migration stream
 933 *        must be unique within any device
 934 * @size: size of the region.
 935 * @ptr: memory to be mapped; must contain at least @size bytes.
 936 *
 937 * Note that this function does not do anything to cause the data in the
 938 * RAM memory region to be migrated; that is the responsibility of the caller.
 939 */
 940void memory_region_init_ram_ptr(MemoryRegion *mr,
 941                                struct Object *owner,
 942                                const char *name,
 943                                uint64_t size,
 944                                void *ptr);
 945
 946/**
 947 * memory_region_init_ram_device_ptr:  Initialize RAM device memory region from
 948 *                                     a user-provided pointer.
 949 *
 950 * A RAM device represents a mapping to a physical device, such as to a PCI
 951 * MMIO BAR of an vfio-pci assigned device.  The memory region may be mapped
 952 * into the VM address space and access to the region will modify memory
 953 * directly.  However, the memory region should not be included in a memory
 954 * dump (device may not be enabled/mapped at the time of the dump), and
 955 * operations incompatible with manipulating MMIO should be avoided.  Replaces
 956 * skip_dump flag.
 957 *
 958 * @mr: the #MemoryRegion to be initialized.
 959 * @owner: the object that tracks the region's reference count
 960 * @name: the name of the region.
 961 * @size: size of the region.
 962 * @ptr: memory to be mapped; must contain at least @size bytes.
 963 *
 964 * Note that this function does not do anything to cause the data in the
 965 * RAM memory region to be migrated; that is the responsibility of the caller.
 966 * (For RAM device memory regions, migrating the contents rarely makes sense.)
 967 */
 968void memory_region_init_ram_device_ptr(MemoryRegion *mr,
 969                                       struct Object *owner,
 970                                       const char *name,
 971                                       uint64_t size,
 972                                       void *ptr);
 973
 974/**
 975 * memory_region_init_alias: Initialize a memory region that aliases all or a
 976 *                           part of another memory region.
 977 *
 978 * @mr: the #MemoryRegion to be initialized.
 979 * @owner: the object that tracks the region's reference count
 980 * @name: used for debugging; not visible to the user or ABI
 981 * @orig: the region to be referenced; @mr will be equivalent to
 982 *        @orig between @offset and @offset + @size - 1.
 983 * @offset: start of the section in @orig to be referenced.
 984 * @size: size of the region.
 985 */
 986void memory_region_init_alias(MemoryRegion *mr,
 987                              struct Object *owner,
 988                              const char *name,
 989                              MemoryRegion *orig,
 990                              hwaddr offset,
 991                              uint64_t size);
 992
 993/**
 994 * memory_region_init_rom_nomigrate: Initialize a ROM memory region.
 995 *
 996 * This has the same effect as calling memory_region_init_ram_nomigrate()
 997 * and then marking the resulting region read-only with
 998 * memory_region_set_readonly().
 999 *
1000 * Note that this function does not do anything to cause the data in the
1001 * RAM side of the memory region to be migrated; that is the responsibility
1002 * of the caller.
1003 *
1004 * @mr: the #MemoryRegion to be initialized.
1005 * @owner: the object that tracks the region's reference count
1006 * @name: Region name, becomes part of RAMBlock name used in migration stream
1007 *        must be unique within any device
1008 * @size: size of the region.
1009 * @errp: pointer to Error*, to store an error if it happens.
1010 */
1011void memory_region_init_rom_nomigrate(MemoryRegion *mr,
1012                                      struct Object *owner,
1013                                      const char *name,
1014                                      uint64_t size,
1015                                      Error **errp);
1016
1017/**
1018 * memory_region_init_rom_device_nomigrate:  Initialize a ROM memory region.
1019 *                                 Writes are handled via callbacks.
1020 *
1021 * Note that this function does not do anything to cause the data in the
1022 * RAM side of the memory region to be migrated; that is the responsibility
1023 * of the caller.
1024 *
1025 * @mr: the #MemoryRegion to be initialized.
1026 * @owner: the object that tracks the region's reference count
1027 * @ops: callbacks for write access handling (must not be NULL).
1028 * @opaque: passed to the read and write callbacks of the @ops structure.
1029 * @name: Region name, becomes part of RAMBlock name used in migration stream
1030 *        must be unique within any device
1031 * @size: size of the region.
1032 * @errp: pointer to Error*, to store an error if it happens.
1033 */
1034void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
1035                                             struct Object *owner,
1036                                             const MemoryRegionOps *ops,
1037                                             void *opaque,
1038                                             const char *name,
1039                                             uint64_t size,
1040                                             Error **errp);
1041
1042/**
1043 * memory_region_init_iommu: Initialize a memory region of a custom type
1044 * that translates addresses
1045 *
1046 * An IOMMU region translates addresses and forwards accesses to a target
1047 * memory region.
1048 *
1049 * The IOMMU implementation must define a subclass of TYPE_IOMMU_MEMORY_REGION.
1050 * @_iommu_mr should be a pointer to enough memory for an instance of
1051 * that subclass, @instance_size is the size of that subclass, and
1052 * @mrtypename is its name. This function will initialize @_iommu_mr as an
1053 * instance of the subclass, and its methods will then be called to handle
1054 * accesses to the memory region. See the documentation of
1055 * #IOMMUMemoryRegionClass for further details.
1056 *
1057 * @_iommu_mr: the #IOMMUMemoryRegion to be initialized
1058 * @instance_size: the IOMMUMemoryRegion subclass instance size
1059 * @mrtypename: the type name of the #IOMMUMemoryRegion
1060 * @owner: the object that tracks the region's reference count
1061 * @name: used for debugging; not visible to the user or ABI
1062 * @size: size of the region.
1063 */
1064void memory_region_init_iommu(void *_iommu_mr,
1065                              size_t instance_size,
1066                              const char *mrtypename,
1067                              Object *owner,
1068                              const char *name,
1069                              uint64_t size);
1070
1071/**
1072 * memory_region_init_ram - Initialize RAM memory region.  Accesses into the
1073 *                          region will modify memory directly.
1074 *
1075 * @mr: the #MemoryRegion to be initialized
1076 * @owner: the object that tracks the region's reference count (must be
1077 *         TYPE_DEVICE or a subclass of TYPE_DEVICE, or NULL)
1078 * @name: name of the memory region
1079 * @size: size of the region in bytes
1080 * @errp: pointer to Error*, to store an error if it happens.
1081 *
1082 * This function allocates RAM for a board model or device, and
1083 * arranges for it to be migrated (by calling vmstate_register_ram()
1084 * if @owner is a DeviceState, or vmstate_register_ram_global() if
1085 * @owner is NULL).
1086 *
1087 * TODO: Currently we restrict @owner to being either NULL (for
1088 * global RAM regions with no owner) or devices, so that we can
1089 * give the RAM block a unique name for migration purposes.
1090 * We should lift this restriction and allow arbitrary Objects.
1091 * If you pass a non-NULL non-device @owner then we will assert.
1092 */
1093void memory_region_init_ram(MemoryRegion *mr,
1094                            struct Object *owner,
1095                            const char *name,
1096                            uint64_t size,
1097                            Error **errp);
1098
1099/**
1100 * memory_region_init_rom: Initialize a ROM memory region.
1101 *
1102 * This has the same effect as calling memory_region_init_ram()
1103 * and then marking the resulting region read-only with
1104 * memory_region_set_readonly(). This includes arranging for the
1105 * contents to be migrated.
1106 *
1107 * TODO: Currently we restrict @owner to being either NULL (for
1108 * global RAM regions with no owner) or devices, so that we can
1109 * give the RAM block a unique name for migration purposes.
