xref: /openbmc/qemu/include/exec/memory.h (revision 76f4afb4)
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 #define DIRTY_MEMORY_VGA       0
20 #define DIRTY_MEMORY_CODE      1
21 #define DIRTY_MEMORY_MIGRATION 2
22 #define DIRTY_MEMORY_NUM       3        /* num of dirty bits */
23 
24 #include <stdint.h>
25 #include <stdbool.h>
26 #include "qemu-common.h"
27 #include "exec/cpu-common.h"
28 #ifndef CONFIG_USER_ONLY
29 #include "exec/hwaddr.h"
30 #endif
31 #include "exec/memattrs.h"
32 #include "qemu/queue.h"
33 #include "qemu/int128.h"
34 #include "qemu/notify.h"
35 #include "qapi/error.h"
36 #include "qom/object.h"
37 #include "qemu/rcu.h"
38 
39 #define MAX_PHYS_ADDR_SPACE_BITS 62
40 #define MAX_PHYS_ADDR            (((hwaddr)1 << MAX_PHYS_ADDR_SPACE_BITS) - 1)
41 
42 #define TYPE_MEMORY_REGION "qemu:memory-region"
43 #define MEMORY_REGION(obj) \
44         OBJECT_CHECK(MemoryRegion, (obj), TYPE_MEMORY_REGION)
45 
46 typedef struct MemoryRegionOps MemoryRegionOps;
47 typedef struct MemoryRegionMmio MemoryRegionMmio;
48 
49 struct MemoryRegionMmio {
50     CPUReadMemoryFunc *read[3];
51     CPUWriteMemoryFunc *write[3];
52 };
53 
54 typedef struct IOMMUTLBEntry IOMMUTLBEntry;
55 
56 /* See address_space_translate: bit 0 is read, bit 1 is write.  */
57 typedef enum {
58     IOMMU_NONE = 0,
59     IOMMU_RO   = 1,
60     IOMMU_WO   = 2,
61     IOMMU_RW   = 3,
62 } IOMMUAccessFlags;
63 
64 struct IOMMUTLBEntry {
65     AddressSpace    *target_as;
66     hwaddr           iova;
67     hwaddr           translated_addr;
68     hwaddr           addr_mask;  /* 0xfff = 4k translation */
69     IOMMUAccessFlags perm;
70 };
71 
72 /* New-style MMIO accessors can indicate that the transaction failed.
73  * A zero (MEMTX_OK) response means success; anything else is a failure
74  * of some kind. The memory subsystem will bitwise-OR together results
75  * if it is synthesizing an operation from multiple smaller accesses.
76  */
77 #define MEMTX_OK 0
78 #define MEMTX_ERROR             (1U << 0) /* device returned an error */
79 #define MEMTX_DECODE_ERROR      (1U << 1) /* nothing at that address */
80 typedef uint32_t MemTxResult;
81 
82 /*
83  * Memory region callbacks
84  */
85 struct MemoryRegionOps {
86     /* Read from the memory region. @addr is relative to @mr; @size is
87      * in bytes. */
88     uint64_t (*read)(void *opaque,
89                      hwaddr addr,
90                      unsigned size);
91     /* Write to the memory region. @addr is relative to @mr; @size is
92      * in bytes. */
93     void (*write)(void *opaque,
94                   hwaddr addr,
95                   uint64_t data,
96                   unsigned size);
97 
98     MemTxResult (*read_with_attrs)(void *opaque,
99                                    hwaddr addr,
100                                    uint64_t *data,
101                                    unsigned size,
102                                    MemTxAttrs attrs);
103     MemTxResult (*write_with_attrs)(void *opaque,
104                                     hwaddr addr,
105                                     uint64_t data,
106                                     unsigned size,
107                                     MemTxAttrs attrs);
108 
109     enum device_endian endianness;
110     /* Guest-visible constraints: */
111     struct {
112         /* If nonzero, specify bounds on access sizes beyond which a machine
113          * check is thrown.
114          */
115         unsigned min_access_size;
116         unsigned max_access_size;
117         /* If true, unaligned accesses are supported.  Otherwise unaligned
118          * accesses throw machine checks.
119          */
120          bool unaligned;
121         /*
122          * If present, and returns #false, the transaction is not accepted
123          * by the device (and results in machine dependent behaviour such
124          * as a machine check exception).
125          */
126         bool (*accepts)(void *opaque, hwaddr addr,
127                         unsigned size, bool is_write);
128     } valid;
129     /* Internal implementation constraints: */
130     struct {
131         /* If nonzero, specifies the minimum size implemented.  Smaller sizes
132          * will be rounded upwards and a partial result will be returned.
133          */
134         unsigned min_access_size;
135         /* If nonzero, specifies the maximum size implemented.  Larger sizes
136          * will be done as a series of accesses with smaller sizes.
137          */
138         unsigned max_access_size;
139         /* If true, unaligned accesses are supported.  Otherwise all accesses
140          * are converted to (possibly multiple) naturally aligned accesses.
141          */
142         bool unaligned;
143     } impl;
144 
145     /* If .read and .write are not present, old_mmio may be used for
146      * backwards compatibility with old mmio registration
147      */
148     const MemoryRegionMmio old_mmio;
149 };
150 
151 typedef struct MemoryRegionIOMMUOps MemoryRegionIOMMUOps;
152 
153 struct MemoryRegionIOMMUOps {
154     /* Return a TLB entry that contains a given address. */
155     IOMMUTLBEntry (*translate)(MemoryRegion *iommu, hwaddr addr, bool is_write);
156 };
157 
158 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
159 typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
160 
161 struct MemoryRegion {
162     Object parent_obj;
163     /* All fields are private - violators will be prosecuted */
164     const MemoryRegionOps *ops;
165     const MemoryRegionIOMMUOps *iommu_ops;
166     void *opaque;
167     MemoryRegion *container;
168     Int128 size;
169     hwaddr addr;
170     void (*destructor)(MemoryRegion *mr);
171     ram_addr_t ram_addr;
172     uint64_t align;
173     bool subpage;
174     bool terminates;
175     bool romd_mode;
176     bool ram;
177     bool skip_dump;
178     bool readonly; /* For RAM regions */
179     bool enabled;
180     bool rom_device;
181     bool warning_printed; /* For reservations */
182     bool flush_coalesced_mmio;
183     MemoryRegion *alias;
184     hwaddr alias_offset;
185     int32_t priority;
186     bool may_overlap;
187     QTAILQ_HEAD(subregions, MemoryRegion) subregions;
188     QTAILQ_ENTRY(MemoryRegion) subregions_link;
189     QTAILQ_HEAD(coalesced_ranges, CoalescedMemoryRange) coalesced;
190     const char *name;
191     uint8_t dirty_log_mask;
192     unsigned ioeventfd_nb;
193     MemoryRegionIoeventfd *ioeventfds;
194     NotifierList iommu_notify;
195 };
196 
197 /**
198  * MemoryListener: callbacks structure for updates to the physical memory map
199  *
200  * Allows a component to adjust to changes in the guest-visible memory map.
