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-rw-r--r--include/system/dma.h2
-rw-r--r--include/system/hostmem.h2
-rw-r--r--include/system/kvm_int.h2
-rw-r--r--include/system/memory.h3197
-rw-r--r--include/system/vhost-user-backend.h2
5 files changed, 3201 insertions, 4 deletions
diff --git a/include/system/dma.h b/include/system/dma.h
index e142f7efa6..aaa03b9711 100644
--- a/include/system/dma.h
+++ b/include/system/dma.h
@@ -10,7 +10,7 @@
 #ifndef DMA_H
 #define DMA_H
 
-#include "exec/memory.h"
+#include "system/memory.h"
 #include "exec/address-spaces.h"
 #include "block/block.h"
 #include "block/accounting.h"
diff --git a/include/system/hostmem.h b/include/system/hostmem.h
index 62642e602c..88fa791ac7 100644
--- a/include/system/hostmem.h
+++ b/include/system/hostmem.h
@@ -16,7 +16,7 @@
 #include "system/numa.h"
 #include "qapi/qapi-types-machine.h"
 #include "qom/object.h"
-#include "exec/memory.h"
+#include "system/memory.h"
 #include "qemu/bitmap.h"
 #include "qemu/thread-context.h"
 
diff --git a/include/system/kvm_int.h b/include/system/kvm_int.h
index 4de6106869..756a3c0a25 100644
--- a/include/system/kvm_int.h
+++ b/include/system/kvm_int.h
@@ -9,7 +9,7 @@
 #ifndef QEMU_KVM_INT_H
 #define QEMU_KVM_INT_H
 
-#include "exec/memory.h"
+#include "system/memory.h"
 #include "qapi/qapi-types-common.h"
 #include "qemu/accel.h"
 #include "qemu/queue.h"
diff --git a/include/system/memory.h b/include/system/memory.h
new file mode 100644
index 0000000000..fbbf4cf911
--- /dev/null
+++ b/include/system/memory.h
@@ -0,0 +1,3197 @@
+/*
+ * Physical memory management API
+ *
+ * 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.
+ *
+ */
+
+#ifndef SYSTEM_MEMORY_H
+#define SYSTEM_MEMORY_H
+
+#include "exec/cpu-common.h"
+#include "exec/hwaddr.h"
+#include "exec/memattrs.h"
+#include "exec/memop.h"
+#include "exec/ramlist.h"
+#include "exec/tswap.h"
+#include "qemu/bswap.h"
+#include "qemu/queue.h"
+#include "qemu/int128.h"
+#include "qemu/range.h"
+#include "qemu/notify.h"
+#include "qom/object.h"
+#include "qemu/rcu.h"
+
+#define RAM_ADDR_INVALID (~(ram_addr_t)0)
+
+#define MAX_PHYS_ADDR_SPACE_BITS 62
+#define MAX_PHYS_ADDR            (((hwaddr)1 << MAX_PHYS_ADDR_SPACE_BITS) - 1)
+
+#define TYPE_MEMORY_REGION "memory-region"
+DECLARE_INSTANCE_CHECKER(MemoryRegion, MEMORY_REGION,
+                         TYPE_MEMORY_REGION)
+
+#define TYPE_IOMMU_MEMORY_REGION "iommu-memory-region"
+typedef struct IOMMUMemoryRegionClass IOMMUMemoryRegionClass;
+DECLARE_OBJ_CHECKERS(IOMMUMemoryRegion, IOMMUMemoryRegionClass,
+                     IOMMU_MEMORY_REGION, TYPE_IOMMU_MEMORY_REGION)
+
+#define TYPE_RAM_DISCARD_MANAGER "ram-discard-manager"
+typedef struct RamDiscardManagerClass RamDiscardManagerClass;
+typedef struct RamDiscardManager RamDiscardManager;
+DECLARE_OBJ_CHECKERS(RamDiscardManager, RamDiscardManagerClass,
+                     RAM_DISCARD_MANAGER, TYPE_RAM_DISCARD_MANAGER);
+
+#ifdef CONFIG_FUZZ
+void fuzz_dma_read_cb(size_t addr,
+                      size_t len,
+                      MemoryRegion *mr);
+#else
+static inline void fuzz_dma_read_cb(size_t addr,
+                                    size_t len,
+                                    MemoryRegion *mr)
+{
+    /* Do Nothing */
+}
+#endif
+
+/* Possible bits for global_dirty_log_{start|stop} */
+
+/* Dirty tracking enabled because migration is running */
+#define GLOBAL_DIRTY_MIGRATION  (1U << 0)
+
+/* Dirty tracking enabled because measuring dirty rate */
+#define GLOBAL_DIRTY_DIRTY_RATE (1U << 1)
+
+/* Dirty tracking enabled because dirty limit */
+#define GLOBAL_DIRTY_LIMIT      (1U << 2)
+
+#define GLOBAL_DIRTY_MASK  (0x7)
+
+extern unsigned int global_dirty_tracking;
+
+typedef struct MemoryRegionOps MemoryRegionOps;
+
+struct ReservedRegion {
+    Range range;
+    unsigned type;
+};
+
+/**
+ * struct MemoryRegionSection: describes a fragment of a #MemoryRegion
+ *
+ * @mr: the region, or %NULL if empty
+ * @fv: the flat view of the address space the region is mapped in
+ * @offset_within_region: the beginning of the section, relative to @mr's start
+ * @size: the size of the section; will not exceed @mr's boundaries
+ * @offset_within_address_space: the address of the first byte of the section
+ *     relative to the region's address space
+ * @readonly: writes to this section are ignored
+ * @nonvolatile: this section is non-volatile
+ * @unmergeable: this section should not get merged with adjacent sections
+ */
+struct MemoryRegionSection {
+    Int128 size;
+    MemoryRegion *mr;
+    FlatView *fv;
+    hwaddr offset_within_region;
+    hwaddr offset_within_address_space;
+    bool readonly;
+    bool nonvolatile;
+    bool unmergeable;
+};
+
+typedef struct IOMMUTLBEntry IOMMUTLBEntry;
+
+/* See address_space_translate: bit 0 is read, bit 1 is write.  */
+typedef enum {
+    IOMMU_NONE = 0,
+    IOMMU_RO   = 1,
+    IOMMU_WO   = 2,
+    IOMMU_RW   = 3,
+} IOMMUAccessFlags;
+
+#define IOMMU_ACCESS_FLAG(r, w) (((r) ? IOMMU_RO : 0) | ((w) ? IOMMU_WO : 0))
+
+struct IOMMUTLBEntry {
+    AddressSpace    *target_as;
+    hwaddr           iova;
+    hwaddr           translated_addr;
+    hwaddr           addr_mask;  /* 0xfff = 4k translation */
+    IOMMUAccessFlags perm;
+};
+
+/*
+ * Bitmap for different IOMMUNotifier capabilities. Each notifier can
+ * register with one or multiple IOMMU Notifier capability bit(s).
+ *
+ * Normally there're two use cases for the notifiers:
+ *
+ *   (1) When the device needs accurate synchronizations of the vIOMMU page
+ *       tables, it needs to register with both MAP|UNMAP notifies (which
+ *       is defined as IOMMU_NOTIFIER_IOTLB_EVENTS below).
+ *
+ *       Regarding to accurate synchronization, it's when the notified
+ *       device maintains a shadow page table and must be notified on each
+ *       guest MAP (page table entry creation) and UNMAP (invalidation)
+ *       events (e.g. VFIO). Both notifications must be accurate so that
+ *       the shadow page table is fully in sync with the guest view.
+ *
+ *   (2) When the device doesn't need accurate synchronizations of the
+ *       vIOMMU page tables, it needs to register only with UNMAP or
+ *       DEVIOTLB_UNMAP notifies.
+ *
+ *       It's when the device maintains a cache of IOMMU translations
+ *       (IOTLB) and is able to fill that cache by requesting translations
+ *       from the vIOMMU through a protocol similar to ATS (Address
+ *       Translation Service).
