xref: /openbmc/qemu/include/exec/memory.h (revision 354908ce)
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 
50 extern bool global_dirty_log;
51 
52 typedef struct MemoryRegionOps MemoryRegionOps;
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 #define IOMMU_ACCESS_FLAG(r, w) (((r) ? IOMMU_RO : 0) | ((w) ? IOMMU_WO : 0))
65 
66 struct IOMMUTLBEntry {
67     AddressSpace    *target_as;
68     hwaddr           iova;
69     hwaddr           translated_addr;
70     hwaddr           addr_mask;  /* 0xfff = 4k translation */
71     IOMMUAccessFlags perm;
72 };
73 
74 /*
75  * Bitmap for different IOMMUNotifier capabilities. Each notifier can
76  * register with one or multiple IOMMU Notifier capability bit(s).
77  */
78 typedef enum {
79     IOMMU_NOTIFIER_NONE = 0,
80     /* Notify cache invalidations */
81     IOMMU_NOTIFIER_UNMAP = 0x1,
82     /* Notify entry changes (newly created entries) */
83     IOMMU_NOTIFIER_MAP = 0x2,
84 } IOMMUNotifierFlag;
85 
86 #define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP)
87 
88 struct IOMMUNotifier;
89 typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier,
90                             IOMMUTLBEntry *data);
91 
92 struct IOMMUNotifier {
93     IOMMUNotify notify;
94     IOMMUNotifierFlag notifier_flags;
95     /* Notify for address space range start <= addr <= end */
96     hwaddr start;
97     hwaddr end;
98     int iommu_idx;
99     QLIST_ENTRY(IOMMUNotifier) node;
100 };
101 typedef struct IOMMUNotifier IOMMUNotifier;
102 
103 /* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
104 #define RAM_PREALLOC   (1 << 0)
105 
106 /* RAM is mmap-ed with MAP_SHARED */
107 #define RAM_SHARED     (1 << 1)
108 
109 /* Only a portion of RAM (used_length) is actually used, and migrated.
110  * This used_length size can change across reboots.
111  */
112 #define RAM_RESIZEABLE (1 << 2)
113 
114 /* UFFDIO_ZEROPAGE is available on this RAMBlock to atomically
115  * zero the page and wake waiting processes.
116  * (Set during postcopy)
117  */
118 #define RAM_UF_ZEROPAGE (1 << 3)
119 
120 /* RAM can be migrated */
121 #define RAM_MIGRATABLE (1 << 4)
122 
123 /* RAM is a persistent kind memory */
124 #define RAM_PMEM (1 << 5)
125 
126 static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
127                                        IOMMUNotifierFlag flags,
128                                        hwaddr start, hwaddr end,
129                                        int iommu_idx)
130 {
131     n->notify = fn;
132     n->notifier_flags = flags;
133     n->start = start;
134     n->end = end;
135     n->iommu_idx = iommu_idx;
136 }
137 
138 /*
139  * Memory region callbacks
140  */
141 struct MemoryRegionOps {
142     /* Read from the memory region. @addr is relative to @mr; @size is
143      * in bytes. */
144     uint64_t (*read)(void *opaque,
145                      hwaddr addr,
146                      unsigned size);
147     /* Write to the memory region. @addr is relative to @mr; @size is
148      * in bytes. */
149     void (*write)(void *opaque,
150                   hwaddr addr,
151                   uint64_t data,
152                   unsigned size);
153 
154     MemTxResult (*read_with_attrs)(void *opaque,
155                                    hwaddr addr,
156                                    uint64_t *data,
157                                    unsigned size,
158                                    MemTxAttrs attrs);
159     MemTxResult (*write_with_attrs)(void *opaque,
160                                     hwaddr addr,
161                                     uint64_t data,
162                                     unsigned size,
163                                     MemTxAttrs attrs);
164 
165     enum device_endian endianness;
166     /* Guest-visible constraints: */
167     struct {
168         /* If nonzero, specify bounds on access sizes beyond which a machine
169          * check is thrown.
170          */
171         unsigned min_access_size;
172         unsigned max_access_size;
173         /* If true, unaligned accesses are supported.  Otherwise unaligned
174          * accesses throw machine checks.
175          */
176          bool unaligned;
177         /*
178          * If present, and returns #false, the transaction is not accepted
179          * by the device (and results in machine dependent behaviour such
180          * as a machine check exception).
181          */
182         bool (*accepts)(void *opaque, hwaddr addr,
183                         unsigned size, bool is_write,
184                         MemTxAttrs attrs);
185     } valid;
186     /* Internal implementation constraints: */
187     struct {
188         /* If nonzero, specifies the minimum size implemented.  Smaller sizes
189          * will be rounded upwards and a partial result will be returned.
190          */
191         unsigned min_access_size;
192         /* If nonzero, specifies the maximum size implemented.  Larger sizes
193          * will be done as a series of accesses with smaller sizes.
194          */
195         unsigned max_access_size;
196         /* If true, unaligned accesses are supported.  Otherwise all accesses
197          * are converted to (possibly multiple) naturally aligned accesses.
198          */
199         bool unaligned;
200     } impl;
201 };
202 
203 typedef struct MemoryRegionClass {
204     /* private */
205     ObjectClass parent_class;
206 } MemoryRegionClass;
207 
208 
209 enum IOMMUMemoryRegionAttr {
210     IOMMU_ATTR_SPAPR_TCE_FD
211 };
212 
213 /**
214  * IOMMUMemoryRegionClass:
215  *
216  * All IOMMU implementations need to subclass TYPE_IOMMU_MEMORY_REGION
217  * and provide an implementation of at least the @translate method here
218  * to handle requests to the memory region. Other methods are optional.
219  *
220  * The IOMMU implementation must use the IOMMU notifier infrastructure
221  * to report whenever mappings are changed, by calling
222  * memory_region_notify_iommu() (or, if necessary, by calling
223  * memory_region_notify_one() for each registered notifier).
224  *
225  * Conceptually an IOMMU provides a mapping from input address
226  * to an output TLB entry. If the IOMMU is aware of memory transaction
227  * attributes and the output TLB entry depends on the transaction
228  * attributes, we represent this using IOMMU indexes. Each index
229  * selects a particular translation table that the IOMMU has:
230  *   @attrs_to_index returns the IOMMU index for a set of transaction attributes
231  *   @translate takes an input address and an IOMMU index
232  * and the mapping returned can only depend on the input address and the
233  * IOMMU index.
234  *
235  * Most IOMMUs don't care about the transaction attributes and support
236  * only a single IOMMU index. A more complex IOMMU might have one index
237  * for secure transactions and one for non-secure transactions.
238  */
239 typedef struct IOMMUMemoryRegionClass {
240     /* private */
241     MemoryRegionClass parent_class;
242 
243     /*
244      * Return a TLB entry that contains a given address.
245      *
246      * The IOMMUAccessFlags indicated via @flag are optional and may
247      * be specified as IOMMU_NONE to indicate that the caller needs
248      * the full translation information for both reads and writes. If
249      * the access flags are specified then the IOMMU implementation
250      * may use this as an optimization, to stop doing a page table
251      * walk as soon as it knows that the requested permissions are not
252      * allowed. If IOMMU_NONE is passed then the IOMMU must do the
253      * full page table walk and report the permissions in the returned
254      * IOMMUTLBEntry. (Note that this implies that an IOMMU may not
255      * return different mappings for reads and writes.)
256      *
257      * The returned information remains valid while the caller is
258      * holding the big QEMU lock or is inside an RCU critical section;
259      * if the caller wishes to cache the mapping beyond that it must
260      * register an IOMMU notifier so it can invalidate its cached
261      * information when the IOMMU mapping changes.
262      *
263      * @iommu: the IOMMUMemoryRegion
264      * @hwaddr: address to be translated within the memory region
265      * @flag: requested access permissions
266      * @iommu_idx: IOMMU index for the translation
267      */
268     IOMMUTLBEntry (*translate)(IOMMUMemoryRegion *iommu, hwaddr addr,
269                                IOMMUAccessFlags flag, int iommu_idx);
270     /* Returns minimum supported page size in bytes.
271      * If this method is not provided then the minimum is assumed to
272      * be TARGET_PAGE_SIZE.
273      *
274      * @iommu: the IOMMUMemoryRegion
275      */
276     uint64_t (*get_min_page_size)(IOMMUMemoryRegion *iommu);
277     /* Called when IOMMU Notifier flag changes (ie when the set of
278      * events which IOMMU users are requesting notification for changes).
279      * Optional method -- need not be provided if the IOMMU does not
280      * need to know exactly which events must be notified.
281      *
282      * @iommu: the IOMMUMemoryRegion
283      * @old_flags: events which previously needed to be notified
284      * @new_flags: events which now need to be notified
285      *
286      * Returns 0 on success, or a negative errno; in particular
287      * returns -EINVAL if the new flag bitmap is not supported by the
288      * IOMMU memory region. In case of failure, the error object
289      * must be created
290      */
291     int (*notify_flag_changed)(IOMMUMemoryRegion *iommu,
292                                IOMMUNotifierFlag old_flags,
293                                IOMMUNotifierFlag new_flags,
294                                Error **errp);
295     /* Called to handle memory_region_iommu_replay().
296      *
297      * The default implementation of memory_region_iommu_replay() is to
298      * call the IOMMU translate method for every page in the address space
299      * with flag == IOMMU_NONE and then call the notifier if translate
300      * returns a valid mapping. If this method is implemented then it
301      * overrides the default behaviour, and must provide the full semantics
302      * of memory_region_iommu_replay(), by calling @notifier for every
303      * translation present in the IOMMU.
304      *
305      * Optional method -- an IOMMU only needs to provide this method
306      * if the default is inefficient or produces undesirable side effects.
307      *
308      * Note: this is not related to record-and-replay functionality.
309      */
310     void (*replay)(IOMMUMemoryRegion *iommu, IOMMUNotifier *notifier);
311 
312     /* Get IOMMU misc attributes. This is an optional method that
313      * can be used to allow users of the IOMMU to get implementation-specific
314      * information. The IOMMU implements this method to handle calls
315      * by IOMMU users to memory_region_iommu_get_attr() by filling in
316      * the arbitrary data pointer for any IOMMUMemoryRegionAttr values that
317      * the IOMMU supports. If the method is unimplemented then
318      * memory_region_iommu_get_attr() will always return -EINVAL.
319      *
320      * @iommu: the IOMMUMemoryRegion
321      * @attr: attribute being queried
322      * @data: memory to fill in with the attribute data
323      *
324      * Returns 0 on success, or a negative errno; in particular
325      * returns -EINVAL for unrecognized or unimplemented attribute types.
326      */
327     int (*get_attr)(IOMMUMemoryRegion *iommu, enum IOMMUMemoryRegionAttr attr,
328                     void *data);
329 
330     /* Return the IOMMU index to use for a given set of transaction attributes.
331      *
332      * Optional method: if an IOMMU only supports a single IOMMU index then
333      * the default implementation of memory_region_iommu_attrs_to_index()
334      * will return 0.
335      *
336      * The indexes supported by an IOMMU must be contiguous, starting at 0.
337      *
338      * @iommu: the IOMMUMemoryRegion
339      * @attrs: memory transaction attributes
340      */
341     int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs);
342 
343     /* Return the number of IOMMU indexes this IOMMU supports.
344      *
345      * Optional method: if this method is not provided, then
346      * memory_region_iommu_num_indexes() will return 1, indicating that
347      * only a single IOMMU index is supported.