1110 * We should lift this restriction and allow arbitrary Objects.
1111 * If you pass a non-NULL non-device @owner then we will assert.
1112 *
1113 * @mr: the #MemoryRegion to be initialized.
1114 * @owner: the object that tracks the region's reference count
1115 * @name: Region name, becomes part of RAMBlock name used in migration stream
1116 *        must be unique within any device
1117 * @size: size of the region.
1118 * @errp: pointer to Error*, to store an error if it happens.
1119 */
1120void memory_region_init_rom(MemoryRegion *mr,
1121                            struct Object *owner,
1122                            const char *name,
1123                            uint64_t size,
1124                            Error **errp);
1125
1126/**
1127 * memory_region_init_rom_device:  Initialize a ROM memory region.
1128 *                                 Writes are handled via callbacks.
1129 *
1130 * This function initializes a memory region backed by RAM for reads
1131 * and callbacks for writes, and arranges for the RAM backing to
1132 * be migrated (by calling vmstate_register_ram()
1133 * if @owner is a DeviceState, or vmstate_register_ram_global() if
1134 * @owner is NULL).
1135 *
1136 * TODO: Currently we restrict @owner to being either NULL (for
1137 * global RAM regions with no owner) or devices, so that we can
1138 * give the RAM block a unique name for migration purposes.
1139 * We should lift this restriction and allow arbitrary Objects.
1140 * If you pass a non-NULL non-device @owner then we will assert.
1141 *
1142 * @mr: the #MemoryRegion to be initialized.
1143 * @owner: the object that tracks the region's reference count
1144 * @ops: callbacks for write access handling (must not be NULL).
1145 * @opaque: passed to the read and write callbacks of the @ops structure.
1146 * @name: Region name, becomes part of RAMBlock name used in migration stream
1147 *        must be unique within any device
1148 * @size: size of the region.
1149 * @errp: pointer to Error*, to store an error if it happens.
1150 */
1151void memory_region_init_rom_device(MemoryRegion *mr,
1152                                   struct Object *owner,
1153                                   const MemoryRegionOps *ops,
1154                                   void *opaque,
1155                                   const char *name,
1156                                   uint64_t size,
1157                                   Error **errp);
1158
1159
1160/**
1161 * memory_region_owner: get a memory region's owner.
1162 *
1163 * @mr: the memory region being queried.
1164 */
1165struct Object *memory_region_owner(MemoryRegion *mr);
1166
1167/**
1168 * memory_region_size: get a memory region's size.
1169 *
1170 * @mr: the memory region being queried.
1171 */
1172uint64_t memory_region_size(MemoryRegion *mr);
1173
1174/**
1175 * memory_region_is_ram: check whether a memory region is random access
1176 *
1177 * Returns %true if a memory region is random access.
1178 *
1179 * @mr: the memory region being queried
1180 */
1181static inline bool memory_region_is_ram(MemoryRegion *mr)
1182{
1183    return mr->ram;
1184}
1185
1186/**
1187 * memory_region_is_ram_device: check whether a memory region is a ram device
1188 *
1189 * Returns %true if a memory region is a device backed ram region
1190 *
1191 * @mr: the memory region being queried
1192 */
1193bool memory_region_is_ram_device(MemoryRegion *mr);
1194
1195/**
1196 * memory_region_is_romd: check whether a memory region is in ROMD mode
1197 *
1198 * Returns %true if a memory region is a ROM device and currently set to allow
1199 * direct reads.
1200 *
1201 * @mr: the memory region being queried
1202 */
1203static inline bool memory_region_is_romd(MemoryRegion *mr)
1204{
1205    return mr->rom_device && mr->romd_mode;
1206}
1207
1208/**
1209 * memory_region_get_iommu: check whether a memory region is an iommu
1210 *
1211 * Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
1212 * otherwise NULL.
1213 *
1214 * @mr: the memory region being queried
1215 */
1216static inline IOMMUMemoryRegion *memory_region_get_iommu(MemoryRegion *mr)
1217{
1218    if (mr->alias) {
1219        return memory_region_get_iommu(mr->alias);
1220    }
1221    if (mr->is_iommu) {
1222        return (IOMMUMemoryRegion *) mr;
1223    }
1224    return NULL;
1225}
1226
1227/**
1228 * memory_region_get_iommu_class_nocheck: returns iommu memory region class
1229 *   if an iommu or NULL if not
1230 *
1231 * Returns pointer to IOMMUMemoryRegionClass if a memory region is an iommu,
1232 * otherwise NULL. This is fast path avoiding QOM checking, use with caution.
1233 *
1234 * @iommu_mr: the memory region being queried
1235 */
1236static inline IOMMUMemoryRegionClass *memory_region_get_iommu_class_nocheck(
1237        IOMMUMemoryRegion *iommu_mr)
1238{
1239    return (IOMMUMemoryRegionClass *) (((Object *)iommu_mr)->class);
1240}
1241
1242#define memory_region_is_iommu(mr) (memory_region_get_iommu(mr) != NULL)
1243
1244/**
1245 * memory_region_iommu_get_min_page_size: get minimum supported page size
1246 * for an iommu
1247 *
1248 * Returns minimum supported page size for an iommu.
1249 *
1250 * @iommu_mr: the memory region being queried
1251 */
1252uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr);
1253
1254/**
1255 * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
1256 *
1257 * The notification type will be decided by entry.perm bits:
1258 *
1259 * - For UNMAP (cache invalidation) notifies: set entry.perm to IOMMU_NONE.
1260 * - For MAP (newly added entry) notifies: set entry.perm to the
1261 *   permission of the page (which is definitely !IOMMU_NONE).
1262 *
1263 * Note: for any IOMMU implementation, an in-place mapping change
1264 * should be notified with an UNMAP followed by a MAP.
1265 *
1266 * @iommu_mr: the memory region that was changed
1267 * @iommu_idx: the IOMMU index for the translation table which has changed
1268 * @entry: the new entry in the IOMMU translation table.  The entry
1269 *         replaces all old entries for the same virtual I/O address range.
1270 *         Deleted entries have .@perm == 0.
1271 */
1272void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
1273                                int iommu_idx,
1274                                IOMMUTLBEntry entry);
1275
1276/**
1277 * memory_region_notify_one: notify a change in an IOMMU translation
1278 *                           entry to a single notifier
1279 *
1280 * This works just like memory_region_notify_iommu(), but it only
1281 * notifies a specific notifier, not all of them.
1282 *
1283 * @notifier: the notifier to be notified
1284 * @entry: the new entry in the IOMMU translation table.  The entry
1285 *         replaces all old entries for the same virtual I/O address range.
1286 *         Deleted entries have .@perm == 0.
1287 */
1288void memory_region_notify_one(IOMMUNotifier *notifier,
1289                              IOMMUTLBEntry *entry);
1290
1291/**
1292 * memory_region_register_iommu_notifier: register a notifier for changes to
1293 * IOMMU translation entries.
1294 *
1295 * Returns 0 on success, or a negative errno otherwise. In particular,
1296 * -EINVAL indicates that at least one of the attributes of the notifier
1297 * is not supported (flag/range) by the IOMMU memory region. In case of error
1298 * the error object must be created.
1299 *
1300 * @mr: the memory region to observe
1301 * @n: the IOMMUNotifier to be added; the notify callback receives a
1302 *     pointer to an #IOMMUTLBEntry as the opaque value; the pointer
1303 *     ceases to be valid on exit from the notifier.
1304 * @errp: pointer to Error*, to store an error if it happens.
