xref: /openbmc/qemu/include/exec/memory.h (revision 4011a686)
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 "memory-region"
37 DECLARE_INSTANCE_CHECKER(MemoryRegion, MEMORY_REGION,
38                          TYPE_MEMORY_REGION)
39 
40 #define TYPE_IOMMU_MEMORY_REGION "iommu-memory-region"
41 typedef struct IOMMUMemoryRegionClass IOMMUMemoryRegionClass;
42 DECLARE_OBJ_CHECKERS(IOMMUMemoryRegion, IOMMUMemoryRegionClass,
43                      IOMMU_MEMORY_REGION, TYPE_IOMMU_MEMORY_REGION)
44 
45 #ifdef CONFIG_FUZZ
46 void fuzz_dma_read_cb(size_t addr,
47                       size_t len,
48                       MemoryRegion *mr);
49 #else
50 static inline void fuzz_dma_read_cb(size_t addr,
51                                     size_t len,
52                                     MemoryRegion *mr)
53 {
54     /* Do Nothing */
55 }
56 #endif
57 
58 extern bool global_dirty_log;
59 
60 typedef struct MemoryRegionOps MemoryRegionOps;
61 
62 struct ReservedRegion {
63     hwaddr low;
64     hwaddr high;
65     unsigned type;
66 };
67 
68 typedef struct IOMMUTLBEntry IOMMUTLBEntry;
69 
70 /* See address_space_translate: bit 0 is read, bit 1 is write.  */
71 typedef enum {
72     IOMMU_NONE = 0,
73     IOMMU_RO   = 1,
74     IOMMU_WO   = 2,
75     IOMMU_RW   = 3,
76 } IOMMUAccessFlags;
77 
78 #define IOMMU_ACCESS_FLAG(r, w) (((r) ? IOMMU_RO : 0) | ((w) ? IOMMU_WO : 0))
79 
80 struct IOMMUTLBEntry {
81     AddressSpace    *target_as;
82     hwaddr           iova;
83     hwaddr           translated_addr;
84     hwaddr           addr_mask;  /* 0xfff = 4k translation */
85     IOMMUAccessFlags perm;
86 };
87 
88 /*
89  * Bitmap for different IOMMUNotifier capabilities. Each notifier can
90  * register with one or multiple IOMMU Notifier capability bit(s).
91  */
92 typedef enum {
93     IOMMU_NOTIFIER_NONE = 0,
94     /* Notify cache invalidations */
95     IOMMU_NOTIFIER_UNMAP = 0x1,
96     /* Notify entry changes (newly created entries) */
97     IOMMU_NOTIFIER_MAP = 0x2,
98     /* Notify changes on device IOTLB entries */
99     IOMMU_NOTIFIER_DEVIOTLB_UNMAP = 0x04,
100 } IOMMUNotifierFlag;
101 
102 #define IOMMU_NOTIFIER_IOTLB_EVENTS (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP)
103 #define IOMMU_NOTIFIER_DEVIOTLB_EVENTS IOMMU_NOTIFIER_DEVIOTLB_UNMAP
104 #define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_IOTLB_EVENTS | \
105                             IOMMU_NOTIFIER_DEVIOTLB_EVENTS)
106 
107 struct IOMMUNotifier;
108 typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier,
109                             IOMMUTLBEntry *data);
110 
111 struct IOMMUNotifier {
112     IOMMUNotify notify;
113     IOMMUNotifierFlag notifier_flags;
114     /* Notify for address space range start <= addr <= end */
115     hwaddr start;
116     hwaddr end;
117     int iommu_idx;
118     QLIST_ENTRY(IOMMUNotifier) node;
119 };
120 typedef struct IOMMUNotifier IOMMUNotifier;
121 
122 typedef struct IOMMUTLBEvent {
123     IOMMUNotifierFlag type;
124     IOMMUTLBEntry entry;
125 } IOMMUTLBEvent;
126 
127 /* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
128 #define RAM_PREALLOC   (1 << 0)
129 
130 /* RAM is mmap-ed with MAP_SHARED */
131 #define RAM_SHARED     (1 << 1)
132 
133 /* Only a portion of RAM (used_length) is actually used, and migrated.
134  * This used_length size can change across reboots.
135  */
136 #define RAM_RESIZEABLE (1 << 2)
137 
138 /* UFFDIO_ZEROPAGE is available on this RAMBlock to atomically
139  * zero the page and wake waiting processes.
140  * (Set during postcopy)
141  */
142 #define RAM_UF_ZEROPAGE (1 << 3)
143 
144 /* RAM can be migrated */
145 #define RAM_MIGRATABLE (1 << 4)
146 
147 /* RAM is a persistent kind memory */
148 #define RAM_PMEM (1 << 5)
149 
150 
151 /*
152  * UFFDIO_WRITEPROTECT is used on this RAMBlock to
153  * support 'write-tracking' migration type.
154  * Implies ram_state->ram_wt_enabled.
155  */
156 #define RAM_UF_WRITEPROTECT (1 << 6)
157 
158 static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
159                                        IOMMUNotifierFlag flags,
160                                        hwaddr start, hwaddr end,
161                                        int iommu_idx)
162 {
163     n->notify = fn;
164     n->notifier_flags = flags;
165     n->start = start;
166     n->end = end;
167     n->iommu_idx = iommu_idx;
168 }
169 
170 /*
171  * Memory region callbacks
172  */
173 struct MemoryRegionOps {
174     /* Read from the memory region. @addr is relative to @mr; @size is
175      * in bytes. */
176     uint64_t (*read)(void *opaque,
177                      hwaddr addr,
178                      unsigned size);
179     /* Write to the memory region. @addr is relative to @mr; @size is
180      * in bytes. */
181     void (*write)(void *opaque,
182                   hwaddr addr,
183                   uint64_t data,
184                   unsigned size);
185 
186     MemTxResult (*read_with_attrs)(void *opaque,
187                                    hwaddr addr,
188                                    uint64_t *data,
189                                    unsigned size,
190                                    MemTxAttrs attrs);
191     MemTxResult (*write_with_attrs)(void *opaque,
192                                     hwaddr addr,
193                                     uint64_t data,
194                                     unsigned size,
195                                     MemTxAttrs attrs);
196 
197     enum device_endian endianness;
198     /* Guest-visible constraints: */
199     struct {
200         /* If nonzero, specify bounds on access sizes beyond which a machine
201          * check is thrown.
202          */
203         unsigned min_access_size;
204         unsigned max_access_size;
205         /* If true, unaligned accesses are supported.  Otherwise unaligned
206          * accesses throw machine checks.
207          */
208          bool unaligned;
209         /*
210          * If present, and returns #false, the transaction is not accepted
211          * by the device (and results in machine dependent behaviour such
212          * as a machine check exception).
213          */
214         bool (*accepts)(void *opaque, hwaddr addr,
215                         unsigned size, bool is_write,
216                         MemTxAttrs attrs);
217     } valid;
218     /* Internal implementation constraints: */
219     struct {
220         /* If nonzero, specifies the minimum size implemented.  Smaller sizes
221          * will be rounded upwards and a partial result will be returned.
222          */
223         unsigned min_access_size;
224         /* If nonzero, specifies the maximum size implemented.  Larger sizes
225          * will be done as a series of accesses with smaller sizes.
226          */
227         unsigned max_access_size;
228         /* If true, unaligned accesses are supported.  Otherwise all accesses
229          * are converted to (possibly multiple) naturally aligned accesses.
230          */
231         bool unaligned;
232     } impl;
233 };
234 
235 typedef struct MemoryRegionClass {
236     /* private */
237     ObjectClass parent_class;
238 } MemoryRegionClass;
239 
240 
241 enum IOMMUMemoryRegionAttr {
242     IOMMU_ATTR_SPAPR_TCE_FD
243 };
244 
245 /*
246  * IOMMUMemoryRegionClass:
247  *
248  * All IOMMU implementations need to subclass TYPE_IOMMU_MEMORY_REGION
249  * and provide an implementation of at least the @translate method here
250  * to handle requests to the memory region. Other methods are optional.
251  *
252  * The IOMMU implementation must use the IOMMU notifier infrastructure
253  * to report whenever mappings are changed, by calling
254  * memory_region_notify_iommu() (or, if necessary, by calling
255  * memory_region_notify_iommu_one() for each registered notifier).
256  *
257  * Conceptually an IOMMU provides a mapping from input address
258  * to an output TLB entry. If the IOMMU is aware of memory transaction
259  * attributes and the output TLB entry depends on the transaction
260  * attributes, we represent this using IOMMU indexes. Each index
261  * selects a particular translation table that the IOMMU has:
262  *
263  *   @attrs_to_index returns the IOMMU index for a set of transaction attributes
264  *
265  *   @translate takes an input address and an IOMMU index
266  *
267  * and the mapping returned can only depend on the input address and the
268  * IOMMU index.
269  *
270  * Most IOMMUs don't care about the transaction attributes and support
271  * only a single IOMMU index. A more complex IOMMU might have one index
272  * for secure transactions and one for non-secure transactions.
273  */
274 struct IOMMUMemoryRegionClass {
275     /* private: */
276     MemoryRegionClass parent_class;
277 
278     /* public: */
279     /**
280      * @translate:
281      *
282      * Return a TLB entry that contains a given address.
283      *
284      * The IOMMUAccessFlags indicated via @flag are optional and may
285      * be specified as IOMMU_NONE to indicate that the caller needs
286      * the full translation information for both reads and writes. If
287      * the access flags are specified then the IOMMU implementation
288      * may use this as an optimization, to stop doing a page table
289      * walk as soon as it knows that the requested permissions are not
290      * allowed. If IOMMU_NONE is passed then the IOMMU must do the
291      * full page table walk and report the permissions in the returned
292      * IOMMUTLBEntry. (Note that this implies that an IOMMU may not
293      * return different mappings for reads and writes.)
294      *
295      * The returned information remains valid while the caller is
296      * holding the big QEMU lock or is inside an RCU critical section;
297      * if the caller wishes to cache the mapping beyond that it must
298      * register an IOMMU notifier so it can invalidate its cached
299      * information when the IOMMU mapping changes.
300      *
301      * @iommu: the IOMMUMemoryRegion
302      *
303      * @hwaddr: address to be translated within the memory region
304      *
305      * @flag: requested access permission
306      *
307      * @iommu_idx: IOMMU index for the translation
308      */
309     IOMMUTLBEntry (*translate)(IOMMUMemoryRegion *iommu, hwaddr addr,
310                                IOMMUAccessFlags flag, int iommu_idx);
311     /**
312      * @get_min_page_size:
313      *
314      * Returns minimum supported page size in bytes.
315      *
316      * If this method is not provided then the minimum is assumed to
317      * be TARGET_PAGE_SIZE.
318      *
319      * @iommu: the IOMMUMemoryRegion
320      */
321     uint64_t (*get_min_page_size)(IOMMUMemoryRegion *iommu);
322     /**
323      * @notify_flag_changed:
324      *
325      * Called when IOMMU Notifier flag changes (ie when the set of
326      * events which IOMMU users are requesting notification for changes).
327      * Optional method -- need not be provided if the IOMMU does not
328      * need to know exactly which events must be notified.
329      *
330      * @iommu: the IOMMUMemoryRegion
331      *
332      * @old_flags: events which previously needed to be notified
333      *
334      * @new_flags: events which now need to be notified
335      *
336      * Returns 0 on success, or a negative errno; in particular
337      * returns -EINVAL if the new flag bitmap is not supported by the
338      * IOMMU memory region. In case of failure, the error object
339      * must be created
340      */
341     int (*notify_flag_changed)(IOMMUMemoryRegion *iommu,
342                                IOMMUNotifierFlag old_flags,
343                                IOMMUNotifierFlag new_flags,
344                                Error **errp);
345     /**
346      * @replay:
347      *
348      * Called to handle memory_region_iommu_replay().
349      *
350      * The default implementation of memory_region_iommu_replay() is to
351      * call the IOMMU translate method for every page in the address space
352      * with flag == IOMMU_NONE and then call the notifier if translate
353      * returns a valid mapping. If this method is implemented then it
354      * overrides the default behaviour, and must provide the full semantics
355      * of memory_region_iommu_replay(), by calling @notifier for every
356      * translation present in the IOMMU.