201  * Use with memory_listener_register() and memory_listener_unregister().
202  */
203 struct MemoryListener {
204     void (*begin)(MemoryListener *listener);
205     void (*commit)(MemoryListener *listener);
206     void (*region_add)(MemoryListener *listener, MemoryRegionSection *section);
207     void (*region_del)(MemoryListener *listener, MemoryRegionSection *section);
208     void (*region_nop)(MemoryListener *listener, MemoryRegionSection *section);
209     void (*log_start)(MemoryListener *listener, MemoryRegionSection *section,
210                       int old, int new);
211     void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section,
212                      int old, int new);
213     void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
214     void (*log_global_start)(MemoryListener *listener);
215     void (*log_global_stop)(MemoryListener *listener);
216     void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
217                         bool match_data, uint64_t data, EventNotifier *e);
218     void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
219                         bool match_data, uint64_t data, EventNotifier *e);
220     void (*coalesced_mmio_add)(MemoryListener *listener, MemoryRegionSection *section,
221                                hwaddr addr, hwaddr len);
222     void (*coalesced_mmio_del)(MemoryListener *listener, MemoryRegionSection *section,
223                                hwaddr addr, hwaddr len);
224     /* Lower = earlier (during add), later (during del) */
225     unsigned priority;
226     AddressSpace *address_space_filter;
227     QTAILQ_ENTRY(MemoryListener) link;
228 };
229 
230 /**
231  * AddressSpace: describes a mapping of addresses to #MemoryRegion objects
232  */
233 struct AddressSpace {
234     /* All fields are private. */
235     struct rcu_head rcu;
236     char *name;
237     MemoryRegion *root;
238 
239     /* Accessed via RCU.  */
240     struct FlatView *current_map;
241 
242     int ioeventfd_nb;
243     struct MemoryRegionIoeventfd *ioeventfds;
244     struct AddressSpaceDispatch *dispatch;
245     struct AddressSpaceDispatch *next_dispatch;
246     MemoryListener dispatch_listener;
247 
248     QTAILQ_ENTRY(AddressSpace) address_spaces_link;
249 };
250 
251 /**
252  * MemoryRegionSection: describes a fragment of a #MemoryRegion
253  *
254  * @mr: the region, or %NULL if empty
255  * @address_space: the address space the region is mapped in
256  * @offset_within_region: the beginning of the section, relative to @mr's start
257  * @size: the size of the section; will not exceed @mr's boundaries
258  * @offset_within_address_space: the address of the first byte of the section
259  *     relative to the region's address space
260  * @readonly: writes to this section are ignored
261  */
262 struct MemoryRegionSection {
263     MemoryRegion *mr;
264     AddressSpace *address_space;
265     hwaddr offset_within_region;
266     Int128 size;
267     hwaddr offset_within_address_space;
268     bool readonly;
269 };
270 
271 /**
272  * memory_region_init: Initialize a memory region
273  *
274  * The region typically acts as a container for other memory regions.  Use
275  * memory_region_add_subregion() to add subregions.
276  *
277  * @mr: the #MemoryRegion to be initialized
278  * @owner: the object that tracks the region's reference count
279  * @name: used for debugging; not visible to the user or ABI
280  * @size: size of the region; any subregions beyond this size will be clipped
281  */
282 void memory_region_init(MemoryRegion *mr,
283                         struct Object *owner,
284                         const char *name,
285                         uint64_t size);
286 
287 /**
288  * memory_region_ref: Add 1 to a memory region's reference count
289  *
290  * Whenever memory regions are accessed outside the BQL, they need to be
291  * preserved against hot-unplug.  MemoryRegions actually do not have their
292  * own reference count; they piggyback on a QOM object, their "owner".
293  * This function adds a reference to the owner.
294  *
295  * All MemoryRegions must have an owner if they can disappear, even if the
296  * device they belong to operates exclusively under the BQL.  This is because
297  * the region could be returned at any time by memory_region_find, and this
298  * is usually under guest control.
299  *
300  * @mr: the #MemoryRegion
301  */
302 void memory_region_ref(MemoryRegion *mr);
303 
304 /**
305  * memory_region_unref: Remove 1 to a memory region's reference count
306  *
307  * Whenever memory regions are accessed outside the BQL, they need to be
308  * preserved against hot-unplug.  MemoryRegions actually do not have their
309  * own reference count; they piggyback on a QOM object, their "owner".
310  * This function removes a reference to the owner and possibly destroys it.
311  *
312  * @mr: the #MemoryRegion
313  */
314 void memory_region_unref(MemoryRegion *mr);
315 
316 /**
317  * memory_region_init_io: Initialize an I/O memory region.
318  *
319  * Accesses into the region will cause the callbacks in @ops to be called.
320  * if @size is nonzero, subregions will be clipped to @size.
321  *
322  * @mr: the #MemoryRegion to be initialized.
323  * @owner: the object that tracks the region's reference count
324  * @ops: a structure containing read and write callbacks to be used when
325  *       I/O is performed on the region.
326  * @opaque: passed to to the read and write callbacks of the @ops structure.
327  * @name: used for debugging; not visible to the user or ABI
328  * @size: size of the region.
