qemu

memory.c (115722B)

---

 /*
  * Physical memory management
  *
  * Copyright 2011 Red Hat, Inc. and/or its affiliates
  *
  * Authors:
  *  Avi Kivity <avi@redhat.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
  *
  * Contributions after 2012-01-13 are licensed under the terms of the
  * GNU GPL, version 2 or (at your option) any later version.
  */
 
 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "qapi/error.h"
 #include "exec/memory.h"
 #include "qapi/visitor.h"
 #include "qemu/bitops.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/qemu-print.h"
 #include "qom/object.h"
 #include "trace.h"
 
 #include "exec/memory-internal.h"
 #include "exec/ram_addr.h"
 #include "sysemu/kvm.h"
 #include "sysemu/runstate.h"
 #include "sysemu/tcg.h"
 #include "qemu/accel.h"
 #include "hw/boards.h"
 #include "migration/vmstate.h"
 #include "exec/address-spaces.h"
 
 //#define DEBUG_UNASSIGNED
 
 static unsigned memory_region_transaction_depth;
 static bool memory_region_update_pending;
 static bool ioeventfd_update_pending;
 unsigned int global_dirty_tracking;
 
 static QTAILQ_HEAD(, MemoryListener) memory_listeners
     = QTAILQ_HEAD_INITIALIZER(memory_listeners);
 
 static QTAILQ_HEAD(, AddressSpace) address_spaces
     = QTAILQ_HEAD_INITIALIZER(address_spaces);
 
 static GHashTable *flat_views;
 
 typedef struct AddrRange AddrRange;
 
 /*
  * Note that signed integers are needed for negative offsetting in aliases
  * (large MemoryRegion::alias_offset).
  */
 struct AddrRange {
     Int128 start;
     Int128 size;
 };
 
 static AddrRange addrrange_make(Int128 start, Int128 size)
 {
     return (AddrRange) { start, size };
 }
 
 static bool addrrange_equal(AddrRange r1, AddrRange r2)
 {
     return int128_eq(r1.start, r2.start) && int128_eq(r1.size, r2.size);
 }
 
 static Int128 addrrange_end(AddrRange r)
 {
     return int128_add(r.start, r.size);
 }
 
 static AddrRange addrrange_shift(AddrRange range, Int128 delta)
 {
     int128_addto(&range.start, delta);
     return range;
 }
 
 static bool addrrange_contains(AddrRange range, Int128 addr)
 {
     return int128_ge(addr, range.start)
         && int128_lt(addr, addrrange_end(range));
 }
 
 static bool addrrange_intersects(AddrRange r1, AddrRange r2)
 {
     return addrrange_contains(r1, r2.start)
         || addrrange_contains(r2, r1.start);
 }
 
 static AddrRange addrrange_intersection(AddrRange r1, AddrRange r2)
 {
     Int128 start = int128_max(r1.start, r2.start);
     Int128 end = int128_min(addrrange_end(r1), addrrange_end(r2));
     return addrrange_make(start, int128_sub(end, start));
 }
 
 enum ListenerDirection { Forward, Reverse };
 
 #define MEMORY_LISTENER_CALL_GLOBAL(_callback, _direction, _args...)    \
     do {                                                                \
         MemoryListener *_listener;                                      \
                                                                         \
         switch (_direction) {                                           \
         case Forward:                                                   \
             QTAILQ_FOREACH(_listener, &memory_listeners, link) {        \
                 if (_listener->_callback) {                             \
                     _listener->_callback(_listener, ##_args);           \
                 }                                                       \
             }                                                           \
             break;                                                      \
         case Reverse:                                                   \
             QTAILQ_FOREACH_REVERSE(_listener, &memory_listeners, link) { \
                 if (_listener->_callback) {                             \
                     _listener->_callback(_listener, ##_args);           \
                 }                                                       \
             }                                                           \
             break;                                                      \
         default:                                                        \
             abort();                                                    \
         }                                                               \
     } while (0)
 
 #define MEMORY_LISTENER_CALL(_as, _callback, _direction, _section, _args...) \
     do {                                                                \
         MemoryListener *_listener;                                      \
                                                                         \
         switch (_direction) {                                           \
         case Forward:                                                   \
             QTAILQ_FOREACH(_listener, &(_as)->listeners, link_as) {     \
                 if (_listener->_callback) {                             \
                     _listener->_callback(_listener, _section, ##_args); \
                 }                                                       \
             }                                                           \
             break;                                                      \
         case Reverse:                                                   \
             QTAILQ_FOREACH_REVERSE(_listener, &(_as)->listeners, link_as) { \
                 if (_listener->_callback) {                             \
                     _listener->_callback(_listener, _section, ##_args); \
                 }                                                       \
             }                                                           \
             break;                                                      \
         default:                                                        \
             abort();                                                    \
         }                                                               \
     } while (0)
 
 /* No need to ref/unref .mr, the FlatRange keeps it alive.  */
 #define MEMORY_LISTENER_UPDATE_REGION(fr, as, dir, callback, _args...)  \
     do {                                                                \
         MemoryRegionSection mrs = section_from_flat_range(fr,           \
                 address_space_to_flatview(as));                         \
         MEMORY_LISTENER_CALL(as, callback, dir, &mrs, ##_args);         \
     } while(0)
 
 struct CoalescedMemoryRange {
     AddrRange addr;
     QTAILQ_ENTRY(CoalescedMemoryRange) link;
 };
 
 struct MemoryRegionIoeventfd {
     AddrRange addr;
     bool match_data;
     uint64_t data;
     EventNotifier *e;
 };
 
 static bool memory_region_ioeventfd_before(MemoryRegionIoeventfd *a,
                                            MemoryRegionIoeventfd *b)
 {
     if (int128_lt(a->addr.start, b->addr.start)) {
         return true;
     } else if (int128_gt(a->addr.start, b->addr.start)) {
         return false;
     } else if (int128_lt(a->addr.size, b->addr.size)) {
         return true;
     } else if (int128_gt(a->addr.size, b->addr.size)) {
         return false;
     } else if (a->match_data < b->match_data) {
         return true;
     } else  if (a->match_data > b->match_data) {
         return false;
     } else if (a->match_data) {
         if (a->data < b->data) {
             return true;
         } else if (a->data > b->data) {
             return false;
         }
     }
     if (a->e < b->e) {
         return true;
     } else if (a->e > b->e) {
         return false;
     }
     return false;
 }
 
 static bool memory_region_ioeventfd_equal(MemoryRegionIoeventfd *a,
                                           MemoryRegionIoeventfd *b)
 {
     if (int128_eq(a->addr.start, b->addr.start) &&
         (!int128_nz(a->addr.size) || !int128_nz(b->addr.size) ||
          (int128_eq(a->addr.size, b->addr.size) &&
           (a->match_data == b->match_data) &&
           ((a->match_data && (a->data == b->data)) || !a->match_data) &&
           (a->e == b->e))))
         return true;
 
     return false;
 }
 
 /* Range of memory in the global map.  Addresses are absolute. */
 struct FlatRange {
     MemoryRegion *mr;
     hwaddr offset_in_region;
     AddrRange addr;
     uint8_t dirty_log_mask;
     bool romd_mode;
     bool readonly;
     bool nonvolatile;
 };
 
 #define FOR_EACH_FLAT_RANGE(var, view)          \
     for (var = (view)->ranges; var < (view)->ranges + (view)->nr; ++var)
 
 static inline MemoryRegionSection
 section_from_flat_range(FlatRange *fr, FlatView *fv)
 {
     return (MemoryRegionSection) {
         .mr = fr->mr,
         .fv = fv,
         .offset_within_region = fr->offset_in_region,
         .size = fr->addr.size,
         .offset_within_address_space = int128_get64(fr->addr.start),
         .readonly = fr->readonly,
         .nonvolatile = fr->nonvolatile,
     };
 }
 
 static bool flatrange_equal(FlatRange *a, FlatRange *b)
 {
     return a->mr == b->mr
         && addrrange_equal(a->addr, b->addr)
         && a->offset_in_region == b->offset_in_region
         && a->romd_mode == b->romd_mode
         && a->readonly == b->readonly
         && a->nonvolatile == b->nonvolatile;
 }
 
 static FlatView *flatview_new(MemoryRegion *mr_root)
 {
     FlatView *view;
 
     view = g_new0(FlatView, 1);
     view->ref = 1;
     view->root = mr_root;
     memory_region_ref(mr_root);
     trace_flatview_new(view, mr_root);
 
     return view;
 }
 
 /* Insert a range into a given position.  Caller is responsible for maintaining
  * sorting order.
  */
 static void flatview_insert(FlatView *view, unsigned pos, FlatRange *range)
 {
     if (view->nr == view->nr_allocated) {
         view->nr_allocated = MAX(2 * view->nr, 10);
         view->ranges = g_realloc(view->ranges,
                                     view->nr_allocated * sizeof(*view->ranges));
     }
     memmove(view->ranges + pos + 1, view->ranges + pos,
             (view->nr - pos) * sizeof(FlatRange));
     view->ranges[pos] = *range;
     memory_region_ref(range->mr);
     ++view->nr;
 }
 
 static void flatview_destroy(FlatView *view)
 {
     int i;
 
     trace_flatview_destroy(view, view->root);
     if (view->dispatch) {
         address_space_dispatch_free(view->dispatch);
     }
     for (i = 0; i < view->nr; i++) {
         memory_region_unref(view->ranges[i].mr);
     }
     g_free(view->ranges);
     memory_region_unref(view->root);
     g_free(view);
 }
 
 static bool flatview_ref(FlatView *view)
 {
     return qatomic_fetch_inc_nonzero(&view->ref) > 0;
 }
 
 void flatview_unref(FlatView *view)
 {
     if (qatomic_fetch_dec(&view->ref) == 1) {
         trace_flatview_destroy_rcu(view, view->root);
         assert(view->root);
         call_rcu(view, flatview_destroy, rcu);
     }
 }
 
 static bool can_merge(FlatRange *r1, FlatRange *r2)
 {
     return int128_eq(addrrange_end(r1->addr), r2->addr.start)
         && r1->mr == r2->mr
         && int128_eq(int128_add(int128_make64(r1->offset_in_region),
                                 r1->addr.size),
                      int128_make64(r2->offset_in_region))
         && r1->dirty_log_mask == r2->dirty_log_mask
         && r1->romd_mode == r2->romd_mode
         && r1->readonly == r2->readonly
         && r1->nonvolatile == r2->nonvolatile;
 }
 
 /* Attempt to simplify a view by merging adjacent ranges */
 static void flatview_simplify(FlatView *view)
 {
     unsigned i, j, k;
 
     i = 0;
     while (i < view->nr) {
         j = i + 1;
         while (j < view->nr
                && can_merge(&view->ranges[j-1], &view->ranges[j])) {
             int128_addto(&view->ranges[i].addr.size, view->ranges[j].addr.size);
             ++j;
         }
         ++i;
         for (k = i; k < j; k++) {
             memory_region_unref(view->ranges[k].mr);
         }
         memmove(&view->ranges[i], &view->ranges[j],
                 (view->nr - j) * sizeof(view->ranges[j]));
         view->nr -= j - i;
     }
 }
 
 static bool memory_region_big_endian(MemoryRegion *mr)
 {
 #if TARGET_BIG_ENDIAN
     return mr->ops->endianness != DEVICE_LITTLE_ENDIAN;
 #else
     return mr->ops->endianness == DEVICE_BIG_ENDIAN;
 #endif
 }
 
 static void adjust_endianness(MemoryRegion *mr, uint64_t *data, MemOp op)
 {
     if ((op & MO_BSWAP) != devend_memop(mr->ops->endianness)) {
         switch (op & MO_SIZE) {
         case MO_8:
             break;
         case MO_16:
             *data = bswap16(*data);
             break;
         case MO_32:
             *data = bswap32(*data);
             break;
         case MO_64:
             *data = bswap64(*data);
             break;
         default:
             g_assert_not_reached();
         }
     }
 }
 
 static inline void memory_region_shift_read_access(uint64_t *value,
                                                    signed shift,
                                                    uint64_t mask,
                                                    uint64_t tmp)
 {
     if (shift >= 0) {
         *value |= (tmp & mask) << shift;
     } else {
         *value |= (tmp & mask) >> -shift;
     }
 }
 
 static inline uint64_t memory_region_shift_write_access(uint64_t *value,
                                                         signed shift,
                                                         uint64_t mask)
 {
     uint64_t tmp;
 
     if (shift >= 0) {
         tmp = (*value >> shift) & mask;
     } else {
         tmp = (*value << -shift) & mask;
     }
 
     return tmp;
 }
 
 static hwaddr memory_region_to_absolute_addr(MemoryRegion *mr, hwaddr offset)
 {
     MemoryRegion *root;
     hwaddr abs_addr = offset;
 
     abs_addr += mr->addr;
     for (root = mr; root->container; ) {
         root = root->container;
         abs_addr += root->addr;
     }
 
     return abs_addr;
 }
 
 static int get_cpu_index(void)
 {
     if (current_cpu) {
         return current_cpu->cpu_index;
     }
     return -1;
 }
 
 static MemTxResult  memory_region_read_accessor(MemoryRegion *mr,
                                                 hwaddr addr,
                                                 uint64_t *value,
                                                 unsigned size,
                                                 signed shift,
                                                 uint64_t mask,
                                                 MemTxAttrs attrs)
 {
     uint64_t tmp;
 
     tmp = mr->ops->read(mr->opaque, addr, size);
     if (mr->subpage) {
         trace_memory_region_subpage_read(get_cpu_index(), mr, addr, tmp, size);
     } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_READ)) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
         trace_memory_region_ops_read(get_cpu_index(), mr, abs_addr, tmp, size,
                                      memory_region_name(mr));
     }
     memory_region_shift_read_access(value, shift, mask, tmp);
     return MEMTX_OK;
 }
 