+ *
+ *       Note that in this mode the vIOMMU will not maintain a shadowed
+ *       page table for the address space, and the UNMAP messages can cover
+ *       more than the pages that used to get mapped.  The IOMMU notifiee
+ *       should be able to take care of over-sized invalidations.
+ */
+typedef enum {
+    IOMMU_NOTIFIER_NONE = 0,
+    /* Notify cache invalidations */
+    IOMMU_NOTIFIER_UNMAP = 0x1,
+    /* Notify entry changes (newly created entries) */
+    IOMMU_NOTIFIER_MAP = 0x2,
+    /* Notify changes on device IOTLB entries */
+    IOMMU_NOTIFIER_DEVIOTLB_UNMAP = 0x04,
+} IOMMUNotifierFlag;
+
+#define IOMMU_NOTIFIER_IOTLB_EVENTS (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP)
+#define IOMMU_NOTIFIER_DEVIOTLB_EVENTS IOMMU_NOTIFIER_DEVIOTLB_UNMAP
+#define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_IOTLB_EVENTS | \
+                            IOMMU_NOTIFIER_DEVIOTLB_EVENTS)
+
+struct IOMMUNotifier;
+typedef void (*IOMMUNotify)(struct IOMMUNotifier *notifier,
+                            IOMMUTLBEntry *data);
+
+struct IOMMUNotifier {
+    IOMMUNotify notify;
+    IOMMUNotifierFlag notifier_flags;
+    /* Notify for address space range start <= addr <= end */
+    hwaddr start;
+    hwaddr end;
+    int iommu_idx;
+    QLIST_ENTRY(IOMMUNotifier) node;
+};
+typedef struct IOMMUNotifier IOMMUNotifier;
+
+typedef struct IOMMUTLBEvent {
+    IOMMUNotifierFlag type;
+    IOMMUTLBEntry entry;
+} IOMMUTLBEvent;
+
+/* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
+#define RAM_PREALLOC   (1 << 0)
+
+/* RAM is mmap-ed with MAP_SHARED */
+#define RAM_SHARED     (1 << 1)
+
+/* Only a portion of RAM (used_length) is actually used, and migrated.
+ * Resizing RAM while migrating can result in the migration being canceled.
+ */
+#define RAM_RESIZEABLE (1 << 2)
+
+/* UFFDIO_ZEROPAGE is available on this RAMBlock to atomically
+ * zero the page and wake waiting processes.
+ * (Set during postcopy)
+ */
+#define RAM_UF_ZEROPAGE (1 << 3)
+
+/* RAM can be migrated */
+#define RAM_MIGRATABLE (1 << 4)
+
+/* RAM is a persistent kind memory */
+#define RAM_PMEM (1 << 5)
+
+
+/*
+ * UFFDIO_WRITEPROTECT is used on this RAMBlock to
+ * support 'write-tracking' migration type.
+ * Implies ram_state->ram_wt_enabled.
+ */
+#define RAM_UF_WRITEPROTECT (1 << 6)
+
+/*
+ * RAM is mmap-ed with MAP_NORESERVE. When set, reserving swap space (or huge
+ * pages if applicable) is skipped: will bail out if not supported. When not
+ * set, the OS will do the reservation, if supported for the memory type.
+ */
+#define RAM_NORESERVE (1 << 7)
+
+/* RAM that isn't accessible through normal means. */
+#define RAM_PROTECTED (1 << 8)
+
+/* RAM is an mmap-ed named file */
+#define RAM_NAMED_FILE (1 << 9)
+
+/* RAM is mmap-ed read-only */
+#define RAM_READONLY (1 << 10)
+
+/* RAM FD is opened read-only */
+#define RAM_READONLY_FD (1 << 11)
+
+/* RAM can be private that has kvm guest memfd backend */
+#define RAM_GUEST_MEMFD   (1 << 12)
+
+/*
+ * In RAMBlock creation functions, if MAP_SHARED is 0 in the flags parameter,
+ * the implementation may still create a shared mapping if other conditions
+ * require it.  Callers who specifically want a private mapping, eg objects
+ * specified by the user, must pass RAM_PRIVATE.
+ * After RAMBlock creation, MAP_SHARED in the block's flags indicates whether
+ * the block is shared or private, and MAP_PRIVATE is omitted.
+ */
+#define RAM_PRIVATE (1 << 13)
+
+static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
+                                       IOMMUNotifierFlag flags,
+                                       hwaddr start, hwaddr end,
+                                       int iommu_idx)
+{
+    n->notify = fn;
+    n->notifier_flags = flags;
+    n->start = start;
+    n->end = end;
+    n->iommu_idx = iommu_idx;
+}
+
+/*
+ * Memory region callbacks
+ */
+struct MemoryRegionOps {
+    /* Read from the memory region. @addr is relative to @mr; @size is
+     * in bytes. */
+    uint64_t (*read)(void *opaque,
+                     hwaddr addr,
+                     unsigned size);
+    /* Write to the memory region. @addr is relative to @mr; @size is
+     * in bytes. */
+    void (*write)(void *opaque,
+                  hwaddr addr,
+                  uint64_t data,
+                  unsigned size);
+
+    MemTxResult (*read_with_attrs)(void *opaque,
+                                   hwaddr addr,
+                                   uint64_t *data,
+                                   unsigned size,
+                                   MemTxAttrs attrs);
+    MemTxResult (*write_with_attrs)(void *opaque,
+                                    hwaddr addr,
+                                    uint64_t data,
+                                    unsigned size,
+                                    MemTxAttrs attrs);
+
+    enum device_endian endianness;
+    /* Guest-visible constraints: */
+    struct {
+        /* If nonzero, specify bounds on access sizes beyond which a machine
+         * check is thrown.
+         */
+        unsigned min_access_size;
+        unsigned max_access_size;
+        /* If true, unaligned accesses are supported.  Otherwise unaligned
+         * accesses throw machine checks.
+         */
+         bool unaligned;
+        /*
+         * If present, and returns #false, the transaction is not accepted
+         * by the device (and results in machine dependent behaviour such
+         * as a machine check exception).
+         */
+        bool (*accepts)(void *opaque, hwaddr addr,
+                        unsigned size, bool is_write,
+                        MemTxAttrs attrs);
+    } valid;
+    /* Internal implementation constraints: */
+    struct {
+        /* If nonzero, specifies the minimum size implemented.  Smaller sizes
+         * will be rounded upwards and a partial result will be returned.
+         */
+        unsigned min_access_size;
+        /* If nonzero, specifies the maximum size implemented.  Larger sizes
+         * will be done as a series of accesses with smaller sizes.
+         */
+        unsigned max_access_size;
+        /* If true, unaligned accesses are supported.  Otherwise all accesses
+         * are converted to (possibly multiple) naturally aligned accesses.
+         */
+        bool unaligned;
+    } impl;
+};
+
+typedef struct MemoryRegionClass {
+    /* private */
+    ObjectClass parent_class;
+} MemoryRegionClass;
+
+
+enum IOMMUMemoryRegionAttr {
+    IOMMU_ATTR_SPAPR_TCE_FD
+};
+
+/*
+ * IOMMUMemoryRegionClass:
+ *
+ * All IOMMU implementations need to subclass TYPE_IOMMU_MEMORY_REGION
+ * and provide an implementation of at least the @translate method here
+ * to handle requests to the memory region. Other methods are optional.
+ *
+ * The IOMMU implementation must use the IOMMU notifier infrastructure
+ * to report whenever mappings are changed, by calling
+ * memory_region_notify_iommu() (or, if necessary, by calling
+ * memory_region_notify_iommu_one() for each registered notifier).