329  */
330 void memory_region_init_io(MemoryRegion *mr,
331                            struct Object *owner,
332                            const MemoryRegionOps *ops,
333                            void *opaque,
334                            const char *name,
335                            uint64_t size);
336 
337 /**
338  * memory_region_init_ram:  Initialize RAM memory region.  Accesses into the
339  *                          region will modify memory directly.
340  *
341  * @mr: the #MemoryRegion to be initialized.
342  * @owner: the object that tracks the region's reference count
343  * @name: the name of the region.
344  * @size: size of the region.
345  * @errp: pointer to Error*, to store an error if it happens.
346  */
347 void memory_region_init_ram(MemoryRegion *mr,
348                             struct Object *owner,
349                             const char *name,
350                             uint64_t size,
351                             Error **errp);
352 
353 /**
354  * memory_region_init_resizeable_ram:  Initialize memory region with resizeable
355  *                                     RAM.  Accesses into the region will
356  *                                     modify memory directly.  Only an initial
357  *                                     portion of this RAM is actually used.
358  *                                     The used size can change across reboots.
359  *
360  * @mr: the #MemoryRegion to be initialized.
361  * @owner: the object that tracks the region's reference count
362  * @name: the name of the region.
363  * @size: used size of the region.
364  * @max_size: max size of the region.
365  * @resized: callback to notify owner about used size change.
366  * @errp: pointer to Error*, to store an error if it happens.
367  */
368 void memory_region_init_resizeable_ram(MemoryRegion *mr,
369                                        struct Object *owner,
370                                        const char *name,
371                                        uint64_t size,
372                                        uint64_t max_size,
373                                        void (*resized)(const char*,
374                                                        uint64_t length,
375                                                        void *host),
376                                        Error **errp);
377 #ifdef __linux__
378 /**
379  * memory_region_init_ram_from_file:  Initialize RAM memory region with a
380  *                                    mmap-ed backend.
381  *
382  * @mr: the #MemoryRegion to be initialized.
383  * @owner: the object that tracks the region's reference count
384  * @name: the name of the region.
385  * @size: size of the region.
386  * @share: %true if memory must be mmaped with the MAP_SHARED flag
387  * @path: the path in which to allocate the RAM.
388  * @errp: pointer to Error*, to store an error if it happens.
389  */
390 void memory_region_init_ram_from_file(MemoryRegion *mr,
391                                       struct Object *owner,
392                                       const char *name,
393                                       uint64_t size,
394                                       bool share,
395                                       const char *path,
396                                       Error **errp);
397 #endif
398 
399 /**
400  * memory_region_init_ram_ptr:  Initialize RAM memory region from a
401  *                              user-provided pointer.  Accesses into the
402  *                              region will modify memory directly.
403  *
404  * @mr: the #MemoryRegion to be initialized.
405  * @owner: the object that tracks the region's reference count
406  * @name: the name of the region.
407  * @size: size of the region.
408  * @ptr: memory to be mapped; must contain at least @size bytes.
409  */
410 void memory_region_init_ram_ptr(MemoryRegion *mr,
411                                 struct Object *owner,
412                                 const char *name,
413                                 uint64_t size,
414                                 void *ptr);
415 
416 /**
417  * memory_region_init_alias: Initialize a memory region that aliases all or a
418  *                           part of another memory region.
419  *
420  * @mr: the #MemoryRegion to be initialized.
421  * @owner: the object that tracks the region's reference count
422  * @name: used for debugging; not visible to the user or ABI
423  * @orig: the region to be referenced; @mr will be equivalent to
424  *        @orig between @offset and @offset + @size - 1.
425  * @offset: start of the section in @orig to be referenced.
426  * @size: size of the region.
427  */
428 void memory_region_init_alias(MemoryRegion *mr,
429                               struct Object *owner,
430                               const char *name,
431                               MemoryRegion *orig,
432                               hwaddr offset,
433                               uint64_t size);
434 
435 /**
436  * memory_region_init_rom_device:  Initialize a ROM memory region.  Writes are
437  *                                 handled via callbacks.
438  *
439  * @mr: the #MemoryRegion to be initialized.
440  * @owner: the object that tracks the region's reference count
441  * @ops: callbacks for write access handling.
442  * @name: the name of the region.
443  * @size: size of the region.
444  * @errp: pointer to Error*, to store an error if it happens.
445  */
446 void memory_region_init_rom_device(MemoryRegion *mr,
447                                    struct Object *owner,
448                                    const MemoryRegionOps *ops,
449                                    void *opaque,
450                                    const char *name,
451                                    uint64_t size,
452                                    Error **errp);
453 
454 /**
455  * memory_region_init_reservation: Initialize a memory region that reserves
456  *                                 I/O space.
457  *
458  * A reservation region primariy serves debugging purposes.  It claims I/O
459  * space that is not supposed to be handled by QEMU itself.  Any access via
460  * the memory API will cause an abort().
461  *
462  * @mr: the #MemoryRegion to be initialized
463  * @owner: the object that tracks the region's reference count
464  * @name: used for debugging; not visible to the user or ABI
465  * @size: size of the region.
466  */
467 void memory_region_init_reservation(MemoryRegion *mr,
468                                     struct Object *owner,
469                                     const char *name,
470                                     uint64_t size);
471 
472 /**
473  * memory_region_init_iommu: Initialize a memory region that translates
474  * addresses
475  *
476  * An IOMMU region translates addresses and forwards accesses to a target
477  * memory region.
478  *
479  * @mr: the #MemoryRegion to be initialized
480  * @owner: the object that tracks the region's reference count
481  * @ops: a function that translates addresses into the @target region
482  * @name: used for debugging; not visible to the user or ABI
483  * @size: size of the region.
484  */
485 void memory_region_init_iommu(MemoryRegion *mr,
486                               struct Object *owner,
487                               const MemoryRegionIOMMUOps *ops,
488                               const char *name,
489                               uint64_t size);
490 
491 /**
492  * memory_region_owner: get a memory region's owner.
493  *
494  * @mr: the memory region being queried.
495  */
496 struct Object *memory_region_owner(MemoryRegion *mr);
497 
498 /**
499  * memory_region_size: get a memory region's size.
500  *
501  * @mr: the memory region being queried.