 static MemTxResult memory_region_read_with_attrs_accessor(MemoryRegion *mr,
                                                           hwaddr addr,
                                                           uint64_t *value,
                                                           unsigned size,
                                                           signed shift,
                                                           uint64_t mask,
                                                           MemTxAttrs attrs)
 {
     uint64_t tmp = 0;
     MemTxResult r;
 
     r = mr->ops->read_with_attrs(mr->opaque, addr, &tmp, size, attrs);
     if (mr->subpage) {
         trace_memory_region_subpage_read(get_cpu_index(), mr, addr, tmp, size);
     } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_READ)) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
         trace_memory_region_ops_read(get_cpu_index(), mr, abs_addr, tmp, size,
                                      memory_region_name(mr));
     }
     memory_region_shift_read_access(value, shift, mask, tmp);
     return r;
 }
 
 static MemTxResult memory_region_write_accessor(MemoryRegion *mr,
                                                 hwaddr addr,
                                                 uint64_t *value,
                                                 unsigned size,
                                                 signed shift,
                                                 uint64_t mask,
                                                 MemTxAttrs attrs)
 {
     uint64_t tmp = memory_region_shift_write_access(value, shift, mask);
 
     if (mr->subpage) {
         trace_memory_region_subpage_write(get_cpu_index(), mr, addr, tmp, size);
     } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_WRITE)) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
         trace_memory_region_ops_write(get_cpu_index(), mr, abs_addr, tmp, size,
                                       memory_region_name(mr));
     }
     mr->ops->write(mr->opaque, addr, tmp, size);
     return MEMTX_OK;
 }
 
 static MemTxResult memory_region_write_with_attrs_accessor(MemoryRegion *mr,
                                                            hwaddr addr,
                                                            uint64_t *value,
                                                            unsigned size,
                                                            signed shift,
                                                            uint64_t mask,
                                                            MemTxAttrs attrs)
 {
     uint64_t tmp = memory_region_shift_write_access(value, shift, mask);
 
     if (mr->subpage) {
         trace_memory_region_subpage_write(get_cpu_index(), mr, addr, tmp, size);
     } else if (trace_event_get_state_backends(TRACE_MEMORY_REGION_OPS_WRITE)) {
         hwaddr abs_addr = memory_region_to_absolute_addr(mr, addr);
         trace_memory_region_ops_write(get_cpu_index(), mr, abs_addr, tmp, size,
                                       memory_region_name(mr));
     }
     return mr->ops->write_with_attrs(mr->opaque, addr, tmp, size, attrs);
 }
 
 static MemTxResult access_with_adjusted_size(hwaddr addr,
                                       uint64_t *value,
                                       unsigned size,
                                       unsigned access_size_min,
                                       unsigned access_size_max,
                                       MemTxResult (*access_fn)
                                                   (MemoryRegion *mr,
                                                    hwaddr addr,
                                                    uint64_t *value,
                                                    unsigned size,
                                                    signed shift,
                                                    uint64_t mask,
                                                    MemTxAttrs attrs),
                                       MemoryRegion *mr,
                                       MemTxAttrs attrs)
 {
     uint64_t access_mask;
     unsigned access_size;
     unsigned i;
     MemTxResult r = MEMTX_OK;
 
     if (!access_size_min) {
         access_size_min = 1;
     }
     if (!access_size_max) {
         access_size_max = 4;
     }
 
     /* FIXME: support unaligned access? */
     access_size = MAX(MIN(size, access_size_max), access_size_min);
     access_mask = MAKE_64BIT_MASK(0, access_size * 8);
     if (memory_region_big_endian(mr)) {
         for (i = 0; i < size; i += access_size) {
             r |= access_fn(mr, addr + i, value, access_size,
                         (size - access_size - i) * 8, access_mask, attrs);
         }
     } else {
         for (i = 0; i < size; i += access_size) {
             r |= access_fn(mr, addr + i, value, access_size, i * 8,
                         access_mask, attrs);
         }
     }
     return r;
 }
 
 static AddressSpace *memory_region_to_address_space(MemoryRegion *mr)
 {
     AddressSpace *as;
 
     while (mr->container) {
         mr = mr->container;
     }
     QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
         if (mr == as->root) {
             return as;
         }
     }
     return NULL;
 }
 
 /* Render a memory region into the global view.  Ranges in @view obscure
  * ranges in @mr.
  */
 static void render_memory_region(FlatView *view,
                                  MemoryRegion *mr,
                                  Int128 base,
                                  AddrRange clip,
                                  bool readonly,
                                  bool nonvolatile)
 {
     MemoryRegion *subregion;
     unsigned i;
     hwaddr offset_in_region;
     Int128 remain;
     Int128 now;
     FlatRange fr;
     AddrRange tmp;
 
     if (!mr->enabled) {
         return;
     }
 
     int128_addto(&base, int128_make64(mr->addr));
     readonly |= mr->readonly;
     nonvolatile |= mr->nonvolatile;
 
     tmp = addrrange_make(base, mr->size);
 
     if (!addrrange_intersects(tmp, clip)) {
         return;
     }
 
     clip = addrrange_intersection(tmp, clip);
 
     if (mr->alias) {
         int128_subfrom(&base, int128_make64(mr->alias->addr));
         int128_subfrom(&base, int128_make64(mr->alias_offset));
         render_memory_region(view, mr->alias, base, clip,
                              readonly, nonvolatile);
         return;
     }
 
     /* Render subregions in priority order. */
     QTAILQ_FOREACH(subregion, &mr->subregions, subregions_link) {
         render_memory_region(view, subregion, base, clip,
                              readonly, nonvolatile);
     }
 
     if (!mr->terminates) {
         return;
     }
 
     offset_in_region = int128_get64(int128_sub(clip.start, base));
     base = clip.start;
     remain = clip.size;
 
     fr.mr = mr;
     fr.dirty_log_mask = memory_region_get_dirty_log_mask(mr);
     fr.romd_mode = mr->romd_mode;
     fr.readonly = readonly;
     fr.nonvolatile = nonvolatile;
 
     /* Render the region itself into any gaps left by the current view. */
     for (i = 0; i < view->nr && int128_nz(remain); ++i) {
         if (int128_ge(base, addrrange_end(view->ranges[i].addr))) {
             continue;
         }
         if (int128_lt(base, view->ranges[i].addr.start)) {
             now = int128_min(remain,
                              int128_sub(view->ranges[i].addr.start, base));
             fr.offset_in_region = offset_in_region;
             fr.addr = addrrange_make(base, now);
             flatview_insert(view, i, &fr);
             ++i;
             int128_addto(&base, now);
             offset_in_region += int128_get64(now);
             int128_subfrom(&remain, now);
         }
         now = int128_sub(int128_min(int128_add(base, remain),
                                     addrrange_end(view->ranges[i].addr)),
                          base);
         int128_addto(&base, now);
         offset_in_region += int128_get64(now);
         int128_subfrom(&remain, now);
     }
     if (int128_nz(remain)) {
         fr.offset_in_region = offset_in_region;
         fr.addr = addrrange_make(base, remain);
         flatview_insert(view, i, &fr);
     }
 }
 
 void flatview_for_each_range(FlatView *fv, flatview_cb cb , void *opaque)
 {
     FlatRange *fr;
 
     assert(fv);
     assert(cb);
 
     FOR_EACH_FLAT_RANGE(fr, fv) {
         if (cb(fr->addr.start, fr->addr.size, fr->mr,
                fr->offset_in_region, opaque)) {
             break;
         }
     }
 }
 
 static MemoryRegion *memory_region_get_flatview_root(MemoryRegion *mr)
 {
     while (mr->enabled) {
         if (mr->alias) {
             if (!mr->alias_offset && int128_ge(mr->size, mr->alias->size)) {
                 /* The alias is included in its entirety.  Use it as
                  * the "real" root, so that we can share more FlatViews.
                  */
                 mr = mr->alias;
                 continue;
             }
         } else if (!mr->terminates) {
             unsigned int found = 0;
             MemoryRegion *child, *next = NULL;
             QTAILQ_FOREACH(child, &mr->subregions, subregions_link) {
                 if (child->enabled) {
                     if (++found > 1) {
                         next = NULL;
                         break;
                     }
                     if (!child->addr && int128_ge(mr->size, child->size)) {
                         /* A child is included in its entirety.  If it's the only
                          * enabled one, use it in the hope of finding an alias down the
                          * way. This will also let us share FlatViews.
                          */
                         next = child;
                     }
                 }
             }
             if (found == 0) {
                 return NULL;
             }
             if (next) {
                 mr = next;
                 continue;
             }
         }
 
         return mr;
     }
 
     return NULL;
 }
 
 /* Render a memory topology into a list of disjoint absolute ranges. */
 static FlatView *generate_memory_topology(MemoryRegion *mr)
 {
     int i;
     FlatView *view;
 
     view = flatview_new(mr);
 
     if (mr) {
         render_memory_region(view, mr, int128_zero(),
                              addrrange_make(int128_zero(), int128_2_64()),
                              false, false);
     }
     flatview_simplify(view);
 
     view->dispatch = address_space_dispatch_new(view);
     for (i = 0; i < view->nr; i++) {
         MemoryRegionSection mrs =
             section_from_flat_range(&view->ranges[i], view);
         flatview_add_to_dispatch(view, &mrs);
     }
     address_space_dispatch_compact(view->dispatch);
     g_hash_table_replace(flat_views, mr, view);
 
     return view;
 }
 
 static void address_space_add_del_ioeventfds(AddressSpace *as,
                                              MemoryRegionIoeventfd *fds_new,
                                              unsigned fds_new_nb,
                                              MemoryRegionIoeventfd *fds_old,
                                              unsigned fds_old_nb)
 {
     unsigned iold, inew;
     MemoryRegionIoeventfd *fd;
     MemoryRegionSection section;
 
     /* Generate a symmetric difference of the old and new fd sets, adding
      * and deleting as necessary.
      */
 
     iold = inew = 0;
     while (iold < fds_old_nb || inew < fds_new_nb) {
         if (iold < fds_old_nb
             && (inew == fds_new_nb
                 || memory_region_ioeventfd_before(&fds_old[iold],
                                                   &fds_new[inew]))) {
             fd = &fds_old[iold];
             section = (MemoryRegionSection) {
                 .fv = address_space_to_flatview(as),
                 .offset_within_address_space = int128_get64(fd->addr.start),
                 .size = fd->addr.size,
             };
             MEMORY_LISTENER_CALL(as, eventfd_del, Forward, &section,
                                  fd->match_data, fd->data, fd->e);
             ++iold;
         } else if (inew < fds_new_nb
                    && (iold == fds_old_nb
                        || memory_region_ioeventfd_before(&fds_new[inew],
                                                          &fds_old[iold]))) {
             fd = &fds_new[inew];
             section = (MemoryRegionSection) {
                 .fv = address_space_to_flatview(as),
                 .offset_within_address_space = int128_get64(fd->addr.start),
                 .size = fd->addr.size,
             };
             MEMORY_LISTENER_CALL(as, eventfd_add, Reverse, &section,
                                  fd->match_data, fd->data, fd->e);
             ++inew;
         } else {
             ++iold;
             ++inew;
         }
     }
 }
 
 FlatView *address_space_get_flatview(AddressSpace *as)
 {
     FlatView *view;
 
     RCU_READ_LOCK_GUARD();
     do {
         view = address_space_to_flatview(as);
         /* If somebody has replaced as->current_map concurrently,
          * flatview_ref returns false.
          */
     } while (!flatview_ref(view));
     return view;
 }
 
 static void address_space_update_ioeventfds(AddressSpace *as)
 {
     FlatView *view;
     FlatRange *fr;
     unsigned ioeventfd_nb = 0;
     unsigned ioeventfd_max;
     MemoryRegionIoeventfd *ioeventfds;
     AddrRange tmp;
     unsigned i;
 
     /*
      * It is likely that the number of ioeventfds hasn't changed much, so use
      * the previous size as the starting value, with some headroom to avoid
      * gratuitous reallocations.
      */
     ioeventfd_max = QEMU_ALIGN_UP(as->ioeventfd_nb, 4);
     ioeventfds = g_new(MemoryRegionIoeventfd, ioeventfd_max);
 
     view = address_space_get_flatview(as);
     FOR_EACH_FLAT_RANGE(fr, view) {
         for (i = 0; i < fr->mr->ioeventfd_nb; ++i) {
             tmp = addrrange_shift(fr->mr->ioeventfds[i].addr,
                                   int128_sub(fr->addr.start,
                                              int128_make64(fr->offset_in_region)));
             if (addrrange_intersects(fr->addr, tmp)) {
                 ++ioeventfd_nb;
                 if (ioeventfd_nb > ioeventfd_max) {
                     ioeventfd_max = MAX(ioeventfd_max * 2, 4);
                     ioeventfds = g_realloc(ioeventfds,
                             ioeventfd_max * sizeof(*ioeventfds));
                 }
                 ioeventfds[ioeventfd_nb-1] = fr->mr->ioeventfds[i];
                 ioeventfds[ioeventfd_nb-1].addr = tmp;
             }
         }
     }
 
     address_space_add_del_ioeventfds(as, ioeventfds, ioeventfd_nb,
                                      as->ioeventfds, as->ioeventfd_nb);
 
     g_free(as->ioeventfds);
     as->ioeventfds = ioeventfds;
     as->ioeventfd_nb = ioeventfd_nb;
     flatview_unref(view);
 }
 