1305 */
1306int memory_region_register_iommu_notifier(MemoryRegion *mr,
1307                                          IOMMUNotifier *n, Error **errp);
1308
1309/**
1310 * memory_region_iommu_replay: replay existing IOMMU translations to
1311 * a notifier with the minimum page granularity returned by
1312 * mr->iommu_ops->get_page_size().
1313 *
1314 * Note: this is not related to record-and-replay functionality.
1315 *
1316 * @iommu_mr: the memory region to observe
1317 * @n: the notifier to which to replay iommu mappings
1318 */
1319void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n);
1320
1321/**
1322 * memory_region_unregister_iommu_notifier: unregister a notifier for
1323 * changes to IOMMU translation entries.
1324 *
1325 * @mr: the memory region which was observed and for which notity_stopped()
1326 *      needs to be called
1327 * @n: the notifier to be removed.
1328 */
1329void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
1330                                             IOMMUNotifier *n);
1331
1332/**
1333 * memory_region_iommu_get_attr: return an IOMMU attr if get_attr() is
1334 * defined on the IOMMU.
1335 *
1336 * Returns 0 on success, or a negative errno otherwise. In particular,
1337 * -EINVAL indicates that the IOMMU does not support the requested
1338 * attribute.
1339 *
1340 * @iommu_mr: the memory region
1341 * @attr: the requested attribute
1342 * @data: a pointer to the requested attribute data
1343 */
1344int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
1345                                 enum IOMMUMemoryRegionAttr attr,
1346                                 void *data);
1347
1348/**
1349 * memory_region_iommu_attrs_to_index: return the IOMMU index to
1350 * use for translations with the given memory transaction attributes.
1351 *
1352 * @iommu_mr: the memory region
1353 * @attrs: the memory transaction attributes
1354 */
1355int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr,
1356                                       MemTxAttrs attrs);
1357
1358/**
1359 * memory_region_iommu_num_indexes: return the total number of IOMMU
1360 * indexes that this IOMMU supports.
1361 *
1362 * @iommu_mr: the memory region
1363 */
1364int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr);
1365
1366/**
1367 * memory_region_name: get a memory region's name
1368 *
1369 * Returns the string that was used to initialize the memory region.
1370 *
1371 * @mr: the memory region being queried
1372 */
1373const char *memory_region_name(const MemoryRegion *mr);
1374
1375/**
1376 * memory_region_is_logging: return whether a memory region is logging writes
1377 *
1378 * Returns %true if the memory region is logging writes for the given client
1379 *
1380 * @mr: the memory region being queried
1381 * @client: the client being queried
1382 */
1383bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
1384
1385/**
1386 * memory_region_get_dirty_log_mask: return the clients for which a
1387 * memory region is logging writes.
1388 *
1389 * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
1390 * are the bit indices.
1391 *
1392 * @mr: the memory region being queried
1393 */
1394uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
1395
1396/**
1397 * memory_region_is_rom: check whether a memory region is ROM
1398 *
1399 * Returns %true if a memory region is read-only memory.
1400 *
1401 * @mr: the memory region being queried
1402 */
1403static inline bool memory_region_is_rom(MemoryRegion *mr)
1404{
1405    return mr->ram && mr->readonly;
1406}
1407
1408/**
1409 * memory_region_is_nonvolatile: check whether a memory region is non-volatile
1410 *
1411 * Returns %true is a memory region is non-volatile memory.
1412 *
1413 * @mr: the memory region being queried
1414 */
1415static inline bool memory_region_is_nonvolatile(MemoryRegion *mr)
1416{
1417    return mr->nonvolatile;
1418}
1419
1420/**
1421 * memory_region_get_fd: Get a file descriptor backing a RAM memory region.
1422 *
1423 * Returns a file descriptor backing a file-based RAM memory region,
1424 * or -1 if the region is not a file-based RAM memory region.
1425 *
1426 * @mr: the RAM or alias memory region being queried.
1427 */
1428int memory_region_get_fd(MemoryRegion *mr);
1429
1430/**
1431 * memory_region_from_host: Convert a pointer into a RAM memory region
1432 * and an offset within it.
1433 *
1434 * Given a host pointer inside a RAM memory region (created with
1435 * memory_region_init_ram() or memory_region_init_ram_ptr()), return
1436 * the MemoryRegion and the offset within it.
1437 *
1438 * Use with care; by the time this function returns, the returned pointer is
1439 * not protected by RCU anymore.  If the caller is not within an RCU critical
1440 * section and does not hold the iothread lock, it must have other means of
1441 * protecting the pointer, such as a reference to the region that includes
1442 * the incoming ram_addr_t.
1443 *
1444 * @ptr: the host pointer to be converted
1445 * @offset: the offset within memory region
1446 */
1447MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
1448
1449/**
1450 * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
1451 *
1452 * Returns a host pointer to a RAM memory region (created with
1453 * memory_region_init_ram() or memory_region_init_ram_ptr()).
1454 *
1455 * Use with care; by the time this function returns, the returned pointer is
1456 * not protected by RCU anymore.  If the caller is not within an RCU critical
1457 * section and does not hold the iothread lock, it must have other means of
1458 * protecting the pointer, such as a reference to the region that includes
1459 * the incoming ram_addr_t.
1460 *
1461 * @mr: the memory region being queried.
1462 */
1463void *memory_region_get_ram_ptr(MemoryRegion *mr);
1464
1465/* memory_region_ram_resize: Resize a RAM region.
1466 *
1467 * Only legal before guest might have detected the memory size: e.g. on
1468 * incoming migration, or right after reset.
1469 *
1470 * @mr: a memory region created with @memory_region_init_resizeable_ram.
1471 * @newsize: the new size the region
1472 * @errp: pointer to Error*, to store an error if it happens.
1473 */
1474void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
1475                              Error **errp);
1476
1477/**
1478 * memory_region_msync: Synchronize selected address range of
1479 * a memory mapped region
1480 *
1481 * @mr: the memory region to be msync
1482 * @addr: the initial address of the range to be sync
1483 * @size: the size of the range to be sync
1484 */
1485void memory_region_msync(MemoryRegion *mr, hwaddr addr, hwaddr size);
1486
1487/**
1488 * memory_region_writeback: Trigger cache writeback for
1489 * selected address range
1490 *
1491 * @mr: the memory region to be updated
1492 * @addr: the initial address of the range to be written back
1493 * @size: the size of the range to be written back
1494 */
1495void memory_region_writeback(MemoryRegion *mr, hwaddr addr, hwaddr size);
1496
1497/**
1498 * memory_region_set_log: Turn dirty logging on or off for a region.
1499 *
1500 * Turns dirty logging on or off for a specified client (display, migration).
1501 * Only meaningful for RAM regions.
1502 *
1503 * @mr: the memory region being updated.
1504 * @log: whether dirty logging is to be enabled or disabled.
1505 * @client: the user of the logging information; %DIRTY_MEMORY_VGA only.
1506 */
1507void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client);
1508
1509/**
1510 * memory_region_set_dirty: Mark a range of bytes as dirty in a memory region.
1511 *
1512 * Marks a range of bytes as dirty, after it has been dirtied outside
1513 * guest code.
1514 *
1515 * @mr: the memory region being dirtied.
1516 * @addr: the address (relative to the start of the region) being dirtied.
1517 * @size: size of the range being dirtied.
1518 */
1519void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
1520                             hwaddr size);
1521
1522/**
1523 * memory_region_clear_dirty_bitmap - clear dirty bitmap for memory range
1524 *
1525 * This function is called when the caller wants to clear the remote
1526 * dirty bitmap of a memory range within the memory region.  This can
1527 * be used by e.g. KVM to manually clear dirty log when
1528 * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is declared support by the host
1529 * kernel.