357      *
358      * Optional method -- an IOMMU only needs to provide this method
359      * if the default is inefficient or produces undesirable side effects.
360      *
361      * Note: this is not related to record-and-replay functionality.
362      */
363     void (*replay)(IOMMUMemoryRegion *iommu, IOMMUNotifier *notifier);
364 
365     /**
366      * @get_attr:
367      *
368      * Get IOMMU misc attributes. This is an optional method that
369      * can be used to allow users of the IOMMU to get implementation-specific
370      * information. The IOMMU implements this method to handle calls
371      * by IOMMU users to memory_region_iommu_get_attr() by filling in
372      * the arbitrary data pointer for any IOMMUMemoryRegionAttr values that
373      * the IOMMU supports. If the method is unimplemented then
374      * memory_region_iommu_get_attr() will always return -EINVAL.
375      *
376      * @iommu: the IOMMUMemoryRegion
377      *
378      * @attr: attribute being queried
379      *
380      * @data: memory to fill in with the attribute data
381      *
382      * Returns 0 on success, or a negative errno; in particular
383      * returns -EINVAL for unrecognized or unimplemented attribute types.
384      */
385     int (*get_attr)(IOMMUMemoryRegion *iommu, enum IOMMUMemoryRegionAttr attr,
386                     void *data);
387 
388     /**
389      * @attrs_to_index:
390      *
391      * Return the IOMMU index to use for a given set of transaction attributes.
392      *
393      * Optional method: if an IOMMU only supports a single IOMMU index then
394      * the default implementation of memory_region_iommu_attrs_to_index()
395      * will return 0.
396      *
397      * The indexes supported by an IOMMU must be contiguous, starting at 0.
398      *
399      * @iommu: the IOMMUMemoryRegion
400      * @attrs: memory transaction attributes
401      */
402     int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs);
403 
404     /**
405      * @num_indexes:
406      *
407      * Return the number of IOMMU indexes this IOMMU supports.
408      *
409      * Optional method: if this method is not provided, then
410      * memory_region_iommu_num_indexes() will return 1, indicating that
411      * only a single IOMMU index is supported.
412      *
413      * @iommu: the IOMMUMemoryRegion
414      */
415     int (*num_indexes)(IOMMUMemoryRegion *iommu);
416 
417     /**
418      * @iommu_set_page_size_mask:
419      *
420      * Restrict the page size mask that can be supported with a given IOMMU
421      * memory region. Used for example to propagate host physical IOMMU page
422      * size mask limitations to the virtual IOMMU.
423      *
424      * Optional method: if this method is not provided, then the default global
425      * page mask is used.
426      *
427      * @iommu: the IOMMUMemoryRegion
428      *
429      * @page_size_mask: a bitmask of supported page sizes. At least one bit,
430      * representing the smallest page size, must be set. Additional set bits
431      * represent supported block sizes. For example a host physical IOMMU that
432      * uses page tables with a page size of 4kB, and supports 2MB and 4GB
433      * blocks, will set mask 0x40201000. A granule of 4kB with indiscriminate
434      * block sizes is specified with mask 0xfffffffffffff000.
435      *
436      * Returns 0 on success, or a negative error. In case of failure, the error
437      * object must be created.
438      */
439      int (*iommu_set_page_size_mask)(IOMMUMemoryRegion *iommu,
440                                      uint64_t page_size_mask,
441                                      Error **errp);
442 };
443 
444 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
445 typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
446 
447 /** MemoryRegion:
448  *
449  * A struct representing a memory region.
450  */
451 struct MemoryRegion {
452     Object parent_obj;
453 
454     /* private: */
455 
456     /* The following fields should fit in a cache line */
457     bool romd_mode;
458     bool ram;
459     bool subpage;
460     bool readonly; /* For RAM regions */
461     bool nonvolatile;
462     bool rom_device;
463     bool flush_coalesced_mmio;
464     uint8_t dirty_log_mask;
465     bool is_iommu;
466     RAMBlock *ram_block;
467     Object *owner;
468 
469     const MemoryRegionOps *ops;
470     void *opaque;
471     MemoryRegion *container;
472     Int128 size;
473     hwaddr addr;
474     void (*destructor)(MemoryRegion *mr);
475     uint64_t align;
476     bool terminates;
477     bool ram_device;
478     bool enabled;
479     bool warning_printed; /* For reservations */
480     uint8_t vga_logging_count;
481     MemoryRegion *alias;
482     hwaddr alias_offset;
483     int32_t priority;
484     QTAILQ_HEAD(, MemoryRegion) subregions;
485     QTAILQ_ENTRY(MemoryRegion) subregions_link;
486     QTAILQ_HEAD(, CoalescedMemoryRange) coalesced;
487     const char *name;
488     unsigned ioeventfd_nb;
489     MemoryRegionIoeventfd *ioeventfds;
490 };
491 
492 struct IOMMUMemoryRegion {
493     MemoryRegion parent_obj;
494 
495     QLIST_HEAD(, IOMMUNotifier) iommu_notify;
496     IOMMUNotifierFlag iommu_notify_flags;
497 };
498 
499 #define IOMMU_NOTIFIER_FOREACH(n, mr) \
500     QLIST_FOREACH((n), &(mr)->iommu_notify, node)
501 
502 /**
503  * struct MemoryListener: callbacks structure for updates to the physical memory map
504  *
505  * Allows a component to adjust to changes in the guest-visible memory map.
506  * Use with memory_listener_register() and memory_listener_unregister().
507  */
508 struct MemoryListener {
509     /**
510      * @begin:
511      *
512      * Called at the beginning of an address space update transaction.
513      * Followed by calls to #MemoryListener.region_add(),
514      * #MemoryListener.region_del(), #MemoryListener.region_nop(),
515      * #MemoryListener.log_start() and #MemoryListener.log_stop() in
516      * increasing address order.
517      *
518      * @listener: The #MemoryListener.
519      */
520     void (*begin)(MemoryListener *listener);
521 
522     /**
523      * @commit:
524      *
525      * Called at the end of an address space update transaction,
526      * after the last call to #MemoryListener.region_add(),
527      * #MemoryListener.region_del() or #MemoryListener.region_nop(),
528      * #MemoryListener.log_start() and #MemoryListener.log_stop().
529      *
530      * @listener: The #MemoryListener.
531      */
532     void (*commit)(MemoryListener *listener);
533 
534     /**
535      * @region_add:
536      *
537      * Called during an address space update transaction,
538      * for a section of the address space that is new in this address space
539      * space since the last transaction.
540      *
541      * @listener: The #MemoryListener.
542      * @section: The new #MemoryRegionSection.
543      */
544     void (*region_add)(MemoryListener *listener, MemoryRegionSection *section);
545 
546     /**
547      * @region_del:
548      *
549      * Called during an address space update transaction,
550      * for a section of the address space that has disappeared in the address
551      * space since the last transaction.
552      *
553      * @listener: The #MemoryListener.
554      * @section: The old #MemoryRegionSection.
555      */
556     void (*region_del)(MemoryListener *listener, MemoryRegionSection *section);
557 
558     /**
559      * @region_nop:
560      *
561      * Called during an address space update transaction,
562      * for a section of the address space that is in the same place in the address
563      * space as in the last transaction.
564      *
565      * @listener: The #MemoryListener.
566      * @section: The #MemoryRegionSection.
567      */
568     void (*region_nop)(MemoryListener *listener, MemoryRegionSection *section);
569 
570     /**
571      * @log_start:
572      *
573      * Called during an address space update transaction, after
574      * one of #MemoryListener.region_add(),#MemoryListener.region_del() or
575      * #MemoryListener.region_nop(), if dirty memory logging clients have
576      * become active since the last transaction.
577      *
578      * @listener: The #MemoryListener.
579      * @section: The #MemoryRegionSection.
580      * @old: A bitmap of dirty memory logging clients that were active in
581      * the previous transaction.
582      * @new: A bitmap of dirty memory logging clients that are active in
583      * the current transaction.
584      */
585     void (*log_start)(MemoryListener *listener, MemoryRegionSection *section,
586                       int old, int new);
587 
588     /**
589      * @log_stop:
590      *
591      * Called during an address space update transaction, after
592      * one of #MemoryListener.region_add(), #MemoryListener.region_del() or
593      * #MemoryListener.region_nop() and possibly after
594      * #MemoryListener.log_start(), if dirty memory logging clients have
595      * become inactive since the last transaction.
596      *
597      * @listener: The #MemoryListener.
598      * @section: The #MemoryRegionSection.
599      * @old: A bitmap of dirty memory logging clients that were active in
600      * the previous transaction.
601      * @new: A bitmap of dirty memory logging clients that are active in
602      * the current transaction.
603      */
604     void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section,
605                      int old, int new);
606 
607     /**
608      * @log_sync:
609      *
610      * Called by memory_region_snapshot_and_clear_dirty() and
611      * memory_global_dirty_log_sync(), before accessing QEMU's "official"
612      * copy of the dirty memory bitmap for a #MemoryRegionSection.
613      *
614      * @listener: The #MemoryListener.
615      * @section: The #MemoryRegionSection.
616      */
617     void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
618 
619     /**
620      * @log_clear:
621      *
622      * Called before reading the dirty memory bitmap for a
623      * #MemoryRegionSection.
624      *
625      * @listener: The #MemoryListener.
626      * @section: The #MemoryRegionSection.
627      */
628     void (*log_clear)(MemoryListener *listener, MemoryRegionSection *section);
629 
630     /**
631      * @log_global_start:
632      *
633      * Called by memory_global_dirty_log_start(), which
634      * enables the %DIRTY_LOG_MIGRATION client on all memory regions in
635      * the address space.  #MemoryListener.log_global_start() is also
636      * called when a #MemoryListener is added, if global dirty logging is
637      * active at that time.
638      *
639      * @listener: The #MemoryListener.
640      */
641     void (*log_global_start)(MemoryListener *listener);
642 
643     /**
644      * @log_global_stop:
645      *
646      * Called by memory_global_dirty_log_stop(), which
647      * disables the %DIRTY_LOG_MIGRATION client on all memory regions in
648      * the address space.
649      *
650      * @listener: The #MemoryListener.
651      */
652     void (*log_global_stop)(MemoryListener *listener);
653 
654     /**
655      * @log_global_after_sync:
656      *
657      * Called after reading the dirty memory bitmap
658      * for any #MemoryRegionSection.
659      *
660      * @listener: The #MemoryListener.
661      */
662     void (*log_global_after_sync)(MemoryListener *listener);
663 
664     /**
665      * @eventfd_add:
666      *
667      * Called during an address space update transaction,
668      * for a section of the address space that has had a new ioeventfd
669      * registration since the last transaction.
670      *
671      * @listener: The #MemoryListener.
672      * @section: The new #MemoryRegionSection.
673      * @match_data: The @match_data parameter for the new ioeventfd.
674      * @data: The @data parameter for the new ioeventfd.
675      * @e: The #EventNotifier parameter for the new ioeventfd.
676      */
677     void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
678                         bool match_data, uint64_t data, EventNotifier *e);
679 
680     /**
681      * @eventfd_del:
682      *
683      * Called during an address space update transaction,
684      * for a section of the address space that has dropped an ioeventfd
685      * registration since the last transaction.
686      *
687      * @listener: The #MemoryListener.
688      * @section: The new #MemoryRegionSection.
689      * @match_data: The @match_data parameter for the dropped ioeventfd.
690      * @data: The @data parameter for the dropped ioeventfd.
691      * @e: The #EventNotifier parameter for the dropped ioeventfd.
692      */
693     void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
694                         bool match_data, uint64_t data, EventNotifier *e);
695 
696     /**
697      * @coalesced_io_add:
698      *
699      * Called during an address space update transaction,
700      * for a section of the address space that has had a new coalesced
701      * MMIO range registration since the last transaction.
702      *
703      * @listener: The #MemoryListener.
704      * @section: The new #MemoryRegionSection.
705      * @addr: The starting address for the coalesced MMIO range.
706      * @len: The length of the coalesced MMIO range.
707      */
708     void (*coalesced_io_add)(MemoryListener *listener, MemoryRegionSection *section,
709                                hwaddr addr, hwaddr len);
710 
711     /**
712      * @coalesced_io_del:
713      *
714      * Called during an address space update transaction,
715      * for a section of the address space that has dropped a coalesced
716      * MMIO range since the last transaction.