348      *
349      * @iommu: the IOMMUMemoryRegion
350      */
351     int (*num_indexes)(IOMMUMemoryRegion *iommu);
352 } IOMMUMemoryRegionClass;
353 
354 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
355 typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
356 
357 /** MemoryRegion:
358  *
359  * A struct representing a memory region.
360  */
361 struct MemoryRegion {
362     Object parent_obj;
363 
364     /* private: */
365 
366     /* The following fields should fit in a cache line */
367     bool romd_mode;
368     bool ram;
369     bool subpage;
370     bool readonly; /* For RAM regions */
371     bool nonvolatile;
372     bool rom_device;
373     bool flush_coalesced_mmio;
374     bool global_locking;
375     uint8_t dirty_log_mask;
376     bool is_iommu;
377     RAMBlock *ram_block;
378     Object *owner;
379 
380     const MemoryRegionOps *ops;
381     void *opaque;
382     MemoryRegion *container;
383     Int128 size;
384     hwaddr addr;
385     void (*destructor)(MemoryRegion *mr);
386     uint64_t align;
387     bool terminates;
388     bool ram_device;
389     bool enabled;
390     bool warning_printed; /* For reservations */
391     uint8_t vga_logging_count;
392     MemoryRegion *alias;
393     hwaddr alias_offset;
394     int32_t priority;
395     QTAILQ_HEAD(, MemoryRegion) subregions;
396     QTAILQ_ENTRY(MemoryRegion) subregions_link;
397     QTAILQ_HEAD(, CoalescedMemoryRange) coalesced;
398     const char *name;
399     unsigned ioeventfd_nb;
400     MemoryRegionIoeventfd *ioeventfds;
401 };
402 
403 struct IOMMUMemoryRegion {
404     MemoryRegion parent_obj;
405 
406     QLIST_HEAD(, IOMMUNotifier) iommu_notify;
407     IOMMUNotifierFlag iommu_notify_flags;
408 };
409 
410 #define IOMMU_NOTIFIER_FOREACH(n, mr) \
411     QLIST_FOREACH((n), &(mr)->iommu_notify, node)
412 
413 /**
414  * MemoryListener: callbacks structure for updates to the physical memory map
415  *
416  * Allows a component to adjust to changes in the guest-visible memory map.
417  * Use with memory_listener_register() and memory_listener_unregister().
418  */
419 struct MemoryListener {
420     /**
421      * @begin:
422      *
423      * Called at the beginning of an address space update transaction.
424      * Followed by calls to #MemoryListener.region_add(),
425      * #MemoryListener.region_del(), #MemoryListener.region_nop(),
426      * #MemoryListener.log_start() and #MemoryListener.log_stop() in
427      * increasing address order.
428      *
429      * @listener: The #MemoryListener.
430      */
431     void (*begin)(MemoryListener *listener);
432 
433     /**
434      * @commit:
435      *
436      * Called at the end of an address space update transaction,
437      * after the last call to #MemoryListener.region_add(),
438      * #MemoryListener.region_del() or #MemoryListener.region_nop(),
439      * #MemoryListener.log_start() and #MemoryListener.log_stop().
440      *
441      * @listener: The #MemoryListener.
442      */
443     void (*commit)(MemoryListener *listener);
444 
445     /**
446      * @region_add:
447      *
448      * Called during an address space update transaction,
449      * for a section of the address space that is new in this address space
450      * space since the last transaction.
451      *
452      * @listener: The #MemoryListener.
453      * @section: The new #MemoryRegionSection.
454      */
455     void (*region_add)(MemoryListener *listener, MemoryRegionSection *section);
456 
457     /**
458      * @region_del:
459      *
460      * Called during an address space update transaction,
461      * for a section of the address space that has disappeared in the address
462      * space since the last transaction.
463      *
464      * @listener: The #MemoryListener.
465      * @section: The old #MemoryRegionSection.
466      */
467     void (*region_del)(MemoryListener *listener, MemoryRegionSection *section);
468 
469     /**
470      * @region_nop:
471      *
472      * Called during an address space update transaction,
473      * for a section of the address space that is in the same place in the address
474      * space as in the last transaction.
475      *
476      * @listener: The #MemoryListener.
477      * @section: The #MemoryRegionSection.
478      */
479     void (*region_nop)(MemoryListener *listener, MemoryRegionSection *section);
480 
481     /**
482      * @log_start:
483      *
484      * Called during an address space update transaction, after
485      * one of #MemoryListener.region_add(),#MemoryListener.region_del() or
486      * #MemoryListener.region_nop(), if dirty memory logging clients have
487      * become active since the last transaction.
488      *
489      * @listener: The #MemoryListener.
490      * @section: The #MemoryRegionSection.
491      * @old: A bitmap of dirty memory logging clients that were active in
492      * the previous transaction.
493      * @new: A bitmap of dirty memory logging clients that are active in
494      * the current transaction.
495      */
496     void (*log_start)(MemoryListener *listener, MemoryRegionSection *section,
497                       int old, int new);
498 
499     /**
500      * @log_stop:
501      *
502      * Called during an address space update transaction, after
503      * one of #MemoryListener.region_add(), #MemoryListener.region_del() or
504      * #MemoryListener.region_nop() and possibly after
505      * #MemoryListener.log_start(), if dirty memory logging clients have
506      * become inactive since the last transaction.
507      *
508      * @listener: The #MemoryListener.
509      * @section: The #MemoryRegionSection.
510      * @old: A bitmap of dirty memory logging clients that were active in
511      * the previous transaction.
512      * @new: A bitmap of dirty memory logging clients that are active in
513      * the current transaction.
514      */
515     void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section,
516                      int old, int new);
517 
518     /**
519      * @log_sync:
520      *
521      * Called by memory_region_snapshot_and_clear_dirty() and
522      * memory_global_dirty_log_sync(), before accessing QEMU's "official"
523      * copy of the dirty memory bitmap for a #MemoryRegionSection.
524      *
525      * @listener: The #MemoryListener.
526      * @section: The #MemoryRegionSection.
527      */
528     void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
529 
530     /**
531      * @log_clear:
532      *
533      * Called before reading the dirty memory bitmap for a
534      * #MemoryRegionSection.
535      *
536      * @listener: The #MemoryListener.
537      * @section: The #MemoryRegionSection.
538      */
539     void (*log_clear)(MemoryListener *listener, MemoryRegionSection *section);
540 
541     /**
542      * @log_global_start:
543      *
544      * Called by memory_global_dirty_log_start(), which
545      * enables the %DIRTY_LOG_MIGRATION client on all memory regions in
546      * the address space.  #MemoryListener.log_global_start() is also
547      * called when a #MemoryListener is added, if global dirty logging is
548      * active at that time.
549      *
550      * @listener: The #MemoryListener.
551      */
552     void (*log_global_start)(MemoryListener *listener);
553 
554     /**
555      * @log_global_stop:
556      *
557      * Called by memory_global_dirty_log_stop(), which
558      * disables the %DIRTY_LOG_MIGRATION client on all memory regions in
559      * the address space.
560      *
561      * @listener: The #MemoryListener.
562      */
563     void (*log_global_stop)(MemoryListener *listener);
564 
565     /**
566      * @log_global_after_sync:
567      *
568      * Called after reading the dirty memory bitmap
569      * for any #MemoryRegionSection.
570      *
571      * @listener: The #MemoryListener.
572      */
573     void (*log_global_after_sync)(MemoryListener *listener);
574 
575     /**
576      * @eventfd_add:
577      *
578      * Called during an address space update transaction,
579      * for a section of the address space that has had a new ioeventfd
580      * registration since the last transaction.
581      *
582      * @listener: The #MemoryListener.
583      * @section: The new #MemoryRegionSection.
584      * @match_data: The @match_data parameter for the new ioeventfd.
585      * @data: The @data parameter for the new ioeventfd.
586      * @e: The #EventNotifier parameter for the new ioeventfd.
587      */
588     void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
589                         bool match_data, uint64_t data, EventNotifier *e);
590 
591     /**
592      * @eventfd_del:
593      *
594      * Called during an address space update transaction,
595      * for a section of the address space that has dropped an ioeventfd
596      * registration since the last transaction.
597      *
598      * @listener: The #MemoryListener.
599      * @section: The new #MemoryRegionSection.
600      * @match_data: The @match_data parameter for the dropped ioeventfd.
601      * @data: The @data parameter for the dropped ioeventfd.
602      * @e: The #EventNotifier parameter for the dropped ioeventfd.
603      */
604     void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
605                         bool match_data, uint64_t data, EventNotifier *e);
606 
607     /**
608      * @coalesced_io_add:
609      *
610      * Called during an address space update transaction,
611      * for a section of the address space that has had a new coalesced
612      * MMIO range registration since the last transaction.
613      *
614      * @listener: The #MemoryListener.
615      * @section: The new #MemoryRegionSection.
616      * @addr: The starting address for the coalesced MMIO range.
617      * @len: The length of the coalesced MMIO range.
618      */
619     void (*coalesced_io_add)(MemoryListener *listener, MemoryRegionSection *section,
620                                hwaddr addr, hwaddr len);
621 
622     /**
623      * @coalesced_io_del:
624      *
625      * Called during an address space update transaction,
626      * for a section of the address space that has dropped a coalesced
627      * MMIO range since the last transaction.
628      *
629      * @listener: The #MemoryListener.
630      * @section: The new #MemoryRegionSection.
631      * @addr: The starting address for the coalesced MMIO range.
632      * @len: The length of the coalesced MMIO range.
633      */
634     void (*coalesced_io_del)(MemoryListener *listener, MemoryRegionSection *section,
635                                hwaddr addr, hwaddr len);
636     /**
637      * @priority:
638      *
639      * Govern the order in which memory listeners are invoked. Lower priorities
640      * are invoked earlier for "add" or "start" callbacks, and later for "delete"
641      * or "stop" callbacks.
642      */
643     unsigned priority;
644 
645     /* private: */
646     AddressSpace *address_space;
647     QTAILQ_ENTRY(MemoryListener) link;
648     QTAILQ_ENTRY(MemoryListener) link_as;
649 };
650 
651 /**
652  * AddressSpace: describes a mapping of addresses to #MemoryRegion objects
653  */
654 struct AddressSpace {
655     /* private: */
656     struct rcu_head rcu;
657     char *name;
658     MemoryRegion *root;
659 
660     /* Accessed via RCU.  */
661     struct FlatView *current_map;
662 
663     int ioeventfd_nb;
664     struct MemoryRegionIoeventfd *ioeventfds;
665     QTAILQ_HEAD(, MemoryListener) listeners;
666     QTAILQ_ENTRY(AddressSpace) address_spaces_link;
667 };
668 
669 typedef struct AddressSpaceDispatch AddressSpaceDispatch;
670 typedef struct FlatRange FlatRange;
671 
672 /* Flattened global view of current active memory hierarchy.  Kept in sorted
673  * order.