1530 *
1531 * @mr:     the memory region to clear the dirty log upon
1532 * @start:  start address offset within the memory region
1533 * @len:    length of the memory region to clear dirty bitmap
1534 */
1535void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start,
1536                                      hwaddr len);
1537
1538/**
1539 * memory_region_snapshot_and_clear_dirty: Get a snapshot of the dirty
1540 *                                         bitmap and clear it.
1541 *
1542 * Creates a snapshot of the dirty bitmap, clears the dirty bitmap and
1543 * returns the snapshot.  The snapshot can then be used to query dirty
1544 * status, using memory_region_snapshot_get_dirty.  Snapshotting allows
1545 * querying the same page multiple times, which is especially useful for
1546 * display updates where the scanlines often are not page aligned.
1547 *
1548 * The dirty bitmap region which gets copyed into the snapshot (and
1549 * cleared afterwards) can be larger than requested.  The boundaries
1550 * are rounded up/down so complete bitmap longs (covering 64 pages on
1551 * 64bit hosts) can be copied over into the bitmap snapshot.  Which
1552 * isn't a problem for display updates as the extra pages are outside
1553 * the visible area, and in case the visible area changes a full
1554 * display redraw is due anyway.  Should other use cases for this
1555 * function emerge we might have to revisit this implementation
1556 * detail.
1557 *
1558 * Use g_free to release DirtyBitmapSnapshot.
1559 *
1560 * @mr: the memory region being queried.
1561 * @addr: the address (relative to the start of the region) being queried.
1562 * @size: the size of the range being queried.
1563 * @client: the user of the logging information; typically %DIRTY_MEMORY_VGA.
1564 */
1565DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr,
1566                                                            hwaddr addr,
1567                                                            hwaddr size,
1568                                                            unsigned client);
1569
1570/**
1571 * memory_region_snapshot_get_dirty: Check whether a range of bytes is dirty
1572 *                                   in the specified dirty bitmap snapshot.
1573 *
1574 * @mr: the memory region being queried.
1575 * @snap: the dirty bitmap snapshot
1576 * @addr: the address (relative to the start of the region) being queried.
1577 * @size: the size of the range being queried.
1578 */
1579bool memory_region_snapshot_get_dirty(MemoryRegion *mr,
1580                                      DirtyBitmapSnapshot *snap,
1581                                      hwaddr addr, hwaddr size);
1582
1583/**
1584 * memory_region_reset_dirty: Mark a range of pages as clean, for a specified
1585 *                            client.
1586 *
1587 * Marks a range of pages as no longer dirty.
1588 *
1589 * @mr: the region being updated.
1590 * @addr: the start of the subrange being cleaned.
1591 * @size: the size of the subrange being cleaned.
1592 * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
1593 *          %DIRTY_MEMORY_VGA.
1594 */
1595void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
1596                               hwaddr size, unsigned client);
1597
1598/**
1599 * memory_region_flush_rom_device: Mark a range of pages dirty and invalidate
1600 *                                 TBs (for self-modifying code).
1601 *
1602 * The MemoryRegionOps->write() callback of a ROM device must use this function
1603 * to mark byte ranges that have been modified internally, such as by directly
1604 * accessing the memory returned by memory_region_get_ram_ptr().
1605 *
1606 * This function marks the range dirty and invalidates TBs so that TCG can
1607 * detect self-modifying code.
1608 *
1609 * @mr: the region being flushed.
1610 * @addr: the start, relative to the start of the region, of the range being
1611 *        flushed.
1612 * @size: the size, in bytes, of the range being flushed.
1613 */
1614void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size);
1615
1616/**
1617 * memory_region_set_readonly: Turn a memory region read-only (or read-write)
1618 *
1619 * Allows a memory region to be marked as read-only (turning it into a ROM).
1620 * only useful on RAM regions.
1621 *
1622 * @mr: the region being updated.
1623 * @readonly: whether rhe region is to be ROM or RAM.
1624 */
1625void memory_region_set_readonly(MemoryRegion *mr, bool readonly);
1626
1627/**
1628 * memory_region_set_nonvolatile: Turn a memory region non-volatile
1629 *
1630 * Allows a memory region to be marked as non-volatile.
1631 * only useful on RAM regions.
1632 *
1633 * @mr: the region being updated.
1634 * @nonvolatile: whether rhe region is to be non-volatile.
1635 */
1636void memory_region_set_nonvolatile(MemoryRegion *mr, bool nonvolatile);
1637
1638/**
1639 * memory_region_rom_device_set_romd: enable/disable ROMD mode
1640 *
1641 * Allows a ROM device (initialized with memory_region_init_rom_device() to
1642 * set to ROMD mode (default) or MMIO mode.  When it is in ROMD mode, the
1643 * device is mapped to guest memory and satisfies read access directly.
1644 * When in MMIO mode, reads are forwarded to the #MemoryRegion.read function.
1645 * Writes are always handled by the #MemoryRegion.write function.
1646 *
1647 * @mr: the memory region to be updated
1648 * @romd_mode: %true to put the region into ROMD mode
1649 */
1650void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode);
1651
1652/**
1653 * memory_region_set_coalescing: Enable memory coalescing for the region.
1654 *
1655 * Enabled writes to a region to be queued for later processing. MMIO ->write
1656 * callbacks may be delayed until a non-coalesced MMIO is issued.
1657 * Only useful for IO regions.  Roughly similar to write-combining hardware.
1658 *
1659 * @mr: the memory region to be write coalesced
1660 */
1661void memory_region_set_coalescing(MemoryRegion *mr);
1662
1663/**
1664 * memory_region_add_coalescing: Enable memory coalescing for a sub-range of
1665 *                               a region.
1666 *
1667 * Like memory_region_set_coalescing(), but works on a sub-range of a region.
1668 * Multiple calls can be issued coalesced disjoint ranges.
1669 *
1670 * @mr: the memory region to be updated.
1671 * @offset: the start of the range within the region to be coalesced.
1672 * @size: the size of the subrange to be coalesced.
1673 */
1674void memory_region_add_coalescing(MemoryRegion *mr,
1675                                  hwaddr offset,
1676                                  uint64_t size);
1677
1678/**
1679 * memory_region_clear_coalescing: Disable MMIO coalescing for the region.
1680 *
1681 * Disables any coalescing caused by memory_region_set_coalescing() or
1682 * memory_region_add_coalescing().  Roughly equivalent to uncacheble memory
1683 * hardware.
1684 *
1685 * @mr: the memory region to be updated.
1686 */
1687void memory_region_clear_coalescing(MemoryRegion *mr);
1688
1689/**
1690 * memory_region_set_flush_coalesced: Enforce memory coalescing flush before
1691 *                                    accesses.
1692 *
1693 * Ensure that pending coalesced MMIO request are flushed before the memory
1694 * region is accessed. This property is automatically enabled for all regions
1695 * passed to memory_region_set_coalescing() and memory_region_add_coalescing().
1696 *
1697 * @mr: the memory region to be updated.
1698 */
1699void memory_region_set_flush_coalesced(MemoryRegion *mr);
1700
1701/**
1702 * memory_region_clear_flush_coalesced: Disable memory coalescing flush before
1703 *                                      accesses.
1704 *
1705 * Clear the automatic coalesced MMIO flushing enabled via
1706 * memory_region_set_flush_coalesced. Note that this service has no effect on
1707 * memory regions that have MMIO coalescing enabled for themselves. For them,
1708 * automatic flushing will stop once coalescing is disabled.
1709 *
1710 * @mr: the memory region to be updated.