717      *
718      * @listener: The #MemoryListener.
719      * @section: The new #MemoryRegionSection.
720      * @addr: The starting address for the coalesced MMIO range.
721      * @len: The length of the coalesced MMIO range.
722      */
723     void (*coalesced_io_del)(MemoryListener *listener, MemoryRegionSection *section,
724                                hwaddr addr, hwaddr len);
725     /**
726      * @priority:
727      *
728      * Govern the order in which memory listeners are invoked. Lower priorities
729      * are invoked earlier for "add" or "start" callbacks, and later for "delete"
730      * or "stop" callbacks.
731      */
732     unsigned priority;
733 
734     /* private: */
735     AddressSpace *address_space;
736     QTAILQ_ENTRY(MemoryListener) link;
737     QTAILQ_ENTRY(MemoryListener) link_as;
738 };
739 
740 /**
741  * struct AddressSpace: describes a mapping of addresses to #MemoryRegion objects
742  */
743 struct AddressSpace {
744     /* private: */
745     struct rcu_head rcu;
746     char *name;
747     MemoryRegion *root;
748 
749     /* Accessed via RCU.  */
750     struct FlatView *current_map;
751 
752     int ioeventfd_nb;
753     struct MemoryRegionIoeventfd *ioeventfds;
754     QTAILQ_HEAD(, MemoryListener) listeners;
755     QTAILQ_ENTRY(AddressSpace) address_spaces_link;
756 };
757 
758 typedef struct AddressSpaceDispatch AddressSpaceDispatch;
759 typedef struct FlatRange FlatRange;
760 
761 /* Flattened global view of current active memory hierarchy.  Kept in sorted
762  * order.
763  */
764 struct FlatView {
765     struct rcu_head rcu;
766     unsigned ref;
767     FlatRange *ranges;
768     unsigned nr;
769     unsigned nr_allocated;
770     struct AddressSpaceDispatch *dispatch;
771     MemoryRegion *root;
772 };
773 
774 static inline FlatView *address_space_to_flatview(AddressSpace *as)
775 {
776     return qatomic_rcu_read(&as->current_map);
777 }
778 
779 /**
780  * typedef flatview_cb: callback for flatview_for_each_range()
781  *
782  * @start: start address of the range within the FlatView
783  * @len: length of the range in bytes
784  * @mr: MemoryRegion covering this range
785  * @offset_in_region: offset of the first byte of the range within @mr
786  * @opaque: data pointer passed to flatview_for_each_range()
787  *
788  * Returns: true to stop the iteration, false to keep going.
789  */
790 typedef bool (*flatview_cb)(Int128 start,
791                             Int128 len,
792                             const MemoryRegion *mr,
793                             hwaddr offset_in_region,
794                             void *opaque);
795 
796 /**
797  * flatview_for_each_range: Iterate through a FlatView
798  * @fv: the FlatView to iterate through
799  * @cb: function to call for each range
800  * @opaque: opaque data pointer to pass to @cb
801  *
802  * A FlatView is made up of a list of non-overlapping ranges, each of
803  * which is a slice of a MemoryRegion. This function iterates through
804  * each range in @fv, calling @cb. The callback function can terminate
805  * iteration early by returning 'true'.
806  */
807 void flatview_for_each_range(FlatView *fv, flatview_cb cb, void *opaque);
808 
809 /**
810  * struct MemoryRegionSection: describes a fragment of a #MemoryRegion
811  *
812  * @mr: the region, or %NULL if empty
813  * @fv: the flat view of the address space the region is mapped in
814  * @offset_within_region: the beginning of the section, relative to @mr's start
815  * @size: the size of the section; will not exceed @mr's boundaries
816  * @offset_within_address_space: the address of the first byte of the section
817  *     relative to the region's address space
818  * @readonly: writes to this section are ignored
819  * @nonvolatile: this section is non-volatile
820  */
821 struct MemoryRegionSection {
822     Int128 size;
823     MemoryRegion *mr;
824     FlatView *fv;
825     hwaddr offset_within_region;
826     hwaddr offset_within_address_space;
827     bool readonly;
828     bool nonvolatile;
829 };
830 
831 static inline bool MemoryRegionSection_eq(MemoryRegionSection *a,
832                                           MemoryRegionSection *b)
833 {
834     return a->mr == b->mr &&
835            a->fv == b->fv &&
836            a->offset_within_region == b->offset_within_region &&
837            a->offset_within_address_space == b->offset_within_address_space &&
838            int128_eq(a->size, b->size) &&
839            a->readonly == b->readonly &&
840            a->nonvolatile == b->nonvolatile;
841 }
842 
843 /**
844  * memory_region_init: Initialize a memory region
845  *
846  * The region typically acts as a container for other memory regions.  Use
847  * memory_region_add_subregion() to add subregions.
848  *
849  * @mr: the #MemoryRegion to be initialized
850  * @owner: the object that tracks the region's reference count
851  * @name: used for debugging; not visible to the user or ABI
852  * @size: size of the region; any subregions beyond this size will be clipped
853  */
854 void memory_region_init(MemoryRegion *mr,
855                         Object *owner,
856                         const char *name,
857                         uint64_t size);
858 
859 /**
860  * memory_region_ref: Add 1 to a memory region's reference count
861  *
862  * Whenever memory regions are accessed outside the BQL, they need to be
863  * preserved against hot-unplug.  MemoryRegions actually do not have their
864  * own reference count; they piggyback on a QOM object, their "owner".
865  * This function adds a reference to the owner.
866  *
867  * All MemoryRegions must have an owner if they can disappear, even if the
868  * device they belong to operates exclusively under the BQL.  This is because
869  * the region could be returned at any time by memory_region_find, and this
870  * is usually under guest control.
871  *
872  * @mr: the #MemoryRegion
873  */
874 void memory_region_ref(MemoryRegion *mr);
875 
876 /**
877  * memory_region_unref: Remove 1 to a memory region's reference count
878  *
879  * Whenever memory regions are accessed outside the BQL, they need to be
880  * preserved against hot-unplug.  MemoryRegions actually do not have their
881  * own reference count; they piggyback on a QOM object, their "owner".
882  * This function removes a reference to the owner and possibly destroys it.
883  *
884  * @mr: the #MemoryRegion
885  */
886 void memory_region_unref(MemoryRegion *mr);
887 
888 /**
889  * memory_region_init_io: Initialize an I/O memory region.
890  *
891  * Accesses into the region will cause the callbacks in @ops to be called.
892  * if @size is nonzero, subregions will be clipped to @size.
893  *
894  * @mr: the #MemoryRegion to be initialized.
895  * @owner: the object that tracks the region's reference count
896  * @ops: a structure containing read and write callbacks to be used when
897  *       I/O is performed on the region.
898  * @opaque: passed to the read and write callbacks of the @ops structure.
899  * @name: used for debugging; not visible to the user or ABI
900  * @size: size of the region.
901  */
902 void memory_region_init_io(MemoryRegion *mr,
903                            Object *owner,
904                            const MemoryRegionOps *ops,
905                            void *opaque,
906                            const char *name,
907                            uint64_t size);
908 
909 /**
910  * memory_region_init_ram_nomigrate:  Initialize RAM memory region.  Accesses
911  *                                    into the region will modify memory
912  *                                    directly.
913  *
914  * @mr: the #MemoryRegion to be initialized.
915  * @owner: the object that tracks the region's reference count
916  * @name: Region name, becomes part of RAMBlock name used in migration stream
917  *        must be unique within any device
918  * @size: size of the region.
919  * @errp: pointer to Error*, to store an error if it happens.
920  *
921  * Note that this function does not do anything to cause the data in the
922  * RAM memory region to be migrated; that is the responsibility of the caller.
923  */
924 void memory_region_init_ram_nomigrate(MemoryRegion *mr,
925                                       Object *owner,
926                                       const char *name,
927                                       uint64_t size,
928                                       Error **errp);
929 
930 /**
931  * memory_region_init_ram_shared_nomigrate:  Initialize RAM memory region.
932  *                                           Accesses into the region will
933  *                                           modify memory directly.
934  *
935  * @mr: the #MemoryRegion to be initialized.
936  * @owner: the object that tracks the region's reference count
937  * @name: Region name, becomes part of RAMBlock name used in migration stream
938  *        must be unique within any device
939  * @size: size of the region.
940  * @share: allow remapping RAM to different addresses
941  * @errp: pointer to Error*, to store an error if it happens.
942  *
943  * Note that this function is similar to memory_region_init_ram_nomigrate.
944  * The only difference is part of the RAM region can be remapped.
945  */
946 void memory_region_init_ram_shared_nomigrate(MemoryRegion *mr,
947                                              Object *owner,
948                                              const char *name,
949                                              uint64_t size,
950                                              bool share,
951                                              Error **errp);
952 
953 /**
954  * memory_region_init_resizeable_ram:  Initialize memory region with resizeable
955  *                                     RAM.  Accesses into the region will
956  *                                     modify memory directly.  Only an initial
957  *                                     portion of this RAM is actually used.
958  *                                     The used size can change across reboots.
959  *
960  * @mr: the #MemoryRegion to be initialized.
961  * @owner: the object that tracks the region's reference count
962  * @name: Region name, becomes part of RAMBlock name used in migration stream
963  *        must be unique within any device
964  * @size: used size of the region.
965  * @max_size: max size of the region.
966  * @resized: callback to notify owner about used size change.
967  * @errp: pointer to Error*, to store an error if it happens.
968  *
969  * Note that this function does not do anything to cause the data in the
970  * RAM memory region to be migrated; that is the responsibility of the caller.
971  */
972 void memory_region_init_resizeable_ram(MemoryRegion *mr,
973                                        Object *owner,
974                                        const char *name,
975                                        uint64_t size,
976                                        uint64_t max_size,
977                                        void (*resized)(const char*,
978                                                        uint64_t length,
979                                                        void *host),
980                                        Error **errp);
981 #ifdef CONFIG_POSIX
982 
983 /**
984  * memory_region_init_ram_from_file:  Initialize RAM memory region with a
985  *                                    mmap-ed backend.
986  *
987  * @mr: the #MemoryRegion to be initialized.
988  * @owner: the object that tracks the region's reference count
989  * @name: Region name, becomes part of RAMBlock name used in migration stream
990  *        must be unique within any device
991  * @size: size of the region.
992  * @align: alignment of the region base address; if 0, the default alignment
993  *         (getpagesize()) will be used.
994  * @ram_flags: Memory region features:
995  *             - RAM_SHARED: memory must be mmaped with the MAP_SHARED flag
996  *             - RAM_PMEM: the memory is persistent memory
997  *             Other bits are ignored now.
998  * @path: the path in which to allocate the RAM.
999  * @readonly: true to open @path for reading, false for read/write.
1000  * @errp: pointer to Error*, to store an error if it happens.
1001  *
1002  * Note that this function does not do anything to cause the data in the
1003  * RAM memory region to be migrated; that is the responsibility of the caller.
1004  */
1005 void memory_region_init_ram_from_file(MemoryRegion *mr,
1006                                       Object *owner,
1007                                       const char *name,
1008                                       uint64_t size,
1009                                       uint64_t align,
1010                                       uint32_t ram_flags,
1011                                       const char *path,
1012                                       bool readonly,
1013                                       Error **errp);
1014 
1015 /**
1016  * memory_region_init_ram_from_fd:  Initialize RAM memory region with a
1017  *                                  mmap-ed backend.
1018  *
1019  * @mr: the #MemoryRegion to be initialized.
1020  * @owner: the object that tracks the region's reference count
1021  * @name: the name of the region.
1022  * @size: size of the region.
1023  * @share: %true if memory must be mmaped with the MAP_SHARED flag
1024  * @fd: the fd to mmap.
1025  * @offset: offset within the file referenced by fd
1026  * @errp: pointer to Error*, to store an error if it happens.
1027  *
1028  * Note that this function does not do anything to cause the data in the
1029  * RAM memory region to be migrated; that is the responsibility of the caller.