+ *
+ * Conceptually an IOMMU provides a mapping from input address
+ * to an output TLB entry. If the IOMMU is aware of memory transaction
+ * attributes and the output TLB entry depends on the transaction
+ * attributes, we represent this using IOMMU indexes. Each index
+ * selects a particular translation table that the IOMMU has:
+ *
+ *   @attrs_to_index returns the IOMMU index for a set of transaction attributes
+ *
+ *   @translate takes an input address and an IOMMU index
+ *
+ * and the mapping returned can only depend on the input address and the
+ * IOMMU index.
+ *
+ * Most IOMMUs don't care about the transaction attributes and support
+ * only a single IOMMU index. A more complex IOMMU might have one index
+ * for secure transactions and one for non-secure transactions.
+ */
+struct IOMMUMemoryRegionClass {
+    /* private: */
+    MemoryRegionClass parent_class;
+
+    /* public: */
+    /**
+     * @translate:
+     *
+     * Return a TLB entry that contains a given address.
+     *
+     * The IOMMUAccessFlags indicated via @flag are optional and may
+     * be specified as IOMMU_NONE to indicate that the caller needs
+     * the full translation information for both reads and writes. If
+     * the access flags are specified then the IOMMU implementation
+     * may use this as an optimization, to stop doing a page table
+     * walk as soon as it knows that the requested permissions are not
+     * allowed. If IOMMU_NONE is passed then the IOMMU must do the
+     * full page table walk and report the permissions in the returned
+     * IOMMUTLBEntry. (Note that this implies that an IOMMU may not
+     * return different mappings for reads and writes.)
+     *
+     * The returned information remains valid while the caller is
+     * holding the big QEMU lock or is inside an RCU critical section;
+     * if the caller wishes to cache the mapping beyond that it must
+     * register an IOMMU notifier so it can invalidate its cached
+     * information when the IOMMU mapping changes.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     *
+     * @hwaddr: address to be translated within the memory region
+     *
+     * @flag: requested access permission
+     *
+     * @iommu_idx: IOMMU index for the translation
+     */
+    IOMMUTLBEntry (*translate)(IOMMUMemoryRegion *iommu, hwaddr addr,
+                               IOMMUAccessFlags flag, int iommu_idx);
+    /**
+     * @get_min_page_size:
+     *
+     * Returns minimum supported page size in bytes.
+     *
+     * If this method is not provided then the minimum is assumed to
+     * be TARGET_PAGE_SIZE.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     */
+    uint64_t (*get_min_page_size)(IOMMUMemoryRegion *iommu);
+    /**
+     * @notify_flag_changed:
+     *
+     * Called when IOMMU Notifier flag changes (ie when the set of
+     * events which IOMMU users are requesting notification for changes).
+     * Optional method -- need not be provided if the IOMMU does not
+     * need to know exactly which events must be notified.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     *
+     * @old_flags: events which previously needed to be notified
+     *
+     * @new_flags: events which now need to be notified
+     *
+     * Returns 0 on success, or a negative errno; in particular
+     * returns -EINVAL if the new flag bitmap is not supported by the
+     * IOMMU memory region. In case of failure, the error object
+     * must be created
+     */
+    int (*notify_flag_changed)(IOMMUMemoryRegion *iommu,
+                               IOMMUNotifierFlag old_flags,
+                               IOMMUNotifierFlag new_flags,
+                               Error **errp);
+    /**
+     * @replay:
+     *
+     * Called to handle memory_region_iommu_replay().
+     *
+     * The default implementation of memory_region_iommu_replay() is to
+     * call the IOMMU translate method for every page in the address space
+     * with flag == IOMMU_NONE and then call the notifier if translate
+     * returns a valid mapping. If this method is implemented then it
+     * overrides the default behaviour, and must provide the full semantics
+     * of memory_region_iommu_replay(), by calling @notifier for every
+     * translation present in the IOMMU.
+     *
+     * Optional method -- an IOMMU only needs to provide this method
+     * if the default is inefficient or produces undesirable side effects.
+     *
+     * Note: this is not related to record-and-replay functionality.
+     */
+    void (*replay)(IOMMUMemoryRegion *iommu, IOMMUNotifier *notifier);
+
+    /**
+     * @get_attr:
+     *
+     * Get IOMMU misc attributes. This is an optional method that
+     * can be used to allow users of the IOMMU to get implementation-specific
+     * information. The IOMMU implements this method to handle calls
+     * by IOMMU users to memory_region_iommu_get_attr() by filling in
+     * the arbitrary data pointer for any IOMMUMemoryRegionAttr values that
+     * the IOMMU supports. If the method is unimplemented then
+     * memory_region_iommu_get_attr() will always return -EINVAL.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     *
+     * @attr: attribute being queried
+     *
+     * @data: memory to fill in with the attribute data
+     *
+     * Returns 0 on success, or a negative errno; in particular
+     * returns -EINVAL for unrecognized or unimplemented attribute types.
+     */
+    int (*get_attr)(IOMMUMemoryRegion *iommu, enum IOMMUMemoryRegionAttr attr,
+                    void *data);
+
+    /**
+     * @attrs_to_index:
+     *
+     * Return the IOMMU index to use for a given set of transaction attributes.
+     *
+     * Optional method: if an IOMMU only supports a single IOMMU index then
+     * the default implementation of memory_region_iommu_attrs_to_index()
+     * will return 0.
+     *
+     * The indexes supported by an IOMMU must be contiguous, starting at 0.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     * @attrs: memory transaction attributes
+     */
+    int (*attrs_to_index)(IOMMUMemoryRegion *iommu, MemTxAttrs attrs);
+
+    /**
+     * @num_indexes:
+     *
+     * Return the number of IOMMU indexes this IOMMU supports.
+     *
+     * Optional method: if this method is not provided, then
+     * memory_region_iommu_num_indexes() will return 1, indicating that
+     * only a single IOMMU index is supported.
+     *
+     * @iommu: the IOMMUMemoryRegion
+     */
+    int (*num_indexes)(IOMMUMemoryRegion *iommu);
+};
+
+typedef struct RamDiscardListener RamDiscardListener;
+typedef int (*NotifyRamPopulate)(RamDiscardListener *rdl,
+                                 MemoryRegionSection *section);
+typedef void (*NotifyRamDiscard)(RamDiscardListener *rdl,
+                                 MemoryRegionSection *section);
+
+struct RamDiscardListener {
+    /*
+     * @notify_populate:
+     *
+     * Notification that previously discarded memory is about to get populated.
+     * Listeners are able to object. If any listener objects, already
+     * successfully notified listeners are notified about a discard again.
+     *
+     * @rdl: the #RamDiscardListener getting notified
+     * @section: the #MemoryRegionSection to get populated. The section
+     *           is aligned within the memory region to the minimum granularity
+     *           unless it would exceed the registered section.
+     *
+     * Returns 0 on success. If the notification is rejected by the listener,
+     * an error is returned.
+     */
+    NotifyRamPopulate notify_populate;
+
+    /*
+     * @notify_discard:
+     *
+     * Notification that previously populated memory was discarded successfully
+     * and listeners should drop all references to such memory and prevent
+     * new population (e.g., unmap).
+     *
+     * @rdl: the #RamDiscardListener getting notified
+     * @section: the #MemoryRegionSection to get populated. The section
+     *           is aligned within the memory region to the minimum granularity
+     *           unless it would exceed the registered section.
+     */
+    NotifyRamDiscard notify_discard;
+
+    /*
+     * @double_discard_supported:
+     *
+     * The listener suppors getting @notify_discard notifications that span
+     * already discarded parts.