1711 */
1712void memory_region_clear_flush_coalesced(MemoryRegion *mr);
1713
1714/**
1715 * memory_region_clear_global_locking: Declares that access processing does
1716 *                                     not depend on the QEMU global lock.
1717 *
1718 * By clearing this property, accesses to the memory region will be processed
1719 * outside of QEMU's global lock (unless the lock is held on when issuing the
1720 * access request). In this case, the device model implementing the access
1721 * handlers is responsible for synchronization of concurrency.
1722 *
1723 * @mr: the memory region to be updated.
1724 */
1725void memory_region_clear_global_locking(MemoryRegion *mr);
1726
1727/**
1728 * memory_region_add_eventfd: Request an eventfd to be triggered when a word
1729 *                            is written to a location.
1730 *
1731 * Marks a word in an IO region (initialized with memory_region_init_io())
1732 * as a trigger for an eventfd event.  The I/O callback will not be called.
1733 * The caller must be prepared to handle failure (that is, take the required
1734 * action if the callback _is_ called).
1735 *
1736 * @mr: the memory region being updated.
1737 * @addr: the address within @mr that is to be monitored
1738 * @size: the size of the access to trigger the eventfd
1739 * @match_data: whether to match against @data, instead of just @addr
1740 * @data: the data to match against the guest write
1741 * @e: event notifier to be triggered when @addr, @size, and @data all match.
1742 **/
1743void memory_region_add_eventfd(MemoryRegion *mr,
1744                               hwaddr addr,
1745                               unsigned size,
1746                               bool match_data,
1747                               uint64_t data,
1748                               EventNotifier *e);
1749
1750/**
1751 * memory_region_del_eventfd: Cancel an eventfd.
1752 *
1753 * Cancels an eventfd trigger requested by a previous
1754 * memory_region_add_eventfd() call.
1755 *
1756 * @mr: the memory region being updated.
1757 * @addr: the address within @mr that is to be monitored
1758 * @size: the size of the access to trigger the eventfd
1759 * @match_data: whether to match against @data, instead of just @addr
1760 * @data: the data to match against the guest write
1761 * @e: event notifier to be triggered when @addr, @size, and @data all match.
1762 */
1763void memory_region_del_eventfd(MemoryRegion *mr,
1764                               hwaddr addr,
1765                               unsigned size,
1766                               bool match_data,
1767                               uint64_t data,
1768                               EventNotifier *e);
1769
1770/**
1771 * memory_region_add_subregion: Add a subregion to a container.
1772 *
1773 * Adds a subregion at @offset.  The subregion may not overlap with other
1774 * subregions (except for those explicitly marked as overlapping).  A region
1775 * may only be added once as a subregion (unless removed with
1776 * memory_region_del_subregion()); use memory_region_init_alias() if you
1777 * want a region to be a subregion in multiple locations.
1778 *
1779 * @mr: the region to contain the new subregion; must be a container
1780 *      initialized with memory_region_init().
1781 * @offset: the offset relative to @mr where @subregion is added.
1782 * @subregion: the subregion to be added.
1783 */
1784void memory_region_add_subregion(MemoryRegion *mr,
1785                                 hwaddr offset,
1786                                 MemoryRegion *subregion);
1787/**
1788 * memory_region_add_subregion_overlap: Add a subregion to a container
1789 *                                      with overlap.
1790 *
1791 * Adds a subregion at @offset.  The subregion may overlap with other
1792 * subregions.  Conflicts are resolved by having a higher @priority hide a
1793 * lower @priority. Subregions without priority are taken as @priority 0.
1794 * A region may only be added once as a subregion (unless removed with
1795 * memory_region_del_subregion()); use memory_region_init_alias() if you
1796 * want a region to be a subregion in multiple locations.
1797 *
1798 * @mr: the region to contain the new subregion; must be a container
1799 *      initialized with memory_region_init().
1800 * @offset: the offset relative to @mr where @subregion is added.
1801 * @subregion: the subregion to be added.
1802 * @priority: used for resolving overlaps; highest priority wins.
1803 */
1804void memory_region_add_subregion_overlap(MemoryRegion *mr,
1805                                         hwaddr offset,
1806                                         MemoryRegion *subregion,
1807                                         int priority);
1808
1809/**
1810 * memory_region_get_ram_addr: Get the ram address associated with a memory
1811 *                             region
1812 *
1813 * @mr: the region to be queried
1814 */
1815ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
1816
1817uint64_t memory_region_get_alignment(const MemoryRegion *mr);
1818/**
1819 * memory_region_del_subregion: Remove a subregion.
1820 *
1821 * Removes a subregion from its container.
1822 *
1823 * @mr: the container to be updated.
1824 * @subregion: the region being removed; must be a current subregion of @mr.
1825 */
1826void memory_region_del_subregion(MemoryRegion *mr,
1827                                 MemoryRegion *subregion);
1828
1829/*
1830 * memory_region_set_enabled: dynamically enable or disable a region
1831 *
1832 * Enables or disables a memory region.  A disabled memory region
1833 * ignores all accesses to itself and its subregions.  It does not
1834 * obscure sibling subregions with lower priority - it simply behaves as
1835 * if it was removed from the hierarchy.
1836 *
1837 * Regions default to being enabled.
1838 *
1839 * @mr: the region to be updated
1840 * @enabled: whether to enable or disable the region
1841 */
1842void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
1843
1844/*
1845 * memory_region_set_address: dynamically update the address of a region
1846 *
1847 * Dynamically updates the address of a region, relative to its container.
1848 * May be used on regions are currently part of a memory hierarchy.
1849 *
1850 * @mr: the region to be updated
1851 * @addr: new address, relative to container region
1852 */
1853void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
1854
1855/*
1856 * memory_region_set_size: dynamically update the size of a region.
1857 *
1858 * Dynamically updates the size of a region.
1859 *
1860 * @mr: the region to be updated
1861 * @size: used size of the region.
1862 */
1863void memory_region_set_size(MemoryRegion *mr, uint64_t size);
1864
1865/*
1866 * memory_region_set_alias_offset: dynamically update a memory alias's offset
1867 *
1868 * Dynamically updates the offset into the target region that an alias points
1869 * to, as if the fourth argument to memory_region_init_alias() has changed.
1870 *
1871 * @mr: the #MemoryRegion to be updated; should be an alias.
1872 * @offset: the new offset into the target memory region
1873 */
1874void memory_region_set_alias_offset(MemoryRegion *mr,
1875                                    hwaddr offset);
1876
1877/**
1878 * memory_region_present: checks if an address relative to a @container
1879 * translates into #MemoryRegion within @container
1880 *
1881 * Answer whether a #MemoryRegion within @container covers the address
1882 * @addr.
1883 *
1884 * @container: a #MemoryRegion within which @addr is a relative address
1885 * @addr: the area within @container to be searched
1886 */
1887bool memory_region_present(MemoryRegion *container, hwaddr addr);
1888
1889/**
1890 * memory_region_is_mapped: returns true if #MemoryRegion is mapped
1891 * into any address space.
1892 *
1893 * @mr: a #MemoryRegion which should be checked if it's mapped
1894 */
1895bool memory_region_is_mapped(MemoryRegion *mr);
1896
1897/**
1898 * memory_region_find: translate an address/size relative to a
1899 * MemoryRegion into a #MemoryRegionSection.
1900 *
1901 * Locates the first #MemoryRegion within @mr that overlaps the range
1902 * given by @addr and @size.
1903 *
1904 * Returns a #MemoryRegionSection that describes a contiguous overlap.