1030  */
1031 void memory_region_init_ram_from_fd(MemoryRegion *mr,
1032                                     Object *owner,
1033                                     const char *name,
1034                                     uint64_t size,
1035                                     bool share,
1036                                     int fd,
1037                                     ram_addr_t offset,
1038                                     Error **errp);
1039 #endif
1040 
1041 /**
1042  * memory_region_init_ram_ptr:  Initialize RAM memory region from a
1043  *                              user-provided pointer.  Accesses into the
1044  *                              region will modify memory directly.
1045  *
1046  * @mr: the #MemoryRegion to be initialized.
1047  * @owner: the object that tracks the region's reference count
1048  * @name: Region name, becomes part of RAMBlock name used in migration stream
1049  *        must be unique within any device
1050  * @size: size of the region.
1051  * @ptr: memory to be mapped; must contain at least @size bytes.
1052  *
1053  * Note that this function does not do anything to cause the data in the
1054  * RAM memory region to be migrated; that is the responsibility of the caller.
1055  */
1056 void memory_region_init_ram_ptr(MemoryRegion *mr,
1057                                 Object *owner,
1058                                 const char *name,
1059                                 uint64_t size,
1060                                 void *ptr);
1061 
1062 /**
1063  * memory_region_init_ram_device_ptr:  Initialize RAM device memory region from
1064  *                                     a user-provided pointer.
1065  *
1066  * A RAM device represents a mapping to a physical device, such as to a PCI
1067  * MMIO BAR of an vfio-pci assigned device.  The memory region may be mapped
1068  * into the VM address space and access to the region will modify memory
1069  * directly.  However, the memory region should not be included in a memory
1070  * dump (device may not be enabled/mapped at the time of the dump), and
1071  * operations incompatible with manipulating MMIO should be avoided.  Replaces
1072  * skip_dump flag.
1073  *
1074  * @mr: the #MemoryRegion to be initialized.
1075  * @owner: the object that tracks the region's reference count
1076  * @name: the name of the region.
1077  * @size: size of the region.
1078  * @ptr: memory to be mapped; must contain at least @size bytes.
1079  *
1080  * Note that this function does not do anything to cause the data in the
1081  * RAM memory region to be migrated; that is the responsibility of the caller.
1082  * (For RAM device memory regions, migrating the contents rarely makes sense.)
1083  */
1084 void memory_region_init_ram_device_ptr(MemoryRegion *mr,
1085                                        Object *owner,
1086                                        const char *name,
1087                                        uint64_t size,
1088                                        void *ptr);
1089 
1090 /**
1091  * memory_region_init_alias: Initialize a memory region that aliases all or a
1092  *                           part of another memory region.
1093  *
1094  * @mr: the #MemoryRegion to be initialized.
1095  * @owner: the object that tracks the region's reference count
1096  * @name: used for debugging; not visible to the user or ABI
1097  * @orig: the region to be referenced; @mr will be equivalent to
1098  *        @orig between @offset and @offset + @size - 1.
1099  * @offset: start of the section in @orig to be referenced.
1100  * @size: size of the region.
1101  */
1102 void memory_region_init_alias(MemoryRegion *mr,
1103                               Object *owner,
1104                               const char *name,
1105                               MemoryRegion *orig,
1106                               hwaddr offset,
1107                               uint64_t size);
1108 
1109 /**
1110  * memory_region_init_rom_nomigrate: Initialize a ROM memory region.
1111  *
1112  * This has the same effect as calling memory_region_init_ram_nomigrate()
1113  * and then marking the resulting region read-only with
1114  * memory_region_set_readonly().
1115  *
1116  * Note that this function does not do anything to cause the data in the
1117  * RAM side of the memory region to be migrated; that is the responsibility
1118  * of the caller.
1119  *
1120  * @mr: the #MemoryRegion to be initialized.
1121  * @owner: the object that tracks the region's reference count
1122  * @name: Region name, becomes part of RAMBlock name used in migration stream
1123  *        must be unique within any device
1124  * @size: size of the region.
1125  * @errp: pointer to Error*, to store an error if it happens.
1126  */
1127 void memory_region_init_rom_nomigrate(MemoryRegion *mr,
1128                                       Object *owner,
1129                                       const char *name,
1130                                       uint64_t size,
1131                                       Error **errp);
1132 
1133 /**
1134  * memory_region_init_rom_device_nomigrate:  Initialize a ROM memory region.
1135  *                                 Writes are handled via callbacks.
1136  *
1137  * Note that this function does not do anything to cause the data in the
1138  * RAM side of the memory region to be migrated; that is the responsibility
1139  * of the caller.
1140  *
1141  * @mr: the #MemoryRegion to be initialized.
1142  * @owner: the object that tracks the region's reference count
1143  * @ops: callbacks for write access handling (must not be NULL).
1144  * @opaque: passed to the read and write callbacks of the @ops structure.
1145  * @name: Region name, becomes part of RAMBlock name used in migration stream
1146  *        must be unique within any device
1147  * @size: size of the region.
1148  * @errp: pointer to Error*, to store an error if it happens.
1149  */
1150 void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
1151                                              Object *owner,
1152                                              const MemoryRegionOps *ops,
1153                                              void *opaque,
1154                                              const char *name,
1155                                              uint64_t size,
1156                                              Error **errp);
1157 
1158 /**
1159  * memory_region_init_iommu: Initialize a memory region of a custom type
1160  * that translates addresses
1161  *
1162  * An IOMMU region translates addresses and forwards accesses to a target
1163  * memory region.
1164  *
1165  * The IOMMU implementation must define a subclass of TYPE_IOMMU_MEMORY_REGION.
1166  * @_iommu_mr should be a pointer to enough memory for an instance of
1167  * that subclass, @instance_size is the size of that subclass, and
1168  * @mrtypename is its name. This function will initialize @_iommu_mr as an
1169  * instance of the subclass, and its methods will then be called to handle
1170  * accesses to the memory region. See the documentation of
1171  * #IOMMUMemoryRegionClass for further details.
1172  *
1173  * @_iommu_mr: the #IOMMUMemoryRegion to be initialized
1174  * @instance_size: the IOMMUMemoryRegion subclass instance size
1175  * @mrtypename: the type name of the #IOMMUMemoryRegion
1176  * @owner: the object that tracks the region's reference count
1177  * @name: used for debugging; not visible to the user or ABI
1178  * @size: size of the region.
1179  */
1180 void memory_region_init_iommu(void *_iommu_mr,
1181                               size_t instance_size,
1182                               const char *mrtypename,
1183                               Object *owner,
1184                               const char *name,
1185                               uint64_t size);
1186 
1187 /**
1188  * memory_region_init_ram - Initialize RAM memory region.  Accesses into the
1189  *                          region will modify memory directly.
1190  *
1191  * @mr: the #MemoryRegion to be initialized
1192  * @owner: the object that tracks the region's reference count (must be
1193  *         TYPE_DEVICE or a subclass of TYPE_DEVICE, or NULL)
1194  * @name: name of the memory region
1195  * @size: size of the region in bytes
1196  * @errp: pointer to Error*, to store an error if it happens.
1197  *
1198  * This function allocates RAM for a board model or device, and
1199  * arranges for it to be migrated (by calling vmstate_register_ram()
1200  * if @owner is a DeviceState, or vmstate_register_ram_global() if
1201  * @owner is NULL).
1202  *
1203  * TODO: Currently we restrict @owner to being either NULL (for
1204  * global RAM regions with no owner) or devices, so that we can
1205  * give the RAM block a unique name for migration purposes.
1206  * We should lift this restriction and allow arbitrary Objects.
1207  * If you pass a non-NULL non-device @owner then we will assert.
1208  */
1209 void memory_region_init_ram(MemoryRegion *mr,
1210                             Object *owner,
1211                             const char *name,
1212                             uint64_t size,
1213                             Error **errp);
1214 
1215 /**
1216  * memory_region_init_rom: Initialize a ROM memory region.
1217  *
1218  * This has the same effect as calling memory_region_init_ram()
1219  * and then marking the resulting region read-only with
1220  * memory_region_set_readonly(). This includes arranging for the
1221  * contents to be migrated.
1222  *
1223  * TODO: Currently we restrict @owner to being either NULL (for
1224  * global RAM regions with no owner) or devices, so that we can
1225  * give the RAM block a unique name for migration purposes.
1226  * We should lift this restriction and allow arbitrary Objects.
1227  * If you pass a non-NULL non-device @owner then we will assert.
1228  *
1229  * @mr: the #MemoryRegion to be initialized.
1230  * @owner: the object that tracks the region's reference count
1231  * @name: Region name, becomes part of RAMBlock name used in migration stream
1232  *        must be unique within any device
1233  * @size: size of the region.
1234  * @errp: pointer to Error*, to store an error if it happens.
1235  */
1236 void memory_region_init_rom(MemoryRegion *mr,
1237                             Object *owner,
1238                             const char *name,
1239                             uint64_t size,
1240                             Error **errp);
1241 
1242 /**
1243  * memory_region_init_rom_device:  Initialize a ROM memory region.
1244  *                                 Writes are handled via callbacks.
1245  *
1246  * This function initializes a memory region backed by RAM for reads
1247  * and callbacks for writes, and arranges for the RAM backing to
1248  * be migrated (by calling vmstate_register_ram()
1249  * if @owner is a DeviceState, or vmstate_register_ram_global() if
1250  * @owner is NULL).
1251  *
1252  * TODO: Currently we restrict @owner to being either NULL (for
1253  * global RAM regions with no owner) or devices, so that we can
1254  * give the RAM block a unique name for migration purposes.
1255  * We should lift this restriction and allow arbitrary Objects.
1256  * If you pass a non-NULL non-device @owner then we will assert.
1257  *
1258  * @mr: the #MemoryRegion to be initialized.
1259  * @owner: the object that tracks the region's reference count
1260  * @ops: callbacks for write access handling (must not be NULL).
1261  * @opaque: passed to the read and write callbacks of the @ops structure.
1262  * @name: Region name, becomes part of RAMBlock name used in migration stream
1263  *        must be unique within any device
1264  * @size: size of the region.
1265  * @errp: pointer to Error*, to store an error if it happens.
1266  */
1267 void memory_region_init_rom_device(MemoryRegion *mr,
1268                                    Object *owner,
1269                                    const MemoryRegionOps *ops,
1270                                    void *opaque,
1271                                    const char *name,
1272                                    uint64_t size,
1273                                    Error **errp);
1274 
1275 
1276 /**
1277  * memory_region_owner: get a memory region's owner.
1278  *
1279  * @mr: the memory region being queried.
1280  */
1281 Object *memory_region_owner(MemoryRegion *mr);
1282 
1283 /**
1284  * memory_region_size: get a memory region's size.
1285  *
1286  * @mr: the memory region being queried.
1287  */
1288 uint64_t memory_region_size(MemoryRegion *mr);
1289 
1290 /**
1291  * memory_region_is_ram: check whether a memory region is random access
1292  *
1293  * Returns %true if a memory region is random access.
1294  *
1295  * @mr: the memory region being queried
1296  */
1297 static inline bool memory_region_is_ram(MemoryRegion *mr)
1298 {
1299     return mr->ram;
1300 }
1301 
1302 /**
1303  * memory_region_is_ram_device: check whether a memory region is a ram device
1304  *
1305  * Returns %true if a memory region is a device backed ram region
1306  *
1307  * @mr: the memory region being queried
1308  */
1309 bool memory_region_is_ram_device(MemoryRegion *mr);
1310 
1311 /**
1312  * memory_region_is_romd: check whether a memory region is in ROMD mode
1313  *
1314  * Returns %true if a memory region is a ROM device and currently set to allow
1315  * direct reads.
1316  *
1317  * @mr: the memory region being queried
1318  */
1319 static inline bool memory_region_is_romd(MemoryRegion *mr)
1320 {
1321     return mr->rom_device && mr->romd_mode;
1322 }
1323 
1324 /**
1325  * memory_region_get_iommu: check whether a memory region is an iommu
1326  *
1327  * Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
1328  * otherwise NULL.
1329  *
1330  * @mr: the memory region being queried
1331  */
1332 static inline IOMMUMemoryRegion *memory_region_get_iommu(MemoryRegion *mr)
1333 {
1334     if (mr->alias) {
1335         return memory_region_get_iommu(mr->alias);
1336     }
1337     if (mr->is_iommu) {
1338         return (IOMMUMemoryRegion *) mr;
1339     }
1340     return NULL;
1341 }
1342 
1343 /**
1344  * memory_region_get_iommu_class_nocheck: returns iommu memory region class
1345  *   if an iommu or NULL if not
1346  *
1347  * Returns pointer to IOMMUMemoryRegionClass if a memory region is an iommu,
1348  * otherwise NULL. This is fast path avoiding QOM checking, use with caution.