 /*
  * Notify the memory listeners about the coalesced IO change events of
  * range `cmr'.  Only the part that has intersection of the specified
  * FlatRange will be sent.
  */
 static void flat_range_coalesced_io_notify(FlatRange *fr, AddressSpace *as,
                                            CoalescedMemoryRange *cmr, bool add)
 {
     AddrRange tmp;
 
     tmp = addrrange_shift(cmr->addr,
                           int128_sub(fr->addr.start,
                                      int128_make64(fr->offset_in_region)));
     if (!addrrange_intersects(tmp, fr->addr)) {
         return;
     }
     tmp = addrrange_intersection(tmp, fr->addr);
 
     if (add) {
         MEMORY_LISTENER_UPDATE_REGION(fr, as, Forward, coalesced_io_add,
                                       int128_get64(tmp.start),
                                       int128_get64(tmp.size));
     } else {
         MEMORY_LISTENER_UPDATE_REGION(fr, as, Reverse, coalesced_io_del,
                                       int128_get64(tmp.start),
                                       int128_get64(tmp.size));
     }
 }
 
 static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
 {
     CoalescedMemoryRange *cmr;
 
     QTAILQ_FOREACH(cmr, &fr->mr->coalesced, link) {
         flat_range_coalesced_io_notify(fr, as, cmr, false);
     }
 }
 
 static void flat_range_coalesced_io_add(FlatRange *fr, AddressSpace *as)
 {
     MemoryRegion *mr = fr->mr;
     CoalescedMemoryRange *cmr;
 
     if (QTAILQ_EMPTY(&mr->coalesced)) {
         return;
     }
 
     QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
         flat_range_coalesced_io_notify(fr, as, cmr, true);
     }
 }
 
 static void address_space_update_topology_pass(AddressSpace *as,
                                                const FlatView *old_view,
                                                const FlatView *new_view,
                                                bool adding)
 {
     unsigned iold, inew;
     FlatRange *frold, *frnew;
 
     /* Generate a symmetric difference of the old and new memory maps.
      * Kill ranges in the old map, and instantiate ranges in the new map.
      */
     iold = inew = 0;
     while (iold < old_view->nr || inew < new_view->nr) {
         if (iold < old_view->nr) {
             frold = &old_view->ranges[iold];
         } else {
             frold = NULL;
         }
         if (inew < new_view->nr) {
             frnew = &new_view->ranges[inew];
         } else {
             frnew = NULL;
         }
 
         if (frold
             && (!frnew
                 || int128_lt(frold->addr.start, frnew->addr.start)
                 || (int128_eq(frold->addr.start, frnew->addr.start)
                     && !flatrange_equal(frold, frnew)))) {
             /* In old but not in new, or in both but attributes changed. */
 
             if (!adding) {
                 flat_range_coalesced_io_del(frold, as);
                 MEMORY_LISTENER_UPDATE_REGION(frold, as, Reverse, region_del);
             }
 
             ++iold;
         } else if (frold && frnew && flatrange_equal(frold, frnew)) {
             /* In both and unchanged (except logging may have changed) */
 
             if (adding) {
                 MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, region_nop);
                 if (frnew->dirty_log_mask & ~frold->dirty_log_mask) {
                     MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, log_start,
                                                   frold->dirty_log_mask,
                                                   frnew->dirty_log_mask);
                 }
                 if (frold->dirty_log_mask & ~frnew->dirty_log_mask) {
                     MEMORY_LISTENER_UPDATE_REGION(frnew, as, Reverse, log_stop,
                                                   frold->dirty_log_mask,
                                                   frnew->dirty_log_mask);
                 }
             }
 
             ++iold;
             ++inew;
         } else {
             /* In new */
 
             if (adding) {
                 MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, region_add);
                 flat_range_coalesced_io_add(frnew, as);
             }
 
             ++inew;
         }
     }
 }
 
 static void flatviews_init(void)
 {
     static FlatView *empty_view;
 
     if (flat_views) {
         return;
     }
 
     flat_views = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL,
                                        (GDestroyNotify) flatview_unref);
     if (!empty_view) {
         empty_view = generate_memory_topology(NULL);
         /* We keep it alive forever in the global variable.  */
         flatview_ref(empty_view);
     } else {
         g_hash_table_replace(flat_views, NULL, empty_view);
         flatview_ref(empty_view);
     }
 }
 
 static void flatviews_reset(void)
 {
     AddressSpace *as;
 
     if (flat_views) {
         g_hash_table_unref(flat_views);
         flat_views = NULL;
     }
     flatviews_init();
 
     /* Render unique FVs */
     QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
         MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
 
         if (g_hash_table_lookup(flat_views, physmr)) {
             continue;
         }
 
         generate_memory_topology(physmr);
     }
 }
 
 static void address_space_set_flatview(AddressSpace *as)
 {
     FlatView *old_view = address_space_to_flatview(as);
     MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
     FlatView *new_view = g_hash_table_lookup(flat_views, physmr);
 
     assert(new_view);
 
     if (old_view == new_view) {
         return;
     }
 
     if (old_view) {
         flatview_ref(old_view);
     }
 
     flatview_ref(new_view);
 
     if (!QTAILQ_EMPTY(&as->listeners)) {
         FlatView tmpview = { .nr = 0 }, *old_view2 = old_view;
 
         if (!old_view2) {
             old_view2 = &tmpview;
         }
         address_space_update_topology_pass(as, old_view2, new_view, false);
         address_space_update_topology_pass(as, old_view2, new_view, true);
     }
 
     /* Writes are protected by the BQL.  */
     qatomic_rcu_set(&as->current_map, new_view);
     if (old_view) {
         flatview_unref(old_view);
     }
 
     /* Note that all the old MemoryRegions are still alive up to this
      * point.  This relieves most MemoryListeners from the need to
      * ref/unref the MemoryRegions they get---unless they use them
      * outside the iothread mutex, in which case precise reference
      * counting is necessary.
      */
     if (old_view) {
         flatview_unref(old_view);
     }
 }
 
 static void address_space_update_topology(AddressSpace *as)
 {
     MemoryRegion *physmr = memory_region_get_flatview_root(as->root);
 
     flatviews_init();
     if (!g_hash_table_lookup(flat_views, physmr)) {
         generate_memory_topology(physmr);
     }
     address_space_set_flatview(as);
 }
 
 void memory_region_transaction_begin(void)
 {
     qemu_flush_coalesced_mmio_buffer();
     ++memory_region_transaction_depth;
 }
 
 void memory_region_transaction_commit(void)
 {
     AddressSpace *as;
 
     assert(memory_region_transaction_depth);
     assert(qemu_mutex_iothread_locked());
 
     --memory_region_transaction_depth;
     if (!memory_region_transaction_depth) {
         if (memory_region_update_pending) {
             flatviews_reset();
 
             MEMORY_LISTENER_CALL_GLOBAL(begin, Forward);
 
             QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
                 address_space_set_flatview(as);
                 address_space_update_ioeventfds(as);
             }
             memory_region_update_pending = false;
             ioeventfd_update_pending = false;
             MEMORY_LISTENER_CALL_GLOBAL(commit, Forward);
         } else if (ioeventfd_update_pending) {
             QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
                 address_space_update_ioeventfds(as);
             }
             ioeventfd_update_pending = false;
         }
    }
 }
 
 static void memory_region_destructor_none(MemoryRegion *mr)
 {
 }
 
 static void memory_region_destructor_ram(MemoryRegion *mr)
 {
     qemu_ram_free(mr->ram_block);
 }
 
 static bool memory_region_need_escape(char c)
 {
     return c == '/' || c == '[' || c == '\\' || c == ']';
 }
 
 static char *memory_region_escape_name(const char *name)
 {
     const char *p;
     char *escaped, *q;
     uint8_t c;
     size_t bytes = 0;
 
     for (p = name; *p; p++) {
         bytes += memory_region_need_escape(*p) ? 4 : 1;
     }
     if (bytes == p - name) {
        return g_memdup(name, bytes + 1);
     }
 
     escaped = g_malloc(bytes + 1);
     for (p = name, q = escaped; *p; p++) {
         c = *p;
         if (unlikely(memory_region_need_escape(c))) {
             *q++ = '\\';
             *q++ = 'x';
             *q++ = "0123456789abcdef"[c >> 4];
             c = "0123456789abcdef"[c & 15];
         }
         *q++ = c;
     }
     *q = 0;
     return escaped;
 }
 
 static void memory_region_do_init(MemoryRegion *mr,
                                   Object *owner,
                                   const char *name,
                                   uint64_t size)
 {
     mr->size = int128_make64(size);
     if (size == UINT64_MAX) {
         mr->size = int128_2_64();
     }
     mr->name = g_strdup(name);
     mr->owner = owner;
     mr->ram_block = NULL;
 
     if (name) {
         char *escaped_name = memory_region_escape_name(name);
         char *name_array = g_strdup_printf("%s[*]", escaped_name);
 
         if (!owner) {
             owner = container_get(qdev_get_machine(), "/unattached");
         }
 
         object_property_add_child(owner, name_array, OBJECT(mr));
         object_unref(OBJECT(mr));
         g_free(name_array);
         g_free(escaped_name);
     }
 }
 
 void memory_region_init(MemoryRegion *mr,
                         Object *owner,
                         const char *name,
                         uint64_t size)
 {
     object_initialize(mr, sizeof(*mr), TYPE_MEMORY_REGION);
     memory_region_do_init(mr, owner, name, size);
 }
 
 static void memory_region_get_container(Object *obj, Visitor *v,
                                         const char *name, void *opaque,
                                         Error **errp)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
     char *path = (char *)"";
 
     if (mr->container) {
         path = object_get_canonical_path(OBJECT(mr->container));
     }
     visit_type_str(v, name, &path, errp);
     if (mr->container) {
         g_free(path);
     }
 }
 
 static Object *memory_region_resolve_container(Object *obj, void *opaque,
                                                const char *part)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
 
     return OBJECT(mr->container);
 }
 
 static void memory_region_get_priority(Object *obj, Visitor *v,
                                        const char *name, void *opaque,
                                        Error **errp)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
     int32_t value = mr->priority;
 
     visit_type_int32(v, name, &value, errp);
 }
 
 static void memory_region_get_size(Object *obj, Visitor *v, const char *name,
                                    void *opaque, Error **errp)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
     uint64_t value = memory_region_size(mr);
 
     visit_type_uint64(v, name, &value, errp);
 }
 
 static void memory_region_initfn(Object *obj)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
     ObjectProperty *op;
 
     mr->ops = &unassigned_mem_ops;
     mr->enabled = true;
     mr->romd_mode = true;
     mr->destructor = memory_region_destructor_none;
     QTAILQ_INIT(&mr->subregions);
     QTAILQ_INIT(&mr->coalesced);
 
     op = object_property_add(OBJECT(mr), "container",
                              "link<" TYPE_MEMORY_REGION ">",
                              memory_region_get_container,
                              NULL, /* memory_region_set_container */
                              NULL, NULL);
     op->resolve = memory_region_resolve_container;
 
     object_property_add_uint64_ptr(OBJECT(mr), "addr",
                                    &mr->addr, OBJ_PROP_FLAG_READ);
     object_property_add(OBJECT(mr), "priority", "uint32",
                         memory_region_get_priority,
                         NULL, /* memory_region_set_priority */
                         NULL, NULL);
     object_property_add(OBJECT(mr), "size", "uint64",
                         memory_region_get_size,
                         NULL, /* memory_region_set_size, */
                         NULL, NULL);
 }
 
 static void iommu_memory_region_initfn(Object *obj)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
 
     mr->is_iommu = true;
 }
 
 static uint64_t unassigned_mem_read(void *opaque, hwaddr addr,
                                     unsigned size)
 {
 #ifdef DEBUG_UNASSIGNED
     printf("Unassigned mem read " TARGET_FMT_plx "\n", addr);
 #endif
     return 0;
 }
 
 static void unassigned_mem_write(void *opaque, hwaddr addr,
                                  uint64_t val, unsigned size)
 {
 #ifdef DEBUG_UNASSIGNED
     printf("Unassigned mem write " TARGET_FMT_plx " = 0x%"PRIx64"\n", addr, val);
 #endif
 }
 
 static bool unassigned_mem_accepts(void *opaque, hwaddr addr,
                                    unsigned size, bool is_write,
                                    MemTxAttrs attrs)
 {
     return false;
 }
 
 const MemoryRegionOps unassigned_mem_ops = {
     .valid.accepts = unassigned_mem_accepts,
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
 static uint64_t memory_region_ram_device_read(void *opaque,
                                               hwaddr addr, unsigned size)
 {
     MemoryRegion *mr = opaque;
     uint64_t data = (uint64_t)~0;
 
     switch (size) {
     case 1:
         data = *(uint8_t *)(mr->ram_block->host + addr);
         break;
     case 2:
         data = *(uint16_t *)(mr->ram_block->host + addr);
         break;
     case 4:
         data = *(uint32_t *)(mr->ram_block->host + addr);
         break;
     case 8:
         data = *(uint64_t *)(mr->ram_block->host + addr);
         break;
     }
 
     trace_memory_region_ram_device_read(get_cpu_index(), mr, addr, data, size);
 
     return data;
 }
 
 static void memory_region_ram_device_write(void *opaque, hwaddr addr,
                                            uint64_t data, unsigned size)
 {
     MemoryRegion *mr = opaque;
 
     trace_memory_region_ram_device_write(get_cpu_index(), mr, addr, data, size);
 
     switch (size) {
     case 1:
         *(uint8_t *)(mr->ram_block->host + addr) = (uint8_t)data;
         break;
     case 2:
         *(uint16_t *)(mr->ram_block->host + addr) = (uint16_t)data;
         break;
     case 4:
         *(uint32_t *)(mr->ram_block->host + addr) = (uint32_t)data;
         break;
     case 8:
         *(uint64_t *)(mr->ram_block->host + addr) = data;
         break;
     }
 }
 
 static const MemoryRegionOps ram_device_mem_ops = {
     .read = memory_region_ram_device_read,
     .write = memory_region_ram_device_write,
     .endianness = DEVICE_HOST_ENDIAN,
     .valid = {
         .min_access_size = 1,
         .max_access_size = 8,
         .unaligned = true,
     },
     .impl = {
         .min_access_size = 1,
         .max_access_size = 8,
         .unaligned = true,
     },
 };
 
 bool memory_region_access_valid(MemoryRegion *mr,
                                 hwaddr addr,
                                 unsigned size,
                                 bool is_write,
                                 MemTxAttrs attrs)
 {
     if (mr->ops->valid.accepts
         && !mr->ops->valid.accepts(mr->opaque, addr, size, is_write, attrs)) {
         qemu_log_mask(LOG_GUEST_ERROR, "Invalid %s at addr 0x%" HWADDR_PRIX
                       ", size %u, region '%s', reason: rejected\n",
                       is_write ? "write" : "read",
                       addr, size, memory_region_name(mr));
         return false;
     }
 
     if (!mr->ops->valid.unaligned && (addr & (size - 1))) {
         qemu_log_mask(LOG_GUEST_ERROR, "Invalid %s at addr 0x%" HWADDR_PRIX
                       ", size %u, region '%s', reason: unaligned\n",
                       is_write ? "write" : "read",
                       addr, size, memory_region_name(mr));
         return false;
     }
 