674  */
675 struct FlatView {
676     struct rcu_head rcu;
677     unsigned ref;
678     FlatRange *ranges;
679     unsigned nr;
680     unsigned nr_allocated;
681     struct AddressSpaceDispatch *dispatch;
682     MemoryRegion *root;
683 };
684 
685 static inline FlatView *address_space_to_flatview(AddressSpace *as)
686 {
687     return atomic_rcu_read(&as->current_map);
688 }
689 
690 
691 /**
692  * MemoryRegionSection: describes a fragment of a #MemoryRegion
693  *
694  * @mr: the region, or %NULL if empty
695  * @fv: the flat view of the address space the region is mapped in
696  * @offset_within_region: the beginning of the section, relative to @mr's start
697  * @size: the size of the section; will not exceed @mr's boundaries
698  * @offset_within_address_space: the address of the first byte of the section
699  *     relative to the region's address space
700  * @readonly: writes to this section are ignored
701  * @nonvolatile: this section is non-volatile
702  */
703 struct MemoryRegionSection {
704     Int128 size;
705     MemoryRegion *mr;
706     FlatView *fv;
707     hwaddr offset_within_region;
708     hwaddr offset_within_address_space;
709     bool readonly;
710     bool nonvolatile;
711 };
712 
713 static inline bool MemoryRegionSection_eq(MemoryRegionSection *a,
714                                           MemoryRegionSection *b)
715 {
716     return a->mr == b->mr &&
717            a->fv == b->fv &&
718            a->offset_within_region == b->offset_within_region &&
719            a->offset_within_address_space == b->offset_within_address_space &&
720            int128_eq(a->size, b->size) &&
721            a->readonly == b->readonly &&
722            a->nonvolatile == b->nonvolatile;
723 }
724 
725 /**
726  * memory_region_init: Initialize a memory region
727  *
728  * The region typically acts as a container for other memory regions.  Use
729  * memory_region_add_subregion() to add subregions.
730  *
731  * @mr: the #MemoryRegion to be initialized
732  * @owner: the object that tracks the region's reference count
733  * @name: used for debugging; not visible to the user or ABI
734  * @size: size of the region; any subregions beyond this size will be clipped
735  */
736 void memory_region_init(MemoryRegion *mr,
737                         struct Object *owner,
738                         const char *name,
739                         uint64_t size);
740 
741 /**
742  * memory_region_ref: Add 1 to a memory region's reference count
743  *
744  * Whenever memory regions are accessed outside the BQL, they need to be
745  * preserved against hot-unplug.  MemoryRegions actually do not have their
746  * own reference count; they piggyback on a QOM object, their "owner".
747  * This function adds a reference to the owner.
748  *
749  * All MemoryRegions must have an owner if they can disappear, even if the
750  * device they belong to operates exclusively under the BQL.  This is because
751  * the region could be returned at any time by memory_region_find, and this
752  * is usually under guest control.
753  *
754  * @mr: the #MemoryRegion
755  */
756 void memory_region_ref(MemoryRegion *mr);
757 
758 /**
759  * memory_region_unref: Remove 1 to a memory region's reference count
760  *
761  * Whenever memory regions are accessed outside the BQL, they need to be
762  * preserved against hot-unplug.  MemoryRegions actually do not have their
763  * own reference count; they piggyback on a QOM object, their "owner".
764  * This function removes a reference to the owner and possibly destroys it.
765  *
766  * @mr: the #MemoryRegion
767  */
768 void memory_region_unref(MemoryRegion *mr);
769 
770 /**
771  * memory_region_init_io: Initialize an I/O memory region.
772  *
773  * Accesses into the region will cause the callbacks in @ops to be called.
774  * if @size is nonzero, subregions will be clipped to @size.
775  *
776  * @mr: the #MemoryRegion to be initialized.
777  * @owner: the object that tracks the region's reference count
778  * @ops: a structure containing read and write callbacks to be used when
779  *       I/O is performed on the region.
780  * @opaque: passed to the read and write callbacks of the @ops structure.
781  * @name: used for debugging; not visible to the user or ABI
782  * @size: size of the region.
783  */
784 void memory_region_init_io(MemoryRegion *mr,
785                            struct Object *owner,
786                            const MemoryRegionOps *ops,
787                            void *opaque,
788                            const char *name,
789                            uint64_t size);
790 
791 /**
792  * memory_region_init_ram_nomigrate:  Initialize RAM memory region.  Accesses
793  *                                    into the region will modify memory
794  *                                    directly.
795  *
796  * @mr: the #MemoryRegion to be initialized.
797  * @owner: the object that tracks the region's reference count
798  * @name: Region name, becomes part of RAMBlock name used in migration stream
799  *        must be unique within any device
800  * @size: size of the region.
801  * @errp: pointer to Error*, to store an error if it happens.
802  *
803  * Note that this function does not do anything to cause the data in the
804  * RAM memory region to be migrated; that is the responsibility of the caller.
805  */
806 void memory_region_init_ram_nomigrate(MemoryRegion *mr,
807                                       struct Object *owner,
808                                       const char *name,
809                                       uint64_t size,
810                                       Error **errp);
811 
812 /**
813  * memory_region_init_ram_shared_nomigrate:  Initialize RAM memory region.
814  *                                           Accesses into the region will
815  *                                           modify memory directly.
816  *
817  * @mr: the #MemoryRegion to be initialized.
818  * @owner: the object that tracks the region's reference count
819  * @name: Region name, becomes part of RAMBlock name used in migration stream
820  *        must be unique within any device
821  * @size: size of the region.
822  * @share: allow remapping RAM to different addresses
823  * @errp: pointer to Error*, to store an error if it happens.
824  *
825  * Note that this function is similar to memory_region_init_ram_nomigrate.
826  * The only difference is part of the RAM region can be remapped.
827  */
828 void memory_region_init_ram_shared_nomigrate(MemoryRegion *mr,
829                                              struct Object *owner,
830                                              const char *name,
831                                              uint64_t size,
832                                              bool share,
833                                              Error **errp);
834 
835 /**
836  * memory_region_init_resizeable_ram:  Initialize memory region with resizeable
837  *                                     RAM.  Accesses into the region will
838  *                                     modify memory directly.  Only an initial
839  *                                     portion of this RAM is actually used.
840  *                                     The used size can change across reboots.
841  *
842  * @mr: the #MemoryRegion to be initialized.
843  * @owner: the object that tracks the region's reference count
844  * @name: Region name, becomes part of RAMBlock name used in migration stream
845  *        must be unique within any device
846  * @size: used size of the region.
847  * @max_size: max size of the region.
848  * @resized: callback to notify owner about used size change.
849  * @errp: pointer to Error*, to store an error if it happens.
850  *
851  * Note that this function does not do anything to cause the data in the
852  * RAM memory region to be migrated; that is the responsibility of the caller.
853  */
854 void memory_region_init_resizeable_ram(MemoryRegion *mr,
855                                        struct Object *owner,
856                                        const char *name,
857                                        uint64_t size,
858                                        uint64_t max_size,
859                                        void (*resized)(const char*,
860                                                        uint64_t length,
861                                                        void *host),
862                                        Error **errp);
863 #ifdef CONFIG_POSIX
864 
865 /**
866  * memory_region_init_ram_from_file:  Initialize RAM memory region with a
867  *                                    mmap-ed backend.
868  *
869  * @mr: the #MemoryRegion to be initialized.
870  * @owner: the object that tracks the region's reference count
871  * @name: Region name, becomes part of RAMBlock name used in migration stream
872  *        must be unique within any device
873  * @size: size of the region.
874  * @align: alignment of the region base address; if 0, the default alignment
875  *         (getpagesize()) will be used.
876  * @ram_flags: Memory region features:
877  *             - RAM_SHARED: memory must be mmaped with the MAP_SHARED flag
878  *             - RAM_PMEM: the memory is persistent memory
879  *             Other bits are ignored now.
880  * @path: the path in which to allocate the RAM.
881  * @errp: pointer to Error*, to store an error if it happens.
882  *
883  * Note that this function does not do anything to cause the data in the
884  * RAM memory region to be migrated; that is the responsibility of the caller.
885  */
886 void memory_region_init_ram_from_file(MemoryRegion *mr,
887                                       struct Object *owner,
888                                       const char *name,
889                                       uint64_t size,
890                                       uint64_t align,
891                                       uint32_t ram_flags,
892                                       const char *path,
893                                       Error **errp);
894 
895 /**
896  * memory_region_init_ram_from_fd:  Initialize RAM memory region with a
897  *                                  mmap-ed backend.
898  *
899  * @mr: the #MemoryRegion to be initialized.
900  * @owner: the object that tracks the region's reference count
901  * @name: the name of the region.
902  * @size: size of the region.
903  * @share: %true if memory must be mmaped with the MAP_SHARED flag
904  * @fd: the fd to mmap.
905  * @errp: pointer to Error*, to store an error if it happens.
906  *
907  * Note that this function does not do anything to cause the data in the
908  * RAM memory region to be migrated; that is the responsibility of the caller.
909  */
910 void memory_region_init_ram_from_fd(MemoryRegion *mr,
911                                     struct Object *owner,
912                                     const char *name,
913                                     uint64_t size,
914                                     bool share,
915                                     int fd,
916                                     Error **errp);
917 #endif
918 
919 /**
920  * memory_region_init_ram_ptr:  Initialize RAM memory region from a
921  *                              user-provided pointer.  Accesses into the
922  *                              region will modify memory directly.
923  *
924  * @mr: the #MemoryRegion to be initialized.
925  * @owner: the object that tracks the region's reference count
926  * @name: Region name, becomes part of RAMBlock name used in migration stream
927  *        must be unique within any device
928  * @size: size of the region.
929  * @ptr: memory to be mapped; must contain at least @size bytes.
930  *
931  * Note that this function does not do anything to cause the data in the
932  * RAM memory region to be migrated; that is the responsibility of the caller.
933  */
934 void memory_region_init_ram_ptr(MemoryRegion *mr,
935                                 struct Object *owner,
936                                 const char *name,
937                                 uint64_t size,
938                                 void *ptr);
939 
940 /**
941  * memory_region_init_ram_device_ptr:  Initialize RAM device memory region from
942  *                                     a user-provided pointer.
943  *
944  * A RAM device represents a mapping to a physical device, such as to a PCI
945  * MMIO BAR of an vfio-pci assigned device.  The memory region may be mapped
946  * into the VM address space and access to the region will modify memory
947  * directly.  However, the memory region should not be included in a memory
948  * dump (device may not be enabled/mapped at the time of the dump), and
949  * operations incompatible with manipulating MMIO should be avoided.  Replaces
950  * skip_dump flag.
951  *
952  * @mr: the #MemoryRegion to be initialized.
953  * @owner: the object that tracks the region's reference count
954  * @name: the name of the region.
955  * @size: size of the region.
956  * @ptr: memory to be mapped; must contain at least @size bytes.
957  *
958  * Note that this function does not do anything to cause the data in the
959  * RAM memory region to be migrated; that is the responsibility of the caller.
960  * (For RAM device memory regions, migrating the contents rarely makes sense.)
961  */
962 void memory_region_init_ram_device_ptr(MemoryRegion *mr,
963                                        struct Object *owner,
964                                        const char *name,
965                                        uint64_t size,
966                                        void *ptr);
967 
968 /**
969  * memory_region_init_alias: Initialize a memory region that aliases all or a
970  *                           part of another memory region.
971  *
972  * @mr: the #MemoryRegion to be initialized.
973  * @owner: the object that tracks the region's reference count
974  * @name: used for debugging; not visible to the user or ABI
975  * @orig: the region to be referenced; @mr will be equivalent to
976  *        @orig between @offset and @offset + @size - 1.
977  * @offset: start of the section in @orig to be referenced.
978  * @size: size of the region.