1349  *
1350  * @iommu_mr: the memory region being queried
1351  */
1352 static inline IOMMUMemoryRegionClass *memory_region_get_iommu_class_nocheck(
1353         IOMMUMemoryRegion *iommu_mr)
1354 {
1355     return (IOMMUMemoryRegionClass *) (((Object *)iommu_mr)->class);
1356 }
1357 
1358 #define memory_region_is_iommu(mr) (memory_region_get_iommu(mr) != NULL)
1359 
1360 /**
1361  * memory_region_iommu_get_min_page_size: get minimum supported page size
1362  * for an iommu
1363  *
1364  * Returns minimum supported page size for an iommu.
1365  *
1366  * @iommu_mr: the memory region being queried
1367  */
1368 uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr);
1369 
1370 /**
1371  * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
1372  *
1373  * Note: for any IOMMU implementation, an in-place mapping change
1374  * should be notified with an UNMAP followed by a MAP.
1375  *
1376  * @iommu_mr: the memory region that was changed
1377  * @iommu_idx: the IOMMU index for the translation table which has changed
1378  * @event: TLB event with the new entry in the IOMMU translation table.
1379  *         The entry replaces all old entries for the same virtual I/O address
1380  *         range.
1381  */
1382 void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
1383                                 int iommu_idx,
1384                                 IOMMUTLBEvent event);
1385 
1386 /**
1387  * memory_region_notify_iommu_one: notify a change in an IOMMU translation
1388  *                           entry to a single notifier
1389  *
1390  * This works just like memory_region_notify_iommu(), but it only
1391  * notifies a specific notifier, not all of them.
1392  *
1393  * @notifier: the notifier to be notified
1394  * @event: TLB event with the new entry in the IOMMU translation table.
1395  *         The entry replaces all old entries for the same virtual I/O address
1396  *         range.
1397  */
1398 void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
1399                                     IOMMUTLBEvent *event);
1400 
1401 /**
1402  * memory_region_register_iommu_notifier: register a notifier for changes to
1403  * IOMMU translation entries.
1404  *
1405  * Returns 0 on success, or a negative errno otherwise. In particular,
1406  * -EINVAL indicates that at least one of the attributes of the notifier
1407  * is not supported (flag/range) by the IOMMU memory region. In case of error
1408  * the error object must be created.
1409  *
1410  * @mr: the memory region to observe
1411  * @n: the IOMMUNotifier to be added; the notify callback receives a
1412  *     pointer to an #IOMMUTLBEntry as the opaque value; the pointer
1413  *     ceases to be valid on exit from the notifier.
1414  * @errp: pointer to Error*, to store an error if it happens.
1415  */
1416 int memory_region_register_iommu_notifier(MemoryRegion *mr,
1417                                           IOMMUNotifier *n, Error **errp);
1418 
1419 /**
1420  * memory_region_iommu_replay: replay existing IOMMU translations to
1421  * a notifier with the minimum page granularity returned by
1422  * mr->iommu_ops->get_page_size().
1423  *
1424  * Note: this is not related to record-and-replay functionality.
1425  *
1426  * @iommu_mr: the memory region to observe
1427  * @n: the notifier to which to replay iommu mappings
1428  */
1429 void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n);
1430 
1431 /**
1432  * memory_region_unregister_iommu_notifier: unregister a notifier for
1433  * changes to IOMMU translation entries.
1434  *
1435  * @mr: the memory region which was observed and for which notity_stopped()
1436  *      needs to be called
1437  * @n: the notifier to be removed.
1438  */
1439 void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
1440                                              IOMMUNotifier *n);
1441 
1442 /**
1443  * memory_region_iommu_get_attr: return an IOMMU attr if get_attr() is
1444  * defined on the IOMMU.
1445  *
1446  * Returns 0 on success, or a negative errno otherwise. In particular,
1447  * -EINVAL indicates that the IOMMU does not support the requested
1448  * attribute.
1449  *
1450  * @iommu_mr: the memory region
1451  * @attr: the requested attribute
1452  * @data: a pointer to the requested attribute data
1453  */
1454 int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
1455                                  enum IOMMUMemoryRegionAttr attr,
1456                                  void *data);
1457 
1458 /**
1459  * memory_region_iommu_attrs_to_index: return the IOMMU index to
1460  * use for translations with the given memory transaction attributes.
1461  *
1462  * @iommu_mr: the memory region
1463  * @attrs: the memory transaction attributes
1464  */
1465 int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr,
1466                                        MemTxAttrs attrs);
1467 
1468 /**
1469  * memory_region_iommu_num_indexes: return the total number of IOMMU
1470  * indexes that this IOMMU supports.
1471  *
1472  * @iommu_mr: the memory region
1473  */
1474 int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr);
1475 
1476 /**
1477  * memory_region_iommu_set_page_size_mask: set the supported page
1478  * sizes for a given IOMMU memory region
1479  *
1480  * @iommu_mr: IOMMU memory region
1481  * @page_size_mask: supported page size mask
1482  * @errp: pointer to Error*, to store an error if it happens.
1483  */
1484 int memory_region_iommu_set_page_size_mask(IOMMUMemoryRegion *iommu_mr,
1485                                            uint64_t page_size_mask,
1486                                            Error **errp);
1487 
1488 /**
1489  * memory_region_name: get a memory region's name
1490  *
1491  * Returns the string that was used to initialize the memory region.
1492  *
1493  * @mr: the memory region being queried
1494  */
1495 const char *memory_region_name(const MemoryRegion *mr);
1496 
1497 /**
1498  * memory_region_is_logging: return whether a memory region is logging writes
1499  *
1500  * Returns %true if the memory region is logging writes for the given client
1501  *
1502  * @mr: the memory region being queried
1503  * @client: the client being queried
1504  */
1505 bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
1506 
1507 /**
1508  * memory_region_get_dirty_log_mask: return the clients for which a
1509  * memory region is logging writes.
1510  *
1511  * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
1512  * are the bit indices.
1513  *
1514  * @mr: the memory region being queried
1515  */
1516 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
1517 
1518 /**
1519  * memory_region_is_rom: check whether a memory region is ROM
1520  *
1521  * Returns %true if a memory region is read-only memory.
1522  *
1523  * @mr: the memory region being queried
1524  */
1525 static inline bool memory_region_is_rom(MemoryRegion *mr)
1526 {
1527     return mr->ram && mr->readonly;
1528 }
1529 
1530 /**
1531  * memory_region_is_nonvolatile: check whether a memory region is non-volatile
1532  *
1533  * Returns %true is a memory region is non-volatile memory.
1534  *
1535  * @mr: the memory region being queried
1536  */
1537 static inline bool memory_region_is_nonvolatile(MemoryRegion *mr)
1538 {
1539     return mr->nonvolatile;
1540 }
1541 
1542 /**
1543  * memory_region_get_fd: Get a file descriptor backing a RAM memory region.
1544  *
1545  * Returns a file descriptor backing a file-based RAM memory region,
1546  * or -1 if the region is not a file-based RAM memory region.
1547  *
1548  * @mr: the RAM or alias memory region being queried.
1549  */
1550 int memory_region_get_fd(MemoryRegion *mr);
1551 
1552 /**
1553  * memory_region_from_host: Convert a pointer into a RAM memory region
1554  * and an offset within it.
1555  *
1556  * Given a host pointer inside a RAM memory region (created with
1557  * memory_region_init_ram() or memory_region_init_ram_ptr()), return
1558  * the MemoryRegion and the offset within it.
1559  *
1560  * Use with care; by the time this function returns, the returned pointer is
1561  * not protected by RCU anymore.  If the caller is not within an RCU critical
1562  * section and does not hold the iothread lock, it must have other means of
1563  * protecting the pointer, such as a reference to the region that includes
1564  * the incoming ram_addr_t.
1565  *
1566  * @ptr: the host pointer to be converted
1567  * @offset: the offset within memory region
1568  */
1569 MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
1570 
1571 /**
1572  * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
1573  *
1574  * Returns a host pointer to a RAM memory region (created with
1575  * memory_region_init_ram() or memory_region_init_ram_ptr()).
1576  *
1577  * Use with care; by the time this function returns, the returned pointer is
1578  * not protected by RCU anymore.  If the caller is not within an RCU critical
1579  * section and does not hold the iothread lock, it must have other means of
1580  * protecting the pointer, such as a reference to the region that includes
1581  * the incoming ram_addr_t.
1582  *
1583  * @mr: the memory region being queried.
1584  */
1585 void *memory_region_get_ram_ptr(MemoryRegion *mr);
1586 
1587 /* memory_region_ram_resize: Resize a RAM region.
1588  *
1589  * Only legal before guest might have detected the memory size: e.g. on
1590  * incoming migration, or right after reset.
1591  *
1592  * @mr: a memory region created with @memory_region_init_resizeable_ram.
1593  * @newsize: the new size the region
1594  * @errp: pointer to Error*, to store an error if it happens.
1595  */
1596 void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
1597                               Error **errp);
1598 
1599 /**
1600  * memory_region_msync: Synchronize selected address range of
1601  * a memory mapped region
1602  *
1603  * @mr: the memory region to be msync
1604  * @addr: the initial address of the range to be sync
1605  * @size: the size of the range to be sync
1606  */
1607 void memory_region_msync(MemoryRegion *mr, hwaddr addr, hwaddr size);
1608 
1609 /**
1610  * memory_region_writeback: Trigger cache writeback for
1611  * selected address range
1612  *
1613  * @mr: the memory region to be updated
1614  * @addr: the initial address of the range to be written back
1615  * @size: the size of the range to be written back
1616  */
1617 void memory_region_writeback(MemoryRegion *mr, hwaddr addr, hwaddr size);
1618 
1619 /**
1620  * memory_region_set_log: Turn dirty logging on or off for a region.
1621  *
1622  * Turns dirty logging on or off for a specified client (display, migration).
1623  * Only meaningful for RAM regions.
1624  *
1625  * @mr: the memory region being updated.
1626  * @log: whether dirty logging is to be enabled or disabled.
1627  * @client: the user of the logging information; %DIRTY_MEMORY_VGA only.
1628  */
1629 void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client);
1630 
1631 /**
1632  * memory_region_set_dirty: Mark a range of bytes as dirty in a memory region.
1633  *
1634  * Marks a range of bytes as dirty, after it has been dirtied outside
1635  * guest code.
1636  *
1637  * @mr: the memory region being dirtied.
1638  * @addr: the address (relative to the start of the region) being dirtied.
1639  * @size: size of the range being dirtied.
1640  */
1641 void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
1642                              hwaddr size);
1643 
1644 /**
1645  * memory_region_clear_dirty_bitmap - clear dirty bitmap for memory range
1646  *
1647  * This function is called when the caller wants to clear the remote
1648  * dirty bitmap of a memory range within the memory region.  This can
1649  * be used by e.g. KVM to manually clear dirty log when
1650  * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is declared support by the host
1651  * kernel.
1652  *
1653  * @mr:     the memory region to clear the dirty log upon
1654  * @start:  start address offset within the memory region
1655  * @len:    length of the memory region to clear dirty bitmap
1656  */
1657 void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start,
1658                                       hwaddr len);
1659 
1660 /**
1661  * memory_region_snapshot_and_clear_dirty: Get a snapshot of the dirty
1662  *                                         bitmap and clear it.
1663  *
1664  * Creates a snapshot of the dirty bitmap, clears the dirty bitmap and
1665  * returns the snapshot.  The snapshot can then be used to query dirty
1666  * status, using memory_region_snapshot_get_dirty.  Snapshotting allows
1667  * querying the same page multiple times, which is especially useful for
1668  * display updates where the scanlines often are not page aligned.
1669  *
1670  * The dirty bitmap region which gets copyed into the snapshot (and
1671  * cleared afterwards) can be larger than requested.  The boundaries
1672  * are rounded up/down so complete bitmap longs (covering 64 pages on
1673  * 64bit hosts) can be copied over into the bitmap snapshot.  Which
1674  * isn't a problem for display updates as the extra pages are outside
1675  * the visible area, and in case the visible area changes a full
1676  * display redraw is due anyway.  Should other use cases for this
1677  * function emerge we might have to revisit this implementation
1678  * detail.