502  */
503 uint64_t memory_region_size(MemoryRegion *mr);
504 
505 /**
506  * memory_region_is_ram: check whether a memory region is random access
507  *
508  * Returns %true is a memory region is random access.
509  *
510  * @mr: the memory region being queried
511  */
512 bool memory_region_is_ram(MemoryRegion *mr);
513 
514 /**
515  * memory_region_is_skip_dump: check whether a memory region should not be
516  *                             dumped
517  *
518  * Returns %true is a memory region should not be dumped(e.g. VFIO BAR MMAP).
519  *
520  * @mr: the memory region being queried
521  */
522 bool memory_region_is_skip_dump(MemoryRegion *mr);
523 
524 /**
525  * memory_region_set_skip_dump: Set skip_dump flag, dump will ignore this memory
526  *                              region
527  *
528  * @mr: the memory region being queried
529  */
530 void memory_region_set_skip_dump(MemoryRegion *mr);
531 
532 /**
533  * memory_region_is_romd: check whether a memory region is in ROMD mode
534  *
535  * Returns %true if a memory region is a ROM device and currently set to allow
536  * direct reads.
537  *
538  * @mr: the memory region being queried
539  */
540 static inline bool memory_region_is_romd(MemoryRegion *mr)
541 {
542     return mr->rom_device && mr->romd_mode;
543 }
544 
545 /**
546  * memory_region_is_iommu: check whether a memory region is an iommu
547  *
548  * Returns %true is a memory region is an iommu.
549  *
550  * @mr: the memory region being queried
551  */
552 bool memory_region_is_iommu(MemoryRegion *mr);
553 
554 /**
555  * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
556  *
557  * @mr: the memory region that was changed
558  * @entry: the new entry in the IOMMU translation table.  The entry
559  *         replaces all old entries for the same virtual I/O address range.
560  *         Deleted entries have .@perm == 0.
561  */
562 void memory_region_notify_iommu(MemoryRegion *mr,
563                                 IOMMUTLBEntry entry);
564 
565 /**
566  * memory_region_register_iommu_notifier: register a notifier for changes to
567  * IOMMU translation entries.
568  *
569  * @mr: the memory region to observe
570  * @n: the notifier to be added; the notifier receives a pointer to an
571  *     #IOMMUTLBEntry as the opaque value; the pointer ceases to be
572  *     valid on exit from the notifier.
573  */
574 void memory_region_register_iommu_notifier(MemoryRegion *mr, Notifier *n);
575 
576 /**
577  * memory_region_unregister_iommu_notifier: unregister a notifier for
578  * changes to IOMMU translation entries.
579  *
580  * @n: the notifier to be removed.
581  */
582 void memory_region_unregister_iommu_notifier(Notifier *n);
583 
584 /**
585  * memory_region_name: get a memory region's name
586  *
587  * Returns the string that was used to initialize the memory region.
588  *
589  * @mr: the memory region being queried
590  */
591 const char *memory_region_name(const MemoryRegion *mr);
592 
593 /**
594  * memory_region_is_logging: return whether a memory region is logging writes
595  *
596  * Returns %true if the memory region is logging writes for the given client
597  *
598  * @mr: the memory region being queried
599  * @client: the client being queried
600  */
601 bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
602 
603 /**
604  * memory_region_get_dirty_log_mask: return the clients for which a
605  * memory region is logging writes.
606  *
607  * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
608  * are the bit indices.
609  *
610  * @mr: the memory region being queried
611  */
612 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
613 
614 /**
615  * memory_region_is_rom: check whether a memory region is ROM
616  *
617  * Returns %true is a memory region is read-only memory.
618  *
619  * @mr: the memory region being queried
620  */
621 bool memory_region_is_rom(MemoryRegion *mr);
622 
623 /**
624  * memory_region_get_fd: Get a file descriptor backing a RAM memory region.
625  *
626  * Returns a file descriptor backing a file-based RAM memory region,
627  * or -1 if the region is not a file-based RAM memory region.
628  *
629  * @mr: the RAM or alias memory region being queried.
630  */
631 int memory_region_get_fd(MemoryRegion *mr);
632 
633 /**
634  * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
635  *
636  * Returns a host pointer to a RAM memory region (created with
637  * memory_region_init_ram() or memory_region_init_ram_ptr()).  Use with
638  * care.
639  *
640  * @mr: the memory region being queried.
641  */
642 void *memory_region_get_ram_ptr(MemoryRegion *mr);
643 
644 /* memory_region_ram_resize: Resize a RAM region.
645  *
646  * Only legal before guest might have detected the memory size: e.g. on
647  * incoming migration, or right after reset.
648  *
649  * @mr: a memory region created with @memory_region_init_resizeable_ram.
650  * @newsize: the new size the region
651  * @errp: pointer to Error*, to store an error if it happens.
652  */
653 void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
654                               Error **errp);
655 
656 /**
657  * memory_region_set_log: Turn dirty logging on or off for a region.
658  *
659  * Turns dirty logging on or off for a specified client (display, migration).
660  * Only meaningful for RAM regions.
661  *
662  * @mr: the memory region being updated.
663  * @log: whether dirty logging is to be enabled or disabled.
664  * @client: the user of the logging information; %DIRTY_MEMORY_VGA only.
665  */
666 void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client);
667 
668 /**
669  * memory_region_get_dirty: Check whether a range of bytes is dirty
670  *                          for a specified client.
671  *
672  * Checks whether a range of bytes has been written to since the last
673  * call to memory_region_reset_dirty() with the same @client.  Dirty logging
674  * must be enabled.
675  *
676  * @mr: the memory region being queried.
677  * @addr: the address (relative to the start of the region) being queried.
678  * @size: the size of the range being queried.
679  * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
680  *          %DIRTY_MEMORY_VGA.
681  */
682 bool memory_region_get_dirty(MemoryRegion *mr, hwaddr addr,
683                              hwaddr size, unsigned client);
684 
685 /**
686  * memory_region_set_dirty: Mark a range of bytes as dirty in a memory region.
687  *
688  * Marks a range of bytes as dirty, after it has been dirtied outside
689  * guest code.
690  *
691  * @mr: the memory region being dirtied.
692  * @addr: the address (relative to the start of the region) being dirtied.