1905 * It will have the following characteristics:
1906 * - @size = 0 iff no overlap was found
1907 * - @mr is non-%NULL iff an overlap was found
1908 *
1909 * Remember that in the return value the @offset_within_region is
1910 * relative to the returned region (in the .@mr field), not to the
1911 * @mr argument.
1912 *
1913 * Similarly, the .@offset_within_address_space is relative to the
1914 * address space that contains both regions, the passed and the
1915 * returned one.  However, in the special case where the @mr argument
1916 * has no container (and thus is the root of the address space), the
1917 * following will hold:
1918 * - @offset_within_address_space >= @addr
1919 * - @offset_within_address_space + .@size <= @addr + @size
1920 *
1921 * @mr: a MemoryRegion within which @addr is a relative address
1922 * @addr: start of the area within @as to be searched
1923 * @size: size of the area to be searched
1924 */
1925MemoryRegionSection memory_region_find(MemoryRegion *mr,
1926                                       hwaddr addr, uint64_t size);
1927
1928/**
1929 * memory_global_dirty_log_sync: synchronize the dirty log for all memory
1930 *
1931 * Synchronizes the dirty page log for all address spaces.
1932 */
1933void memory_global_dirty_log_sync(void);
1934
1935/**
1936 * memory_global_dirty_log_sync: synchronize the dirty log for all memory
1937 *
1938 * Synchronizes the vCPUs with a thread that is reading the dirty bitmap.
1939 * This function must be called after the dirty log bitmap is cleared, and
1940 * before dirty guest memory pages are read.  If you are using
1941 * #DirtyBitmapSnapshot, memory_region_snapshot_and_clear_dirty() takes
1942 * care of doing this.
1943 */
1944void memory_global_after_dirty_log_sync(void);
1945
1946/**
1947 * memory_region_transaction_begin: Start a transaction.
1948 *
1949 * During a transaction, changes will be accumulated and made visible
1950 * only when the transaction ends (is committed).
1951 */
1952void memory_region_transaction_begin(void);
1953
1954/**
1955 * memory_region_transaction_commit: Commit a transaction and make changes
1956 *                                   visible to the guest.
1957 */
1958void memory_region_transaction_commit(void);
1959
1960/**
1961 * memory_listener_register: register callbacks to be called when memory
1962 *                           sections are mapped or unmapped into an address
1963 *                           space
1964 *
1965 * @listener: an object containing the callbacks to be called
1966 * @filter: if non-%NULL, only regions in this address space will be observed
1967 */
1968void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
1969
1970/**
1971 * memory_listener_unregister: undo the effect of memory_listener_register()
1972 *
1973 * @listener: an object containing the callbacks to be removed
1974 */
1975void memory_listener_unregister(MemoryListener *listener);
1976
1977/**
1978 * memory_global_dirty_log_start: begin dirty logging for all regions
1979 */
1980void memory_global_dirty_log_start(void);
1981
1982/**
1983 * memory_global_dirty_log_stop: end dirty logging for all regions
1984 */
1985void memory_global_dirty_log_stop(void);
1986
1987void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled);
1988
1989/**
1990 * memory_region_dispatch_read: perform a read directly to the specified
1991 * MemoryRegion.
1992 *
1993 * @mr: #MemoryRegion to access
1994 * @addr: address within that region
1995 * @pval: pointer to uint64_t which the data is written to
1996 * @op: size, sign, and endianness of the memory operation
1997 * @attrs: memory transaction attributes to use for the access
1998 */
1999MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
2000                                        hwaddr addr,
2001                                        uint64_t *pval,
2002                                        MemOp op,
2003                                        MemTxAttrs attrs);
2004/**
2005 * memory_region_dispatch_write: perform a write directly to the specified
2006 * MemoryRegion.
2007 *
2008 * @mr: #MemoryRegion to access
2009 * @addr: address within that region
2010 * @data: data to write
2011 * @op: size, sign, and endianness of the memory operation
2012 * @attrs: memory transaction attributes to use for the access
2013 */
2014MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
2015                                         hwaddr addr,
2016                                         uint64_t data,
2017                                         MemOp op,
2018                                         MemTxAttrs attrs);
2019
2020/**
2021 * address_space_init: initializes an address space
2022 *
2023 * @as: an uninitialized #AddressSpace
2024 * @root: a #MemoryRegion that routes addresses for the address space
2025 * @name: an address space name.  The name is only used for debugging
2026 *        output.
2027 */
2028void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
2029
2030/**
2031 * address_space_destroy: destroy an address space
2032 *
2033 * Releases all resources associated with an address space.  After an address space
2034 * is destroyed, its root memory region (given by address_space_init()) may be destroyed
2035 * as well.
2036 *
2037 * @as: address space to be destroyed
2038 */
2039void address_space_destroy(AddressSpace *as);
2040
2041/**
2042 * address_space_remove_listeners: unregister all listeners of an address space
2043 *
2044 * Removes all callbacks previously registered with memory_listener_register()
2045 * for @as.
2046 *
2047 * @as: an initialized #AddressSpace
2048 */
2049void address_space_remove_listeners(AddressSpace *as);
2050
2051/**
2052 * address_space_rw: read from or write to an address space.
2053 *
2054 * Return a MemTxResult indicating whether the operation succeeded
2055 * or failed (eg unassigned memory, device rejected the transaction,
2056 * IOMMU fault).
2057 *
2058 * @as: #AddressSpace to be accessed
2059 * @addr: address within that address space
2060 * @attrs: memory transaction attributes
2061 * @buf: buffer with the data transferred
2062 * @len: the number of bytes to read or write
2063 * @is_write: indicates the transfer direction
2064 */
2065MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
2066                             MemTxAttrs attrs, void *buf,
2067                             hwaddr len, bool is_write);
2068
2069/**
2070 * address_space_write: write to address space.
2071 *
2072 * Return a MemTxResult indicating whether the operation succeeded
2073 * or failed (eg unassigned memory, device rejected the transaction,
2074 * IOMMU fault).
2075 *
2076 * @as: #AddressSpace to be accessed
2077 * @addr: address within that address space
2078 * @attrs: memory transaction attributes
2079 * @buf: buffer with the data transferred
2080 * @len: the number of bytes to write
2081 */
2082MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
2083                                MemTxAttrs attrs,
2084                                const void *buf, hwaddr len);
2085
2086/**
2087 * address_space_write_rom: write to address space, including ROM.
2088 *
2089 * This function writes to the specified address space, but will
2090 * write data to both ROM and RAM. This is used for non-guest
2091 * writes like writes from the gdb debug stub or initial loading
2092 * of ROM contents.
2093 *
2094 * Note that portions of the write which attempt to write data to
2095 * a device will be silently ignored -- only real RAM and ROM will
2096 * be written to.
2097 *
2098 * Return a MemTxResult indicating whether the operation succeeded
2099 * or failed (eg unassigned memory, device rejected the transaction,
2100 * IOMMU fault).
2101 *
2102 * @as: #AddressSpace to be accessed
2103 * @addr: address within that address space
2104 * @attrs: memory transaction attributes
2105 * @buf: buffer with the data transferred
2106 * @len: the number of bytes to write
2107 */
2108MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
2109                                    MemTxAttrs attrs,
2110                                    const void *buf, hwaddr len);
2111
2112/* address_space_ld*: load from an address space
2113 * address_space_st*: store to an address space
2114 *
2115 * These functions perform a load or store of the byte, word,
2116 * longword or quad to the specified address within the AddressSpace.
2117 * The _le suffixed functions treat the data as little endian;
2118 * _be indicates big endian; no suffix indicates "same endianness
2119 * as guest CPU".