1679  *
1680  * Use g_free to release DirtyBitmapSnapshot.
1681  *
1682  * @mr: the memory region being queried.
1683  * @addr: the address (relative to the start of the region) being queried.
1684  * @size: the size of the range being queried.
1685  * @client: the user of the logging information; typically %DIRTY_MEMORY_VGA.
1686  */
1687 DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr,
1688                                                             hwaddr addr,
1689                                                             hwaddr size,
1690                                                             unsigned client);
1691 
1692 /**
1693  * memory_region_snapshot_get_dirty: Check whether a range of bytes is dirty
1694  *                                   in the specified dirty bitmap snapshot.
1695  *
1696  * @mr: the memory region being queried.
1697  * @snap: the dirty bitmap snapshot
1698  * @addr: the address (relative to the start of the region) being queried.
1699  * @size: the size of the range being queried.
1700  */
1701 bool memory_region_snapshot_get_dirty(MemoryRegion *mr,
1702                                       DirtyBitmapSnapshot *snap,
1703                                       hwaddr addr, hwaddr size);
1704 
1705 /**
1706  * memory_region_reset_dirty: Mark a range of pages as clean, for a specified
1707  *                            client.
1708  *
1709  * Marks a range of pages as no longer dirty.
1710  *
1711  * @mr: the region being updated.
1712  * @addr: the start of the subrange being cleaned.
1713  * @size: the size of the subrange being cleaned.
1714  * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
1715  *          %DIRTY_MEMORY_VGA.
1716  */
1717 void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
1718                                hwaddr size, unsigned client);
1719 
1720 /**
1721  * memory_region_flush_rom_device: Mark a range of pages dirty and invalidate
1722  *                                 TBs (for self-modifying code).
1723  *
1724  * The MemoryRegionOps->write() callback of a ROM device must use this function
1725  * to mark byte ranges that have been modified internally, such as by directly
1726  * accessing the memory returned by memory_region_get_ram_ptr().
1727  *
1728  * This function marks the range dirty and invalidates TBs so that TCG can
1729  * detect self-modifying code.
1730  *
1731  * @mr: the region being flushed.
1732  * @addr: the start, relative to the start of the region, of the range being
1733  *        flushed.
1734  * @size: the size, in bytes, of the range being flushed.
1735  */
1736 void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size);
1737 
1738 /**
1739  * memory_region_set_readonly: Turn a memory region read-only (or read-write)
1740  *
1741  * Allows a memory region to be marked as read-only (turning it into a ROM).
1742  * only useful on RAM regions.
1743  *
1744  * @mr: the region being updated.
1745  * @readonly: whether rhe region is to be ROM or RAM.
1746  */
1747 void memory_region_set_readonly(MemoryRegion *mr, bool readonly);
1748 
1749 /**
1750  * memory_region_set_nonvolatile: Turn a memory region non-volatile
1751  *
1752  * Allows a memory region to be marked as non-volatile.
1753  * only useful on RAM regions.
1754  *
1755  * @mr: the region being updated.
1756  * @nonvolatile: whether rhe region is to be non-volatile.
1757  */
1758 void memory_region_set_nonvolatile(MemoryRegion *mr, bool nonvolatile);
1759 
1760 /**
1761  * memory_region_rom_device_set_romd: enable/disable ROMD mode
1762  *
1763  * Allows a ROM device (initialized with memory_region_init_rom_device() to
1764  * set to ROMD mode (default) or MMIO mode.  When it is in ROMD mode, the
1765  * device is mapped to guest memory and satisfies read access directly.
1766  * When in MMIO mode, reads are forwarded to the #MemoryRegion.read function.
1767  * Writes are always handled by the #MemoryRegion.write function.
1768  *
1769  * @mr: the memory region to be updated
1770  * @romd_mode: %true to put the region into ROMD mode
1771  */
1772 void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode);
1773 
1774 /**
1775  * memory_region_set_coalescing: Enable memory coalescing for the region.
1776  *
1777  * Enabled writes to a region to be queued for later processing. MMIO ->write
1778  * callbacks may be delayed until a non-coalesced MMIO is issued.
1779  * Only useful for IO regions.  Roughly similar to write-combining hardware.
1780  *
1781  * @mr: the memory region to be write coalesced
1782  */
1783 void memory_region_set_coalescing(MemoryRegion *mr);
1784 
1785 /**
1786  * memory_region_add_coalescing: Enable memory coalescing for a sub-range of
1787  *                               a region.
1788  *
1789  * Like memory_region_set_coalescing(), but works on a sub-range of a region.
1790  * Multiple calls can be issued coalesced disjoint ranges.
1791  *
1792  * @mr: the memory region to be updated.
1793  * @offset: the start of the range within the region to be coalesced.
1794  * @size: the size of the subrange to be coalesced.
1795  */
1796 void memory_region_add_coalescing(MemoryRegion *mr,
1797                                   hwaddr offset,
1798                                   uint64_t size);
1799 
1800 /**
1801  * memory_region_clear_coalescing: Disable MMIO coalescing for the region.
1802  *
1803  * Disables any coalescing caused by memory_region_set_coalescing() or
1804  * memory_region_add_coalescing().  Roughly equivalent to uncacheble memory
1805  * hardware.
1806  *
1807  * @mr: the memory region to be updated.
1808  */
1809 void memory_region_clear_coalescing(MemoryRegion *mr);
1810 
1811 /**
1812  * memory_region_set_flush_coalesced: Enforce memory coalescing flush before
1813  *                                    accesses.
1814  *
1815  * Ensure that pending coalesced MMIO request are flushed before the memory
1816  * region is accessed. This property is automatically enabled for all regions
1817  * passed to memory_region_set_coalescing() and memory_region_add_coalescing().
1818  *
1819  * @mr: the memory region to be updated.
1820  */
1821 void memory_region_set_flush_coalesced(MemoryRegion *mr);
1822 
1823 /**
1824  * memory_region_clear_flush_coalesced: Disable memory coalescing flush before
1825  *                                      accesses.
1826  *
1827  * Clear the automatic coalesced MMIO flushing enabled via
1828  * memory_region_set_flush_coalesced. Note that this service has no effect on
1829  * memory regions that have MMIO coalescing enabled for themselves. For them,
1830  * automatic flushing will stop once coalescing is disabled.
1831  *
1832  * @mr: the memory region to be updated.
1833  */
1834 void memory_region_clear_flush_coalesced(MemoryRegion *mr);
1835 
1836 /**
1837  * memory_region_add_eventfd: Request an eventfd to be triggered when a word
1838  *                            is written to a location.
1839  *
1840  * Marks a word in an IO region (initialized with memory_region_init_io())
1841  * as a trigger for an eventfd event.  The I/O callback will not be called.
1842  * The caller must be prepared to handle failure (that is, take the required
1843  * action if the callback _is_ called).
1844  *
1845  * @mr: the memory region being updated.
1846  * @addr: the address within @mr that is to be monitored
1847  * @size: the size of the access to trigger the eventfd
1848  * @match_data: whether to match against @data, instead of just @addr
1849  * @data: the data to match against the guest write
1850  * @e: event notifier to be triggered when @addr, @size, and @data all match.
1851  **/
1852 void memory_region_add_eventfd(MemoryRegion *mr,
1853                                hwaddr addr,
1854                                unsigned size,
1855                                bool match_data,
1856                                uint64_t data,
1857                                EventNotifier *e);
1858 
1859 /**
1860  * memory_region_del_eventfd: Cancel an eventfd.
1861  *
1862  * Cancels an eventfd trigger requested by a previous
1863  * memory_region_add_eventfd() call.
1864  *
1865  * @mr: the memory region being updated.
1866  * @addr: the address within @mr that is to be monitored
1867  * @size: the size of the access to trigger the eventfd
1868  * @match_data: whether to match against @data, instead of just @addr
1869  * @data: the data to match against the guest write
1870  * @e: event notifier to be triggered when @addr, @size, and @data all match.
1871  */
1872 void memory_region_del_eventfd(MemoryRegion *mr,
1873                                hwaddr addr,
1874                                unsigned size,
1875                                bool match_data,
1876                                uint64_t data,
1877                                EventNotifier *e);
1878 
1879 /**
1880  * memory_region_add_subregion: Add a subregion to a container.
1881  *
1882  * Adds a subregion at @offset.  The subregion may not overlap with other
1883  * subregions (except for those explicitly marked as overlapping).  A region
1884  * may only be added once as a subregion (unless removed with
1885  * memory_region_del_subregion()); use memory_region_init_alias() if you
1886  * want a region to be a subregion in multiple locations.
1887  *
1888  * @mr: the region to contain the new subregion; must be a container
1889  *      initialized with memory_region_init().
1890  * @offset: the offset relative to @mr where @subregion is added.
1891  * @subregion: the subregion to be added.
1892  */
1893 void memory_region_add_subregion(MemoryRegion *mr,
1894                                  hwaddr offset,
1895                                  MemoryRegion *subregion);
1896 /**
1897  * memory_region_add_subregion_overlap: Add a subregion to a container
1898  *                                      with overlap.
1899  *
1900  * Adds a subregion at @offset.  The subregion may overlap with other
1901  * subregions.  Conflicts are resolved by having a higher @priority hide a
1902  * lower @priority. Subregions without priority are taken as @priority 0.
1903  * A region may only be added once as a subregion (unless removed with
1904  * memory_region_del_subregion()); use memory_region_init_alias() if you
1905  * want a region to be a subregion in multiple locations.
1906  *
1907  * @mr: the region to contain the new subregion; must be a container
1908  *      initialized with memory_region_init().
1909  * @offset: the offset relative to @mr where @subregion is added.
1910  * @subregion: the subregion to be added.
1911  * @priority: used for resolving overlaps; highest priority wins.
1912  */
1913 void memory_region_add_subregion_overlap(MemoryRegion *mr,
1914                                          hwaddr offset,
1915                                          MemoryRegion *subregion,
1916                                          int priority);
1917 
1918 /**
1919  * memory_region_get_ram_addr: Get the ram address associated with a memory
1920  *                             region
1921  *
1922  * @mr: the region to be queried
1923  */
1924 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
1925 
1926 uint64_t memory_region_get_alignment(const MemoryRegion *mr);
1927 /**
1928  * memory_region_del_subregion: Remove a subregion.
1929  *
1930  * Removes a subregion from its container.
1931  *
1932  * @mr: the container to be updated.
1933  * @subregion: the region being removed; must be a current subregion of @mr.
1934  */
1935 void memory_region_del_subregion(MemoryRegion *mr,
1936                                  MemoryRegion *subregion);
1937 
1938 /*
1939  * memory_region_set_enabled: dynamically enable or disable a region
1940  *
1941  * Enables or disables a memory region.  A disabled memory region
1942  * ignores all accesses to itself and its subregions.  It does not
1943  * obscure sibling subregions with lower priority - it simply behaves as
1944  * if it was removed from the hierarchy.
1945  *
1946  * Regions default to being enabled.
1947  *
1948  * @mr: the region to be updated
1949  * @enabled: whether to enable or disable the region
1950  */
1951 void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
1952 
1953 /*
1954  * memory_region_set_address: dynamically update the address of a region
1955  *
1956  * Dynamically updates the address of a region, relative to its container.
1957  * May be used on regions are currently part of a memory hierarchy.
1958  *
1959  * @mr: the region to be updated
1960  * @addr: new address, relative to container region
1961  */
1962 void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
1963 
1964 /*
1965  * memory_region_set_size: dynamically update the size of a region.
1966  *
1967  * Dynamically updates the size of a region.
1968  *
1969  * @mr: the region to be updated
1970  * @size: used size of the region.
1971  */
1972 void memory_region_set_size(MemoryRegion *mr, uint64_t size);
1973 
1974 /*
1975  * memory_region_set_alias_offset: dynamically update a memory alias's offset
1976  *
1977  * Dynamically updates the offset into the target region that an alias points
1978  * to, as if the fourth argument to memory_region_init_alias() has changed.
1979  *
1980  * @mr: the #MemoryRegion to be updated; should be an alias.