693  * @size: size of the range being dirtied.
694  */
695 void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
696                              hwaddr size);
697 
698 /**
699  * memory_region_test_and_clear_dirty: Check whether a range of bytes is dirty
700  *                                     for a specified client. It clears them.
701  *
702  * Checks whether a range of bytes has been written to since the last
703  * call to memory_region_reset_dirty() with the same @client.  Dirty logging
704  * must be enabled.
705  *
706  * @mr: the memory region being queried.
707  * @addr: the address (relative to the start of the region) being queried.
708  * @size: the size of the range being queried.
709  * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
710  *          %DIRTY_MEMORY_VGA.
711  */
712 bool memory_region_test_and_clear_dirty(MemoryRegion *mr, hwaddr addr,
713                                         hwaddr size, unsigned client);
714 /**
715  * memory_region_sync_dirty_bitmap: Synchronize a region's dirty bitmap with
716  *                                  any external TLBs (e.g. kvm)
717  *
718  * Flushes dirty information from accelerators such as kvm and vhost-net
719  * and makes it available to users of the memory API.
720  *
721  * @mr: the region being flushed.
722  */
723 void memory_region_sync_dirty_bitmap(MemoryRegion *mr);
724 
725 /**
726  * memory_region_reset_dirty: Mark a range of pages as clean, for a specified
727  *                            client.
728  *
729  * Marks a range of pages as no longer dirty.
730  *
731  * @mr: the region being updated.
732  * @addr: the start of the subrange being cleaned.
733  * @size: the size of the subrange being cleaned.
734  * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
735  *          %DIRTY_MEMORY_VGA.
736  */
737 void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
738                                hwaddr size, unsigned client);
739 
740 /**
741  * memory_region_set_readonly: Turn a memory region read-only (or read-write)
742  *
743  * Allows a memory region to be marked as read-only (turning it into a ROM).
744  * only useful on RAM regions.
745  *
746  * @mr: the region being updated.
747  * @readonly: whether rhe region is to be ROM or RAM.
748  */
749 void memory_region_set_readonly(MemoryRegion *mr, bool readonly);
750 
751 /**
752  * memory_region_rom_device_set_romd: enable/disable ROMD mode
753  *
754  * Allows a ROM device (initialized with memory_region_init_rom_device() to
755  * set to ROMD mode (default) or MMIO mode.  When it is in ROMD mode, the
756  * device is mapped to guest memory and satisfies read access directly.
757  * When in MMIO mode, reads are forwarded to the #MemoryRegion.read function.
758  * Writes are always handled by the #MemoryRegion.write function.
759  *
760  * @mr: the memory region to be updated
761  * @romd_mode: %true to put the region into ROMD mode
762  */
763 void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode);
764 
765 /**
766  * memory_region_set_coalescing: Enable memory coalescing for the region.
767  *
768  * Enabled writes to a region to be queued for later processing. MMIO ->write
769  * callbacks may be delayed until a non-coalesced MMIO is issued.
770  * Only useful for IO regions.  Roughly similar to write-combining hardware.
771  *
772  * @mr: the memory region to be write coalesced
773  */
774 void memory_region_set_coalescing(MemoryRegion *mr);
775 
776 /**
777  * memory_region_add_coalescing: Enable memory coalescing for a sub-range of
778  *                               a region.
779  *
780  * Like memory_region_set_coalescing(), but works on a sub-range of a region.
781  * Multiple calls can be issued coalesced disjoint ranges.
782  *
783  * @mr: the memory region to be updated.
784  * @offset: the start of the range within the region to be coalesced.
785  * @size: the size of the subrange to be coalesced.
786  */
787 void memory_region_add_coalescing(MemoryRegion *mr,
788                                   hwaddr offset,
789                                   uint64_t size);
790 
791 /**
792  * memory_region_clear_coalescing: Disable MMIO coalescing for the region.
793  *
794  * Disables any coalescing caused by memory_region_set_coalescing() or
795  * memory_region_add_coalescing().  Roughly equivalent to uncacheble memory
796  * hardware.
797  *
798  * @mr: the memory region to be updated.
799  */
800 void memory_region_clear_coalescing(MemoryRegion *mr);
801 
802 /**
803  * memory_region_set_flush_coalesced: Enforce memory coalescing flush before
804  *                                    accesses.
805  *
806  * Ensure that pending coalesced MMIO request are flushed before the memory
807  * region is accessed. This property is automatically enabled for all regions
808  * passed to memory_region_set_coalescing() and memory_region_add_coalescing().
809  *
810  * @mr: the memory region to be updated.
811  */
812 void memory_region_set_flush_coalesced(MemoryRegion *mr);
813 
814 /**
815  * memory_region_clear_flush_coalesced: Disable memory coalescing flush before
816  *                                      accesses.
817  *
818  * Clear the automatic coalesced MMIO flushing enabled via
819  * memory_region_set_flush_coalesced. Note that this service has no effect on
820  * memory regions that have MMIO coalescing enabled for themselves. For them,
821  * automatic flushing will stop once coalescing is disabled.
822  *
823  * @mr: the memory region to be updated.
824  */
825 void memory_region_clear_flush_coalesced(MemoryRegion *mr);
826 
827 /**
828  * memory_region_add_eventfd: Request an eventfd to be triggered when a word
829  *                            is written to a location.
830  *
831  * Marks a word in an IO region (initialized with memory_region_init_io())
832  * as a trigger for an eventfd event.  The I/O callback will not be called.
833  * The caller must be prepared to handle failure (that is, take the required
834  * action if the callback _is_ called).
835  *
836  * @mr: the memory region being updated.
837  * @addr: the address within @mr that is to be monitored
838  * @size: the size of the access to trigger the eventfd
839  * @match_data: whether to match against @data, instead of just @addr
840  * @data: the data to match against the guest write
841  * @fd: the eventfd to be triggered when @addr, @size, and @data all match.
842  **/
843 void memory_region_add_eventfd(MemoryRegion *mr,
844                                hwaddr addr,
845                                unsigned size,
846                                bool match_data,
847                                uint64_t data,
848                                EventNotifier *e);
849 
850 /**
851  * memory_region_del_eventfd: Cancel an eventfd.