2120 *
2121 * The "guest CPU endianness" accessors are deprecated for use outside
2122 * target-* code; devices should be CPU-agnostic and use either the LE
2123 * or the BE accessors.
2124 *
2125 * @as #AddressSpace to be accessed
2126 * @addr: address within that address space
2127 * @val: data value, for stores
2128 * @attrs: memory transaction attributes
2129 * @result: location to write the success/failure of the transaction;
2130 *   if NULL, this information is discarded
2131 */
2132
2133#define SUFFIX
2134#define ARG1         as
2135#define ARG1_DECL    AddressSpace *as
2136#include "exec/memory_ldst.inc.h"
2137
2138#define SUFFIX
2139#define ARG1         as
2140#define ARG1_DECL    AddressSpace *as
2141#include "exec/memory_ldst_phys.inc.h"
2142
2143struct MemoryRegionCache {
2144    void *ptr;
2145    hwaddr xlat;
2146    hwaddr len;
2147    FlatView *fv;
2148    MemoryRegionSection mrs;
2149    bool is_write;
2150};
2151
2152#define MEMORY_REGION_CACHE_INVALID ((MemoryRegionCache) { .mrs.mr = NULL })
2153
2154
2155/* address_space_ld*_cached: load from a cached #MemoryRegion
2156 * address_space_st*_cached: store into a cached #MemoryRegion
2157 *
2158 * These functions perform a load or store of the byte, word,
2159 * longword or quad to the specified address.  The address is
2160 * a physical address in the AddressSpace, but it must lie within
2161 * a #MemoryRegion that was mapped with address_space_cache_init.
2162 *
2163 * The _le suffixed functions treat the data as little endian;
2164 * _be indicates big endian; no suffix indicates "same endianness
2165 * as guest CPU".
2166 *
2167 * The "guest CPU endianness" accessors are deprecated for use outside
2168 * target-* code; devices should be CPU-agnostic and use either the LE
2169 * or the BE accessors.
2170 *
2171 * @cache: previously initialized #MemoryRegionCache to be accessed
2172 * @addr: address within the address space
2173 * @val: data value, for stores
2174 * @attrs: memory transaction attributes
2175 * @result: location to write the success/failure of the transaction;
2176 *   if NULL, this information is discarded
2177 */
2178
2179#define SUFFIX       _cached_slow
2180#define ARG1         cache
2181#define ARG1_DECL    MemoryRegionCache *cache
2182#include "exec/memory_ldst.inc.h"
2183
2184/* Inline fast path for direct RAM access.  */
2185static inline uint8_t address_space_ldub_cached(MemoryRegionCache *cache,
2186    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
2187{
2188    assert(addr < cache->len);
2189    if (likely(cache->ptr)) {
2190        return ldub_p(cache->ptr + addr);
2191    } else {
2192        return address_space_ldub_cached_slow(cache, addr, attrs, result);
2193    }
2194}
2195
2196static inline void address_space_stb_cached(MemoryRegionCache *cache,
2197    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
2198{
2199    assert(addr < cache->len);
2200    if (likely(cache->ptr)) {
2201        stb_p(cache->ptr + addr, val);
2202    } else {
2203        address_space_stb_cached_slow(cache, addr, val, attrs, result);
2204    }
2205}
2206
2207#define ENDIANNESS   _le
2208#include "exec/memory_ldst_cached.inc.h"
2209
2210#define ENDIANNESS   _be
2211#include "exec/memory_ldst_cached.inc.h"
2212
2213#define SUFFIX       _cached
2214#define ARG1         cache
2215#define ARG1_DECL    MemoryRegionCache *cache
2216#include "exec/memory_ldst_phys.inc.h"
2217
2218/* address_space_cache_init: prepare for repeated access to a physical
2219 * memory region
2220 *
2221 * @cache: #MemoryRegionCache to be filled
2222 * @as: #AddressSpace to be accessed
2223 * @addr: address within that address space
2224 * @len: length of buffer
2225 * @is_write: indicates the transfer direction
2226 *
2227 * Will only work with RAM, and may map a subset of the requested range by
2228 * returning a value that is less than @len.  On failure, return a negative
2229 * errno value.
2230 *
2231 * Because it only works with RAM, this function can be used for
2232 * read-modify-write operations.  In this case, is_write should be %true.
2233 *
2234 * Note that addresses passed to the address_space_*_cached functions
2235 * are relative to @addr.
2236 */
2237int64_t address_space_cache_init(MemoryRegionCache *cache,
2238                                 AddressSpace *as,
2239                                 hwaddr addr,
2240                                 hwaddr len,
2241                                 bool is_write);
2242
2243/**
2244 * address_space_cache_invalidate: complete a write to a #MemoryRegionCache
2245 *
2246 * @cache: The #MemoryRegionCache to operate on.
2247 * @addr: The first physical address that was written, relative to the
2248 * address that was passed to @address_space_cache_init.
2249 * @access_len: The number of bytes that were written starting at @addr.
2250 */
2251void address_space_cache_invalidate(MemoryRegionCache *cache,
2252                                    hwaddr addr,
2253                                    hwaddr access_len);
2254
2255/**
2256 * address_space_cache_destroy: free a #MemoryRegionCache
2257 *
2258 * @cache: The #MemoryRegionCache whose memory should be released.
2259 */
2260void address_space_cache_destroy(MemoryRegionCache *cache);
2261
2262/* address_space_get_iotlb_entry: translate an address into an IOTLB
2263 * entry. Should be called from an RCU critical section.
2264 */
2265IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
2266                                            bool is_write, MemTxAttrs attrs);
2267
2268/* address_space_translate: translate an address range into an address space
2269 * into a MemoryRegion and an address range into that section.  Should be
2270 * called from an RCU critical section, to avoid that the last reference
2271 * to the returned region disappears after address_space_translate returns.
2272 *
2273 * @fv: #FlatView to be accessed
2274 * @addr: address within that address space
2275 * @xlat: pointer to address within the returned memory region section's
2276 * #MemoryRegion.
2277 * @len: pointer to length
2278 * @is_write: indicates the transfer direction
2279 * @attrs: memory attributes
2280 */
2281MemoryRegion *flatview_translate(FlatView *fv,
2282                                 hwaddr addr, hwaddr *xlat,
2283                                 hwaddr *len, bool is_write,
2284                                 MemTxAttrs attrs);
2285
2286static inline MemoryRegion *address_space_translate(AddressSpace *as,
2287                                                    hwaddr addr, hwaddr *xlat,
2288                                                    hwaddr *len, bool is_write,
2289                                                    MemTxAttrs attrs)
2290{
2291    return flatview_translate(address_space_to_flatview(as),
2292                              addr, xlat, len, is_write, attrs);
2293}
2294
2295/* address_space_access_valid: check for validity of accessing an address
2296 * space range
2297 *
2298 * Check whether memory is assigned to the given address space range, and
2299 * access is permitted by any IOMMU regions that are active for the address
2300 * space.
2301 *
2302 * For now, addr and len should be aligned to a page size.  This limitation
2303 * will be lifted in the future.
2304 *
2305 * @as: #AddressSpace to be accessed
2306 * @addr: address within that address space
2307 * @len: length of the area to be checked
2308 * @is_write: indicates the transfer direction
2309 * @attrs: memory attributes
2310 */
2311bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
2312                                bool is_write, MemTxAttrs attrs);
2313
2314/* address_space_map: map a physical memory region into a host virtual address
2315 *
2316 * May map a subset of the requested range, given by and returned in @plen.
2317 * May return %NULL and set *@plen to zero(0), if resources needed to perform
2318 * the mapping are exhausted.
2319 * Use only for reads OR writes - not for read-modify-write operations.