+     */
+    bool double_discard_supported;
+
+    MemoryRegionSection *section;
+    QLIST_ENTRY(RamDiscardListener) next;
+};
+
+static inline void ram_discard_listener_init(RamDiscardListener *rdl,
+                                             NotifyRamPopulate populate_fn,
+                                             NotifyRamDiscard discard_fn,
+                                             bool double_discard_supported)
+{
+    rdl->notify_populate = populate_fn;
+    rdl->notify_discard = discard_fn;
+    rdl->double_discard_supported = double_discard_supported;
+}
+
+typedef int (*ReplayRamPopulate)(MemoryRegionSection *section, void *opaque);
+typedef void (*ReplayRamDiscard)(MemoryRegionSection *section, void *opaque);
+
+/*
+ * RamDiscardManagerClass:
+ *
+ * A #RamDiscardManager coordinates which parts of specific RAM #MemoryRegion
+ * regions are currently populated to be used/accessed by the VM, notifying
+ * after parts were discarded (freeing up memory) and before parts will be
+ * populated (consuming memory), to be used/accessed by the VM.
+ *
+ * A #RamDiscardManager can only be set for a RAM #MemoryRegion while the
+ * #MemoryRegion isn't mapped into an address space yet (either directly
+ * or via an alias); it cannot change while the #MemoryRegion is
+ * mapped into an address space.
+ *
+ * The #RamDiscardManager is intended to be used by technologies that are
+ * incompatible with discarding of RAM (e.g., VFIO, which may pin all
+ * memory inside a #MemoryRegion), and require proper coordination to only
+ * map the currently populated parts, to hinder parts that are expected to
+ * remain discarded from silently getting populated and consuming memory.
+ * Technologies that support discarding of RAM don't have to bother and can
+ * simply map the whole #MemoryRegion.
+ *
+ * An example #RamDiscardManager is virtio-mem, which logically (un)plugs
+ * memory within an assigned RAM #MemoryRegion, coordinated with the VM.
+ * Logically unplugging memory consists of discarding RAM. The VM agreed to not
+ * access unplugged (discarded) memory - especially via DMA. virtio-mem will
+ * properly coordinate with listeners before memory is plugged (populated),
+ * and after memory is unplugged (discarded).
+ *
+ * Listeners are called in multiples of the minimum granularity (unless it
+ * would exceed the registered range) and changes are aligned to the minimum
+ * granularity within the #MemoryRegion. Listeners have to prepare for memory
+ * becoming discarded in a different granularity than it was populated and the
+ * other way around.
+ */
+struct RamDiscardManagerClass {
+    /* private */
+    InterfaceClass parent_class;
+
+    /* public */
+
+    /**
+     * @get_min_granularity:
+     *
+     * Get the minimum granularity in which listeners will get notified
+     * about changes within the #MemoryRegion via the #RamDiscardManager.
+     *
+     * @rdm: the #RamDiscardManager
+     * @mr: the #MemoryRegion
+     *
+     * Returns the minimum granularity.
+     */
+    uint64_t (*get_min_granularity)(const RamDiscardManager *rdm,
+                                    const MemoryRegion *mr);
+
+    /**
+     * @is_populated:
+     *
+     * Check whether the given #MemoryRegionSection is completely populated
+     * (i.e., no parts are currently discarded) via the #RamDiscardManager.
+     * There are no alignment requirements.
+     *
+     * @rdm: the #RamDiscardManager
+     * @section: the #MemoryRegionSection
+     *
+     * Returns whether the given range is completely populated.
+     */
+    bool (*is_populated)(const RamDiscardManager *rdm,
+                         const MemoryRegionSection *section);
+
+    /**
+     * @replay_populated:
+     *
+     * Call the #ReplayRamPopulate callback for all populated parts within the
+     * #MemoryRegionSection via the #RamDiscardManager.
+     *
+     * In case any call fails, no further calls are made.
+     *
+     * @rdm: the #RamDiscardManager
+     * @section: the #MemoryRegionSection
+     * @replay_fn: the #ReplayRamPopulate callback
+     * @opaque: pointer to forward to the callback
+     *
+     * Returns 0 on success, or a negative error if any notification failed.
+     */
+    int (*replay_populated)(const RamDiscardManager *rdm,
+                            MemoryRegionSection *section,
+                            ReplayRamPopulate replay_fn, void *opaque);
+
+    /**
+     * @replay_discarded:
+     *
+     * Call the #ReplayRamDiscard callback for all discarded parts within the
+     * #MemoryRegionSection via the #RamDiscardManager.
+     *
+     * @rdm: the #RamDiscardManager
+     * @section: the #MemoryRegionSection
+     * @replay_fn: the #ReplayRamDiscard callback
+     * @opaque: pointer to forward to the callback
+     */
+    void (*replay_discarded)(const RamDiscardManager *rdm,
+                             MemoryRegionSection *section,
+                             ReplayRamDiscard replay_fn, void *opaque);
+
+    /**
+     * @register_listener:
+     *
+     * Register a #RamDiscardListener for the given #MemoryRegionSection and
+     * immediately notify the #RamDiscardListener about all populated parts
+     * within the #MemoryRegionSection via the #RamDiscardManager.
+     *
+     * In case any notification fails, no further notifications are triggered
+     * and an error is logged.
+     *
+     * @rdm: the #RamDiscardManager
+     * @rdl: the #RamDiscardListener
+     * @section: the #MemoryRegionSection
+     */
+    void (*register_listener)(RamDiscardManager *rdm,
+                              RamDiscardListener *rdl,
+                              MemoryRegionSection *section);
+
+    /**
+     * @unregister_listener:
+     *
+     * Unregister a previously registered #RamDiscardListener via the
+     * #RamDiscardManager after notifying the #RamDiscardListener about all
+     * populated parts becoming unpopulated within the registered
+     * #MemoryRegionSection.
+     *
+     * @rdm: the #RamDiscardManager
+     * @rdl: the #RamDiscardListener
+     */
+    void (*unregister_listener)(RamDiscardManager *rdm,
+                                RamDiscardListener *rdl);
+};
+
+uint64_t ram_discard_manager_get_min_granularity(const RamDiscardManager *rdm,
+                                                 const MemoryRegion *mr);
+
+bool ram_discard_manager_is_populated(const RamDiscardManager *rdm,
+                                      const MemoryRegionSection *section);
+
+int ram_discard_manager_replay_populated(const RamDiscardManager *rdm,
+                                         MemoryRegionSection *section,
+                                         ReplayRamPopulate replay_fn,
+                                         void *opaque);
+
+void ram_discard_manager_replay_discarded(const RamDiscardManager *rdm,
+                                          MemoryRegionSection *section,
+                                          ReplayRamDiscard replay_fn,
+                                          void *opaque);
+
+void ram_discard_manager_register_listener(RamDiscardManager *rdm,
+                                           RamDiscardListener *rdl,
+                                           MemoryRegionSection *section);
+
+void ram_discard_manager_unregister_listener(RamDiscardManager *rdm,
+                                             RamDiscardListener *rdl);
+
+/**
+ * memory_get_xlat_addr: Extract addresses from a TLB entry
+ *
+ * @iotlb: pointer to an #IOMMUTLBEntry
+ * @vaddr: virtual address
+ * @ram_addr: RAM address
+ * @read_only: indicates if writes are allowed
+ * @mr_has_discard_manager: indicates memory is controlled by a
+ *                          RamDiscardManager
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
+                          ram_addr_t *ram_addr, bool *read_only,
+                          bool *mr_has_discard_manager, Error **errp);
+
+typedef struct CoalescedMemoryRange CoalescedMemoryRange;
+typedef struct MemoryRegionIoeventfd MemoryRegionIoeventfd;
+
+/** MemoryRegion:
+ *
+ * A struct representing a memory region.