     /* Treat zero as compatibility all valid */
     if (!mr->ops->valid.max_access_size) {
         return true;
     }
 
     if (size > mr->ops->valid.max_access_size
         || size < mr->ops->valid.min_access_size) {
         qemu_log_mask(LOG_GUEST_ERROR, "Invalid %s at addr 0x%" HWADDR_PRIX
                       ", size %u, region '%s', reason: invalid size "
                       "(min:%u max:%u)\n",
                       is_write ? "write" : "read",
                       addr, size, memory_region_name(mr),
                       mr->ops->valid.min_access_size,
                       mr->ops->valid.max_access_size);
         return false;
     }
     return true;
 }
 
 static MemTxResult memory_region_dispatch_read1(MemoryRegion *mr,
                                                 hwaddr addr,
                                                 uint64_t *pval,
                                                 unsigned size,
                                                 MemTxAttrs attrs)
 {
     *pval = 0;
 
     if (mr->ops->read) {
         return access_with_adjusted_size(addr, pval, size,
                                          mr->ops->impl.min_access_size,
                                          mr->ops->impl.max_access_size,
                                          memory_region_read_accessor,
                                          mr, attrs);
     } else {
         return access_with_adjusted_size(addr, pval, size,
                                          mr->ops->impl.min_access_size,
                                          mr->ops->impl.max_access_size,
                                          memory_region_read_with_attrs_accessor,
                                          mr, attrs);
     }
 }
 
 MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
                                         hwaddr addr,
                                         uint64_t *pval,
                                         MemOp op,
                                         MemTxAttrs attrs)
 {
     unsigned size = memop_size(op);
     MemTxResult r;
 
     if (mr->alias) {
         return memory_region_dispatch_read(mr->alias,
                                            mr->alias_offset + addr,
                                            pval, op, attrs);
     }
     if (!memory_region_access_valid(mr, addr, size, false, attrs)) {
         *pval = unassigned_mem_read(mr, addr, size);
         return MEMTX_DECODE_ERROR;
     }
 
     r = memory_region_dispatch_read1(mr, addr, pval, size, attrs);
     adjust_endianness(mr, pval, op);
     return r;
 }
 
 /* Return true if an eventfd was signalled */
 static bool memory_region_dispatch_write_eventfds(MemoryRegion *mr,
                                                     hwaddr addr,
                                                     uint64_t data,
                                                     unsigned size,
                                                     MemTxAttrs attrs)
 {
     MemoryRegionIoeventfd ioeventfd = {
         .addr = addrrange_make(int128_make64(addr), int128_make64(size)),
         .data = data,
     };
     unsigned i;
 
     for (i = 0; i < mr->ioeventfd_nb; i++) {
         ioeventfd.match_data = mr->ioeventfds[i].match_data;
         ioeventfd.e = mr->ioeventfds[i].e;
 
         if (memory_region_ioeventfd_equal(&ioeventfd, &mr->ioeventfds[i])) {
             event_notifier_set(ioeventfd.e);
             return true;
         }
     }
 
     return false;
 }
 
 MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
                                          hwaddr addr,
                                          uint64_t data,
                                          MemOp op,
                                          MemTxAttrs attrs)
 {
     unsigned size = memop_size(op);
 
     if (mr->alias) {
         return memory_region_dispatch_write(mr->alias,
                                             mr->alias_offset + addr,
                                             data, op, attrs);
     }
     if (!memory_region_access_valid(mr, addr, size, true, attrs)) {
         unassigned_mem_write(mr, addr, data, size);
         return MEMTX_DECODE_ERROR;
     }
 
     adjust_endianness(mr, &data, op);
 
     if ((!kvm_eventfds_enabled()) &&
         memory_region_dispatch_write_eventfds(mr, addr, data, size, attrs)) {
         return MEMTX_OK;
     }
 
     if (mr->ops->write) {
         return access_with_adjusted_size(addr, &data, size,
                                          mr->ops->impl.min_access_size,
                                          mr->ops->impl.max_access_size,
                                          memory_region_write_accessor, mr,
                                          attrs);
     } else {
         return
             access_with_adjusted_size(addr, &data, size,
                                       mr->ops->impl.min_access_size,
                                       mr->ops->impl.max_access_size,
                                       memory_region_write_with_attrs_accessor,
                                       mr, attrs);
     }
 }
 
 void memory_region_init_io(MemoryRegion *mr,
                            Object *owner,
                            const MemoryRegionOps *ops,
                            void *opaque,
                            const char *name,
                            uint64_t size)
 {
     memory_region_init(mr, owner, name, size);
     mr->ops = ops ? ops : &unassigned_mem_ops;
     mr->opaque = opaque;
     mr->terminates = true;
 }
 
 void memory_region_init_ram_nomigrate(MemoryRegion *mr,
                                       Object *owner,
                                       const char *name,
                                       uint64_t size,
                                       Error **errp)
 {
     memory_region_init_ram_flags_nomigrate(mr, owner, name, size, 0, errp);
 }
 
 void memory_region_init_ram_flags_nomigrate(MemoryRegion *mr,
                                             Object *owner,
                                             const char *name,
                                             uint64_t size,
                                             uint32_t ram_flags,
                                             Error **errp)
 {
     Error *err = NULL;
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->ram_block = qemu_ram_alloc(size, ram_flags, mr, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
         error_propagate(errp, err);
     }
 }
 
 void memory_region_init_resizeable_ram(MemoryRegion *mr,
                                        Object *owner,
                                        const char *name,
                                        uint64_t size,
                                        uint64_t max_size,
                                        void (*resized)(const char*,
                                                        uint64_t length,
                                                        void *host),
                                        Error **errp)
 {
     Error *err = NULL;
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->ram_block = qemu_ram_alloc_resizeable(size, max_size, resized,
                                               mr, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
         error_propagate(errp, err);
     }
 }
 
 #ifdef CONFIG_POSIX
 void memory_region_init_ram_from_file(MemoryRegion *mr,
                                       Object *owner,
                                       const char *name,
                                       uint64_t size,
                                       uint64_t align,
                                       uint32_t ram_flags,
                                       const char *path,
                                       bool readonly,
                                       Error **errp)
 {
     Error *err = NULL;
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->readonly = readonly;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->align = align;
     mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path,
                                              readonly, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
         error_propagate(errp, err);
     }
 }
 
 void memory_region_init_ram_from_fd(MemoryRegion *mr,
                                     Object *owner,
                                     const char *name,
                                     uint64_t size,
                                     uint32_t ram_flags,
                                     int fd,
                                     ram_addr_t offset,
                                     Error **errp)
 {
     Error *err = NULL;
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->ram_block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset,
                                            false, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
         error_propagate(errp, err);
     }
 }
 #endif
 
 void memory_region_init_ram_ptr(MemoryRegion *mr,
                                 Object *owner,
                                 const char *name,
                                 uint64_t size,
                                 void *ptr)
 {
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
 
     /* qemu_ram_alloc_from_ptr cannot fail with ptr != NULL.  */
     assert(ptr != NULL);
     mr->ram_block = qemu_ram_alloc_from_ptr(size, ptr, mr, &error_fatal);
 }
 
 void memory_region_init_ram_device_ptr(MemoryRegion *mr,
                                        Object *owner,
                                        const char *name,
                                        uint64_t size,
                                        void *ptr)
 {
     memory_region_init(mr, owner, name, size);
     mr->ram = true;
     mr->terminates = true;
     mr->ram_device = true;
     mr->ops = &ram_device_mem_ops;
     mr->opaque = mr;
     mr->destructor = memory_region_destructor_ram;
 
     /* qemu_ram_alloc_from_ptr cannot fail with ptr != NULL.  */
     assert(ptr != NULL);
     mr->ram_block = qemu_ram_alloc_from_ptr(size, ptr, mr, &error_fatal);
 }
 
 void memory_region_init_alias(MemoryRegion *mr,
                               Object *owner,
                               const char *name,
                               MemoryRegion *orig,
                               hwaddr offset,
                               uint64_t size)
 {
     memory_region_init(mr, owner, name, size);
     mr->alias = orig;
     mr->alias_offset = offset;
 }
 
 void memory_region_init_rom_nomigrate(MemoryRegion *mr,
                                       Object *owner,
                                       const char *name,
                                       uint64_t size,
                                       Error **errp)
 {
     memory_region_init_ram_flags_nomigrate(mr, owner, name, size, 0, errp);
     mr->readonly = true;
 }
 
 void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
                                              Object *owner,
                                              const MemoryRegionOps *ops,
                                              void *opaque,
                                              const char *name,
                                              uint64_t size,
                                              Error **errp)
 {
     Error *err = NULL;
     assert(ops);
     memory_region_init(mr, owner, name, size);
     mr->ops = ops;
     mr->opaque = opaque;
     mr->terminates = true;
     mr->rom_device = true;
     mr->destructor = memory_region_destructor_ram;
     mr->ram_block = qemu_ram_alloc(size, 0, mr, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
         error_propagate(errp, err);
     }
 }
 
 void memory_region_init_iommu(void *_iommu_mr,
                               size_t instance_size,
                               const char *mrtypename,
                               Object *owner,
                               const char *name,
                               uint64_t size)
 {
     struct IOMMUMemoryRegion *iommu_mr;
     struct MemoryRegion *mr;
 
     object_initialize(_iommu_mr, instance_size, mrtypename);
     mr = MEMORY_REGION(_iommu_mr);
     memory_region_do_init(mr, owner, name, size);
     iommu_mr = IOMMU_MEMORY_REGION(mr);
     mr->terminates = true;  /* then re-forwards */
     QLIST_INIT(&iommu_mr->iommu_notify);
     iommu_mr->iommu_notify_flags = IOMMU_NOTIFIER_NONE;
 }
 
 static void memory_region_finalize(Object *obj)
 {
     MemoryRegion *mr = MEMORY_REGION(obj);
 
     assert(!mr->container);
 
     /* We know the region is not visible in any address space (it
      * does not have a container and cannot be a root either because
      * it has no references, so we can blindly clear mr->enabled.
      * memory_region_set_enabled instead could trigger a transaction
      * and cause an infinite loop.
      */
     mr->enabled = false;
     memory_region_transaction_begin();
     while (!QTAILQ_EMPTY(&mr->subregions)) {
         MemoryRegion *subregion = QTAILQ_FIRST(&mr->subregions);
         memory_region_del_subregion(mr, subregion);
     }
     memory_region_transaction_commit();
 
     mr->destructor(mr);
     memory_region_clear_coalescing(mr);
     g_free((char *)mr->name);
     g_free(mr->ioeventfds);
 }
 
 Object *memory_region_owner(MemoryRegion *mr)
 {
     Object *obj = OBJECT(mr);
     return obj->parent;
 }
 
 void memory_region_ref(MemoryRegion *mr)
 {
     /* MMIO callbacks most likely will access data that belongs
      * to the owner, hence the need to ref/unref the owner whenever
      * the memory region is in use.
      *
      * The memory region is a child of its owner.  As long as the
      * owner doesn't call unparent itself on the memory region,
      * ref-ing the owner will also keep the memory region alive.
      * Memory regions without an owner are supposed to never go away;
      * we do not ref/unref them because it slows down DMA sensibly.
      */
     if (mr && mr->owner) {
         object_ref(mr->owner);
     }
 }
 
 void memory_region_unref(MemoryRegion *mr)
 {
     if (mr && mr->owner) {
         object_unref(mr->owner);
     }
 }
 
 uint64_t memory_region_size(MemoryRegion *mr)
 {
     if (int128_eq(mr->size, int128_2_64())) {
         return UINT64_MAX;
     }
     return int128_get64(mr->size);
 }
 
 const char *memory_region_name(const MemoryRegion *mr)
 {
     if (!mr->name) {
         ((MemoryRegion *)mr)->name =
             g_strdup(object_get_canonical_path_component(OBJECT(mr)));
     }
     return mr->name;
 }
 
 bool memory_region_is_ram_device(MemoryRegion *mr)
 {
     return mr->ram_device;
 }
 
 bool memory_region_is_protected(MemoryRegion *mr)
 {
     return mr->ram && (mr->ram_block->flags & RAM_PROTECTED);
 }
 
 uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
 {
     uint8_t mask = mr->dirty_log_mask;
     RAMBlock *rb = mr->ram_block;
 
     if (global_dirty_tracking && ((rb && qemu_ram_is_migratable(rb)) ||
                              memory_region_is_iommu(mr))) {
         mask |= (1 << DIRTY_MEMORY_MIGRATION);
     }
 
     if (tcg_enabled() && rb) {
         /* TCG only cares about dirty memory logging for RAM, not IOMMU.  */
         mask |= (1 << DIRTY_MEMORY_CODE);
     }
     return mask;
 }
 
 bool memory_region_is_logging(MemoryRegion *mr, uint8_t client)
 {
     return memory_region_get_dirty_log_mask(mr) & (1 << client);
 }
 
 static int memory_region_update_iommu_notify_flags(IOMMUMemoryRegion *iommu_mr,
                                                    Error **errp)
 {
     IOMMUNotifierFlag flags = IOMMU_NOTIFIER_NONE;
     IOMMUNotifier *iommu_notifier;
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
     int ret = 0;
 