2320 * Use cpu_register_map_client() to know when retrying the map operation is
2321 * likely to succeed.
2322 *
2323 * @as: #AddressSpace to be accessed
2324 * @addr: address within that address space
2325 * @plen: pointer to length of buffer; updated on return
2326 * @is_write: indicates the transfer direction
2327 * @attrs: memory attributes
2328 */
2329void *address_space_map(AddressSpace *as, hwaddr addr,
2330                        hwaddr *plen, bool is_write, MemTxAttrs attrs);
2331
2332/* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
2333 *
2334 * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
2335 * the amount of memory that was actually read or written by the caller.
2336 *
2337 * @as: #AddressSpace used
2338 * @buffer: host pointer as returned by address_space_map()
2339 * @len: buffer length as returned by address_space_map()
2340 * @access_len: amount of data actually transferred
2341 * @is_write: indicates the transfer direction
2342 */
2343void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
2344                         bool is_write, hwaddr access_len);
2345
2346
2347/* Internal functions, part of the implementation of address_space_read.  */
2348MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
2349                                    MemTxAttrs attrs, void *buf, hwaddr len);
2350MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
2351                                   MemTxAttrs attrs, void *buf,
2352                                   hwaddr len, hwaddr addr1, hwaddr l,
2353                                   MemoryRegion *mr);
2354void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr);
2355
2356/* Internal functions, part of the implementation of address_space_read_cached
2357 * and address_space_write_cached.  */
2358MemTxResult address_space_read_cached_slow(MemoryRegionCache *cache,
2359                                           hwaddr addr, void *buf, hwaddr len);
2360MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
2361                                            hwaddr addr, const void *buf,
2362                                            hwaddr len);
2363
2364static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
2365{
2366    if (is_write) {
2367        return memory_region_is_ram(mr) && !mr->readonly &&
2368               !mr->rom_device && !memory_region_is_ram_device(mr);
2369    } else {
2370        return (memory_region_is_ram(mr) && !memory_region_is_ram_device(mr)) ||
2371               memory_region_is_romd(mr);
2372    }
2373}
2374
2375/**
2376 * address_space_read: read from an address space.
2377 *
2378 * Return a MemTxResult indicating whether the operation succeeded
2379 * or failed (eg unassigned memory, device rejected the transaction,
2380 * IOMMU fault).  Called within RCU critical section.
2381 *
2382 * @as: #AddressSpace to be accessed
2383 * @addr: address within that address space
2384 * @attrs: memory transaction attributes
2385 * @buf: buffer with the data transferred
2386 * @len: length of the data transferred
2387 */
2388static inline __attribute__((__always_inline__))
2389MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
2390                               MemTxAttrs attrs, void *buf,
2391                               hwaddr len)
2392{
2393    MemTxResult result = MEMTX_OK;
2394    hwaddr l, addr1;
2395    void *ptr;
2396    MemoryRegion *mr;
2397    FlatView *fv;
2398
2399    if (__builtin_constant_p(len)) {
2400        if (len) {
2401            RCU_READ_LOCK_GUARD();
2402            fv = address_space_to_flatview(as);
2403            l = len;
2404            mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
2405            if (len == l && memory_access_is_direct(mr, false)) {
2406                ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
2407                memcpy(buf, ptr, len);
2408            } else {
2409                result = flatview_read_continue(fv, addr, attrs, buf, len,
2410                                                addr1, l, mr);
2411            }
2412        }
2413    } else {
2414        result = address_space_read_full(as, addr, attrs, buf, len);
2415    }
2416    return result;
2417}
2418
2419/**
2420 * address_space_read_cached: read from a cached RAM region
2421 *
2422 * @cache: Cached region to be addressed
2423 * @addr: address relative to the base of the RAM region
2424 * @buf: buffer with the data transferred
2425 * @len: length of the data transferred
2426 */
2427static inline MemTxResult
2428address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
2429                          void *buf, hwaddr len)
2430{
2431    assert(addr < cache->len && len <= cache->len - addr);
2432    if (likely(cache->ptr)) {
2433        memcpy(buf, cache->ptr + addr, len);
2434        return MEMTX_OK;
2435    } else {
2436        return address_space_read_cached_slow(cache, addr, buf, len);
2437    }
2438}
2439
2440/**
2441 * address_space_write_cached: write to a cached RAM region
2442 *
2443 * @cache: Cached region to be addressed
2444 * @addr: address relative to the base of the RAM region
2445 * @buf: buffer with the data transferred
2446 * @len: length of the data transferred
2447 */
2448static inline MemTxResult
2449address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
2450                           const void *buf, hwaddr len)
2451{
2452    assert(addr < cache->len && len <= cache->len - addr);
2453    if (likely(cache->ptr)) {
2454        memcpy(cache->ptr + addr, buf, len);
2455        return MEMTX_OK;
2456    } else {
2457        return address_space_write_cached_slow(cache, addr, buf, len);
2458    }
2459}
2460
2461#ifdef NEED_CPU_H
2462/* enum device_endian to MemOp.  */
2463static inline MemOp devend_memop(enum device_endian end)
2464{
2465    QEMU_BUILD_BUG_ON(DEVICE_HOST_ENDIAN != DEVICE_LITTLE_ENDIAN &&
2466                      DEVICE_HOST_ENDIAN != DEVICE_BIG_ENDIAN);
2467
2468#if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
2469    /* Swap if non-host endianness or native (target) endianness */
2470    return (end == DEVICE_HOST_ENDIAN) ? 0 : MO_BSWAP;
2471#else
2472    const int non_host_endianness =
2473        DEVICE_LITTLE_ENDIAN ^ DEVICE_BIG_ENDIAN ^ DEVICE_HOST_ENDIAN;
2474
2475    /* In this case, native (target) endianness needs no swap.  */
2476    return (end == non_host_endianness) ? MO_BSWAP : 0;
2477#endif
2478}
2479#endif
2480
2481/*
2482 * Inhibit technologies that require discarding of pages in RAM blocks, e.g.,
2483 * to manage the actual amount of memory consumed by the VM (then, the memory
2484 * provided by RAM blocks might be bigger than the desired memory consumption).
2485 * This *must* be set if:
2486 * - Discarding parts of a RAM blocks does not result in the change being
2487 *   reflected in the VM and the pages getting freed.
2488 * - All memory in RAM blocks is pinned or duplicated, invaldiating any previous
2489 *   discards blindly.
2490 * - Discarding parts of a RAM blocks will result in integrity issues (e.g.,
2491 *   encrypted VMs).
2492 * Technologies that only temporarily pin the current working set of a
2493 * driver are fine, because we don't expect such pages to be discarded
2494 * (esp. based on guest action like balloon inflation).
2495 *
2496 * This is *not* to be used to protect from concurrent discards (esp.,
2497 * postcopy).
2498 *
2499 * Returns 0 if successful. Returns -EBUSY if a technology that relies on
2500 * discards to work reliably is active.
2501 */
2502int ram_block_discard_disable(bool state);
2503
2504/*
2505 * Inhibit technologies that disable discarding of pages in RAM blocks.
2506 *
2507 * Returns 0 if successful. Returns -EBUSY if discards are already set to
2508 * broken.
2509 */
2510int ram_block_discard_require(bool state);
2511
2512/*
2513 * Test if discarding of memory in ram blocks is disabled.
2514 */
2515bool ram_block_discard_is_disabled(void);
2516
2517/*
2518 * Test if discarding of memory in ram blocks is required to work reliably.
2519 */
2520bool ram_block_discard_is_required(void);
2521
2522#endif
2523
2524#endif
2525