979  */
980 void memory_region_init_alias(MemoryRegion *mr,
981                               struct Object *owner,
982                               const char *name,
983                               MemoryRegion *orig,
984                               hwaddr offset,
985                               uint64_t size);
986 
987 /**
988  * memory_region_init_rom_nomigrate: Initialize a ROM memory region.
989  *
990  * This has the same effect as calling memory_region_init_ram_nomigrate()
991  * and then marking the resulting region read-only with
992  * memory_region_set_readonly().
993  *
994  * Note that this function does not do anything to cause the data in the
995  * RAM side of the memory region to be migrated; that is the responsibility
996  * of the caller.
997  *
998  * @mr: the #MemoryRegion to be initialized.
999  * @owner: the object that tracks the region's reference count
1000  * @name: Region name, becomes part of RAMBlock name used in migration stream
1001  *        must be unique within any device
1002  * @size: size of the region.
1003  * @errp: pointer to Error*, to store an error if it happens.
1004  */
1005 void memory_region_init_rom_nomigrate(MemoryRegion *mr,
1006                                       struct Object *owner,
1007                                       const char *name,
1008                                       uint64_t size,
1009                                       Error **errp);
1010 
1011 /**
1012  * memory_region_init_rom_device_nomigrate:  Initialize a ROM memory region.
1013  *                                 Writes are handled via callbacks.
1014  *
1015  * Note that this function does not do anything to cause the data in the
1016  * RAM side of the memory region to be migrated; that is the responsibility
1017  * of the caller.
1018  *
1019  * @mr: the #MemoryRegion to be initialized.
1020  * @owner: the object that tracks the region's reference count
1021  * @ops: callbacks for write access handling (must not be NULL).
1022  * @opaque: passed to the read and write callbacks of the @ops structure.
1023  * @name: Region name, becomes part of RAMBlock name used in migration stream
1024  *        must be unique within any device
1025  * @size: size of the region.
1026  * @errp: pointer to Error*, to store an error if it happens.
1027  */
1028 void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
1029                                              struct Object *owner,
1030                                              const MemoryRegionOps *ops,
1031                                              void *opaque,
1032                                              const char *name,
1033                                              uint64_t size,
1034                                              Error **errp);
1035 
1036 /**
1037  * memory_region_init_iommu: Initialize a memory region of a custom type
1038  * that translates addresses
1039  *
1040  * An IOMMU region translates addresses and forwards accesses to a target
1041  * memory region.
1042  *
1043  * The IOMMU implementation must define a subclass of TYPE_IOMMU_MEMORY_REGION.
1044  * @_iommu_mr should be a pointer to enough memory for an instance of
1045  * that subclass, @instance_size is the size of that subclass, and
1046  * @mrtypename is its name. This function will initialize @_iommu_mr as an
1047  * instance of the subclass, and its methods will then be called to handle
1048  * accesses to the memory region. See the documentation of
1049  * #IOMMUMemoryRegionClass for further details.
1050  *
1051  * @_iommu_mr: the #IOMMUMemoryRegion to be initialized
1052  * @instance_size: the IOMMUMemoryRegion subclass instance size
1053  * @mrtypename: the type name of the #IOMMUMemoryRegion
1054  * @owner: the object that tracks the region's reference count
1055  * @name: used for debugging; not visible to the user or ABI
1056  * @size: size of the region.
1057  */
1058 void memory_region_init_iommu(void *_iommu_mr,
1059                               size_t instance_size,
1060                               const char *mrtypename,
1061                               Object *owner,
1062                               const char *name,
1063                               uint64_t size);
1064 
1065 /**
1066  * memory_region_init_ram - Initialize RAM memory region.  Accesses into the
1067  *                          region will modify memory directly.
1068  *
1069  * @mr: the #MemoryRegion to be initialized
1070  * @owner: the object that tracks the region's reference count (must be
1071  *         TYPE_DEVICE or a subclass of TYPE_DEVICE, or NULL)
1072  * @name: name of the memory region
1073  * @size: size of the region in bytes
1074  * @errp: pointer to Error*, to store an error if it happens.
1075  *
1076  * This function allocates RAM for a board model or device, and
1077  * arranges for it to be migrated (by calling vmstate_register_ram()
1078  * if @owner is a DeviceState, or vmstate_register_ram_global() if
1079  * @owner is NULL).
1080  *
1081  * TODO: Currently we restrict @owner to being either NULL (for
1082  * global RAM regions with no owner) or devices, so that we can
1083  * give the RAM block a unique name for migration purposes.
1084  * We should lift this restriction and allow arbitrary Objects.
1085  * If you pass a non-NULL non-device @owner then we will assert.
1086  */
1087 void memory_region_init_ram(MemoryRegion *mr,
1088                             struct Object *owner,
1089                             const char *name,
1090                             uint64_t size,
1091                             Error **errp);
1092 
1093 /**
1094  * memory_region_init_rom: Initialize a ROM memory region.
1095  *
1096  * This has the same effect as calling memory_region_init_ram()
1097  * and then marking the resulting region read-only with
1098  * memory_region_set_readonly(). This includes arranging for the
1099  * contents to be migrated.
1100  *
1101  * TODO: Currently we restrict @owner to being either NULL (for
1102  * global RAM regions with no owner) or devices, so that we can
1103  * give the RAM block a unique name for migration purposes.
1104  * We should lift this restriction and allow arbitrary Objects.
1105  * If you pass a non-NULL non-device @owner then we will assert.
1106  *
1107  * @mr: the #MemoryRegion to be initialized.
1108  * @owner: the object that tracks the region's reference count
1109  * @name: Region name, becomes part of RAMBlock name used in migration stream
1110  *        must be unique within any device
1111  * @size: size of the region.
1112  * @errp: pointer to Error*, to store an error if it happens.
1113  */
1114 void memory_region_init_rom(MemoryRegion *mr,
1115                             struct Object *owner,
1116                             const char *name,
1117                             uint64_t size,
1118                             Error **errp);
1119 
1120 /**
1121  * memory_region_init_rom_device:  Initialize a ROM memory region.
1122  *                                 Writes are handled via callbacks.
1123  *
1124  * This function initializes a memory region backed by RAM for reads
1125  * and callbacks for writes, and arranges for the RAM backing to
1126  * be migrated (by calling vmstate_register_ram()
1127  * if @owner is a DeviceState, or vmstate_register_ram_global() if
1128  * @owner is NULL).
1129  *
1130  * TODO: Currently we restrict @owner to being either NULL (for
1131  * global RAM regions with no owner) or devices, so that we can
1132  * give the RAM block a unique name for migration purposes.
1133  * We should lift this restriction and allow arbitrary Objects.
1134  * If you pass a non-NULL non-device @owner then we will assert.
1135  *
1136  * @mr: the #MemoryRegion to be initialized.
1137  * @owner: the object that tracks the region's reference count
1138  * @ops: callbacks for write access handling (must not be NULL).
1139  * @opaque: passed to the read and write callbacks of the @ops structure.
1140  * @name: Region name, becomes part of RAMBlock name used in migration stream
1141  *        must be unique within any device
1142  * @size: size of the region.
1143  * @errp: pointer to Error*, to store an error if it happens.
1144  */
1145 void memory_region_init_rom_device(MemoryRegion *mr,
1146                                    struct Object *owner,
1147                                    const MemoryRegionOps *ops,
1148                                    void *opaque,
1149                                    const char *name,
1150                                    uint64_t size,
1151                                    Error **errp);
1152 
1153 
1154 /**
1155  * memory_region_owner: get a memory region's owner.
1156  *
1157  * @mr: the memory region being queried.
1158  */
1159 struct Object *memory_region_owner(MemoryRegion *mr);
1160 
1161 /**
1162  * memory_region_size: get a memory region's size.
1163  *
1164  * @mr: the memory region being queried.
1165  */
1166 uint64_t memory_region_size(MemoryRegion *mr);
1167 
1168 /**
1169  * memory_region_is_ram: check whether a memory region is random access
1170  *
1171  * Returns %true if a memory region is random access.
1172  *
1173  * @mr: the memory region being queried
1174  */
1175 static inline bool memory_region_is_ram(MemoryRegion *mr)
1176 {
1177     return mr->ram;
1178 }
1179 
1180 /**
1181  * memory_region_is_ram_device: check whether a memory region is a ram device
1182  *
1183  * Returns %true if a memory region is a device backed ram region
1184  *
1185  * @mr: the memory region being queried
1186  */
1187 bool memory_region_is_ram_device(MemoryRegion *mr);
1188 
1189 /**
1190  * memory_region_is_romd: check whether a memory region is in ROMD mode
1191  *
1192  * Returns %true if a memory region is a ROM device and currently set to allow
1193  * direct reads.
1194  *
1195  * @mr: the memory region being queried
1196  */
1197 static inline bool memory_region_is_romd(MemoryRegion *mr)
1198 {
1199     return mr->rom_device && mr->romd_mode;
1200 }
1201 
1202 /**
1203  * memory_region_get_iommu: check whether a memory region is an iommu
1204  *
1205  * Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
1206  * otherwise NULL.
1207  *
1208  * @mr: the memory region being queried
1209  */
1210 static inline IOMMUMemoryRegion *memory_region_get_iommu(MemoryRegion *mr)
1211 {
1212     if (mr->alias) {
1213         return memory_region_get_iommu(mr->alias);
1214     }
1215     if (mr->is_iommu) {
1216         return (IOMMUMemoryRegion *) mr;
1217     }
1218     return NULL;
1219 }
1220 
1221 /**
1222  * memory_region_get_iommu_class_nocheck: returns iommu memory region class
1223  *   if an iommu or NULL if not
1224  *
1225  * Returns pointer to IOMMUMemoryRegionClass if a memory region is an iommu,
1226  * otherwise NULL. This is fast path avoiding QOM checking, use with caution.
1227  *
1228  * @iommu_mr: the memory region being queried
1229  */
1230 static inline IOMMUMemoryRegionClass *memory_region_get_iommu_class_nocheck(
1231         IOMMUMemoryRegion *iommu_mr)
1232 {
1233     return (IOMMUMemoryRegionClass *) (((Object *)iommu_mr)->class);
1234 }
1235 
1236 #define memory_region_is_iommu(mr) (memory_region_get_iommu(mr) != NULL)
1237 
1238 /**
1239  * memory_region_iommu_get_min_page_size: get minimum supported page size
1240  * for an iommu
1241  *
1242  * Returns minimum supported page size for an iommu.
1243  *
1244  * @iommu_mr: the memory region being queried
1245  */
1246 uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr);
1247 
1248 /**
1249  * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
1250  *
1251  * The notification type will be decided by entry.perm bits:
1252  *
1253  * - For UNMAP (cache invalidation) notifies: set entry.perm to IOMMU_NONE.
1254  * - For MAP (newly added entry) notifies: set entry.perm to the
1255  *   permission of the page (which is definitely !IOMMU_NONE).
1256  *
1257  * Note: for any IOMMU implementation, an in-place mapping change
1258  * should be notified with an UNMAP followed by a MAP.
1259  *
1260  * @iommu_mr: the memory region that was changed
1261  * @iommu_idx: the IOMMU index for the translation table which has changed
1262  * @entry: the new entry in the IOMMU translation table.  The entry
1263  *         replaces all old entries for the same virtual I/O address range.
1264  *         Deleted entries have .@perm == 0.