+ */
+struct MemoryRegion {
+    Object parent_obj;
+
+    /* private: */
+
+    /* The following fields should fit in a cache line */
+    bool romd_mode;
+    bool ram;
+    bool subpage;
+    bool readonly; /* For RAM regions */
+    bool nonvolatile;
+    bool rom_device;
+    bool flush_coalesced_mmio;
+    bool unmergeable;
+    uint8_t dirty_log_mask;
+    bool is_iommu;
+    RAMBlock *ram_block;
+    Object *owner;
+    /* owner as TYPE_DEVICE. Used for re-entrancy checks in MR access hotpath */
+    DeviceState *dev;
+
+    const MemoryRegionOps *ops;
+    void *opaque;
+    MemoryRegion *container;
+    int mapped_via_alias; /* Mapped via an alias, container might be NULL */
+    Int128 size;
+    hwaddr addr;
+    void (*destructor)(MemoryRegion *mr);
+    uint64_t align;
+    bool terminates;
+    bool ram_device;
+    bool enabled;
+    uint8_t vga_logging_count;
+    MemoryRegion *alias;
+    hwaddr alias_offset;
+    int32_t priority;
+    QTAILQ_HEAD(, MemoryRegion) subregions;
+    QTAILQ_ENTRY(MemoryRegion) subregions_link;
+    QTAILQ_HEAD(, CoalescedMemoryRange) coalesced;
+    const char *name;
+    unsigned ioeventfd_nb;
+    MemoryRegionIoeventfd *ioeventfds;
+    RamDiscardManager *rdm; /* Only for RAM */
+
+    /* For devices designed to perform re-entrant IO into their own IO MRs */
+    bool disable_reentrancy_guard;
+};
+
+struct IOMMUMemoryRegion {
+    MemoryRegion parent_obj;
+
+    QLIST_HEAD(, IOMMUNotifier) iommu_notify;
+    IOMMUNotifierFlag iommu_notify_flags;
+};
+
+#define IOMMU_NOTIFIER_FOREACH(n, mr) \
+    QLIST_FOREACH((n), &(mr)->iommu_notify, node)
+
+#define MEMORY_LISTENER_PRIORITY_MIN            0
+#define MEMORY_LISTENER_PRIORITY_ACCEL          10
+#define MEMORY_LISTENER_PRIORITY_DEV_BACKEND    10
+
+/**
+ * struct MemoryListener: callbacks structure for updates to the physical memory map
+ *
+ * Allows a component to adjust to changes in the guest-visible memory map.
+ * Use with memory_listener_register() and memory_listener_unregister().
+ */
+struct MemoryListener {
+    /**
+     * @begin:
+     *
+     * Called at the beginning of an address space update transaction.
+     * Followed by calls to #MemoryListener.region_add(),
+     * #MemoryListener.region_del(), #MemoryListener.region_nop(),
+     * #MemoryListener.log_start() and #MemoryListener.log_stop() in
+     * increasing address order.
+     *
+     * @listener: The #MemoryListener.
+     */
+    void (*begin)(MemoryListener *listener);
+
+    /**
+     * @commit:
+     *
+     * Called at the end of an address space update transaction,
+     * after the last call to #MemoryListener.region_add(),
+     * #MemoryListener.region_del() or #MemoryListener.region_nop(),
+     * #MemoryListener.log_start() and #MemoryListener.log_stop().
+     *
+     * @listener: The #MemoryListener.
+     */
+    void (*commit)(MemoryListener *listener);
+
+    /**
+     * @region_add:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that is new in this address space
+     * space since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The new #MemoryRegionSection.
+     */
+    void (*region_add)(MemoryListener *listener, MemoryRegionSection *section);
+
+    /**
+     * @region_del:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that has disappeared in the address
+     * space since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The old #MemoryRegionSection.
+     */
+    void (*region_del)(MemoryListener *listener, MemoryRegionSection *section);
+
+    /**
+     * @region_nop:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that is in the same place in the address
+     * space as in the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The #MemoryRegionSection.
+     */
+    void (*region_nop)(MemoryListener *listener, MemoryRegionSection *section);
+
+    /**
+     * @log_start:
+     *
+     * Called during an address space update transaction, after
+     * one of #MemoryListener.region_add(), #MemoryListener.region_del() or
+     * #MemoryListener.region_nop(), if dirty memory logging clients have
+     * become active since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The #MemoryRegionSection.
+     * @old: A bitmap of dirty memory logging clients that were active in
+     * the previous transaction.
+     * @new: A bitmap of dirty memory logging clients that are active in
+     * the current transaction.
+     */
+    void (*log_start)(MemoryListener *listener, MemoryRegionSection *section,
+                      int old_val, int new_val);
+
+    /**
+     * @log_stop:
+     *
+     * Called during an address space update transaction, after
+     * one of #MemoryListener.region_add(), #MemoryListener.region_del() or
+     * #MemoryListener.region_nop() and possibly after
+     * #MemoryListener.log_start(), if dirty memory logging clients have
+     * become inactive since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The #MemoryRegionSection.
+     * @old: A bitmap of dirty memory logging clients that were active in
+     * the previous transaction.
+     * @new: A bitmap of dirty memory logging clients that are active in
+     * the current transaction.
+     */
+    void (*log_stop)(MemoryListener *listener, MemoryRegionSection *section,
+                     int old_val, int new_val);
+
+    /**
+     * @log_sync:
+     *
+     * Called by memory_region_snapshot_and_clear_dirty() and
+     * memory_global_dirty_log_sync(), before accessing QEMU's "official"
+     * copy of the dirty memory bitmap for a #MemoryRegionSection.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The #MemoryRegionSection.
+     */
+    void (*log_sync)(MemoryListener *listener, MemoryRegionSection *section);
+
+    /**
+     * @log_sync_global:
+     *
+     * This is the global version of @log_sync when the listener does
+     * not have a way to synchronize the log with finer granularity.
+     * When the listener registers with @log_sync_global defined, then
+     * its @log_sync must be NULL.  Vice versa.
+     *
+     * @listener: The #MemoryListener.
+     * @last_stage: The last stage to synchronize the log during migration.
+     * The caller should guarantee that the synchronization with true for
+     * @last_stage is triggered for once after all VCPUs have been stopped.
+     */
+    void (*log_sync_global)(MemoryListener *listener, bool last_stage);
+
+    /**
+     * @log_clear:
+     *
+     * Called before reading the dirty memory bitmap for a
+     * #MemoryRegionSection.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The #MemoryRegionSection.
+     */
+    void (*log_clear)(MemoryListener *listener, MemoryRegionSection *section);
+
+    /**
+     * @log_global_start:
+     *
+     * Called by memory_global_dirty_log_start(), which
+     * enables the %DIRTY_LOG_MIGRATION client on all memory regions in
+     * the address space.  #MemoryListener.log_global_start() is also
+     * called when a #MemoryListener is added, if global dirty logging is
+     * active at that time.
+     *
+     * @listener: The #MemoryListener.
+     * @errp: pointer to Error*, to store an error if it happens.
+     *
+     * Return: true on success, else false setting @errp with error.
+     */
+    bool (*log_global_start)(MemoryListener *listener, Error **errp);
+
+    /**
+     * @log_global_stop:
+     *
+     * Called by memory_global_dirty_log_stop(), which
+     * disables the %DIRTY_LOG_MIGRATION client on all memory regions in
+     * the address space.
+     *
+     * @listener: The #MemoryListener.
+     */
+    void (*log_global_stop)(MemoryListener *listener);
+
+    /**
+     * @log_global_after_sync:
+     *
+     * Called after reading the dirty memory bitmap
+     * for any #MemoryRegionSection.
+     *
+     * @listener: The #MemoryListener.
+     */
+    void (*log_global_after_sync)(MemoryListener *listener);
+
+    /**
+     * @eventfd_add:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that has had a new ioeventfd
+     * registration since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The new #MemoryRegionSection.
+     * @match_data: The @match_data parameter for the new ioeventfd.
+     * @data: The @data parameter for the new ioeventfd.
+     * @e: The #EventNotifier parameter for the new ioeventfd.
+     */
+    void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
+                        bool match_data, uint64_t data, EventNotifier *e);
+
+    /**
+     * @eventfd_del:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that has dropped an ioeventfd
+     * registration since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The new #MemoryRegionSection.
+     * @match_data: The @match_data parameter for the dropped ioeventfd.