852  *
853  * Cancels an eventfd trigger requested by a previous
854  * memory_region_add_eventfd() call.
855  *
856  * @mr: the memory region being updated.
857  * @addr: the address within @mr that is to be monitored
858  * @size: the size of the access to trigger the eventfd
859  * @match_data: whether to match against @data, instead of just @addr
860  * @data: the data to match against the guest write
861  * @fd: the eventfd to be triggered when @addr, @size, and @data all match.
862  */
863 void memory_region_del_eventfd(MemoryRegion *mr,
864                                hwaddr addr,
865                                unsigned size,
866                                bool match_data,
867                                uint64_t data,
868                                EventNotifier *e);
869 
870 /**
871  * memory_region_add_subregion: Add a subregion to a container.
872  *
873  * Adds a subregion at @offset.  The subregion may not overlap with other
874  * subregions (except for those explicitly marked as overlapping).  A region
875  * may only be added once as a subregion (unless removed with
876  * memory_region_del_subregion()); use memory_region_init_alias() if you
877  * want a region to be a subregion in multiple locations.
878  *
879  * @mr: the region to contain the new subregion; must be a container
880  *      initialized with memory_region_init().
881  * @offset: the offset relative to @mr where @subregion is added.
882  * @subregion: the subregion to be added.
883  */
884 void memory_region_add_subregion(MemoryRegion *mr,
885                                  hwaddr offset,
886                                  MemoryRegion *subregion);
887 /**
888  * memory_region_add_subregion_overlap: Add a subregion to a container
889  *                                      with overlap.
890  *
891  * Adds a subregion at @offset.  The subregion may overlap with other
892  * subregions.  Conflicts are resolved by having a higher @priority hide a
893  * lower @priority. Subregions without priority are taken as @priority 0.
894  * A region may only be added once as a subregion (unless removed with
895  * memory_region_del_subregion()); use memory_region_init_alias() if you
896  * want a region to be a subregion in multiple locations.
897  *
898  * @mr: the region to contain the new subregion; must be a container
899  *      initialized with memory_region_init().
900  * @offset: the offset relative to @mr where @subregion is added.
901  * @subregion: the subregion to be added.
902  * @priority: used for resolving overlaps; highest priority wins.
903  */
904 void memory_region_add_subregion_overlap(MemoryRegion *mr,
905                                          hwaddr offset,
906                                          MemoryRegion *subregion,
907                                          int priority);
908 
909 /**
910  * memory_region_get_ram_addr: Get the ram address associated with a memory
911  *                             region
912  *
913  * DO NOT USE THIS FUNCTION.  This is a temporary workaround while the Xen
914  * code is being reworked.
915  */
916 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
917 
918 uint64_t memory_region_get_alignment(const MemoryRegion *mr);
919 /**
920  * memory_region_del_subregion: Remove a subregion.
921  *
922  * Removes a subregion from its container.
923  *
924  * @mr: the container to be updated.
925  * @subregion: the region being removed; must be a current subregion of @mr.
926  */
927 void memory_region_del_subregion(MemoryRegion *mr,
928                                  MemoryRegion *subregion);
929 
930 /*
931  * memory_region_set_enabled: dynamically enable or disable a region
932  *
933  * Enables or disables a memory region.  A disabled memory region
934  * ignores all accesses to itself and its subregions.  It does not
935  * obscure sibling subregions with lower priority - it simply behaves as
936  * if it was removed from the hierarchy.
937  *
938  * Regions default to being enabled.
939  *
940  * @mr: the region to be updated
941  * @enabled: whether to enable or disable the region
942  */
943 void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
944 
945 /*
946  * memory_region_set_address: dynamically update the address of a region
947  *
948  * Dynamically updates the address of a region, relative to its container.
949  * May be used on regions are currently part of a memory hierarchy.
950  *
951  * @mr: the region to be updated
952  * @addr: new address, relative to container region
953  */
954 void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
955 
956 /*
957  * memory_region_set_size: dynamically update the size of a region.
958  *
959  * Dynamically updates the size of a region.
960  *
961  * @mr: the region to be updated
962  * @size: used size of the region.
963  */
964 void memory_region_set_size(MemoryRegion *mr, uint64_t size);
965 
966 /*
967  * memory_region_set_alias_offset: dynamically update a memory alias's offset
968  *
969  * Dynamically updates the offset into the target region that an alias points
970  * to, as if the fourth argument to memory_region_init_alias() has changed.
971  *
972  * @mr: the #MemoryRegion to be updated; should be an alias.
973  * @offset: the new offset into the target memory region
974  */
975 void memory_region_set_alias_offset(MemoryRegion *mr,
976                                     hwaddr offset);
977 
978 /**
979  * memory_region_present: checks if an address relative to a @container
980  * translates into #MemoryRegion within @container
981  *
982  * Answer whether a #MemoryRegion within @container covers the address
983  * @addr.
984  *
985  * @container: a #MemoryRegion within which @addr is a relative address
986  * @addr: the area within @container to be searched
987  */
988 bool memory_region_present(MemoryRegion *container, hwaddr addr);
989 
990 /**
991  * memory_region_is_mapped: returns true if #MemoryRegion is mapped
992  * into any address space.
993  *
994  * @mr: a #MemoryRegion which should be checked if it's mapped
995  */
996 bool memory_region_is_mapped(MemoryRegion *mr);
997 
998 /**
999  * memory_region_find: translate an address/size relative to a
1000  * MemoryRegion into a #MemoryRegionSection.
1001  *
1002  * Locates the first #MemoryRegion within @mr that overlaps the range
1003  * given by @addr and @size.
1004  *
1005  * Returns a #MemoryRegionSection that describes a contiguous overlap.
1006  * It will have the following characteristics:
1007  *    .@size = 0 iff no overlap was found
1008  *    .@mr is non-%NULL iff an overlap was found
1009  *
1010  * Remember that in the return value the @offset_within_region is
1011  * relative to the returned region (in the .@mr field), not to the
1012  * @mr argument.