1265  */
1266 void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
1267                                 int iommu_idx,
1268                                 IOMMUTLBEntry entry);
1269 
1270 /**
1271  * memory_region_notify_one: notify a change in an IOMMU translation
1272  *                           entry to a single notifier
1273  *
1274  * This works just like memory_region_notify_iommu(), but it only
1275  * notifies a specific notifier, not all of them.
1276  *
1277  * @notifier: the notifier to be notified
1278  * @entry: the new entry in the IOMMU translation table.  The entry
1279  *         replaces all old entries for the same virtual I/O address range.
1280  *         Deleted entries have .@perm == 0.
1281  */
1282 void memory_region_notify_one(IOMMUNotifier *notifier,
1283                               IOMMUTLBEntry *entry);
1284 
1285 /**
1286  * memory_region_register_iommu_notifier: register a notifier for changes to
1287  * IOMMU translation entries.
1288  *
1289  * Returns 0 on success, or a negative errno otherwise. In particular,
1290  * -EINVAL indicates that at least one of the attributes of the notifier
1291  * is not supported (flag/range) by the IOMMU memory region. In case of error
1292  * the error object must be created.
1293  *
1294  * @mr: the memory region to observe
1295  * @n: the IOMMUNotifier to be added; the notify callback receives a
1296  *     pointer to an #IOMMUTLBEntry as the opaque value; the pointer
1297  *     ceases to be valid on exit from the notifier.
1298  * @errp: pointer to Error*, to store an error if it happens.
1299  */
1300 int memory_region_register_iommu_notifier(MemoryRegion *mr,
1301                                           IOMMUNotifier *n, Error **errp);
1302 
1303 /**
1304  * memory_region_iommu_replay: replay existing IOMMU translations to
1305  * a notifier with the minimum page granularity returned by
1306  * mr->iommu_ops->get_page_size().
1307  *
1308  * Note: this is not related to record-and-replay functionality.
1309  *
1310  * @iommu_mr: the memory region to observe
1311  * @n: the notifier to which to replay iommu mappings
1312  */
1313 void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n);
1314 
1315 /**
1316  * memory_region_unregister_iommu_notifier: unregister a notifier for
1317  * changes to IOMMU translation entries.
1318  *
1319  * @mr: the memory region which was observed and for which notity_stopped()
1320  *      needs to be called
1321  * @n: the notifier to be removed.
1322  */
1323 void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
1324                                              IOMMUNotifier *n);
1325 
1326 /**
1327  * memory_region_iommu_get_attr: return an IOMMU attr if get_attr() is
1328  * defined on the IOMMU.
1329  *
1330  * Returns 0 on success, or a negative errno otherwise. In particular,
1331  * -EINVAL indicates that the IOMMU does not support the requested
1332  * attribute.
1333  *
1334  * @iommu_mr: the memory region
1335  * @attr: the requested attribute
1336  * @data: a pointer to the requested attribute data
1337  */
1338 int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
1339                                  enum IOMMUMemoryRegionAttr attr,
1340                                  void *data);
1341 
1342 /**
1343  * memory_region_iommu_attrs_to_index: return the IOMMU index to
1344  * use for translations with the given memory transaction attributes.
1345  *
1346  * @iommu_mr: the memory region
1347  * @attrs: the memory transaction attributes
1348  */
1349 int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr,
1350                                        MemTxAttrs attrs);
1351 
1352 /**
1353  * memory_region_iommu_num_indexes: return the total number of IOMMU
1354  * indexes that this IOMMU supports.
1355  *
1356  * @iommu_mr: the memory region
1357  */
1358 int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr);
1359 
1360 /**
1361  * memory_region_name: get a memory region's name
1362  *
1363  * Returns the string that was used to initialize the memory region.
1364  *
1365  * @mr: the memory region being queried
1366  */
1367 const char *memory_region_name(const MemoryRegion *mr);
1368 
1369 /**
1370  * memory_region_is_logging: return whether a memory region is logging writes
1371  *
1372  * Returns %true if the memory region is logging writes for the given client
1373  *
1374  * @mr: the memory region being queried
1375  * @client: the client being queried
1376  */
1377 bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
1378 
1379 /**
1380  * memory_region_get_dirty_log_mask: return the clients for which a
1381  * memory region is logging writes.
1382  *
1383  * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
1384  * are the bit indices.
1385  *
1386  * @mr: the memory region being queried
1387  */
1388 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
1389 
1390 /**
1391  * memory_region_is_rom: check whether a memory region is ROM
1392  *
1393  * Returns %true if a memory region is read-only memory.
1394  *
1395  * @mr: the memory region being queried
1396  */
1397 static inline bool memory_region_is_rom(MemoryRegion *mr)
1398 {
1399     return mr->ram && mr->readonly;
1400 }
1401 
1402 /**
1403  * memory_region_is_nonvolatile: check whether a memory region is non-volatile
1404  *
1405  * Returns %true is a memory region is non-volatile memory.
1406  *
1407  * @mr: the memory region being queried
1408  */
1409 static inline bool memory_region_is_nonvolatile(MemoryRegion *mr)
1410 {
1411     return mr->nonvolatile;
1412 }
1413 
1414 /**
1415  * memory_region_get_fd: Get a file descriptor backing a RAM memory region.
1416  *
1417  * Returns a file descriptor backing a file-based RAM memory region,
1418  * or -1 if the region is not a file-based RAM memory region.
1419  *
1420  * @mr: the RAM or alias memory region being queried.
1421  */
1422 int memory_region_get_fd(MemoryRegion *mr);
1423 
1424 /**
1425  * memory_region_from_host: Convert a pointer into a RAM memory region
1426  * and an offset within it.
1427  *
1428  * Given a host pointer inside a RAM memory region (created with
1429  * memory_region_init_ram() or memory_region_init_ram_ptr()), return
1430  * the MemoryRegion and the offset within it.
1431  *
1432  * Use with care; by the time this function returns, the returned pointer is
1433  * not protected by RCU anymore.  If the caller is not within an RCU critical
1434  * section and does not hold the iothread lock, it must have other means of
1435  * protecting the pointer, such as a reference to the region that includes
1436  * the incoming ram_addr_t.
1437  *
1438  * @ptr: the host pointer to be converted
1439  * @offset: the offset within memory region
1440  */
1441 MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
1442 
1443 /**
1444  * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
1445  *
1446  * Returns a host pointer to a RAM memory region (created with
1447  * memory_region_init_ram() or memory_region_init_ram_ptr()).
1448  *
1449  * Use with care; by the time this function returns, the returned pointer is
1450  * not protected by RCU anymore.  If the caller is not within an RCU critical
1451  * section and does not hold the iothread lock, it must have other means of
1452  * protecting the pointer, such as a reference to the region that includes
1453  * the incoming ram_addr_t.
1454  *
1455  * @mr: the memory region being queried.
1456  */
1457 void *memory_region_get_ram_ptr(MemoryRegion *mr);
1458 
1459 /* memory_region_ram_resize: Resize a RAM region.
1460  *
1461  * Only legal before guest might have detected the memory size: e.g. on
1462  * incoming migration, or right after reset.
1463  *
1464  * @mr: a memory region created with @memory_region_init_resizeable_ram.
1465  * @newsize: the new size the region
1466  * @errp: pointer to Error*, to store an error if it happens.
1467  */
1468 void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
1469                               Error **errp);
1470 
1471 /**
1472  * memory_region_msync: Synchronize selected address range of
1473  * a memory mapped region
1474  *
1475  * @mr: the memory region to be msync
1476  * @addr: the initial address of the range to be sync
1477  * @size: the size of the range to be sync
1478  */
1479 void memory_region_msync(MemoryRegion *mr, hwaddr addr, hwaddr size);
1480 
1481 /**
1482  * memory_region_writeback: Trigger cache writeback for
1483  * selected address range
1484  *
1485  * @mr: the memory region to be updated
1486  * @addr: the initial address of the range to be written back
1487  * @size: the size of the range to be written back
1488  */
1489 void memory_region_writeback(MemoryRegion *mr, hwaddr addr, hwaddr size);
1490 
1491 /**
1492  * memory_region_set_log: Turn dirty logging on or off for a region.
1493  *
1494  * Turns dirty logging on or off for a specified client (display, migration).
1495  * Only meaningful for RAM regions.
1496  *
1497  * @mr: the memory region being updated.
1498  * @log: whether dirty logging is to be enabled or disabled.
1499  * @client: the user of the logging information; %DIRTY_MEMORY_VGA only.
1500  */
1501 void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client);
1502 
1503 /**
1504  * memory_region_set_dirty: Mark a range of bytes as dirty in a memory region.
1505  *
1506  * Marks a range of bytes as dirty, after it has been dirtied outside
1507  * guest code.
1508  *
1509  * @mr: the memory region being dirtied.
1510  * @addr: the address (relative to the start of the region) being dirtied.
1511  * @size: size of the range being dirtied.
1512  */
1513 void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
1514                              hwaddr size);
1515 
1516 /**
1517  * memory_region_clear_dirty_bitmap - clear dirty bitmap for memory range
1518  *
1519  * This function is called when the caller wants to clear the remote
1520  * dirty bitmap of a memory range within the memory region.  This can
1521  * be used by e.g. KVM to manually clear dirty log when
1522  * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is declared support by the host
1523  * kernel.
1524  *
1525  * @mr:     the memory region to clear the dirty log upon
1526  * @start:  start address offset within the memory region
1527  * @len:    length of the memory region to clear dirty bitmap
1528  */
1529 void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start,
1530                                       hwaddr len);
1531 
1532 /**
1533  * memory_region_snapshot_and_clear_dirty: Get a snapshot of the dirty
1534  *                                         bitmap and clear it.
1535  *
1536  * Creates a snapshot of the dirty bitmap, clears the dirty bitmap and
1537  * returns the snapshot.  The snapshot can then be used to query dirty
1538  * status, using memory_region_snapshot_get_dirty.  Snapshotting allows
1539  * querying the same page multiple times, which is especially useful for
1540  * display updates where the scanlines often are not page aligned.
1541  *
1542  * The dirty bitmap region which gets copyed into the snapshot (and
1543  * cleared afterwards) can be larger than requested.  The boundaries
1544  * are rounded up/down so complete bitmap longs (covering 64 pages on
1545  * 64bit hosts) can be copied over into the bitmap snapshot.  Which
1546  * isn't a problem for display updates as the extra pages are outside
1547  * the visible area, and in case the visible area changes a full
1548  * display redraw is due anyway.  Should other use cases for this
1549  * function emerge we might have to revisit this implementation
1550  * detail.
1551  *
1552  * Use g_free to release DirtyBitmapSnapshot.
1553  *
1554  * @mr: the memory region being queried.
1555  * @addr: the address (relative to the start of the region) being queried.
1556  * @size: the size of the range being queried.
1557  * @client: the user of the logging information; typically %DIRTY_MEMORY_VGA.
1558  */
1559 DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr,
1560                                                             hwaddr addr,
1561                                                             hwaddr size,
1562                                                             unsigned client);
1563 
1564 /**
1565  * memory_region_snapshot_get_dirty: Check whether a range of bytes is dirty
1566  *                                   in the specified dirty bitmap snapshot.
1567  *
1568  * @mr: the memory region being queried.
1569  * @snap: the dirty bitmap snapshot
1570  * @addr: the address (relative to the start of the region) being queried.
1571  * @size: the size of the range being queried.
1572  */
1573 bool memory_region_snapshot_get_dirty(MemoryRegion *mr,
1574                                       DirtyBitmapSnapshot *snap,
1575                                       hwaddr addr, hwaddr size);
1576 
1577 /**
1578  * memory_region_reset_dirty: Mark a range of pages as clean, for a specified
1579  *                            client.