     IOMMU_NOTIFIER_FOREACH(iommu_notifier, iommu_mr) {
         flags |= iommu_notifier->notifier_flags;
     }
 
     if (flags != iommu_mr->iommu_notify_flags && imrc->notify_flag_changed) {
         ret = imrc->notify_flag_changed(iommu_mr,
                                         iommu_mr->iommu_notify_flags,
                                         flags, errp);
     }
 
     if (!ret) {
         iommu_mr->iommu_notify_flags = flags;
     }
     return ret;
 }
 
 int memory_region_iommu_set_page_size_mask(IOMMUMemoryRegion *iommu_mr,
                                            uint64_t page_size_mask,
                                            Error **errp)
 {
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
     int ret = 0;
 
     if (imrc->iommu_set_page_size_mask) {
         ret = imrc->iommu_set_page_size_mask(iommu_mr, page_size_mask, errp);
     }
     return ret;
 }
 
 int memory_region_register_iommu_notifier(MemoryRegion *mr,
                                           IOMMUNotifier *n, Error **errp)
 {
     IOMMUMemoryRegion *iommu_mr;
     int ret;
 
     if (mr->alias) {
         return memory_region_register_iommu_notifier(mr->alias, n, errp);
     }
 
     /* We need to register for at least one bitfield */
     iommu_mr = IOMMU_MEMORY_REGION(mr);
     assert(n->notifier_flags != IOMMU_NOTIFIER_NONE);
     assert(n->start <= n->end);
     assert(n->iommu_idx >= 0 &&
            n->iommu_idx < memory_region_iommu_num_indexes(iommu_mr));
 
     QLIST_INSERT_HEAD(&iommu_mr->iommu_notify, n, node);
     ret = memory_region_update_iommu_notify_flags(iommu_mr, errp);
     if (ret) {
         QLIST_REMOVE(n, node);
     }
     return ret;
 }
 
 uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr)
 {
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
 
     if (imrc->get_min_page_size) {
         return imrc->get_min_page_size(iommu_mr);
     }
     return TARGET_PAGE_SIZE;
 }
 
 void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n)
 {
     MemoryRegion *mr = MEMORY_REGION(iommu_mr);
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
     hwaddr addr, granularity;
     IOMMUTLBEntry iotlb;
 
     /* If the IOMMU has its own replay callback, override */
     if (imrc->replay) {
         imrc->replay(iommu_mr, n);
         return;
     }
 
     granularity = memory_region_iommu_get_min_page_size(iommu_mr);
 
     for (addr = 0; addr < memory_region_size(mr); addr += granularity) {
         iotlb = imrc->translate(iommu_mr, addr, IOMMU_NONE, n->iommu_idx);
         if (iotlb.perm != IOMMU_NONE) {
             n->notify(n, &iotlb);
         }
 
         /* if (2^64 - MR size) < granularity, it's possible to get an
          * infinite loop here.  This should catch such a wraparound */
         if ((addr + granularity) < addr) {
             break;
         }
     }
 }
 
 void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
                                              IOMMUNotifier *n)
 {
     IOMMUMemoryRegion *iommu_mr;
 
     if (mr->alias) {
         memory_region_unregister_iommu_notifier(mr->alias, n);
         return;
     }
     QLIST_REMOVE(n, node);
     iommu_mr = IOMMU_MEMORY_REGION(mr);
     memory_region_update_iommu_notify_flags(iommu_mr, NULL);
 }
 
 void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
                                     IOMMUTLBEvent *event)
 {
     IOMMUTLBEntry *entry = &event->entry;
     hwaddr entry_end = entry->iova + entry->addr_mask;
     IOMMUTLBEntry tmp = *entry;
 
     if (event->type == IOMMU_NOTIFIER_UNMAP) {
         assert(entry->perm == IOMMU_NONE);
     }
 
     /*
      * Skip the notification if the notification does not overlap
      * with registered range.
      */
     if (notifier->start > entry_end || notifier->end < entry->iova) {
         return;
     }
 
     if (notifier->notifier_flags & IOMMU_NOTIFIER_DEVIOTLB_UNMAP) {
         /* Crop (iova, addr_mask) to range */
         tmp.iova = MAX(tmp.iova, notifier->start);
         tmp.addr_mask = MIN(entry_end, notifier->end) - tmp.iova;
     } else {
         assert(entry->iova >= notifier->start && entry_end <= notifier->end);
     }
 
     if (event->type & notifier->notifier_flags) {
         notifier->notify(notifier, &tmp);
     }
 }
 
 void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
                                 int iommu_idx,
                                 IOMMUTLBEvent event)
 {
     IOMMUNotifier *iommu_notifier;
 
     assert(memory_region_is_iommu(MEMORY_REGION(iommu_mr)));
 
     IOMMU_NOTIFIER_FOREACH(iommu_notifier, iommu_mr) {
         if (iommu_notifier->iommu_idx == iommu_idx) {
             memory_region_notify_iommu_one(iommu_notifier, &event);
         }
     }
 }
 
 int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
                                  enum IOMMUMemoryRegionAttr attr,
                                  void *data)
 {
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
 
     if (!imrc->get_attr) {
         return -EINVAL;
     }
 
     return imrc->get_attr(iommu_mr, attr, data);
 }
 
 int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr,
                                        MemTxAttrs attrs)
 {
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
 
     if (!imrc->attrs_to_index) {
         return 0;
     }
 
     return imrc->attrs_to_index(iommu_mr, attrs);
 }
 
 int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr)
 {
     IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_GET_CLASS(iommu_mr);
 
     if (!imrc->num_indexes) {
         return 1;
     }
 
     return imrc->num_indexes(iommu_mr);
 }
 
 RamDiscardManager *memory_region_get_ram_discard_manager(MemoryRegion *mr)
 {
     if (!memory_region_is_mapped(mr) || !memory_region_is_ram(mr)) {
         return NULL;
     }
     return mr->rdm;
 }
 
 void memory_region_set_ram_discard_manager(MemoryRegion *mr,
                                            RamDiscardManager *rdm)
 {
     g_assert(memory_region_is_ram(mr) && !memory_region_is_mapped(mr));
     g_assert(!rdm || !mr->rdm);
     mr->rdm = rdm;
 }
 
 uint64_t ram_discard_manager_get_min_granularity(const RamDiscardManager *rdm,
                                                  const MemoryRegion *mr)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->get_min_granularity);
     return rdmc->get_min_granularity(rdm, mr);
 }
 
 bool ram_discard_manager_is_populated(const RamDiscardManager *rdm,
                                       const MemoryRegionSection *section)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->is_populated);
     return rdmc->is_populated(rdm, section);
 }
 
 int ram_discard_manager_replay_populated(const RamDiscardManager *rdm,
                                          MemoryRegionSection *section,
                                          ReplayRamPopulate replay_fn,
                                          void *opaque)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->replay_populated);
     return rdmc->replay_populated(rdm, section, replay_fn, opaque);
 }
 
 void ram_discard_manager_replay_discarded(const RamDiscardManager *rdm,
                                           MemoryRegionSection *section,
                                           ReplayRamDiscard replay_fn,
                                           void *opaque)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->replay_discarded);
     rdmc->replay_discarded(rdm, section, replay_fn, opaque);
 }
 
 void ram_discard_manager_register_listener(RamDiscardManager *rdm,
                                            RamDiscardListener *rdl,
                                            MemoryRegionSection *section)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->register_listener);
     rdmc->register_listener(rdm, rdl, section);
 }
 
 void ram_discard_manager_unregister_listener(RamDiscardManager *rdm,
                                              RamDiscardListener *rdl)
 {
     RamDiscardManagerClass *rdmc = RAM_DISCARD_MANAGER_GET_CLASS(rdm);
 
     g_assert(rdmc->unregister_listener);
     rdmc->unregister_listener(rdm, rdl);
 }
 
 /* Called with rcu_read_lock held.  */
 bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
                           ram_addr_t *ram_addr, bool *read_only,
                           bool *mr_has_discard_manager)
 {
     MemoryRegion *mr;
     hwaddr xlat;
     hwaddr len = iotlb->addr_mask + 1;
     bool writable = iotlb->perm & IOMMU_WO;
 
     if (mr_has_discard_manager) {
         *mr_has_discard_manager = false;
     }
     /*
      * The IOMMU TLB entry we have just covers translation through
      * this IOMMU to its immediate target.  We need to translate
      * it the rest of the way through to memory.
      */
     mr = address_space_translate(&address_space_memory, iotlb->translated_addr,
                                  &xlat, &len, writable, MEMTXATTRS_UNSPECIFIED);
     if (!memory_region_is_ram(mr)) {
         error_report("iommu map to non memory area %" HWADDR_PRIx "", xlat);
         return false;
     } else if (memory_region_has_ram_discard_manager(mr)) {
         RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr);
         MemoryRegionSection tmp = {
             .mr = mr,
             .offset_within_region = xlat,
             .size = int128_make64(len),
         };
         if (mr_has_discard_manager) {
             *mr_has_discard_manager = true;
         }
         /*
          * Malicious VMs can map memory into the IOMMU, which is expected
          * to remain discarded. vfio will pin all pages, populating memory.
          * Disallow that. vmstate priorities make sure any RamDiscardManager
          * were already restored before IOMMUs are restored.
          */
         if (!ram_discard_manager_is_populated(rdm, &tmp)) {
             error_report("iommu map to discarded memory (e.g., unplugged via"
                          " virtio-mem): %" HWADDR_PRIx "",
                          iotlb->translated_addr);
             return false;
         }
     }
 
     /*
      * Translation truncates length to the IOMMU page size,
      * check that it did not truncate too much.
      */
     if (len & iotlb->addr_mask) {
         error_report("iommu has granularity incompatible with target AS");
         return false;
     }
 
     if (vaddr) {
         *vaddr = memory_region_get_ram_ptr(mr) + xlat;
     }
 
     if (ram_addr) {
         *ram_addr = memory_region_get_ram_addr(mr) + xlat;
     }
 
     if (read_only) {
         *read_only = !writable || mr->readonly;
     }
 
     return true;
 }
 
 void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client)
 {
     uint8_t mask = 1 << client;
     uint8_t old_logging;
 
     assert(client == DIRTY_MEMORY_VGA);
     old_logging = mr->vga_logging_count;
     mr->vga_logging_count += log ? 1 : -1;
     if (!!old_logging == !!mr->vga_logging_count) {
         return;
     }
 
     memory_region_transaction_begin();
     mr->dirty_log_mask = (mr->dirty_log_mask & ~mask) | (log * mask);
     memory_region_update_pending |= mr->enabled;
     memory_region_transaction_commit();
 }
 
 void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
                              hwaddr size)
 {
     assert(mr->ram_block);
     cpu_physical_memory_set_dirty_range(memory_region_get_ram_addr(mr) + addr,
                                         size,
                                         memory_region_get_dirty_log_mask(mr));
 }
 
 /*
  * If memory region `mr' is NULL, do global sync.  Otherwise, sync
  * dirty bitmap for the specified memory region.
  */
 static void memory_region_sync_dirty_bitmap(MemoryRegion *mr)
 {
     MemoryListener *listener;
     AddressSpace *as;
     FlatView *view;
     FlatRange *fr;
 
     /* If the same address space has multiple log_sync listeners, we
      * visit that address space's FlatView multiple times.  But because
      * log_sync listeners are rare, it's still cheaper than walking each
      * address space once.
      */
     QTAILQ_FOREACH(listener, &memory_listeners, link) {
         if (listener->log_sync) {
             as = listener->address_space;
             view = address_space_get_flatview(as);
             FOR_EACH_FLAT_RANGE(fr, view) {
                 if (fr->dirty_log_mask && (!mr || fr->mr == mr)) {
                     MemoryRegionSection mrs = section_from_flat_range(fr, view);
                     listener->log_sync(listener, &mrs);
                 }
             }
             flatview_unref(view);
             trace_memory_region_sync_dirty(mr ? mr->name : "(all)", listener->name, 0);
         } else if (listener->log_sync_global) {
             /*
              * No matter whether MR is specified, what we can do here
              * is to do a global sync, because we are not capable to
              * sync in a finer granularity.
              */
             listener->log_sync_global(listener);
             trace_memory_region_sync_dirty(mr ? mr->name : "(all)", listener->name, 1);
         }
     }
 }
 
 void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start,
                                       hwaddr len)
 {
     MemoryRegionSection mrs;
     MemoryListener *listener;
     AddressSpace *as;
     FlatView *view;
     FlatRange *fr;
     hwaddr sec_start, sec_end, sec_size;
 
     QTAILQ_FOREACH(listener, &memory_listeners, link) {
         if (!listener->log_clear) {
             continue;
         }
         as = listener->address_space;
         view = address_space_get_flatview(as);
         FOR_EACH_FLAT_RANGE(fr, view) {
             if (!fr->dirty_log_mask || fr->mr != mr) {
                 /*
                  * Clear dirty bitmap operation only applies to those
                  * regions whose dirty logging is at least enabled
                  */
                 continue;
             }
 
             mrs = section_from_flat_range(fr, view);
 
             sec_start = MAX(mrs.offset_within_region, start);
             sec_end = mrs.offset_within_region + int128_get64(mrs.size);
             sec_end = MIN(sec_end, start + len);
 
             if (sec_start >= sec_end) {
                 /*
                  * If this memory region section has no intersection
                  * with the requested range, skip.
                  */
                 continue;
             }
 
             /* Valid case; shrink the section if needed */
             mrs.offset_within_address_space +=
                 sec_start - mrs.offset_within_region;
             mrs.offset_within_region = sec_start;
             sec_size = sec_end - sec_start;
             mrs.size = int128_make64(sec_size);
             listener->log_clear(listener, &mrs);
         }
         flatview_unref(view);
     }
 }
 
 DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr,
                                                             hwaddr addr,
                                                             hwaddr size,
                                                             unsigned client)
 {
     DirtyBitmapSnapshot *snapshot;
     assert(mr->ram_block);
     memory_region_sync_dirty_bitmap(mr);
     snapshot = cpu_physical_memory_snapshot_and_clear_dirty(mr, addr, size, client);
     memory_global_after_dirty_log_sync();
     return snapshot;
 }
 
 bool memory_region_snapshot_get_dirty(MemoryRegion *mr, DirtyBitmapSnapshot *snap,
                                       hwaddr addr, hwaddr size)
 {
     assert(mr->ram_block);
     return cpu_physical_memory_snapshot_get_dirty(snap,
                 memory_region_get_ram_addr(mr) + addr, size);
 }
 
 void memory_region_set_readonly(MemoryRegion *mr, bool readonly)
 {
     if (mr->readonly != readonly) {
         memory_region_transaction_begin();
         mr->readonly = readonly;
         memory_region_update_pending |= mr->enabled;
         memory_region_transaction_commit();
     }
 }
 
 void memory_region_set_nonvolatile(MemoryRegion *mr, bool nonvolatile)
 {
     if (mr->nonvolatile != nonvolatile) {
         memory_region_transaction_begin();
         mr->nonvolatile = nonvolatile;
         memory_region_update_pending |= mr->enabled;
         memory_region_transaction_commit();
     }
 }
 
 void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode)
 {
     if (mr->romd_mode != romd_mode) {
         memory_region_transaction_begin();
         mr->romd_mode = romd_mode;
         memory_region_update_pending |= mr->enabled;
         memory_region_transaction_commit();
     }
 }
 
 void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
                                hwaddr size, unsigned client)
 {
     assert(mr->ram_block);
     cpu_physical_memory_test_and_clear_dirty(
         memory_region_get_ram_addr(mr) + addr, size, client);
 }
 
 int memory_region_get_fd(MemoryRegion *mr)
 {
     int fd;
 
     RCU_READ_LOCK_GUARD();
     while (mr->alias) {
         mr = mr->alias;
     }
     fd = mr->ram_block->fd;
 
     return fd;
 }
 
 void *memory_region_get_ram_ptr(MemoryRegion *mr)
 {
     void *ptr;
     uint64_t offset = 0;
 
     RCU_READ_LOCK_GUARD();
     while (mr->alias) {
         offset += mr->alias_offset;
         mr = mr->alias;
     }
     assert(mr->ram_block);
     ptr = qemu_map_ram_ptr(mr->ram_block, offset);
 
     return ptr;
 }
 
 MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset)
 {
     RAMBlock *block;
 
     block = qemu_ram_block_from_host(ptr, false, offset);
     if (!block) {
         return NULL;
     }
 
     return block->mr;
 }
 
 ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr)
 {
     return mr->ram_block ? mr->ram_block->offset : RAM_ADDR_INVALID;
 }
 
 void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize, Error **errp)
 {
     assert(mr->ram_block);
 
     qemu_ram_resize(mr->ram_block, newsize, errp);
 }
 
 void memory_region_msync(MemoryRegion *mr, hwaddr addr, hwaddr size)
 {
     if (mr->ram_block) {
         qemu_ram_msync(mr->ram_block, addr, size);
     }
 }
 
 void memory_region_writeback(MemoryRegion *mr, hwaddr addr, hwaddr size)
 {
     /*
      * Might be extended case needed to cover
      * different types of memory regions
      */
     if (mr->dirty_log_mask) {
         memory_region_msync(mr, addr, size);
     }
 }
 
 /*
  * Call proper memory listeners about the change on the newly
  * added/removed CoalescedMemoryRange.
  */
 static void memory_region_update_coalesced_range(MemoryRegion *mr,
                                                  CoalescedMemoryRange *cmr,
                                                  bool add)
 {
     AddressSpace *as;
     FlatView *view;
     FlatRange *fr;
 
     QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
         view = address_space_get_flatview(as);
         FOR_EACH_FLAT_RANGE(fr, view) {
             if (fr->mr == mr) {
                 flat_range_coalesced_io_notify(fr, as, cmr, add);
             }
         }
         flatview_unref(view);
     }
 }
 
 void memory_region_set_coalescing(MemoryRegion *mr)
 {
     memory_region_clear_coalescing(mr);
     memory_region_add_coalescing(mr, 0, int128_get64(mr->size));
 }
 
 void memory_region_add_coalescing(MemoryRegion *mr,
                                   hwaddr offset,
                                   uint64_t size)
 {
     CoalescedMemoryRange *cmr = g_malloc(sizeof(*cmr));
 
     cmr->addr = addrrange_make(int128_make64(offset), int128_make64(size));
     QTAILQ_INSERT_TAIL(&mr->coalesced, cmr, link);
     memory_region_update_coalesced_range(mr, cmr, true);
     memory_region_set_flush_coalesced(mr);
 }
 
 void memory_region_clear_coalescing(MemoryRegion *mr)
 {
     CoalescedMemoryRange *cmr;
 
     if (QTAILQ_EMPTY(&mr->coalesced)) {
         return;
     }
 
     qemu_flush_coalesced_mmio_buffer();
     mr->flush_coalesced_mmio = false;
 
     while (!QTAILQ_EMPTY(&mr->coalesced)) {
         cmr = QTAILQ_FIRST(&mr->coalesced);
         QTAILQ_REMOVE(&mr->coalesced, cmr, link);
         memory_region_update_coalesced_range(mr, cmr, false);
         g_free(cmr);
     }
 }
 
 void memory_region_set_flush_coalesced(MemoryRegion *mr)
 {
     mr->flush_coalesced_mmio = true;
 }
 
 void memory_region_clear_flush_coalesced(MemoryRegion *mr)
 {
     qemu_flush_coalesced_mmio_buffer();
     if (QTAILQ_EMPTY(&mr->coalesced)) {
         mr->flush_coalesced_mmio = false;
     }
 }
 
 static bool userspace_eventfd_warning;
 
 void memory_region_add_eventfd(MemoryRegion *mr,
                                hwaddr addr,
                                unsigned size,
                                bool match_data,
                                uint64_t data,
                                EventNotifier *e)
 {
     MemoryRegionIoeventfd mrfd = {
         .addr.start = int128_make64(addr),
         .addr.size = int128_make64(size),
         .match_data = match_data,
         .data = data,
         .e = e,
     };
     unsigned i;
 
     if (kvm_enabled() && (!(kvm_eventfds_enabled() ||
                             userspace_eventfd_warning))) {
         userspace_eventfd_warning = true;
         error_report("Using eventfd without MMIO binding in KVM. "
                      "Suboptimal performance expected");
     }
 
     if (size) {
         adjust_endianness(mr, &mrfd.data, size_memop(size) | MO_TE);
     }
     memory_region_transaction_begin();
     for (i = 0; i < mr->ioeventfd_nb; ++i) {
         if (memory_region_ioeventfd_before(&mrfd, &mr->ioeventfds[i])) {
             break;
         }
     }
     ++mr->ioeventfd_nb;
     mr->ioeventfds = g_realloc(mr->ioeventfds,
                                   sizeof(*mr->ioeventfds) * mr->ioeventfd_nb);
     memmove(&mr->ioeventfds[i+1], &mr->ioeventfds[i],
             sizeof(*mr->ioeventfds) * (mr->ioeventfd_nb-1 - i));
     mr->ioeventfds[i] = mrfd;
     ioeventfd_update_pending |= mr->enabled;
     memory_region_transaction_commit();
 }
 
 void memory_region_del_eventfd(MemoryRegion *mr,
                                hwaddr addr,
                                unsigned size,
                                bool match_data,
                                uint64_t data,
                                EventNotifier *e)
 {
     MemoryRegionIoeventfd mrfd = {
         .addr.start = int128_make64(addr),
         .addr.size = int128_make64(size),
         .match_data = match_data,
         .data = data,
         .e = e,
     };
     unsigned i;
 
     if (size) {
         adjust_endianness(mr, &mrfd.data, size_memop(size) | MO_TE);
     }
     memory_region_transaction_begin();
     for (i = 0; i < mr->ioeventfd_nb; ++i) {
         if (memory_region_ioeventfd_equal(&mrfd, &mr->ioeventfds[i])) {
             break;
         }
     }
     assert(i != mr->ioeventfd_nb);
     memmove(&mr->ioeventfds[i], &mr->ioeventfds[i+1],
             sizeof(*mr->ioeventfds) * (mr->ioeventfd_nb - (i+1)));
     --mr->ioeventfd_nb;
     mr->ioeventfds = g_realloc(mr->ioeventfds,
                                   sizeof(*mr->ioeventfds)*mr->ioeventfd_nb + 1);
     ioeventfd_update_pending |= mr->enabled;
     memory_region_transaction_commit();
 }
 
 static void memory_region_update_container_subregions(MemoryRegion *subregion)
 {
     MemoryRegion *mr = subregion->container;
     MemoryRegion *other;
 
     memory_region_transaction_begin();
 
     memory_region_ref(subregion);
     QTAILQ_FOREACH(other, &mr->subregions, subregions_link) {
         if (subregion->priority >= other->priority) {
             QTAILQ_INSERT_BEFORE(other, subregion, subregions_link);
             goto done;
         }
     }
     QTAILQ_INSERT_TAIL(&mr->subregions, subregion, subregions_link);
 done:
     memory_region_update_pending |= mr->enabled && subregion->enabled;
     memory_region_transaction_commit();
 }
 
 static void memory_region_add_subregion_common(MemoryRegion *mr,
                                                hwaddr offset,
                                                MemoryRegion *subregion)
 {
     MemoryRegion *alias;
 
     assert(!subregion->container);
     subregion->container = mr;
     for (alias = subregion->alias; alias; alias = alias->alias) {
         alias->mapped_via_alias++;
     }
     subregion->addr = offset;
     memory_region_update_container_subregions(subregion);
 }
 
 void memory_region_add_subregion(MemoryRegion *mr,
                                  hwaddr offset,
                                  MemoryRegion *subregion)
 {
     subregion->priority = 0;
     memory_region_add_subregion_common(mr, offset, subregion);
 }
 
 void memory_region_add_subregion_overlap(MemoryRegion *mr,
                                          hwaddr offset,
                                          MemoryRegion *subregion,
                                          int priority)
 {
     subregion->priority = priority;
     memory_region_add_subregion_common(mr, offset, subregion);
 }
 
 void memory_region_del_subregion(MemoryRegion *mr,
                                  MemoryRegion *subregion)
 {
     MemoryRegion *alias;
 
     memory_region_transaction_begin();
     assert(subregion->container == mr);
     subregion->container = NULL;
     for (alias = subregion->alias; alias; alias = alias->alias) {
         alias->mapped_via_alias--;
         assert(alias->mapped_via_alias >= 0);
     }
     QTAILQ_REMOVE(&mr->subregions, subregion, subregions_link);
     memory_region_unref(subregion);
     memory_region_update_pending |= mr->enabled && subregion->enabled;
     memory_region_transaction_commit();
 }
 
 void memory_region_set_enabled(MemoryRegion *mr, bool enabled)
 {
     if (enabled == mr->enabled) {
         return;
     }
     memory_region_transaction_begin();
     mr->enabled = enabled;
     memory_region_update_pending = true;
     memory_region_transaction_commit();
 }
 
 void memory_region_set_size(MemoryRegion *mr, uint64_t size)
 {
     Int128 s = int128_make64(size);
 
     if (size == UINT64_MAX) {
         s = int128_2_64();
     }
     if (int128_eq(s, mr->size)) {
         return;
     }
     memory_region_transaction_begin();
     mr->size = s;
     memory_region_update_pending = true;
     memory_region_transaction_commit();
 }
 
 static void memory_region_readd_subregion(MemoryRegion *mr)
 {
     MemoryRegion *container = mr->container;
 
     if (container) {
         memory_region_transaction_begin();
         memory_region_ref(mr);
         memory_region_del_subregion(container, mr);
         memory_region_add_subregion_common(container, mr->addr, mr);
         memory_region_unref(mr);
         memory_region_transaction_commit();
     }
 }
 
 void memory_region_set_address(MemoryRegion *mr, hwaddr addr)
 {
     if (addr != mr->addr) {
         mr->addr = addr;
         memory_region_readd_subregion(mr);
     }
 }
 
 void memory_region_set_alias_offset(MemoryRegion *mr, hwaddr offset)
 {
     assert(mr->alias);
 
     if (offset == mr->alias_offset) {
         return;
     }
 
     memory_region_transaction_begin();
     mr->alias_offset = offset;
     memory_region_update_pending |= mr->enabled;
     memory_region_transaction_commit();
 }
 
 uint64_t memory_region_get_alignment(const MemoryRegion *mr)
 {
     return mr->align;
 }
 
 static int cmp_flatrange_addr(const void *addr_, const void *fr_)
 {
     const AddrRange *addr = addr_;
     const FlatRange *fr = fr_;
 
     if (int128_le(addrrange_end(*addr), fr->addr.start)) {
         return -1;
     } else if (int128_ge(addr->start, addrrange_end(fr->addr))) {
         return 1;
     }
     return 0;
 }
 
 static FlatRange *flatview_lookup(FlatView *view, AddrRange addr)
 {
     return bsearch(&addr, view->ranges, view->nr,
                    sizeof(FlatRange), cmp_flatrange_addr);
 }
 
 bool memory_region_is_mapped(MemoryRegion *mr)
 {
     return !!mr->container || mr->mapped_via_alias;
 }
 