+     * @data: The @data parameter for the dropped ioeventfd.
+     * @e: The #EventNotifier parameter for the dropped ioeventfd.
+     */
+    void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
+                        bool match_data, uint64_t data, EventNotifier *e);
+
+    /**
+     * @coalesced_io_add:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that has had a new coalesced
+     * MMIO range registration since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The new #MemoryRegionSection.
+     * @addr: The starting address for the coalesced MMIO range.
+     * @len: The length of the coalesced MMIO range.
+     */
+    void (*coalesced_io_add)(MemoryListener *listener, MemoryRegionSection *section,
+                               hwaddr addr, hwaddr len);
+
+    /**
+     * @coalesced_io_del:
+     *
+     * Called during an address space update transaction,
+     * for a section of the address space that has dropped a coalesced
+     * MMIO range since the last transaction.
+     *
+     * @listener: The #MemoryListener.
+     * @section: The new #MemoryRegionSection.
+     * @addr: The starting address for the coalesced MMIO range.
+     * @len: The length of the coalesced MMIO range.
+     */
+    void (*coalesced_io_del)(MemoryListener *listener, MemoryRegionSection *section,
+                               hwaddr addr, hwaddr len);
+    /**
+     * @priority:
+     *
+     * Govern the order in which memory listeners are invoked. Lower priorities
+     * are invoked earlier for "add" or "start" callbacks, and later for "delete"
+     * or "stop" callbacks.
+     */
+    unsigned priority;
+
+    /**
+     * @name:
+     *
+     * Name of the listener.  It can be used in contexts where we'd like to
+     * identify one memory listener with the rest.
+     */
+    const char *name;
+
+    /* private: */
+    AddressSpace *address_space;
+    QTAILQ_ENTRY(MemoryListener) link;
+    QTAILQ_ENTRY(MemoryListener) link_as;
+};
+
+typedef struct AddressSpaceMapClient {
+    QEMUBH *bh;
+    QLIST_ENTRY(AddressSpaceMapClient) link;
+} AddressSpaceMapClient;
+
+#define DEFAULT_MAX_BOUNCE_BUFFER_SIZE (4096)
+
+/**
+ * struct AddressSpace: describes a mapping of addresses to #MemoryRegion objects
+ */
+struct AddressSpace {
+    /* private: */
+    struct rcu_head rcu;
+    char *name;
+    MemoryRegion *root;
+
+    /* Accessed via RCU.  */
+    struct FlatView *current_map;
+
+    int ioeventfd_nb;
+    int ioeventfd_notifiers;
+    struct MemoryRegionIoeventfd *ioeventfds;
+    QTAILQ_HEAD(, MemoryListener) listeners;
+    QTAILQ_ENTRY(AddressSpace) address_spaces_link;
+
+    /*
+     * Maximum DMA bounce buffer size used for indirect memory map requests.
+     * This limits the total size of bounce buffer allocations made for
+     * DMA requests to indirect memory regions within this AddressSpace. DMA
+     * requests that exceed the limit (e.g. due to overly large requested size
+     * or concurrent DMA requests having claimed too much buffer space) will be
+     * rejected and left to the caller to handle.
+     */
+    size_t max_bounce_buffer_size;
+    /* Total size of bounce buffers currently allocated, atomically accessed */
+    size_t bounce_buffer_size;
+    /* List of callbacks to invoke when buffers free up */
+    QemuMutex map_client_list_lock;
+    QLIST_HEAD(, AddressSpaceMapClient) map_client_list;
+};
+
+typedef struct AddressSpaceDispatch AddressSpaceDispatch;
+typedef struct FlatRange FlatRange;
+
+/* Flattened global view of current active memory hierarchy.  Kept in sorted
+ * order.
+ */
+struct FlatView {
+    struct rcu_head rcu;
+    unsigned ref;
+    FlatRange *ranges;
+    unsigned nr;
+    unsigned nr_allocated;
+    struct AddressSpaceDispatch *dispatch;
+    MemoryRegion *root;
+};
+
+static inline FlatView *address_space_to_flatview(AddressSpace *as)
+{
+    return qatomic_rcu_read(&as->current_map);
+}
+
+/**
+ * typedef flatview_cb: callback for flatview_for_each_range()
+ *
+ * @start: start address of the range within the FlatView
+ * @len: length of the range in bytes
+ * @mr: MemoryRegion covering this range
+ * @offset_in_region: offset of the first byte of the range within @mr
+ * @opaque: data pointer passed to flatview_for_each_range()
+ *
+ * Returns: true to stop the iteration, false to keep going.
+ */
+typedef bool (*flatview_cb)(Int128 start,
+                            Int128 len,
+                            const MemoryRegion *mr,
+                            hwaddr offset_in_region,
+                            void *opaque);
+
+/**
+ * flatview_for_each_range: Iterate through a FlatView
+ * @fv: the FlatView to iterate through
+ * @cb: function to call for each range
+ * @opaque: opaque data pointer to pass to @cb
+ *
+ * A FlatView is made up of a list of non-overlapping ranges, each of
+ * which is a slice of a MemoryRegion. This function iterates through
+ * each range in @fv, calling @cb. The callback function can terminate
+ * iteration early by returning 'true'.
+ */
+void flatview_for_each_range(FlatView *fv, flatview_cb cb, void *opaque);
+
+static inline bool MemoryRegionSection_eq(MemoryRegionSection *a,
+                                          MemoryRegionSection *b)
+{
+    return a->mr == b->mr &&
+           a->fv == b->fv &&
+           a->offset_within_region == b->offset_within_region &&
+           a->offset_within_address_space == b->offset_within_address_space &&
+           int128_eq(a->size, b->size) &&
+           a->readonly == b->readonly &&
+           a->nonvolatile == b->nonvolatile;
+}
+
+/**
+ * memory_region_section_new_copy: Copy a memory region section
+ *
+ * Allocate memory for a new copy, copy the memory region section, and
+ * properly take a reference on all relevant members.
+ *
+ * @s: the #MemoryRegionSection to copy
+ */
+MemoryRegionSection *memory_region_section_new_copy(MemoryRegionSection *s);
+
+/**
+ * memory_region_section_free_copy: Free a copied memory region section
+ *
+ * Free a copy of a memory section created via memory_region_section_new_copy().
+ * properly dropping references on all relevant members.
+ *
+ * @s: the #MemoryRegionSection to copy
+ */
+void memory_region_section_free_copy(MemoryRegionSection *s);
+
+/**
+ * memory_region_init: Initialize a memory region
+ *
+ * The region typically acts as a container for other memory regions.  Use
+ * memory_region_add_subregion() to add subregions.
+ *
+ * @mr: the #MemoryRegion to be initialized
+ * @owner: the object that tracks the region's reference count
+ * @name: used for debugging; not visible to the user or ABI
+ * @size: size of the region; any subregions beyond this size will be clipped
+ */
+void memory_region_init(MemoryRegion *mr,
+                        Object *owner,
+                        const char *name,
+                        uint64_t size);
+
+/**
+ * memory_region_ref: Add 1 to a memory region's reference count
+ *
+ * Whenever memory regions are accessed outside the BQL, they need to be
+ * preserved against hot-unplug.  MemoryRegions actually do not have their
+ * own reference count; they piggyback on a QOM object, their "owner".
+ * This function adds a reference to the owner.
+ *
+ * All MemoryRegions must have an owner if they can disappear, even if the
+ * device they belong to operates exclusively under the BQL.  This is because
+ * the region could be returned at any time by memory_region_find, and this
+ * is usually under guest control.
+ *
+ * @mr: the #MemoryRegion
+ */
+void memory_region_ref(MemoryRegion *mr);
+
+/**
+ * memory_region_unref: Remove 1 to a memory region's reference count
+ *
+ * Whenever memory regions are accessed outside the BQL, they need to be
+ * preserved against hot-unplug.  MemoryRegions actually do not have their
+ * own reference count; they piggyback on a QOM object, their "owner".