1981  * @offset: the new offset into the target memory region
1982  */
1983 void memory_region_set_alias_offset(MemoryRegion *mr,
1984                                     hwaddr offset);
1985 
1986 /**
1987  * memory_region_present: checks if an address relative to a @container
1988  * translates into #MemoryRegion within @container
1989  *
1990  * Answer whether a #MemoryRegion within @container covers the address
1991  * @addr.
1992  *
1993  * @container: a #MemoryRegion within which @addr is a relative address
1994  * @addr: the area within @container to be searched
1995  */
1996 bool memory_region_present(MemoryRegion *container, hwaddr addr);
1997 
1998 /**
1999  * memory_region_is_mapped: returns true if #MemoryRegion is mapped
2000  * into any address space.
2001  *
2002  * @mr: a #MemoryRegion which should be checked if it's mapped
2003  */
2004 bool memory_region_is_mapped(MemoryRegion *mr);
2005 
2006 /**
2007  * memory_region_find: translate an address/size relative to a
2008  * MemoryRegion into a #MemoryRegionSection.
2009  *
2010  * Locates the first #MemoryRegion within @mr that overlaps the range
2011  * given by @addr and @size.
2012  *
2013  * Returns a #MemoryRegionSection that describes a contiguous overlap.
2014  * It will have the following characteristics:
2015  * - @size = 0 iff no overlap was found
2016  * - @mr is non-%NULL iff an overlap was found
2017  *
2018  * Remember that in the return value the @offset_within_region is
2019  * relative to the returned region (in the .@mr field), not to the
2020  * @mr argument.
2021  *
2022  * Similarly, the .@offset_within_address_space is relative to the
2023  * address space that contains both regions, the passed and the
2024  * returned one.  However, in the special case where the @mr argument
2025  * has no container (and thus is the root of the address space), the
2026  * following will hold:
2027  * - @offset_within_address_space >= @addr
2028  * - @offset_within_address_space + .@size <= @addr + @size
2029  *
2030  * @mr: a MemoryRegion within which @addr is a relative address
2031  * @addr: start of the area within @as to be searched
2032  * @size: size of the area to be searched
2033  */
2034 MemoryRegionSection memory_region_find(MemoryRegion *mr,
2035                                        hwaddr addr, uint64_t size);
2036 
2037 /**
2038  * memory_global_dirty_log_sync: synchronize the dirty log for all memory
2039  *
2040  * Synchronizes the dirty page log for all address spaces.
2041  */
2042 void memory_global_dirty_log_sync(void);
2043 
2044 /**
2045  * memory_global_dirty_log_sync: synchronize the dirty log for all memory
2046  *
2047  * Synchronizes the vCPUs with a thread that is reading the dirty bitmap.
2048  * This function must be called after the dirty log bitmap is cleared, and
2049  * before dirty guest memory pages are read.  If you are using
2050  * #DirtyBitmapSnapshot, memory_region_snapshot_and_clear_dirty() takes
2051  * care of doing this.
2052  */
2053 void memory_global_after_dirty_log_sync(void);
2054 
2055 /**
2056  * memory_region_transaction_begin: Start a transaction.
2057  *
2058  * During a transaction, changes will be accumulated and made visible
2059  * only when the transaction ends (is committed).
2060  */
2061 void memory_region_transaction_begin(void);
2062 
2063 /**
2064  * memory_region_transaction_commit: Commit a transaction and make changes
2065  *                                   visible to the guest.
2066  */
2067 void memory_region_transaction_commit(void);
2068 
2069 /**
2070  * memory_listener_register: register callbacks to be called when memory
2071  *                           sections are mapped or unmapped into an address
2072  *                           space
2073  *
2074  * @listener: an object containing the callbacks to be called
2075  * @filter: if non-%NULL, only regions in this address space will be observed
2076  */
2077 void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
2078 
2079 /**
2080  * memory_listener_unregister: undo the effect of memory_listener_register()
2081  *
2082  * @listener: an object containing the callbacks to be removed
2083  */
2084 void memory_listener_unregister(MemoryListener *listener);
2085 
2086 /**
2087  * memory_global_dirty_log_start: begin dirty logging for all regions
2088  */
2089 void memory_global_dirty_log_start(void);
2090 
2091 /**
2092  * memory_global_dirty_log_stop: end dirty logging for all regions
2093  */
2094 void memory_global_dirty_log_stop(void);
2095 
2096 void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled);
2097 
2098 /**
2099  * memory_region_dispatch_read: perform a read directly to the specified
2100  * MemoryRegion.
2101  *
2102  * @mr: #MemoryRegion to access
2103  * @addr: address within that region
2104  * @pval: pointer to uint64_t which the data is written to
2105  * @op: size, sign, and endianness of the memory operation
2106  * @attrs: memory transaction attributes to use for the access
2107  */
2108 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
2109                                         hwaddr addr,
2110                                         uint64_t *pval,
2111                                         MemOp op,
2112                                         MemTxAttrs attrs);
2113 /**
2114  * memory_region_dispatch_write: perform a write directly to the specified
2115  * MemoryRegion.
2116  *
2117  * @mr: #MemoryRegion to access
2118  * @addr: address within that region
2119  * @data: data to write
2120  * @op: size, sign, and endianness of the memory operation
2121  * @attrs: memory transaction attributes to use for the access
2122  */
2123 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
2124                                          hwaddr addr,
2125                                          uint64_t data,
2126                                          MemOp op,
2127                                          MemTxAttrs attrs);
2128 
2129 /**
2130  * address_space_init: initializes an address space
2131  *
2132  * @as: an uninitialized #AddressSpace
2133  * @root: a #MemoryRegion that routes addresses for the address space
2134  * @name: an address space name.  The name is only used for debugging
2135  *        output.
2136  */
2137 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
2138 
2139 /**
2140  * address_space_destroy: destroy an address space
2141  *
2142  * Releases all resources associated with an address space.  After an address space
2143  * is destroyed, its root memory region (given by address_space_init()) may be destroyed
2144  * as well.
2145  *
2146  * @as: address space to be destroyed
2147  */
2148 void address_space_destroy(AddressSpace *as);
2149 
2150 /**
2151  * address_space_remove_listeners: unregister all listeners of an address space
2152  *
2153  * Removes all callbacks previously registered with memory_listener_register()
2154  * for @as.
2155  *
2156  * @as: an initialized #AddressSpace
2157  */
2158 void address_space_remove_listeners(AddressSpace *as);
2159 
2160 /**
2161  * address_space_rw: read from or write to an address space.
2162  *
2163  * Return a MemTxResult indicating whether the operation succeeded
2164  * or failed (eg unassigned memory, device rejected the transaction,
2165  * IOMMU fault).
2166  *
2167  * @as: #AddressSpace to be accessed
2168  * @addr: address within that address space
2169  * @attrs: memory transaction attributes
2170  * @buf: buffer with the data transferred
2171  * @len: the number of bytes to read or write
2172  * @is_write: indicates the transfer direction
2173  */
2174 MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
2175                              MemTxAttrs attrs, void *buf,
2176                              hwaddr len, bool is_write);
2177 
2178 /**
2179  * address_space_write: write to address space.
2180  *
2181  * Return a MemTxResult indicating whether the operation succeeded
2182  * or failed (eg unassigned memory, device rejected the transaction,
2183  * IOMMU fault).
2184  *
2185  * @as: #AddressSpace to be accessed
2186  * @addr: address within that address space
2187  * @attrs: memory transaction attributes
2188  * @buf: buffer with the data transferred
2189  * @len: the number of bytes to write
2190  */
2191 MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
2192                                 MemTxAttrs attrs,
2193                                 const void *buf, hwaddr len);
2194 
2195 /**
2196  * address_space_write_rom: write to address space, including ROM.
2197  *
2198  * This function writes to the specified address space, but will
2199  * write data to both ROM and RAM. This is used for non-guest
2200  * writes like writes from the gdb debug stub or initial loading
2201  * of ROM contents.
2202  *
2203  * Note that portions of the write which attempt to write data to
2204  * a device will be silently ignored -- only real RAM and ROM will
2205  * be written to.
2206  *
2207  * Return a MemTxResult indicating whether the operation succeeded
2208  * or failed (eg unassigned memory, device rejected the transaction,
2209  * IOMMU fault).
2210  *
2211  * @as: #AddressSpace to be accessed
2212  * @addr: address within that address space
2213  * @attrs: memory transaction attributes
2214  * @buf: buffer with the data transferred
2215  * @len: the number of bytes to write
2216  */
2217 MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
2218                                     MemTxAttrs attrs,
2219                                     const void *buf, hwaddr len);
2220 
2221 /* address_space_ld*: load from an address space
2222  * address_space_st*: store to an address space
2223  *
2224  * These functions perform a load or store of the byte, word,
2225  * longword or quad to the specified address within the AddressSpace.
2226  * The _le suffixed functions treat the data as little endian;
2227  * _be indicates big endian; no suffix indicates "same endianness
2228  * as guest CPU".
2229  *
2230  * The "guest CPU endianness" accessors are deprecated for use outside
2231  * target-* code; devices should be CPU-agnostic and use either the LE
2232  * or the BE accessors.
2233  *
2234  * @as #AddressSpace to be accessed
2235  * @addr: address within that address space
2236  * @val: data value, for stores
2237  * @attrs: memory transaction attributes
2238  * @result: location to write the success/failure of the transaction;
2239  *   if NULL, this information is discarded
2240  */
2241 
2242 #define SUFFIX
2243 #define ARG1         as
2244 #define ARG1_DECL    AddressSpace *as
2245 #include "exec/memory_ldst.h.inc"
2246 
2247 #define SUFFIX
2248 #define ARG1         as
2249 #define ARG1_DECL    AddressSpace *as
2250 #include "exec/memory_ldst_phys.h.inc"
2251 
2252 struct MemoryRegionCache {
2253     void *ptr;
2254     hwaddr xlat;
2255     hwaddr len;
2256     FlatView *fv;
2257     MemoryRegionSection mrs;
2258     bool is_write;
2259 };
2260 
2261 #define MEMORY_REGION_CACHE_INVALID ((MemoryRegionCache) { .mrs.mr = NULL })
2262 
2263 
2264 /* address_space_ld*_cached: load from a cached #MemoryRegion
2265  * address_space_st*_cached: store into a cached #MemoryRegion
2266  *
2267  * These functions perform a load or store of the byte, word,
2268  * longword or quad to the specified address.  The address is
2269  * a physical address in the AddressSpace, but it must lie within
2270  * a #MemoryRegion that was mapped with address_space_cache_init.
2271  *
2272  * The _le suffixed functions treat the data as little endian;
2273  * _be indicates big endian; no suffix indicates "same endianness
2274  * as guest CPU".
2275  *
2276  * The "guest CPU endianness" accessors are deprecated for use outside
2277  * target-* code; devices should be CPU-agnostic and use either the LE
2278  * or the BE accessors.
2279  *
2280  * @cache: previously initialized #MemoryRegionCache to be accessed
2281  * @addr: address within the address space
2282  * @val: data value, for stores
2283  * @attrs: memory transaction attributes
2284  * @result: location to write the success/failure of the transaction;
2285  *   if NULL, this information is discarded
2286  */
2287 
2288 #define SUFFIX       _cached_slow
2289 #define ARG1         cache
2290 #define ARG1_DECL    MemoryRegionCache *cache
2291 #include "exec/memory_ldst.h.inc"
2292 
2293 /* Inline fast path for direct RAM access.  */
2294 static inline uint8_t address_space_ldub_cached(MemoryRegionCache *cache,
2295     hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
2296 {
2297     assert(addr < cache->len);
2298     if (likely(cache->ptr)) {
2299         return ldub_p(cache->ptr + addr);
2300     } else {
2301         return address_space_ldub_cached_slow(cache, addr, attrs, result);
2302     }
2303 }
2304 
2305 static inline void address_space_stb_cached(MemoryRegionCache *cache,
2306     hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
2307 {
2308     assert(addr < cache->len);
2309     if (likely(cache->ptr)) {
2310         stb_p(cache->ptr + addr, val);
2311     } else {
2312         address_space_stb_cached_slow(cache, addr, val, attrs, result);
2313     }
2314 }
2315 
2316 #define ENDIANNESS   _le
2317 #include "exec/memory_ldst_cached.h.inc"
2318 
2319 #define ENDIANNESS   _be
2320 #include "exec/memory_ldst_cached.h.inc"
2321 
2322 #define SUFFIX       _cached
2323 #define ARG1         cache
2324 #define ARG1_DECL    MemoryRegionCache *cache
2325 #include "exec/memory_ldst_phys.h.inc"
2326 
2327 /* address_space_cache_init: prepare for repeated access to a physical
2328  * memory region
2329  *
2330  * @cache: #MemoryRegionCache to be filled
2331  * @as: #AddressSpace to be accessed
2332  * @addr: address within that address space
2333  * @len: length of buffer
2334  * @is_write: indicates the transfer direction
2335  *
2336  * Will only work with RAM, and may map a subset of the requested range by
2337  * returning a value that is less than @len.  On failure, return a negative
2338  * errno value.