1580  *
1581  * Marks a range of pages as no longer dirty.
1582  *
1583  * @mr: the region being updated.
1584  * @addr: the start of the subrange being cleaned.
1585  * @size: the size of the subrange being cleaned.
1586  * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
1587  *          %DIRTY_MEMORY_VGA.
1588  */
1589 void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
1590                                hwaddr size, unsigned client);
1591 
1592 /**
1593  * memory_region_flush_rom_device: Mark a range of pages dirty and invalidate
1594  *                                 TBs (for self-modifying code).
1595  *
1596  * The MemoryRegionOps->write() callback of a ROM device must use this function
1597  * to mark byte ranges that have been modified internally, such as by directly
1598  * accessing the memory returned by memory_region_get_ram_ptr().
1599  *
1600  * This function marks the range dirty and invalidates TBs so that TCG can
1601  * detect self-modifying code.
1602  *
1603  * @mr: the region being flushed.
1604  * @addr: the start, relative to the start of the region, of the range being
1605  *        flushed.
1606  * @size: the size, in bytes, of the range being flushed.
1607  */
1608 void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size);
1609 
1610 /**
1611  * memory_region_set_readonly: Turn a memory region read-only (or read-write)
1612  *
1613  * Allows a memory region to be marked as read-only (turning it into a ROM).
1614  * only useful on RAM regions.
1615  *
1616  * @mr: the region being updated.
1617  * @readonly: whether rhe region is to be ROM or RAM.
1618  */
1619 void memory_region_set_readonly(MemoryRegion *mr, bool readonly);
1620 
1621 /**
1622  * memory_region_set_nonvolatile: Turn a memory region non-volatile
1623  *
1624  * Allows a memory region to be marked as non-volatile.
1625  * only useful on RAM regions.
1626  *
1627  * @mr: the region being updated.
1628  * @nonvolatile: whether rhe region is to be non-volatile.
1629  */
1630 void memory_region_set_nonvolatile(MemoryRegion *mr, bool nonvolatile);
1631 
1632 /**
1633  * memory_region_rom_device_set_romd: enable/disable ROMD mode
1634  *
1635  * Allows a ROM device (initialized with memory_region_init_rom_device() to
1636  * set to ROMD mode (default) or MMIO mode.  When it is in ROMD mode, the
1637  * device is mapped to guest memory and satisfies read access directly.
1638  * When in MMIO mode, reads are forwarded to the #MemoryRegion.read function.
1639  * Writes are always handled by the #MemoryRegion.write function.
1640  *
1641  * @mr: the memory region to be updated
1642  * @romd_mode: %true to put the region into ROMD mode
1643  */
1644 void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode);
1645 
1646 /**
1647  * memory_region_set_coalescing: Enable memory coalescing for the region.
1648  *
1649  * Enabled writes to a region to be queued for later processing. MMIO ->write
1650  * callbacks may be delayed until a non-coalesced MMIO is issued.
1651  * Only useful for IO regions.  Roughly similar to write-combining hardware.
1652  *
1653  * @mr: the memory region to be write coalesced
1654  */
1655 void memory_region_set_coalescing(MemoryRegion *mr);
1656 
1657 /**
1658  * memory_region_add_coalescing: Enable memory coalescing for a sub-range of
1659  *                               a region.
1660  *
1661  * Like memory_region_set_coalescing(), but works on a sub-range of a region.
1662  * Multiple calls can be issued coalesced disjoint ranges.
1663  *
1664  * @mr: the memory region to be updated.
1665  * @offset: the start of the range within the region to be coalesced.
1666  * @size: the size of the subrange to be coalesced.
1667  */
1668 void memory_region_add_coalescing(MemoryRegion *mr,
1669                                   hwaddr offset,
1670                                   uint64_t size);
1671 
1672 /**
1673  * memory_region_clear_coalescing: Disable MMIO coalescing for the region.
1674  *
1675  * Disables any coalescing caused by memory_region_set_coalescing() or
1676  * memory_region_add_coalescing().  Roughly equivalent to uncacheble memory
1677  * hardware.
1678  *
1679  * @mr: the memory region to be updated.
1680  */
1681 void memory_region_clear_coalescing(MemoryRegion *mr);
1682 
1683 /**
1684  * memory_region_set_flush_coalesced: Enforce memory coalescing flush before
1685  *                                    accesses.
1686  *
1687  * Ensure that pending coalesced MMIO request are flushed before the memory
1688  * region is accessed. This property is automatically enabled for all regions
1689  * passed to memory_region_set_coalescing() and memory_region_add_coalescing().
1690  *
1691  * @mr: the memory region to be updated.
1692  */
1693 void memory_region_set_flush_coalesced(MemoryRegion *mr);
1694 
1695 /**
1696  * memory_region_clear_flush_coalesced: Disable memory coalescing flush before
1697  *                                      accesses.
1698  *
1699  * Clear the automatic coalesced MMIO flushing enabled via
1700  * memory_region_set_flush_coalesced. Note that this service has no effect on
1701  * memory regions that have MMIO coalescing enabled for themselves. For them,
1702  * automatic flushing will stop once coalescing is disabled.
1703  *
1704  * @mr: the memory region to be updated.
1705  */
1706 void memory_region_clear_flush_coalesced(MemoryRegion *mr);
1707 
1708 /**
1709  * memory_region_clear_global_locking: Declares that access processing does
1710  *                                     not depend on the QEMU global lock.
1711  *
1712  * By clearing this property, accesses to the memory region will be processed
1713  * outside of QEMU's global lock (unless the lock is held on when issuing the
1714  * access request). In this case, the device model implementing the access
1715  * handlers is responsible for synchronization of concurrency.
1716  *
1717  * @mr: the memory region to be updated.
1718  */
1719 void memory_region_clear_global_locking(MemoryRegion *mr);
1720 
1721 /**
1722  * memory_region_add_eventfd: Request an eventfd to be triggered when a word
1723  *                            is written to a location.
1724  *
1725  * Marks a word in an IO region (initialized with memory_region_init_io())
1726  * as a trigger for an eventfd event.  The I/O callback will not be called.
1727  * The caller must be prepared to handle failure (that is, take the required
1728  * action if the callback _is_ called).
1729  *
1730  * @mr: the memory region being updated.
1731  * @addr: the address within @mr that is to be monitored
1732  * @size: the size of the access to trigger the eventfd
1733  * @match_data: whether to match against @data, instead of just @addr
1734  * @data: the data to match against the guest write
1735  * @e: event notifier to be triggered when @addr, @size, and @data all match.
1736  **/
1737 void memory_region_add_eventfd(MemoryRegion *mr,
1738                                hwaddr addr,
1739                                unsigned size,
1740                                bool match_data,
1741                                uint64_t data,
1742                                EventNotifier *e);
1743 
1744 /**
1745  * memory_region_del_eventfd: Cancel an eventfd.
1746  *
1747  * Cancels an eventfd trigger requested by a previous
1748  * memory_region_add_eventfd() call.
1749  *
1750  * @mr: the memory region being updated.
1751  * @addr: the address within @mr that is to be monitored
1752  * @size: the size of the access to trigger the eventfd
1753  * @match_data: whether to match against @data, instead of just @addr
1754  * @data: the data to match against the guest write
1755  * @e: event notifier to be triggered when @addr, @size, and @data all match.
1756  */
1757 void memory_region_del_eventfd(MemoryRegion *mr,
1758                                hwaddr addr,
1759                                unsigned size,
1760                                bool match_data,
1761                                uint64_t data,
1762                                EventNotifier *e);
1763 
1764 /**
1765  * memory_region_add_subregion: Add a subregion to a container.
1766  *
1767  * Adds a subregion at @offset.  The subregion may not overlap with other
1768  * subregions (except for those explicitly marked as overlapping).  A region
1769  * may only be added once as a subregion (unless removed with
1770  * memory_region_del_subregion()); use memory_region_init_alias() if you
1771  * want a region to be a subregion in multiple locations.
1772  *
1773  * @mr: the region to contain the new subregion; must be a container
1774  *      initialized with memory_region_init().
1775  * @offset: the offset relative to @mr where @subregion is added.
1776  * @subregion: the subregion to be added.
1777  */
1778 void memory_region_add_subregion(MemoryRegion *mr,
1779                                  hwaddr offset,
1780                                  MemoryRegion *subregion);
1781 /**
1782  * memory_region_add_subregion_overlap: Add a subregion to a container
1783  *                                      with overlap.
1784  *
1785  * Adds a subregion at @offset.  The subregion may overlap with other
1786  * subregions.  Conflicts are resolved by having a higher @priority hide a
1787  * lower @priority. Subregions without priority are taken as @priority 0.
1788  * A region may only be added once as a subregion (unless removed with
1789  * memory_region_del_subregion()); use memory_region_init_alias() if you
1790  * want a region to be a subregion in multiple locations.
1791  *
1792  * @mr: the region to contain the new subregion; must be a container
1793  *      initialized with memory_region_init().
1794  * @offset: the offset relative to @mr where @subregion is added.
1795  * @subregion: the subregion to be added.
1796  * @priority: used for resolving overlaps; highest priority wins.
1797  */
1798 void memory_region_add_subregion_overlap(MemoryRegion *mr,
1799                                          hwaddr offset,
1800                                          MemoryRegion *subregion,
1801                                          int priority);
1802 
1803 /**
1804  * memory_region_get_ram_addr: Get the ram address associated with a memory
1805  *                             region
1806  *
1807  * @mr: the region to be queried
1808  */
1809 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
1810 
1811 uint64_t memory_region_get_alignment(const MemoryRegion *mr);
1812 /**
1813  * memory_region_del_subregion: Remove a subregion.
1814  *
1815  * Removes a subregion from its container.
1816  *
1817  * @mr: the container to be updated.
1818  * @subregion: the region being removed; must be a current subregion of @mr.
1819  */
1820 void memory_region_del_subregion(MemoryRegion *mr,
1821                                  MemoryRegion *subregion);
1822 
1823 /*
1824  * memory_region_set_enabled: dynamically enable or disable a region
1825  *
1826  * Enables or disables a memory region.  A disabled memory region
1827  * ignores all accesses to itself and its subregions.  It does not
1828  * obscure sibling subregions with lower priority - it simply behaves as
1829  * if it was removed from the hierarchy.
1830  *
1831  * Regions default to being enabled.
1832  *
1833  * @mr: the region to be updated
1834  * @enabled: whether to enable or disable the region
1835  */
1836 void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
1837 
1838 /*
1839  * memory_region_set_address: dynamically update the address of a region
1840  *
1841  * Dynamically updates the address of a region, relative to its container.
1842  * May be used on regions are currently part of a memory hierarchy.
1843  *
1844  * @mr: the region to be updated
1845  * @addr: new address, relative to container region
1846  */
1847 void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
1848 
1849 /*
1850  * memory_region_set_size: dynamically update the size of a region.
1851  *
1852  * Dynamically updates the size of a region.
1853  *
1854  * @mr: the region to be updated
1855  * @size: used size of the region.
1856  */
1857 void memory_region_set_size(MemoryRegion *mr, uint64_t size);
1858 
1859 /*
1860  * memory_region_set_alias_offset: dynamically update a memory alias's offset
1861  *
1862  * Dynamically updates the offset into the target region that an alias points
1863  * to, as if the fourth argument to memory_region_init_alias() has changed.