+ * This function removes a reference to the owner and possibly destroys it.
+ *
+ * @mr: the #MemoryRegion
+ */
+void memory_region_unref(MemoryRegion *mr);
+
+/**
+ * memory_region_init_io: Initialize an I/O memory region.
+ *
+ * Accesses into the region will cause the callbacks in @ops to be called.
+ * if @size is nonzero, subregions will be clipped to @size.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @ops: a structure containing read and write callbacks to be used when
+ *       I/O is performed on the region.
+ * @opaque: passed to the read and write callbacks of the @ops structure.
+ * @name: used for debugging; not visible to the user or ABI
+ * @size: size of the region.
+ */
+void memory_region_init_io(MemoryRegion *mr,
+                           Object *owner,
+                           const MemoryRegionOps *ops,
+                           void *opaque,
+                           const char *name,
+                           uint64_t size);
+
+/**
+ * memory_region_init_ram_nomigrate:  Initialize RAM memory region.  Accesses
+ *                                    into the region will modify memory
+ *                                    directly.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_ram_nomigrate(MemoryRegion *mr,
+                                      Object *owner,
+                                      const char *name,
+                                      uint64_t size,
+                                      Error **errp);
+
+/**
+ * memory_region_init_ram_flags_nomigrate:  Initialize RAM memory region.
+ *                                          Accesses into the region will
+ *                                          modify memory directly.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_NORESERVE,
+ *             RAM_GUEST_MEMFD.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_ram_flags_nomigrate(MemoryRegion *mr,
+                                            Object *owner,
+                                            const char *name,
+                                            uint64_t size,
+                                            uint32_t ram_flags,
+                                            Error **errp);
+
+/**
+ * memory_region_init_resizeable_ram:  Initialize memory region with resizable
+ *                                     RAM.  Accesses into the region will
+ *                                     modify memory directly.  Only an initial
+ *                                     portion of this RAM is actually used.
+ *                                     Changing the size while migrating
+ *                                     can result in the migration being
+ *                                     canceled.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: used size of the region.
+ * @max_size: max size of the region.
+ * @resized: callback to notify owner about used size change.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool 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);
+#ifdef CONFIG_POSIX
+
+/**
+ * memory_region_init_ram_from_file:  Initialize RAM memory region with a
+ *                                    mmap-ed backend.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @align: alignment of the region base address; if 0, the default alignment
+ *         (getpagesize()) will be used.
+ * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
+ *             RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
+ *             RAM_READONLY_FD, RAM_GUEST_MEMFD
+ * @path: the path in which to allocate the RAM.
+ * @offset: offset within the file referenced by path
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool 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,
+                                      ram_addr_t offset,
+                                      Error **errp);
+
+/**
+ * memory_region_init_ram_from_fd:  Initialize RAM memory region with a
+ *                                  mmap-ed backend.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
+ *             RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY,
+ *             RAM_READONLY_FD, RAM_GUEST_MEMFD
+ * @fd: the fd to mmap.
+ * @offset: offset within the file referenced by fd
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool 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);
+#endif
+
+/**
+ * memory_region_init_ram_ptr:  Initialize RAM memory region from a
+ *                              user-provided pointer.  Accesses into the
+ *                              region will modify memory directly.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @ptr: memory to be mapped; must contain at least @size bytes.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ */
+void memory_region_init_ram_ptr(MemoryRegion *mr,
+                                Object *owner,
+                                const char *name,
+                                uint64_t size,
+                                void *ptr);
+
+/**
+ * memory_region_init_ram_device_ptr:  Initialize RAM device memory region from
+ *                                     a user-provided pointer.
+ *
+ * A RAM device represents a mapping to a physical device, such as to a PCI
+ * MMIO BAR of an vfio-pci assigned device.  The memory region may be mapped
+ * into the VM address space and access to the region will modify memory
+ * directly.  However, the memory region should not be included in a memory
+ * dump (device may not be enabled/mapped at the time of the dump), and
+ * operations incompatible with manipulating MMIO should be avoided.  Replaces
+ * skip_dump flag.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @ptr: memory to be mapped; must contain at least @size bytes.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM memory region to be migrated; that is the responsibility of the caller.
+ * (For RAM device memory regions, migrating the contents rarely makes sense.)
+ */
+void memory_region_init_ram_device_ptr(MemoryRegion *mr,
+                                       Object *owner,
+                                       const char *name,
+                                       uint64_t size,
+                                       void *ptr);
+
+/**
+ * memory_region_init_alias: Initialize a memory region that aliases all or a
+ *                           part of another memory region.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: used for debugging; not visible to the user or ABI
+ * @orig: the region to be referenced; @mr will be equivalent to
+ *        @orig between @offset and @offset + @size - 1.
+ * @offset: start of the section in @orig to be referenced.
+ * @size: size of the region.
+ */
+void memory_region_init_alias(MemoryRegion *mr,
+                              Object *owner,
+                              const char *name,
+                              MemoryRegion *orig,
+                              hwaddr offset,
+                              uint64_t size);
+
+/**
+ * memory_region_init_rom_nomigrate: Initialize a ROM memory region.
+ *
+ * This has the same effect as calling memory_region_init_ram_nomigrate()
+ * and then marking the resulting region read-only with
+ * memory_region_set_readonly().
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM side of the memory region to be migrated; that is the responsibility
+ * of the caller.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_rom_nomigrate(MemoryRegion *mr,
+                                      Object *owner,
+                                      const char *name,
+                                      uint64_t size,
+                                      Error **errp);
+
+/**
+ * memory_region_init_rom_device_nomigrate:  Initialize a ROM memory region.
+ *                                 Writes are handled via callbacks.
+ *
+ * Note that this function does not do anything to cause the data in the
+ * RAM side of the memory region to be migrated; that is the responsibility
+ * of the caller.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @ops: callbacks for write access handling (must not be NULL).
+ * @opaque: passed to the read and write callbacks of the @ops structure.
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_rom_device_nomigrate(MemoryRegion *mr,
+                                             Object *owner,
+                                             const MemoryRegionOps *ops,
+                                             void *opaque,
+                                             const char *name,
+                                             uint64_t size,
+                                             Error **errp);
+
+/**
+ * memory_region_init_iommu: Initialize a memory region of a custom type
+ * that translates addresses
+ *
+ * An IOMMU region translates addresses and forwards accesses to a target
+ * memory region.
+ *
+ * The IOMMU implementation must define a subclass of TYPE_IOMMU_MEMORY_REGION.
+ * @_iommu_mr should be a pointer to enough memory for an instance of
+ * that subclass, @instance_size is the size of that subclass, and
+ * @mrtypename is its name. This function will initialize @_iommu_mr as an
+ * instance of the subclass, and its methods will then be called to handle
+ * accesses to the memory region. See the documentation of
+ * #IOMMUMemoryRegionClass for further details.
+ *
+ * @_iommu_mr: the #IOMMUMemoryRegion to be initialized
+ * @instance_size: the IOMMUMemoryRegion subclass instance size
+ * @mrtypename: the type name of the #IOMMUMemoryRegion
+ * @owner: the object that tracks the region's reference count
+ * @name: used for debugging; not visible to the user or ABI
+ * @size: size of the region.
+ */
+void memory_region_init_iommu(void *_iommu_mr,
+                              size_t instance_size,
+                              const char *mrtypename,
+                              Object *owner,
+                              const char *name,
+                              uint64_t size);
+
+/**
+ * memory_region_init_ram - Initialize RAM memory region.  Accesses into the
+ *                          region will modify memory directly.
+ *
+ * @mr: the #MemoryRegion to be initialized
+ * @owner: the object that tracks the region's reference count (must be
+ *         TYPE_DEVICE or a subclass of TYPE_DEVICE, or NULL)
+ * @name: name of the memory region
+ * @size: size of the region in bytes
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * This function allocates RAM for a board model or device, and
+ * arranges for it to be migrated (by calling vmstate_register_ram()
+ * if @owner is a DeviceState, or vmstate_register_ram_global() if
+ * @owner is NULL).