2339  *
2340  * Because it only works with RAM, this function can be used for
2341  * read-modify-write operations.  In this case, is_write should be %true.
2342  *
2343  * Note that addresses passed to the address_space_*_cached functions
2344  * are relative to @addr.
2345  */
2346 int64_t address_space_cache_init(MemoryRegionCache *cache,
2347                                  AddressSpace *as,
2348                                  hwaddr addr,
2349                                  hwaddr len,
2350                                  bool is_write);
2351 
2352 /**
2353  * address_space_cache_invalidate: complete a write to a #MemoryRegionCache
2354  *
2355  * @cache: The #MemoryRegionCache to operate on.
2356  * @addr: The first physical address that was written, relative to the
2357  * address that was passed to @address_space_cache_init.
2358  * @access_len: The number of bytes that were written starting at @addr.
2359  */
2360 void address_space_cache_invalidate(MemoryRegionCache *cache,
2361                                     hwaddr addr,
2362                                     hwaddr access_len);
2363 
2364 /**
2365  * address_space_cache_destroy: free a #MemoryRegionCache
2366  *
2367  * @cache: The #MemoryRegionCache whose memory should be released.
2368  */
2369 void address_space_cache_destroy(MemoryRegionCache *cache);
2370 
2371 /* address_space_get_iotlb_entry: translate an address into an IOTLB
2372  * entry. Should be called from an RCU critical section.
2373  */
2374 IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
2375                                             bool is_write, MemTxAttrs attrs);
2376 
2377 /* address_space_translate: translate an address range into an address space
2378  * into a MemoryRegion and an address range into that section.  Should be
2379  * called from an RCU critical section, to avoid that the last reference
2380  * to the returned region disappears after address_space_translate returns.
2381  *
2382  * @fv: #FlatView to be accessed
2383  * @addr: address within that address space
2384  * @xlat: pointer to address within the returned memory region section's
2385  * #MemoryRegion.
2386  * @len: pointer to length
2387  * @is_write: indicates the transfer direction
2388  * @attrs: memory attributes
2389  */
2390 MemoryRegion *flatview_translate(FlatView *fv,
2391                                  hwaddr addr, hwaddr *xlat,
2392                                  hwaddr *len, bool is_write,
2393                                  MemTxAttrs attrs);
2394 
2395 static inline MemoryRegion *address_space_translate(AddressSpace *as,
2396                                                     hwaddr addr, hwaddr *xlat,
2397                                                     hwaddr *len, bool is_write,
2398                                                     MemTxAttrs attrs)
2399 {
2400     return flatview_translate(address_space_to_flatview(as),
2401                               addr, xlat, len, is_write, attrs);
2402 }
2403 
2404 /* address_space_access_valid: check for validity of accessing an address
2405  * space range
2406  *
2407  * Check whether memory is assigned to the given address space range, and
2408  * access is permitted by any IOMMU regions that are active for the address
2409  * space.
2410  *
2411  * For now, addr and len should be aligned to a page size.  This limitation
2412  * will be lifted in the future.
2413  *
2414  * @as: #AddressSpace to be accessed
2415  * @addr: address within that address space
2416  * @len: length of the area to be checked
2417  * @is_write: indicates the transfer direction
2418  * @attrs: memory attributes
2419  */
2420 bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
2421                                 bool is_write, MemTxAttrs attrs);
2422 
2423 /* address_space_map: map a physical memory region into a host virtual address
2424  *
2425  * May map a subset of the requested range, given by and returned in @plen.
2426  * May return %NULL and set *@plen to zero(0), if resources needed to perform
2427  * the mapping are exhausted.
2428  * Use only for reads OR writes - not for read-modify-write operations.
2429  * Use cpu_register_map_client() to know when retrying the map operation is
2430  * likely to succeed.
2431  *
2432  * @as: #AddressSpace to be accessed
2433  * @addr: address within that address space
2434  * @plen: pointer to length of buffer; updated on return
2435  * @is_write: indicates the transfer direction
2436  * @attrs: memory attributes
2437  */
2438 void *address_space_map(AddressSpace *as, hwaddr addr,
2439                         hwaddr *plen, bool is_write, MemTxAttrs attrs);
2440 
2441 /* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
2442  *
2443  * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
2444  * the amount of memory that was actually read or written by the caller.
2445  *
2446  * @as: #AddressSpace used
2447  * @buffer: host pointer as returned by address_space_map()
2448  * @len: buffer length as returned by address_space_map()
2449  * @access_len: amount of data actually transferred
2450  * @is_write: indicates the transfer direction
2451  */
2452 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
2453                          bool is_write, hwaddr access_len);
2454 
2455 
2456 /* Internal functions, part of the implementation of address_space_read.  */
2457 MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
2458                                     MemTxAttrs attrs, void *buf, hwaddr len);
2459 MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
2460                                    MemTxAttrs attrs, void *buf,
2461                                    hwaddr len, hwaddr addr1, hwaddr l,
2462                                    MemoryRegion *mr);
2463 void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr);
2464 
2465 /* Internal functions, part of the implementation of address_space_read_cached
2466  * and address_space_write_cached.  */
2467 MemTxResult address_space_read_cached_slow(MemoryRegionCache *cache,
2468                                            hwaddr addr, void *buf, hwaddr len);
2469 MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
2470                                             hwaddr addr, const void *buf,
2471                                             hwaddr len);
2472 
2473 static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
2474 {
2475     if (is_write) {
2476         return memory_region_is_ram(mr) && !mr->readonly &&
2477                !mr->rom_device && !memory_region_is_ram_device(mr);
2478     } else {
2479         return (memory_region_is_ram(mr) && !memory_region_is_ram_device(mr)) ||
2480                memory_region_is_romd(mr);
2481     }
2482 }
2483 
2484 /**
2485  * address_space_read: read from an address space.
2486  *
2487  * Return a MemTxResult indicating whether the operation succeeded
2488  * or failed (eg unassigned memory, device rejected the transaction,
2489  * IOMMU fault).  Called within RCU critical section.
2490  *
2491  * @as: #AddressSpace to be accessed
2492  * @addr: address within that address space
2493  * @attrs: memory transaction attributes
2494  * @buf: buffer with the data transferred
2495  * @len: length of the data transferred
2496  */
2497 static inline __attribute__((__always_inline__))
2498 MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
2499                                MemTxAttrs attrs, void *buf,
2500                                hwaddr len)
2501 {
2502     MemTxResult result = MEMTX_OK;
2503     hwaddr l, addr1;
2504     void *ptr;
2505     MemoryRegion *mr;
2506     FlatView *fv;
2507 
2508     if (__builtin_constant_p(len)) {
2509         if (len) {
2510             RCU_READ_LOCK_GUARD();
2511             fv = address_space_to_flatview(as);
2512             l = len;
2513             mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
2514             if (len == l && memory_access_is_direct(mr, false)) {
2515                 ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
2516                 memcpy(buf, ptr, len);
2517             } else {
2518                 result = flatview_read_continue(fv, addr, attrs, buf, len,
2519                                                 addr1, l, mr);
2520             }
2521         }
2522     } else {
2523         result = address_space_read_full(as, addr, attrs, buf, len);
2524     }
2525     return result;
2526 }
2527 
2528 /**
2529  * address_space_read_cached: read from a cached RAM region
2530  *
2531  * @cache: Cached region to be addressed
2532  * @addr: address relative to the base of the RAM region
2533  * @buf: buffer with the data transferred
2534  * @len: length of the data transferred
2535  */
2536 static inline MemTxResult
2537 address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
2538                           void *buf, hwaddr len)
2539 {
2540     assert(addr < cache->len && len <= cache->len - addr);
2541     fuzz_dma_read_cb(cache->xlat + addr, len, cache->mrs.mr);
2542     if (likely(cache->ptr)) {
2543         memcpy(buf, cache->ptr + addr, len);
2544         return MEMTX_OK;
2545     } else {
2546         return address_space_read_cached_slow(cache, addr, buf, len);
2547     }
2548 }
2549 
2550 /**
2551  * address_space_write_cached: write to a cached RAM region
2552  *
2553  * @cache: Cached region to be addressed
2554  * @addr: address relative to the base of the RAM region
2555  * @buf: buffer with the data transferred
2556  * @len: length of the data transferred
2557  */
2558 static inline MemTxResult
2559 address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
2560                            const void *buf, hwaddr len)
2561 {
2562     assert(addr < cache->len && len <= cache->len - addr);
2563     if (likely(cache->ptr)) {
2564         memcpy(cache->ptr + addr, buf, len);
2565         return MEMTX_OK;
2566     } else {
2567         return address_space_write_cached_slow(cache, addr, buf, len);
2568     }
2569 }
2570 
2571 #ifdef NEED_CPU_H
2572 /* enum device_endian to MemOp.  */
2573 static inline MemOp devend_memop(enum device_endian end)
2574 {
2575     QEMU_BUILD_BUG_ON(DEVICE_HOST_ENDIAN != DEVICE_LITTLE_ENDIAN &&
2576                       DEVICE_HOST_ENDIAN != DEVICE_BIG_ENDIAN);
2577 
2578 #if defined(HOST_WORDS_BIGENDIAN) != defined(TARGET_WORDS_BIGENDIAN)
2579     /* Swap if non-host endianness or native (target) endianness */
2580     return (end == DEVICE_HOST_ENDIAN) ? 0 : MO_BSWAP;
2581 #else
2582     const int non_host_endianness =
2583         DEVICE_LITTLE_ENDIAN ^ DEVICE_BIG_ENDIAN ^ DEVICE_HOST_ENDIAN;
2584 
2585     /* In this case, native (target) endianness needs no swap.  */
2586     return (end == non_host_endianness) ? MO_BSWAP : 0;
2587 #endif
2588 }
2589 #endif
2590 
2591 /*
2592  * Inhibit technologies that require discarding of pages in RAM blocks, e.g.,
2593  * to manage the actual amount of memory consumed by the VM (then, the memory
2594  * provided by RAM blocks might be bigger than the desired memory consumption).
2595  * This *must* be set if:
2596  * - Discarding parts of a RAM blocks does not result in the change being
2597  *   reflected in the VM and the pages getting freed.
2598  * - All memory in RAM blocks is pinned or duplicated, invaldiating any previous
2599  *   discards blindly.
2600  * - Discarding parts of a RAM blocks will result in integrity issues (e.g.,
2601  *   encrypted VMs).
2602  * Technologies that only temporarily pin the current working set of a
2603  * driver are fine, because we don't expect such pages to be discarded
2604  * (esp. based on guest action like balloon inflation).
2605  *
2606  * This is *not* to be used to protect from concurrent discards (esp.,
2607  * postcopy).
2608  *
2609  * Returns 0 if successful. Returns -EBUSY if a technology that relies on
2610  * discards to work reliably is active.
2611  */
2612 int ram_block_discard_disable(bool state);
2613 
2614 /*
2615  * Inhibit technologies that disable discarding of pages in RAM blocks.
2616  *
2617  * Returns 0 if successful. Returns -EBUSY if discards are already set to
2618  * broken.
2619  */
2620 int ram_block_discard_require(bool state);
2621 
2622 /*
2623  * Test if discarding of memory in ram blocks is disabled.
2624  */
2625 bool ram_block_discard_is_disabled(void);
2626 
2627 /*
2628  * Test if discarding of memory in ram blocks is required to work reliably.
2629  */
2630 bool ram_block_discard_is_required(void);
2631 
2632 #endif
2633 
2634 #endif
2635