1013  *
1014  * Similarly, the .@offset_within_address_space is relative to the
1015  * address space that contains both regions, the passed and the
1016  * returned one.  However, in the special case where the @mr argument
1017  * has no container (and thus is the root of the address space), the
1018  * following will hold:
1019  *    .@offset_within_address_space >= @addr
1020  *    .@offset_within_address_space + .@size <= @addr + @size
1021  *
1022  * @mr: a MemoryRegion within which @addr is a relative address
1023  * @addr: start of the area within @as to be searched
1024  * @size: size of the area to be searched
1025  */
1026 MemoryRegionSection memory_region_find(MemoryRegion *mr,
1027                                        hwaddr addr, uint64_t size);
1028 
1029 /**
1030  * address_space_sync_dirty_bitmap: synchronize the dirty log for all memory
1031  *
1032  * Synchronizes the dirty page log for an entire address space.
1033  * @as: the address space that contains the memory being synchronized
1034  */
1035 void address_space_sync_dirty_bitmap(AddressSpace *as);
1036 
1037 /**
1038  * memory_region_transaction_begin: Start a transaction.
1039  *
1040  * During a transaction, changes will be accumulated and made visible
1041  * only when the transaction ends (is committed).
1042  */
1043 void memory_region_transaction_begin(void);
1044 
1045 /**
1046  * memory_region_transaction_commit: Commit a transaction and make changes
1047  *                                   visible to the guest.
1048  */
1049 void memory_region_transaction_commit(void);
1050 
1051 /**
1052  * memory_listener_register: register callbacks to be called when memory
1053  *                           sections are mapped or unmapped into an address
1054  *                           space
1055  *
1056  * @listener: an object containing the callbacks to be called
1057  * @filter: if non-%NULL, only regions in this address space will be observed
1058  */
1059 void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
1060 
1061 /**
1062  * memory_listener_unregister: undo the effect of memory_listener_register()
1063  *
1064  * @listener: an object containing the callbacks to be removed
1065  */
1066 void memory_listener_unregister(MemoryListener *listener);
1067 
1068 /**
1069  * memory_global_dirty_log_start: begin dirty logging for all regions
1070  */
1071 void memory_global_dirty_log_start(void);
1072 
1073 /**
1074  * memory_global_dirty_log_stop: end dirty logging for all regions
1075  */
1076 void memory_global_dirty_log_stop(void);
1077 
1078 void mtree_info(fprintf_function mon_printf, void *f);
1079 
1080 /**
1081  * memory_region_dispatch_read: perform a read directly to the specified
1082  * MemoryRegion.
1083  *
1084  * @mr: #MemoryRegion to access
1085  * @addr: address within that region
1086  * @pval: pointer to uint64_t which the data is written to
1087  * @size: size of the access in bytes
1088  * @attrs: memory transaction attributes to use for the access
1089  */
1090 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
1091                                         hwaddr addr,
1092                                         uint64_t *pval,
1093                                         unsigned size,
1094                                         MemTxAttrs attrs);
1095 /**
1096  * memory_region_dispatch_write: perform a write directly to the specified
1097  * MemoryRegion.
1098  *
1099  * @mr: #MemoryRegion to access
1100  * @addr: address within that region
1101  * @data: data to write
1102  * @size: size of the access in bytes
1103  * @attrs: memory transaction attributes to use for the access
1104  */
1105 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
1106                                          hwaddr addr,
1107                                          uint64_t data,
1108                                          unsigned size,
1109                                          MemTxAttrs attrs);
1110 
1111 /**
1112  * address_space_init: initializes an address space
1113  *
1114  * @as: an uninitialized #AddressSpace
1115  * @root: a #MemoryRegion that routes addesses for the address space
1116  * @name: an address space name.  The name is only used for debugging
1117  *        output.
1118  */
1119 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
1120 
1121 
1122 /**
1123  * address_space_destroy: destroy an address space
1124  *
1125  * Releases all resources associated with an address space.  After an address space
1126  * is destroyed, its root memory region (given by address_space_init()) may be destroyed
1127  * as well.
1128  *
1129  * @as: address space to be destroyed
1130  */
1131 void address_space_destroy(AddressSpace *as);
1132 
1133 /**
1134  * address_space_rw: read from or write to an address space.
1135  *
1136  * Return a MemTxResult indicating whether the operation succeeded
1137  * or failed (eg unassigned memory, device rejected the transaction,
1138  * IOMMU fault).
1139  *
1140  * @as: #AddressSpace to be accessed
1141  * @addr: address within that address space
1142  * @attrs: memory transaction attributes
1143  * @buf: buffer with the data transferred
1144  * @is_write: indicates the transfer direction
1145  */
1146 MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
1147                              MemTxAttrs attrs, uint8_t *buf,
1148                              int len, bool is_write);
1149 
1150 /**
1151  * address_space_write: write to address space.
1152  *
1153  * Return a MemTxResult indicating whether the operation succeeded
1154  * or failed (eg unassigned memory, device rejected the transaction,
1155  * IOMMU fault).
1156  *
1157  * @as: #AddressSpace to be accessed
1158  * @addr: address within that address space
1159  * @attrs: memory transaction attributes
1160  * @buf: buffer with the data transferred
1161  */
1162 MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
1163                                 MemTxAttrs attrs,
1164                                 const uint8_t *buf, int len);
1165 
1166 /**
1167  * address_space_read: read from an address space.
1168  *
1169  * Return a MemTxResult indicating whether the operation succeeded
1170  * or failed (eg unassigned memory, device rejected the transaction,
1171  * IOMMU fault).
1172  *
1173  * @as: #AddressSpace to be accessed
1174  * @addr: address within that address space
1175  * @attrs: memory transaction attributes
1176  * @buf: buffer with the data transferred
1177  */
1178 MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
1179                                uint8_t *buf, int len);
1180 
1181 /**
1182  * address_space_ld*: load from an address space
1183  * address_space_st*: store to an address space
1184  *
1185  * These functions perform a load or store of the byte, word,
1186  * longword or quad to the specified address within the AddressSpace.
1187  * The _le suffixed functions treat the data as little endian;
1188  * _be indicates big endian; no suffix indicates "same endianness
1189  * as guest CPU".
1190  *
1191  * The "guest CPU endianness" accessors are deprecated for use outside
1192  * target-* code; devices should be CPU-agnostic and use either the LE
1193  * or the BE accessors.