 /* Same as memory_region_find, but it does not add a reference to the
  * returned region.  It must be called from an RCU critical section.
  */
 static MemoryRegionSection memory_region_find_rcu(MemoryRegion *mr,
                                                   hwaddr addr, uint64_t size)
 {
     MemoryRegionSection ret = { .mr = NULL };
     MemoryRegion *root;
     AddressSpace *as;
     AddrRange range;
     FlatView *view;
     FlatRange *fr;
 
     addr += mr->addr;
     for (root = mr; root->container; ) {
         root = root->container;
         addr += root->addr;
     }
 
     as = memory_region_to_address_space(root);
     if (!as) {
         return ret;
     }
     range = addrrange_make(int128_make64(addr), int128_make64(size));
 
     view = address_space_to_flatview(as);
     fr = flatview_lookup(view, range);
     if (!fr) {
         return ret;
     }
 
     while (fr > view->ranges && addrrange_intersects(fr[-1].addr, range)) {
         --fr;
     }
 
     ret.mr = fr->mr;
     ret.fv = view;
     range = addrrange_intersection(range, fr->addr);
     ret.offset_within_region = fr->offset_in_region;
     ret.offset_within_region += int128_get64(int128_sub(range.start,
                                                         fr->addr.start));
     ret.size = range.size;
     ret.offset_within_address_space = int128_get64(range.start);
     ret.readonly = fr->readonly;
     ret.nonvolatile = fr->nonvolatile;
     return ret;
 }
 
 MemoryRegionSection memory_region_find(MemoryRegion *mr,
                                        hwaddr addr, uint64_t size)
 {
     MemoryRegionSection ret;
     RCU_READ_LOCK_GUARD();
     ret = memory_region_find_rcu(mr, addr, size);
     if (ret.mr) {
         memory_region_ref(ret.mr);
     }
     return ret;
 }
 
 MemoryRegionSection *memory_region_section_new_copy(MemoryRegionSection *s)
 {
     MemoryRegionSection *tmp = g_new(MemoryRegionSection, 1);
 
     *tmp = *s;
     if (tmp->mr) {
         memory_region_ref(tmp->mr);
     }
     if (tmp->fv) {
         bool ret  = flatview_ref(tmp->fv);
 
         g_assert(ret);
     }
     return tmp;
 }
 
 void memory_region_section_free_copy(MemoryRegionSection *s)
 {
     if (s->fv) {
         flatview_unref(s->fv);
     }
     if (s->mr) {
         memory_region_unref(s->mr);
     }
     g_free(s);
 }
 
 bool memory_region_present(MemoryRegion *container, hwaddr addr)
 {
     MemoryRegion *mr;
 
     RCU_READ_LOCK_GUARD();
     mr = memory_region_find_rcu(container, addr, 1).mr;
     return mr && mr != container;
 }
 
 void memory_global_dirty_log_sync(void)
 {
     memory_region_sync_dirty_bitmap(NULL);
 }
 
 void memory_global_after_dirty_log_sync(void)
 {
     MEMORY_LISTENER_CALL_GLOBAL(log_global_after_sync, Forward);
 }
 
 /*
  * Dirty track stop flags that are postponed due to VM being stopped.  Should
  * only be used within vmstate_change hook.
  */
 static unsigned int postponed_stop_flags;
 static VMChangeStateEntry *vmstate_change;
 static void memory_global_dirty_log_stop_postponed_run(void);
 
 void memory_global_dirty_log_start(unsigned int flags)
 {
     unsigned int old_flags;
 
     assert(flags && !(flags & (~GLOBAL_DIRTY_MASK)));
 
     if (vmstate_change) {
         /* If there is postponed stop(), operate on it first */
         postponed_stop_flags &= ~flags;
         memory_global_dirty_log_stop_postponed_run();
     }
 
     flags &= ~global_dirty_tracking;
     if (!flags) {
         return;
     }
 
     old_flags = global_dirty_tracking;
     global_dirty_tracking |= flags;
     trace_global_dirty_changed(global_dirty_tracking);
 
     if (!old_flags) {
         MEMORY_LISTENER_CALL_GLOBAL(log_global_start, Forward);
         memory_region_transaction_begin();
         memory_region_update_pending = true;
         memory_region_transaction_commit();
     }
 }
 
 static void memory_global_dirty_log_do_stop(unsigned int flags)
 {
     assert(flags && !(flags & (~GLOBAL_DIRTY_MASK)));
     assert((global_dirty_tracking & flags) == flags);
     global_dirty_tracking &= ~flags;
 
     trace_global_dirty_changed(global_dirty_tracking);
 
     if (!global_dirty_tracking) {
         memory_region_transaction_begin();
         memory_region_update_pending = true;
         memory_region_transaction_commit();
         MEMORY_LISTENER_CALL_GLOBAL(log_global_stop, Reverse);
     }
 }
 
 /*
  * Execute the postponed dirty log stop operations if there is, then reset
  * everything (including the flags and the vmstate change hook).
  */
 static void memory_global_dirty_log_stop_postponed_run(void)
 {
     /* This must be called with the vmstate handler registered */
     assert(vmstate_change);
 
     /* Note: postponed_stop_flags can be cleared in log start routine */
     if (postponed_stop_flags) {
         memory_global_dirty_log_do_stop(postponed_stop_flags);
         postponed_stop_flags = 0;
     }
 
     qemu_del_vm_change_state_handler(vmstate_change);
     vmstate_change = NULL;
 }
 
 static void memory_vm_change_state_handler(void *opaque, bool running,
                                            RunState state)
 {
     if (running) {
         memory_global_dirty_log_stop_postponed_run();
     }
 }
 
 void memory_global_dirty_log_stop(unsigned int flags)
 {
     if (!runstate_is_running()) {
         /* Postpone the dirty log stop, e.g., to when VM starts again */
         if (vmstate_change) {
             /* Batch with previous postponed flags */
             postponed_stop_flags |= flags;
         } else {
             postponed_stop_flags = flags;
             vmstate_change = qemu_add_vm_change_state_handler(
                 memory_vm_change_state_handler, NULL);
         }
         return;
     }
 
     memory_global_dirty_log_do_stop(flags);
 }
 
 static void listener_add_address_space(MemoryListener *listener,
                                        AddressSpace *as)
 {
     FlatView *view;
     FlatRange *fr;
 
     if (listener->begin) {
         listener->begin(listener);
     }
     if (global_dirty_tracking) {
         if (listener->log_global_start) {
             listener->log_global_start(listener);
         }
     }
 
     view = address_space_get_flatview(as);
     FOR_EACH_FLAT_RANGE(fr, view) {
         MemoryRegionSection section = section_from_flat_range(fr, view);
 
         if (listener->region_add) {
             listener->region_add(listener, &section);
         }
         if (fr->dirty_log_mask && listener->log_start) {
             listener->log_start(listener, &section, 0, fr->dirty_log_mask);
         }
     }
     if (listener->commit) {
         listener->commit(listener);
     }
     flatview_unref(view);
 }
 
 static void listener_del_address_space(MemoryListener *listener,
                                        AddressSpace *as)
 {
     FlatView *view;
     FlatRange *fr;
 
     if (listener->begin) {
         listener->begin(listener);
     }
     view = address_space_get_flatview(as);
     FOR_EACH_FLAT_RANGE(fr, view) {
         MemoryRegionSection section = section_from_flat_range(fr, view);
 
         if (fr->dirty_log_mask && listener->log_stop) {
             listener->log_stop(listener, &section, fr->dirty_log_mask, 0);
         }
         if (listener->region_del) {
             listener->region_del(listener, &section);
         }
     }
     if (listener->commit) {
         listener->commit(listener);
     }
     flatview_unref(view);
 }
 
 void memory_listener_register(MemoryListener *listener, AddressSpace *as)
 {
     MemoryListener *other = NULL;
 
     /* Only one of them can be defined for a listener */
     assert(!(listener->log_sync && listener->log_sync_global));
 
     listener->address_space = as;
     if (QTAILQ_EMPTY(&memory_listeners)
         || listener->priority >= QTAILQ_LAST(&memory_listeners)->priority) {
         QTAILQ_INSERT_TAIL(&memory_listeners, listener, link);
     } else {
         QTAILQ_FOREACH(other, &memory_listeners, link) {
             if (listener->priority < other->priority) {
                 break;
             }
         }
         QTAILQ_INSERT_BEFORE(other, listener, link);
     }
 
     if (QTAILQ_EMPTY(&as->listeners)
         || listener->priority >= QTAILQ_LAST(&as->listeners)->priority) {
         QTAILQ_INSERT_TAIL(&as->listeners, listener, link_as);
     } else {
         QTAILQ_FOREACH(other, &as->listeners, link_as) {
             if (listener->priority < other->priority) {
                 break;
             }
         }
         QTAILQ_INSERT_BEFORE(other, listener, link_as);
     }
 
     listener_add_address_space(listener, as);
 }
 
 void memory_listener_unregister(MemoryListener *listener)
 {
     if (!listener->address_space) {
         return;
     }
 
     listener_del_address_space(listener, listener->address_space);
     QTAILQ_REMOVE(&memory_listeners, listener, link);
     QTAILQ_REMOVE(&listener->address_space->listeners, listener, link_as);
     listener->address_space = NULL;
 }
 
 void address_space_remove_listeners(AddressSpace *as)
 {
     while (!QTAILQ_EMPTY(&as->listeners)) {
         memory_listener_unregister(QTAILQ_FIRST(&as->listeners));
     }
 }
 
 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
 {
     memory_region_ref(root);
     as->root = root;
     as->current_map = NULL;
     as->ioeventfd_nb = 0;
     as->ioeventfds = NULL;
     QTAILQ_INIT(&as->listeners);
     QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);
     as->name = g_strdup(name ? name : "anonymous");
     address_space_update_topology(as);
     address_space_update_ioeventfds(as);
 }
 
 static void do_address_space_destroy(AddressSpace *as)
 {
     assert(QTAILQ_EMPTY(&as->listeners));
 
     flatview_unref(as->current_map);
     g_free(as->name);
     g_free(as->ioeventfds);
     memory_region_unref(as->root);
 }
 
 void address_space_destroy(AddressSpace *as)
 {
     MemoryRegion *root = as->root;
 
     /* Flush out anything from MemoryListeners listening in on this */
     memory_region_transaction_begin();
     as->root = NULL;
     memory_region_transaction_commit();
     QTAILQ_REMOVE(&address_spaces, as, address_spaces_link);
 
     /* At this point, as->dispatch and as->current_map are dummy
      * entries that the guest should never use.  Wait for the old
      * values to expire before freeing the data.
      */
     as->root = root;
     call_rcu(as, do_address_space_destroy, rcu);
 }
 
 static const char *memory_region_type(MemoryRegion *mr)
 {
     if (mr->alias) {
         return memory_region_type(mr->alias);
     }
     if (memory_region_is_ram_device(mr)) {
         return "ramd";
     } else if (memory_region_is_romd(mr)) {
         return "romd";
     } else if (memory_region_is_rom(mr)) {
         return "rom";
     } else if (memory_region_is_ram(mr)) {
         return "ram";
     } else {
         return "i/o";
     }
 }
 
 typedef struct MemoryRegionList MemoryRegionList;
 
 struct MemoryRegionList {
     const MemoryRegion *mr;
     QTAILQ_ENTRY(MemoryRegionList) mrqueue;
 };
 
 typedef QTAILQ_HEAD(, MemoryRegionList) MemoryRegionListHead;
 
 #define MR_SIZE(size) (int128_nz(size) ? (hwaddr)int128_get64( \
                            int128_sub((size), int128_one())) : 0)
 #define MTREE_INDENT "  "
 
 static void mtree_expand_owner(const char *label, Object *obj)
 {
     DeviceState *dev = (DeviceState *) object_dynamic_cast(obj, TYPE_DEVICE);
 
     qemu_printf(" %s:{%s", label, dev ? "dev" : "obj");
     if (dev && dev->id) {
         qemu_printf(" id=%s", dev->id);
     } else {
         char *canonical_path = object_get_canonical_path(obj);
         if (canonical_path) {
             qemu_printf(" path=%s", canonical_path);
             g_free(canonical_path);
         } else {
             qemu_printf(" type=%s", object_get_typename(obj));
         }
     }
     qemu_printf("}");
 }
 
 static void mtree_print_mr_owner(const MemoryRegion *mr)
 {
     Object *owner = mr->owner;
     Object *parent = memory_region_owner((MemoryRegion *)mr);
 
     if (!owner && !parent) {
         qemu_printf(" orphan");
         return;
     }
     if (owner) {
         mtree_expand_owner("owner", owner);
     }
     if (parent && parent != owner) {
         mtree_expand_owner("parent", parent);
     }
 }
 
 static void mtree_print_mr(const MemoryRegion *mr, unsigned int level,
                            hwaddr base,
                            MemoryRegionListHead *alias_print_queue,
                            bool owner, bool display_disabled)
 {
     MemoryRegionList *new_ml, *ml, *next_ml;
     MemoryRegionListHead submr_print_queue;
     const MemoryRegion *submr;
     unsigned int i;
     hwaddr cur_start, cur_end;
 
     if (!mr) {
         return;
     }
 
     cur_start = base + mr->addr;
     cur_end = cur_start + MR_SIZE(mr->size);
 
     /*
      * Try to detect overflow of memory region. This should never
      * happen normally. When it happens, we dump something to warn the
      * user who is observing this.
      */
     if (cur_start < base || cur_end < cur_start) {
         qemu_printf("[DETECTED OVERFLOW!] ");
     }
 
     if (mr->alias) {
         MemoryRegionList *ml;
         bool found = false;
 