1864  *
1865  * @mr: the #MemoryRegion to be updated; should be an alias.
1866  * @offset: the new offset into the target memory region
1867  */
1868 void memory_region_set_alias_offset(MemoryRegion *mr,
1869                                     hwaddr offset);
1870 
1871 /**
1872  * memory_region_present: checks if an address relative to a @container
1873  * translates into #MemoryRegion within @container
1874  *
1875  * Answer whether a #MemoryRegion within @container covers the address
1876  * @addr.
1877  *
1878  * @container: a #MemoryRegion within which @addr is a relative address
1879  * @addr: the area within @container to be searched
1880  */
1881 bool memory_region_present(MemoryRegion *container, hwaddr addr);
1882 
1883 /**
1884  * memory_region_is_mapped: returns true if #MemoryRegion is mapped
1885  * into any address space.
1886  *
1887  * @mr: a #MemoryRegion which should be checked if it's mapped
1888  */
1889 bool memory_region_is_mapped(MemoryRegion *mr);
1890 
1891 /**
1892  * memory_region_find: translate an address/size relative to a
1893  * MemoryRegion into a #MemoryRegionSection.
1894  *
1895  * Locates the first #MemoryRegion within @mr that overlaps the range
1896  * given by @addr and @size.
1897  *
1898  * Returns a #MemoryRegionSection that describes a contiguous overlap.
1899  * It will have the following characteristics:
1900  * - @size = 0 iff no overlap was found
1901  * - @mr is non-%NULL iff an overlap was found
1902  *
1903  * Remember that in the return value the @offset_within_region is
1904  * relative to the returned region (in the .@mr field), not to the
1905  * @mr argument.
1906  *
1907  * Similarly, the .@offset_within_address_space is relative to the
1908  * address space that contains both regions, the passed and the
1909  * returned one.  However, in the special case where the @mr argument
1910  * has no container (and thus is the root of the address space), the
1911  * following will hold:
1912  * - @offset_within_address_space >= @addr
1913  * - @offset_within_address_space + .@size <= @addr + @size
1914  *
1915  * @mr: a MemoryRegion within which @addr is a relative address
1916  * @addr: start of the area within @as to be searched
1917  * @size: size of the area to be searched
1918  */
1919 MemoryRegionSection memory_region_find(MemoryRegion *mr,
1920                                        hwaddr addr, uint64_t size);
1921 
1922 /**
1923  * memory_global_dirty_log_sync: synchronize the dirty log for all memory
1924  *
1925  * Synchronizes the dirty page log for all address spaces.
1926  */
1927 void memory_global_dirty_log_sync(void);
1928 
1929 /**
1930  * memory_global_dirty_log_sync: synchronize the dirty log for all memory
1931  *
1932  * Synchronizes the vCPUs with a thread that is reading the dirty bitmap.
1933  * This function must be called after the dirty log bitmap is cleared, and
1934  * before dirty guest memory pages are read.  If you are using
1935  * #DirtyBitmapSnapshot, memory_region_snapshot_and_clear_dirty() takes
1936  * care of doing this.
1937  */
1938 void memory_global_after_dirty_log_sync(void);
1939 
1940 /**
1941  * memory_region_transaction_begin: Start a transaction.
1942  *
1943  * During a transaction, changes will be accumulated and made visible
1944  * only when the transaction ends (is committed).
1945  */
1946 void memory_region_transaction_begin(void);
1947 
1948 /**
1949  * memory_region_transaction_commit: Commit a transaction and make changes
1950  *                                   visible to the guest.
1951  */
1952 void memory_region_transaction_commit(void);
1953 
1954 /**
1955  * memory_listener_register: register callbacks to be called when memory
1956  *                           sections are mapped or unmapped into an address
1957  *                           space
1958  *
1959  * @listener: an object containing the callbacks to be called
1960  * @filter: if non-%NULL, only regions in this address space will be observed
1961  */
1962 void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
1963 
1964 /**
1965  * memory_listener_unregister: undo the effect of memory_listener_register()
1966  *
1967  * @listener: an object containing the callbacks to be removed
1968  */
1969 void memory_listener_unregister(MemoryListener *listener);
1970 
1971 /**
1972  * memory_global_dirty_log_start: begin dirty logging for all regions
1973  */
1974 void memory_global_dirty_log_start(void);
1975 
1976 /**
1977  * memory_global_dirty_log_stop: end dirty logging for all regions
1978  */
1979 void memory_global_dirty_log_stop(void);
1980 
1981 void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled);
1982 
1983 /**
1984  * memory_region_dispatch_read: perform a read directly to the specified
1985  * MemoryRegion.
1986  *
1987  * @mr: #MemoryRegion to access
1988  * @addr: address within that region
1989  * @pval: pointer to uint64_t which the data is written to
1990  * @op: size, sign, and endianness of the memory operation
1991  * @attrs: memory transaction attributes to use for the access
1992  */
1993 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
1994                                         hwaddr addr,
1995                                         uint64_t *pval,
1996                                         MemOp op,
1997                                         MemTxAttrs attrs);
1998 /**
1999  * memory_region_dispatch_write: perform a write directly to the specified
2000  * MemoryRegion.
2001  *
2002  * @mr: #MemoryRegion to access
2003  * @addr: address within that region
2004  * @data: data to write
2005  * @op: size, sign, and endianness of the memory operation
2006  * @attrs: memory transaction attributes to use for the access
2007  */
2008 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
2009                                          hwaddr addr,
2010                                          uint64_t data,
2011                                          MemOp op,
2012                                          MemTxAttrs attrs);
2013 
2014 /**
2015  * address_space_init: initializes an address space
2016  *
2017  * @as: an uninitialized #AddressSpace
2018  * @root: a #MemoryRegion that routes addresses for the address space
2019  * @name: an address space name.  The name is only used for debugging
2020  *        output.
2021  */
2022 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
2023 
2024 /**
2025  * address_space_destroy: destroy an address space
2026  *
2027  * Releases all resources associated with an address space.  After an address space
2028  * is destroyed, its root memory region (given by address_space_init()) may be destroyed
2029  * as well.
2030  *
2031  * @as: address space to be destroyed
2032  */
2033 void address_space_destroy(AddressSpace *as);
2034 
2035 /**
2036  * address_space_remove_listeners: unregister all listeners of an address space
2037  *
2038  * Removes all callbacks previously registered with memory_listener_register()
2039  * for @as.
2040  *
2041  * @as: an initialized #AddressSpace
2042  */
2043 void address_space_remove_listeners(AddressSpace *as);
2044 
2045 /**
2046  * address_space_rw: read from or write to an address space.
2047  *
2048  * Return a MemTxResult indicating whether the operation succeeded
2049  * or failed (eg unassigned memory, device rejected the transaction,
2050  * IOMMU fault).
2051  *
2052  * @as: #AddressSpace to be accessed
2053  * @addr: address within that address space
2054  * @attrs: memory transaction attributes
2055  * @buf: buffer with the data transferred
2056  * @len: the number of bytes to read or write
2057  * @is_write: indicates the transfer direction
2058  */
2059 MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
2060                              MemTxAttrs attrs, void *buf,
2061                              hwaddr len, bool is_write);
2062 
2063 /**
2064  * address_space_write: write to address space.
2065  *
2066  * Return a MemTxResult indicating whether the operation succeeded
2067  * or failed (eg unassigned memory, device rejected the transaction,
2068  * IOMMU fault).
2069  *
2070  * @as: #AddressSpace to be accessed
2071  * @addr: address within that address space
2072  * @attrs: memory transaction attributes
2073  * @buf: buffer with the data transferred
2074  * @len: the number of bytes to write
2075  */
2076 MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
2077                                 MemTxAttrs attrs,
2078                                 const void *buf, hwaddr len);
2079 
2080 /**
2081  * address_space_write_rom: write to address space, including ROM.
2082  *
2083  * This function writes to the specified address space, but will
2084  * write data to both ROM and RAM. This is used for non-guest
2085  * writes like writes from the gdb debug stub or initial loading
2086  * of ROM contents.
2087  *
2088  * Note that portions of the write which attempt to write data to
2089  * a device will be silently ignored -- only real RAM and ROM will
2090  * be written to.
2091  *
2092  * Return a MemTxResult indicating whether the operation succeeded
2093  * or failed (eg unassigned memory, device rejected the transaction,
2094  * IOMMU fault).
2095  *
2096  * @as: #AddressSpace to be accessed
2097  * @addr: address within that address space
2098  * @attrs: memory transaction attributes
2099  * @buf: buffer with the data transferred
2100  * @len: the number of bytes to write
2101  */
2102 MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
2103                                     MemTxAttrs attrs,
2104                                     const void *buf, hwaddr len);
2105 
2106 /* address_space_ld*: load from an address space
2107  * address_space_st*: store to an address space
2108  *
2109  * These functions perform a load or store of the byte, word,
2110  * longword or quad to the specified address within the AddressSpace.
2111  * The _le suffixed functions treat the data as little endian;
2112  * _be indicates big endian; no suffix indicates "same endianness
2113  * as guest CPU".
2114  *
2115  * The "guest CPU endianness" accessors are deprecated for use outside
2116  * target-* code; devices should be CPU-agnostic and use either the LE
2117  * or the BE accessors.
2118  *
2119  * @as #AddressSpace to be accessed
2120  * @addr: address within that address space
2121  * @val: data value, for stores
2122  * @attrs: memory transaction attributes
2123  * @result: location to write the success/failure of the transaction;
2124  *   if NULL, this information is discarded
2125  */
2126 
2127 #define SUFFIX
2128 #define ARG1         as
2129 #define ARG1_DECL    AddressSpace *as
2130 #include "exec/memory_ldst.inc.h"
2131 
2132 #define SUFFIX
2133 #define ARG1         as
2134 #define ARG1_DECL    AddressSpace *as
2135 #include "exec/memory_ldst_phys.inc.h"
2136 
2137 struct MemoryRegionCache {
2138     void *ptr;
2139     hwaddr xlat;
2140     hwaddr len;
2141     FlatView *fv;
2142     MemoryRegionSection mrs;
2143     bool is_write;
2144 };
2145 
2146 #define MEMORY_REGION_CACHE_INVALID ((MemoryRegionCache) { .mrs.mr = NULL })
2147 
2148 
2149 /* address_space_ld*_cached: load from a cached #MemoryRegion
2150  * address_space_st*_cached: store into a cached #MemoryRegion
2151  *
2152  * These functions perform a load or store of the byte, word,
2153  * longword or quad to the specified address.  The address is
2154  * a physical address in the AddressSpace, but it must lie within
2155  * a #MemoryRegion that was mapped with address_space_cache_init.
2156  *
2157  * The _le suffixed functions treat the data as little endian;
2158  * _be indicates big endian; no suffix indicates "same endianness
2159  * as guest CPU".
2160  *
2161  * The "guest CPU endianness" accessors are deprecated for use outside
2162  * target-* code; devices should be CPU-agnostic and use either the LE
2163  * or the BE accessors.