1194  *
1195  * @as #AddressSpace to be accessed
1196  * @addr: address within that address space
1197  * @val: data value, for stores
1198  * @attrs: memory transaction attributes
1199  * @result: location to write the success/failure of the transaction;
1200  *   if NULL, this information is discarded
1201  */
1202 uint32_t address_space_ldub(AddressSpace *as, hwaddr addr,
1203                             MemTxAttrs attrs, MemTxResult *result);
1204 uint32_t address_space_lduw_le(AddressSpace *as, hwaddr addr,
1205                             MemTxAttrs attrs, MemTxResult *result);
1206 uint32_t address_space_lduw_be(AddressSpace *as, hwaddr addr,
1207                             MemTxAttrs attrs, MemTxResult *result);
1208 uint32_t address_space_ldl_le(AddressSpace *as, hwaddr addr,
1209                             MemTxAttrs attrs, MemTxResult *result);
1210 uint32_t address_space_ldl_be(AddressSpace *as, hwaddr addr,
1211                             MemTxAttrs attrs, MemTxResult *result);
1212 uint64_t address_space_ldq_le(AddressSpace *as, hwaddr addr,
1213                             MemTxAttrs attrs, MemTxResult *result);
1214 uint64_t address_space_ldq_be(AddressSpace *as, hwaddr addr,
1215                             MemTxAttrs attrs, MemTxResult *result);
1216 void address_space_stb(AddressSpace *as, hwaddr addr, uint32_t val,
1217                             MemTxAttrs attrs, MemTxResult *result);
1218 void address_space_stw_le(AddressSpace *as, hwaddr addr, uint32_t val,
1219                             MemTxAttrs attrs, MemTxResult *result);
1220 void address_space_stw_be(AddressSpace *as, hwaddr addr, uint32_t val,
1221                             MemTxAttrs attrs, MemTxResult *result);
1222 void address_space_stl_le(AddressSpace *as, hwaddr addr, uint32_t val,
1223                             MemTxAttrs attrs, MemTxResult *result);
1224 void address_space_stl_be(AddressSpace *as, hwaddr addr, uint32_t val,
1225                             MemTxAttrs attrs, MemTxResult *result);
1226 void address_space_stq_le(AddressSpace *as, hwaddr addr, uint64_t val,
1227                             MemTxAttrs attrs, MemTxResult *result);
1228 void address_space_stq_be(AddressSpace *as, hwaddr addr, uint64_t val,
1229                             MemTxAttrs attrs, MemTxResult *result);
1230 
1231 #ifdef NEED_CPU_H
1232 uint32_t address_space_lduw(AddressSpace *as, hwaddr addr,
1233                             MemTxAttrs attrs, MemTxResult *result);
1234 uint32_t address_space_ldl(AddressSpace *as, hwaddr addr,
1235                             MemTxAttrs attrs, MemTxResult *result);
1236 uint64_t address_space_ldq(AddressSpace *as, hwaddr addr,
1237                             MemTxAttrs attrs, MemTxResult *result);
1238 void address_space_stl_notdirty(AddressSpace *as, hwaddr addr, uint32_t val,
1239                             MemTxAttrs attrs, MemTxResult *result);
1240 void address_space_stw(AddressSpace *as, hwaddr addr, uint32_t val,
1241                             MemTxAttrs attrs, MemTxResult *result);
1242 void address_space_stl(AddressSpace *as, hwaddr addr, uint32_t val,
1243                             MemTxAttrs attrs, MemTxResult *result);
1244 void address_space_stq(AddressSpace *as, hwaddr addr, uint64_t val,
1245                             MemTxAttrs attrs, MemTxResult *result);
1246 #endif
1247 
1248 /* address_space_translate: translate an address range into an address space
1249  * into a MemoryRegion and an address range into that section.  Should be
1250  * called from an RCU critical section, to avoid that the last reference
1251  * to the returned region disappears after address_space_translate returns.
1252  *
1253  * @as: #AddressSpace to be accessed
1254  * @addr: address within that address space
1255  * @xlat: pointer to address within the returned memory region section's
1256  * #MemoryRegion.
1257  * @len: pointer to length
1258  * @is_write: indicates the transfer direction
1259  */
1260 MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
1261                                       hwaddr *xlat, hwaddr *len,
1262                                       bool is_write);
1263 
1264 /* address_space_access_valid: check for validity of accessing an address
1265  * space range
1266  *
1267  * Check whether memory is assigned to the given address space range, and
1268  * access is permitted by any IOMMU regions that are active for the address
1269  * space.
1270  *
1271  * For now, addr and len should be aligned to a page size.  This limitation
1272  * will be lifted in the future.
1273  *
1274  * @as: #AddressSpace to be accessed
1275  * @addr: address within that address space
1276  * @len: length of the area to be checked
1277  * @is_write: indicates the transfer direction
1278  */
1279 bool address_space_access_valid(AddressSpace *as, hwaddr addr, int len, bool is_write);
1280 
1281 /* address_space_map: map a physical memory region into a host virtual address
1282  *
1283  * May map a subset of the requested range, given by and returned in @plen.
1284  * May return %NULL if resources needed to perform the mapping are exhausted.
1285  * Use only for reads OR writes - not for read-modify-write operations.
1286  * Use cpu_register_map_client() to know when retrying the map operation is
1287  * likely to succeed.
1288  *
1289  * @as: #AddressSpace to be accessed
1290  * @addr: address within that address space
1291  * @plen: pointer to length of buffer; updated on return
1292  * @is_write: indicates the transfer direction
1293  */
1294 void *address_space_map(AddressSpace *as, hwaddr addr,
1295                         hwaddr *plen, bool is_write);
1296 
1297 /* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
1298  *
1299  * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
1300  * the amount of memory that was actually read or written by the caller.
1301  *
1302  * @as: #AddressSpace used
1303  * @addr: address within that address space
1304  * @len: buffer length as returned by address_space_map()
1305  * @access_len: amount of data actually transferred
1306  * @is_write: indicates the transfer direction
1307  */
1308 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
1309                          int is_write, hwaddr access_len);
1310 
1311 
1312 #endif
1313 
1314 #endif
1315