         /* check if the alias is already in the queue */
         QTAILQ_FOREACH(ml, alias_print_queue, mrqueue) {
             if (ml->mr == mr->alias) {
                 found = true;
             }
         }
 
         if (!found) {
             ml = g_new(MemoryRegionList, 1);
             ml->mr = mr->alias;
             QTAILQ_INSERT_TAIL(alias_print_queue, ml, mrqueue);
         }
         if (mr->enabled || display_disabled) {
             for (i = 0; i < level; i++) {
                 qemu_printf(MTREE_INDENT);
             }
             qemu_printf(TARGET_FMT_plx "-" TARGET_FMT_plx
                         " (prio %d, %s%s): alias %s @%s " TARGET_FMT_plx
                         "-" TARGET_FMT_plx "%s",
                         cur_start, cur_end,
                         mr->priority,
                         mr->nonvolatile ? "nv-" : "",
                         memory_region_type((MemoryRegion *)mr),
                         memory_region_name(mr),
                         memory_region_name(mr->alias),
                         mr->alias_offset,
                         mr->alias_offset + MR_SIZE(mr->size),
                         mr->enabled ? "" : " [disabled]");
             if (owner) {
                 mtree_print_mr_owner(mr);
             }
             qemu_printf("\n");
         }
     } else {
         if (mr->enabled || display_disabled) {
             for (i = 0; i < level; i++) {
                 qemu_printf(MTREE_INDENT);
             }
             qemu_printf(TARGET_FMT_plx "-" TARGET_FMT_plx
                         " (prio %d, %s%s): %s%s",
                         cur_start, cur_end,
                         mr->priority,
                         mr->nonvolatile ? "nv-" : "",
                         memory_region_type((MemoryRegion *)mr),
                         memory_region_name(mr),
                         mr->enabled ? "" : " [disabled]");
             if (owner) {
                 mtree_print_mr_owner(mr);
             }
             qemu_printf("\n");
         }
     }
 
     QTAILQ_INIT(&submr_print_queue);
 
     QTAILQ_FOREACH(submr, &mr->subregions, subregions_link) {
         new_ml = g_new(MemoryRegionList, 1);
         new_ml->mr = submr;
         QTAILQ_FOREACH(ml, &submr_print_queue, mrqueue) {
             if (new_ml->mr->addr < ml->mr->addr ||
                 (new_ml->mr->addr == ml->mr->addr &&
                  new_ml->mr->priority > ml->mr->priority)) {
                 QTAILQ_INSERT_BEFORE(ml, new_ml, mrqueue);
                 new_ml = NULL;
                 break;
             }
         }
         if (new_ml) {
             QTAILQ_INSERT_TAIL(&submr_print_queue, new_ml, mrqueue);
         }
     }
 
     QTAILQ_FOREACH(ml, &submr_print_queue, mrqueue) {
         mtree_print_mr(ml->mr, level + 1, cur_start,
                        alias_print_queue, owner, display_disabled);
     }
 
     QTAILQ_FOREACH_SAFE(ml, &submr_print_queue, mrqueue, next_ml) {
         g_free(ml);
     }
 }
 
 struct FlatViewInfo {
     int counter;
     bool dispatch_tree;
     bool owner;
     AccelClass *ac;
 };
 
 static void mtree_print_flatview(gpointer key, gpointer value,
                                  gpointer user_data)
 {
     FlatView *view = key;
     GArray *fv_address_spaces = value;
     struct FlatViewInfo *fvi = user_data;
     FlatRange *range = &view->ranges[0];
     MemoryRegion *mr;
     int n = view->nr;
     int i;
     AddressSpace *as;
 
     qemu_printf("FlatView #%d\n", fvi->counter);
     ++fvi->counter;
 
     for (i = 0; i < fv_address_spaces->len; ++i) {
         as = g_array_index(fv_address_spaces, AddressSpace*, i);
         qemu_printf(" AS \"%s\", root: %s",
                     as->name, memory_region_name(as->root));
         if (as->root->alias) {
             qemu_printf(", alias %s", memory_region_name(as->root->alias));
         }
         qemu_printf("\n");
     }
 
     qemu_printf(" Root memory region: %s\n",
       view->root ? memory_region_name(view->root) : "(none)");
 
     if (n <= 0) {
         qemu_printf(MTREE_INDENT "No rendered FlatView\n\n");
         return;
     }
 
     while (n--) {
         mr = range->mr;
         if (range->offset_in_region) {
             qemu_printf(MTREE_INDENT TARGET_FMT_plx "-" TARGET_FMT_plx
                         " (prio %d, %s%s): %s @" TARGET_FMT_plx,
                         int128_get64(range->addr.start),
                         int128_get64(range->addr.start)
                         + MR_SIZE(range->addr.size),
                         mr->priority,
                         range->nonvolatile ? "nv-" : "",
                         range->readonly ? "rom" : memory_region_type(mr),
                         memory_region_name(mr),
                         range->offset_in_region);
         } else {
             qemu_printf(MTREE_INDENT TARGET_FMT_plx "-" TARGET_FMT_plx
                         " (prio %d, %s%s): %s",
                         int128_get64(range->addr.start),
                         int128_get64(range->addr.start)
                         + MR_SIZE(range->addr.size),
                         mr->priority,
                         range->nonvolatile ? "nv-" : "",
                         range->readonly ? "rom" : memory_region_type(mr),
                         memory_region_name(mr));
         }
         if (fvi->owner) {
             mtree_print_mr_owner(mr);
         }
 
         if (fvi->ac) {
             for (i = 0; i < fv_address_spaces->len; ++i) {
                 as = g_array_index(fv_address_spaces, AddressSpace*, i);
                 if (fvi->ac->has_memory(current_machine, as,
                                         int128_get64(range->addr.start),
                                         MR_SIZE(range->addr.size) + 1)) {
                     qemu_printf(" %s", fvi->ac->name);
                 }
             }
         }
         qemu_printf("\n");
         range++;
     }
 
 #if !defined(CONFIG_USER_ONLY)
     if (fvi->dispatch_tree && view->root) {
         mtree_print_dispatch(view->dispatch, view->root);
     }
 #endif
 
     qemu_printf("\n");
 }
 
 static gboolean mtree_info_flatview_free(gpointer key, gpointer value,
                                       gpointer user_data)
 {
     FlatView *view = key;
     GArray *fv_address_spaces = value;
 
     g_array_unref(fv_address_spaces);
     flatview_unref(view);
 
     return true;
 }
 
 static void mtree_info_flatview(bool dispatch_tree, bool owner)
 {
     struct FlatViewInfo fvi = {
         .counter = 0,
         .dispatch_tree = dispatch_tree,
         .owner = owner,
     };
     AddressSpace *as;
     FlatView *view;
     GArray *fv_address_spaces;
     GHashTable *views = g_hash_table_new(g_direct_hash, g_direct_equal);
     AccelClass *ac = ACCEL_GET_CLASS(current_accel());
 
     if (ac->has_memory) {
         fvi.ac = ac;
     }
 
     /* Gather all FVs in one table */
     QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
         view = address_space_get_flatview(as);
 
         fv_address_spaces = g_hash_table_lookup(views, view);
         if (!fv_address_spaces) {
             fv_address_spaces = g_array_new(false, false, sizeof(as));
             g_hash_table_insert(views, view, fv_address_spaces);
         }
 
         g_array_append_val(fv_address_spaces, as);
     }
 
     /* Print */
     g_hash_table_foreach(views, mtree_print_flatview, &fvi);
 
     /* Free */
     g_hash_table_foreach_remove(views, mtree_info_flatview_free, 0);
     g_hash_table_unref(views);
 }
 
 struct AddressSpaceInfo {
     MemoryRegionListHead *ml_head;
     bool owner;
     bool disabled;
 };
 
 /* Returns negative value if a < b; zero if a = b; positive value if a > b. */
 static gint address_space_compare_name(gconstpointer a, gconstpointer b)
 {
     const AddressSpace *as_a = a;
     const AddressSpace *as_b = b;
 
     return g_strcmp0(as_a->name, as_b->name);
 }
 
 static void mtree_print_as_name(gpointer data, gpointer user_data)
 {
     AddressSpace *as = data;
 
     qemu_printf("address-space: %s\n", as->name);
 }
 
 static void mtree_print_as(gpointer key, gpointer value, gpointer user_data)
 {
     MemoryRegion *mr = key;
     GSList *as_same_root_mr_list = value;
     struct AddressSpaceInfo *asi = user_data;
 
     g_slist_foreach(as_same_root_mr_list, mtree_print_as_name, NULL);
     mtree_print_mr(mr, 1, 0, asi->ml_head, asi->owner, asi->disabled);
     qemu_printf("\n");
 }
 
 static gboolean mtree_info_as_free(gpointer key, gpointer value,
                                    gpointer user_data)
 {
     GSList *as_same_root_mr_list = value;
 
     g_slist_free(as_same_root_mr_list);
 
     return true;
 }
 
 static void mtree_info_as(bool dispatch_tree, bool owner, bool disabled)
 {
     MemoryRegionListHead ml_head;
     MemoryRegionList *ml, *ml2;
     AddressSpace *as;
     GHashTable *views = g_hash_table_new(g_direct_hash, g_direct_equal);
     GSList *as_same_root_mr_list;
     struct AddressSpaceInfo asi = {
         .ml_head = &ml_head,
         .owner = owner,
         .disabled = disabled,
     };
 
     QTAILQ_INIT(&ml_head);
 
     QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
         /* Create hashtable, key=AS root MR, value = list of AS */
         as_same_root_mr_list = g_hash_table_lookup(views, as->root);
         as_same_root_mr_list = g_slist_insert_sorted(as_same_root_mr_list, as,
                                                      address_space_compare_name);
         g_hash_table_insert(views, as->root, as_same_root_mr_list);
     }
 
     /* print address spaces */
     g_hash_table_foreach(views, mtree_print_as, &asi);
     g_hash_table_foreach_remove(views, mtree_info_as_free, 0);
     g_hash_table_unref(views);
 
     /* print aliased regions */
     QTAILQ_FOREACH(ml, &ml_head, mrqueue) {
         qemu_printf("memory-region: %s\n", memory_region_name(ml->mr));
         mtree_print_mr(ml->mr, 1, 0, &ml_head, owner, disabled);
         qemu_printf("\n");
     }
 
     QTAILQ_FOREACH_SAFE(ml, &ml_head, mrqueue, ml2) {
         g_free(ml);
     }
 }
 
 void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled)
 {
     if (flatview) {
         mtree_info_flatview(dispatch_tree, owner);
     } else {
         mtree_info_as(dispatch_tree, owner, disabled);
     }
 }
 
 void memory_region_init_ram(MemoryRegion *mr,
                             Object *owner,
                             const char *name,
                             uint64_t size,
                             Error **errp)
 {
     DeviceState *owner_dev;
     Error *err = NULL;
 
     memory_region_init_ram_nomigrate(mr, owner, name, size, &err);
     if (err) {
         error_propagate(errp, err);
         return;
     }
     /* This will assert if owner is neither NULL nor a DeviceState.
      * We only want the owner here for the purposes of defining a
      * unique name for migration. TODO: Ideally we should implement
      * a naming scheme for Objects which are not DeviceStates, in
      * which case we can relax this restriction.
      */
     owner_dev = DEVICE(owner);
     vmstate_register_ram(mr, owner_dev);
 }
 
 void memory_region_init_rom(MemoryRegion *mr,
                             Object *owner,
                             const char *name,
                             uint64_t size,
                             Error **errp)
 {
     DeviceState *owner_dev;
     Error *err = NULL;
 
     memory_region_init_rom_nomigrate(mr, owner, name, size, &err);
     if (err) {
         error_propagate(errp, err);
         return;
     }
     /* This will assert if owner is neither NULL nor a DeviceState.
      * We only want the owner here for the purposes of defining a
      * unique name for migration. TODO: Ideally we should implement
      * a naming scheme for Objects which are not DeviceStates, in
      * which case we can relax this restriction.
      */
     owner_dev = DEVICE(owner);
     vmstate_register_ram(mr, owner_dev);
 }
 
 void memory_region_init_rom_device(MemoryRegion *mr,
                                    Object *owner,
                                    const MemoryRegionOps *ops,
                                    void *opaque,
                                    const char *name,
                                    uint64_t size,
                                    Error **errp)
 {
     DeviceState *owner_dev;
     Error *err = NULL;
 
     memory_region_init_rom_device_nomigrate(mr, owner, ops, opaque,
                                             name, size, &err);
     if (err) {
         error_propagate(errp, err);
         return;
     }
     /* This will assert if owner is neither NULL nor a DeviceState.
      * We only want the owner here for the purposes of defining a
      * unique name for migration. TODO: Ideally we should implement
      * a naming scheme for Objects which are not DeviceStates, in
      * which case we can relax this restriction.
      */
     owner_dev = DEVICE(owner);
     vmstate_register_ram(mr, owner_dev);
 }
 
 /*
  * Support softmmu builds with CONFIG_FUZZ using a weak symbol and a stub for
  * the fuzz_dma_read_cb callback
  */
 #ifdef CONFIG_FUZZ
 void __attribute__((weak)) fuzz_dma_read_cb(size_t addr,
                       size_t len,
                       MemoryRegion *mr)
 {
 }
 #endif
 
 static const TypeInfo memory_region_info = {
     .parent             = TYPE_OBJECT,
     .name               = TYPE_MEMORY_REGION,
     .class_size         = sizeof(MemoryRegionClass),
     .instance_size      = sizeof(MemoryRegion),
     .instance_init      = memory_region_initfn,
     .instance_finalize  = memory_region_finalize,
 };
 
 static const TypeInfo iommu_memory_region_info = {
     .parent             = TYPE_MEMORY_REGION,
     .name               = TYPE_IOMMU_MEMORY_REGION,
     .class_size         = sizeof(IOMMUMemoryRegionClass),
     .instance_size      = sizeof(IOMMUMemoryRegion),
     .instance_init      = iommu_memory_region_initfn,
     .abstract           = true,
 };
 
 static const TypeInfo ram_discard_manager_info = {
     .parent             = TYPE_INTERFACE,
     .name               = TYPE_RAM_DISCARD_MANAGER,
     .class_size         = sizeof(RamDiscardManagerClass),
 };
 
 static void memory_register_types(void)
 {
     type_register_static(&memory_region_info);
     type_register_static(&iommu_memory_region_info);
     type_register_static(&ram_discard_manager_info);
 }
 
 type_init(memory_register_types)