2164  *
2165  * @cache: previously initialized #MemoryRegionCache to be accessed
2166  * @addr: address within the address space
2167  * @val: data value, for stores
2168  * @attrs: memory transaction attributes
2169  * @result: location to write the success/failure of the transaction;
2170  *   if NULL, this information is discarded
2171  */
2172 
2173 #define SUFFIX       _cached_slow
2174 #define ARG1         cache
2175 #define ARG1_DECL    MemoryRegionCache *cache
2176 #include "exec/memory_ldst.inc.h"
2177 
2178 /* Inline fast path for direct RAM access.  */
2179 static inline uint8_t address_space_ldub_cached(MemoryRegionCache *cache,
2180     hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
2181 {
2182     assert(addr < cache->len);
2183     if (likely(cache->ptr)) {
2184         return ldub_p(cache->ptr + addr);
2185     } else {
2186         return address_space_ldub_cached_slow(cache, addr, attrs, result);
2187     }
2188 }
2189 
2190 static inline void address_space_stb_cached(MemoryRegionCache *cache,
2191     hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
2192 {
2193     assert(addr < cache->len);
2194     if (likely(cache->ptr)) {
2195         stb_p(cache->ptr + addr, val);
2196     } else {
2197         address_space_stb_cached_slow(cache, addr, val, attrs, result);
2198     }
2199 }
2200 
2201 #define ENDIANNESS   _le
2202 #include "exec/memory_ldst_cached.inc.h"
2203 
2204 #define ENDIANNESS   _be
2205 #include "exec/memory_ldst_cached.inc.h"
2206 
2207 #define SUFFIX       _cached
2208 #define ARG1         cache
2209 #define ARG1_DECL    MemoryRegionCache *cache
2210 #include "exec/memory_ldst_phys.inc.h"
2211 
2212 /* address_space_cache_init: prepare for repeated access to a physical
2213  * memory region
2214  *
2215  * @cache: #MemoryRegionCache to be filled
2216  * @as: #AddressSpace to be accessed
2217  * @addr: address within that address space
2218  * @len: length of buffer
2219  * @is_write: indicates the transfer direction
2220  *
2221  * Will only work with RAM, and may map a subset of the requested range by
2222  * returning a value that is less than @len.  On failure, return a negative
2223  * errno value.
2224  *
2225  * Because it only works with RAM, this function can be used for
2226  * read-modify-write operations.  In this case, is_write should be %true.
2227  *
2228  * Note that addresses passed to the address_space_*_cached functions
2229  * are relative to @addr.
2230  */
2231 int64_t address_space_cache_init(MemoryRegionCache *cache,
2232                                  AddressSpace *as,
2233                                  hwaddr addr,
2234                                  hwaddr len,
2235                                  bool is_write);
2236 
2237 /**
2238  * address_space_cache_invalidate: complete a write to a #MemoryRegionCache
2239  *
2240  * @cache: The #MemoryRegionCache to operate on.
2241  * @addr: The first physical address that was written, relative to the
2242  * address that was passed to @address_space_cache_init.
2243  * @access_len: The number of bytes that were written starting at @addr.
2244  */
2245 void address_space_cache_invalidate(MemoryRegionCache *cache,
2246                                     hwaddr addr,
2247                                     hwaddr access_len);
2248 
2249 /**
2250  * address_space_cache_destroy: free a #MemoryRegionCache
2251  *
2252  * @cache: The #MemoryRegionCache whose memory should be released.
2253  */
2254 void address_space_cache_destroy(MemoryRegionCache *cache);
2255 
2256 /* address_space_get_iotlb_entry: translate an address into an IOTLB
2257  * entry. Should be called from an RCU critical section.
2258  */
2259 IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
2260                                             bool is_write, MemTxAttrs attrs);
2261 
2262 /* address_space_translate: translate an address range into an address space
2263  * into a MemoryRegion and an address range into that section.  Should be
2264  * called from an RCU critical section, to avoid that the last reference
2265  * to the returned region disappears after address_space_translate returns.
2266  *
2267  * @fv: #FlatView to be accessed
2268  * @addr: address within that address space
2269  * @xlat: pointer to address within the returned memory region section's
2270  * #MemoryRegion.
2271  * @len: pointer to length
2272  * @is_write: indicates the transfer direction
2273  * @attrs: memory attributes
2274  */
2275 MemoryRegion *flatview_translate(FlatView *fv,
2276                                  hwaddr addr, hwaddr *xlat,
2277                                  hwaddr *len, bool is_write,
2278                                  MemTxAttrs attrs);
2279 
2280 static inline MemoryRegion *address_space_translate(AddressSpace *as,
2281                                                     hwaddr addr, hwaddr *xlat,
2282                                                     hwaddr *len, bool is_write,
2283                                                     MemTxAttrs attrs)
2284 {
2285     return flatview_translate(address_space_to_flatview(as),
2286                               addr, xlat, len, is_write, attrs);
2287 }
2288 
2289 /* address_space_access_valid: check for validity of accessing an address
2290  * space range
2291  *
2292  * Check whether memory is assigned to the given address space range, and
2293  * access is permitted by any IOMMU regions that are active for the address
2294  * space.
2295  *
2296  * For now, addr and len should be aligned to a page size.  This limitation
2297  * will be lifted in the future.
2298  *
2299  * @as: #AddressSpace to be accessed
2300  * @addr: address within that address space
2301  * @len: length of the area to be checked
2302  * @is_write: indicates the transfer direction
2303  * @attrs: memory attributes
2304  */
2305 bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
2306                                 bool is_write, MemTxAttrs attrs);
2307 
2308 /* address_space_map: map a physical memory region into a host virtual address
2309  *
2310  * May map a subset of the requested range, given by and returned in @plen.
2311  * May return %NULL and set *@plen to zero(0), if resources needed to perform
2312  * the mapping are exhausted.
2313  * Use only for reads OR writes - not for read-modify-write operations.
2314  * Use cpu_register_map_client() to know when retrying the map operation is
2315  * likely to succeed.
2316  *
2317  * @as: #AddressSpace to be accessed
2318  * @addr: address within that address space
2319  * @plen: pointer to length of buffer; updated on return
2320  * @is_write: indicates the transfer direction
2321  * @attrs: memory attributes
2322  */
2323 void *address_space_map(AddressSpace *as, hwaddr addr,
2324                         hwaddr *plen, bool is_write, MemTxAttrs attrs);
2325 
2326 /* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
2327  *
2328  * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
2329  * the amount of memory that was actually read or written by the caller.
2330  *
2331  * @as: #AddressSpace used
2332  * @buffer: host pointer as returned by address_space_map()
2333  * @len: buffer length as returned by address_space_map()
2334  * @access_len: amount of data actually transferred
2335  * @is_write: indicates the transfer direction
2336  */
2337 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
2338                          bool is_write, hwaddr access_len);
2339 
2340 
2341 /* Internal functions, part of the implementation of address_space_read.  */
2342 MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
2343                                     MemTxAttrs attrs, void *buf, hwaddr len);
2344 MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
2345                                    MemTxAttrs attrs, void *buf,
2346                                    hwaddr len, hwaddr addr1, hwaddr l,
2347                                    MemoryRegion *mr);
2348 void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr);
2349 
2350 /* Internal functions, part of the implementation of address_space_read_cached
2351  * and address_space_write_cached.  */
2352 MemTxResult address_space_read_cached_slow(MemoryRegionCache *cache,
2353                                            hwaddr addr, void *buf, hwaddr len);
2354 MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
2355                                             hwaddr addr, const void *buf,
2356                                             hwaddr len);
2357 
2358 static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
2359 {
2360     if (is_write) {
2361         return memory_region_is_ram(mr) && !mr->readonly &&
2362                !mr->rom_device && !memory_region_is_ram_device(mr);
2363     } else {
2364         return (memory_region_is_ram(mr) && !memory_region_is_ram_device(mr)) ||
2365                memory_region_is_romd(mr);
2366     }
2367 }
2368 
2369 /**
2370  * address_space_read: read from an address space.
2371  *
2372  * Return a MemTxResult indicating whether the operation succeeded
2373  * or failed (eg unassigned memory, device rejected the transaction,
2374  * IOMMU fault).  Called within RCU critical section.
2375  *
2376  * @as: #AddressSpace to be accessed
2377  * @addr: address within that address space
2378  * @attrs: memory transaction attributes
2379  * @buf: buffer with the data transferred
2380  * @len: length of the data transferred
2381  */
2382 static inline __attribute__((__always_inline__))
2383 MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
2384                                MemTxAttrs attrs, void *buf,
2385                                hwaddr len)
2386 {
2387     MemTxResult result = MEMTX_OK;
2388     hwaddr l, addr1;
2389     void *ptr;
2390     MemoryRegion *mr;
2391     FlatView *fv;
2392 
2393     if (__builtin_constant_p(len)) {
2394         if (len) {
2395             RCU_READ_LOCK_GUARD();
2396             fv = address_space_to_flatview(as);
2397             l = len;
2398             mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
2399             if (len == l && memory_access_is_direct(mr, false)) {
2400                 ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
2401                 memcpy(buf, ptr, len);
2402             } else {
2403                 result = flatview_read_continue(fv, addr, attrs, buf, len,
2404                                                 addr1, l, mr);
2405             }
2406         }
2407     } else {
2408         result = address_space_read_full(as, addr, attrs, buf, len);
2409     }
2410     return result;
2411 }
2412 
2413 /**
2414  * address_space_read_cached: read from a cached RAM region
2415  *
2416  * @cache: Cached region to be addressed
2417  * @addr: address relative to the base of the RAM region
2418  * @buf: buffer with the data transferred
2419  * @len: length of the data transferred
2420  */
2421 static inline MemTxResult
2422 address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
2423                           void *buf, hwaddr len)
2424 {
2425     assert(addr < cache->len && len <= cache->len - addr);
2426     if (likely(cache->ptr)) {
2427         memcpy(buf, cache->ptr + addr, len);
2428         return MEMTX_OK;
2429     } else {
2430         return address_space_read_cached_slow(cache, addr, buf, len);
2431     }
2432 }
2433 
2434 /**
2435  * address_space_write_cached: write to a cached RAM region
2436  *
2437  * @cache: Cached region to be addressed
2438  * @addr: address relative to the base of the RAM region
2439  * @buf: buffer with the data transferred
2440  * @len: length of the data transferred
2441  */
2442 static inline MemTxResult
2443 address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
2444                            const void *buf, hwaddr len)
2445 {
2446     assert(addr < cache->len && len <= cache->len - addr);
2447     if (likely(cache->ptr)) {
2448         memcpy(cache->ptr + addr, buf, len);
2449         return MEMTX_OK;
2450     } else {
2451         return address_space_write_cached_slow(cache, addr, buf, len);
2452     }
2453 }
2454 
2455 #ifdef NEED_CPU_H
2456 /* enum device_endian to MemOp.  */
2457 static inline MemOp devend_memop(enum device_endian end)
2458 {
2459     QEMU_BUILD_BUG_ON(DEVICE_HOST_ENDIAN != DEVICE_LITTLE_ENDIAN &&
2460                       DEVICE_HOST_ENDIAN != DEVICE_BIG_ENDIAN);
2461 
2462 #if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
2463     /* Swap if non-host endianness or native (target) endianness */
2464     return (end == DEVICE_HOST_ENDIAN) ? 0 : MO_BSWAP;
2465 #else
2466     const int non_host_endianness =
2467         DEVICE_LITTLE_ENDIAN ^ DEVICE_BIG_ENDIAN ^ DEVICE_HOST_ENDIAN;
2468 
2469     /* In this case, native (target) endianness needs no swap.  */
2470     return (end == non_host_endianness) ? MO_BSWAP : 0;
2471 #endif
2472 }
2473 #endif
2474 
2475 #endif
2476 
2477 #endif
2478