+ *
+ * TODO: Currently we restrict @owner to being either NULL (for
+ * global RAM regions with no owner) or devices, so that we can
+ * give the RAM block a unique name for migration purposes.
+ * We should lift this restriction and allow arbitrary Objects.
+ * If you pass a non-NULL non-device @owner then we will assert.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_ram(MemoryRegion *mr,
+                            Object *owner,
+                            const char *name,
+                            uint64_t size,
+                            Error **errp);
+
+bool memory_region_init_ram_guest_memfd(MemoryRegion *mr,
+                                        Object *owner,
+                                        const char *name,
+                                        uint64_t size,
+                                        Error **errp);
+
+/**
+ * memory_region_init_rom: Initialize a ROM memory region.
+ *
+ * This has the same effect as calling memory_region_init_ram()
+ * and then marking the resulting region read-only with
+ * memory_region_set_readonly(). This includes arranging for the
+ * contents to be migrated.
+ *
+ * TODO: Currently we restrict @owner to being either NULL (for
+ * global RAM regions with no owner) or devices, so that we can
+ * give the RAM block a unique name for migration purposes.
+ * We should lift this restriction and allow arbitrary Objects.
+ * If you pass a non-NULL non-device @owner then we will assert.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_rom(MemoryRegion *mr,
+                            Object *owner,
+                            const char *name,
+                            uint64_t size,
+                            Error **errp);
+
+/**
+ * memory_region_init_rom_device:  Initialize a ROM memory region.
+ *                                 Writes are handled via callbacks.
+ *
+ * This function initializes a memory region backed by RAM for reads
+ * and callbacks for writes, and arranges for the RAM backing to
+ * be migrated (by calling vmstate_register_ram()
+ * if @owner is a DeviceState, or vmstate_register_ram_global() if
+ * @owner is NULL).
+ *
+ * TODO: Currently we restrict @owner to being either NULL (for
+ * global RAM regions with no owner) or devices, so that we can
+ * give the RAM block a unique name for migration purposes.
+ * We should lift this restriction and allow arbitrary Objects.
+ * If you pass a non-NULL non-device @owner then we will assert.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @ops: callbacks for write access handling (must not be NULL).
+ * @opaque: passed to the read and write callbacks of the @ops structure.
+ * @name: Region name, becomes part of RAMBlock name used in migration stream
+ *        must be unique within any device
+ * @size: size of the region.
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_region_init_rom_device(MemoryRegion *mr,
+                                   Object *owner,
+                                   const MemoryRegionOps *ops,
+                                   void *opaque,
+                                   const char *name,
+                                   uint64_t size,
+                                   Error **errp);
+
+
+/**
+ * memory_region_owner: get a memory region's owner.
+ *
+ * @mr: the memory region being queried.
+ */
+Object *memory_region_owner(MemoryRegion *mr);
+
+/**
+ * memory_region_size: get a memory region's size.
+ *
+ * @mr: the memory region being queried.
+ */
+uint64_t memory_region_size(MemoryRegion *mr);
+
+/**
+ * memory_region_is_ram: check whether a memory region is random access
+ *
+ * Returns %true if a memory region is random access.
+ *
+ * @mr: the memory region being queried
+ */
+static inline bool memory_region_is_ram(MemoryRegion *mr)
+{
+    return mr->ram;
+}
+
+/**
+ * memory_region_is_ram_device: check whether a memory region is a ram device
+ *
+ * Returns %true if a memory region is a device backed ram region
+ *
+ * @mr: the memory region being queried
+ */
+bool memory_region_is_ram_device(MemoryRegion *mr);
+
+/**
+ * memory_region_is_romd: check whether a memory region is in ROMD mode
+ *
+ * Returns %true if a memory region is a ROM device and currently set to allow
+ * direct reads.
+ *
+ * @mr: the memory region being queried
+ */
+static inline bool memory_region_is_romd(MemoryRegion *mr)
+{
+    return mr->rom_device && mr->romd_mode;
+}
+
+/**
+ * memory_region_is_protected: check whether a memory region is protected
+ *
+ * Returns %true if a memory region is protected RAM and cannot be accessed
+ * via standard mechanisms, e.g. DMA.
+ *
+ * @mr: the memory region being queried
+ */
+bool memory_region_is_protected(MemoryRegion *mr);
+
+/**
+ * memory_region_has_guest_memfd: check whether a memory region has guest_memfd
+ *     associated
+ *
+ * Returns %true if a memory region's ram_block has valid guest_memfd assigned.
+ *
+ * @mr: the memory region being queried
+ */
+bool memory_region_has_guest_memfd(MemoryRegion *mr);
+
+/**
+ * memory_region_get_iommu: check whether a memory region is an iommu
+ *
+ * Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
+ * otherwise NULL.
+ *
+ * @mr: the memory region being queried
+ */
+static inline IOMMUMemoryRegion *memory_region_get_iommu(MemoryRegion *mr)
+{
+    if (mr->alias) {
+        return memory_region_get_iommu(mr->alias);
+    }
+    if (mr->is_iommu) {
+        return (IOMMUMemoryRegion *) mr;
+    }
+    return NULL;
+}
+
+/**
+ * memory_region_get_iommu_class_nocheck: returns iommu memory region class
+ *   if an iommu or NULL if not
+ *
+ * Returns pointer to IOMMUMemoryRegionClass if a memory region is an iommu,
+ * otherwise NULL. This is fast path avoiding QOM checking, use with caution.
+ *
+ * @iommu_mr: the memory region being queried
+ */
+static inline IOMMUMemoryRegionClass *memory_region_get_iommu_class_nocheck(
+        IOMMUMemoryRegion *iommu_mr)
+{
+    return (IOMMUMemoryRegionClass *) (((Object *)iommu_mr)->class);
+}
+
+#define memory_region_is_iommu(mr) (memory_region_get_iommu(mr) != NULL)
+
+/**
+ * memory_region_iommu_get_min_page_size: get minimum supported page size
+ * for an iommu
+ *
+ * Returns minimum supported page size for an iommu.
+ *
+ * @iommu_mr: the memory region being queried
+ */
+uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr);
+
+/**
+ * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
+ *
+ * Note: for any IOMMU implementation, an in-place mapping change
+ * should be notified with an UNMAP followed by a MAP.
+ *
+ * @iommu_mr: the memory region that was changed
+ * @iommu_idx: the IOMMU index for the translation table which has changed
+ * @event: TLB event with the new entry in the IOMMU translation table.
+ *         The entry replaces all old entries for the same virtual I/O address
+ *         range.
+ */
+void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
+                                int iommu_idx,
+                                const IOMMUTLBEvent event);
+
+/**
+ * memory_region_notify_iommu_one: notify a change in an IOMMU translation
+ *                           entry to a single notifier
+ *
+ * This works just like memory_region_notify_iommu(), but it only
+ * notifies a specific notifier, not all of them.
+ *
+ * @notifier: the notifier to be notified
+ * @event: TLB event with the new entry in the IOMMU translation table.
+ *         The entry replaces all old entries for the same virtual I/O address
+ *         range.
+ */
+void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
+                                    const IOMMUTLBEvent *event);
+
+/**
+ * memory_region_unmap_iommu_notifier_range: notify a unmap for an IOMMU
+ *                                           translation that covers the
+ *                                           range of a notifier
+ *
+ * @notifier: the notifier to be notified
+ */
+void memory_region_unmap_iommu_notifier_range(IOMMUNotifier *notifier);
+
+
+/**
+ * memory_region_register_iommu_notifier: register a notifier for changes to
+ * IOMMU translation entries.
+ *
+ * Returns 0 on success, or a negative errno otherwise. In particular,
+ * -EINVAL indicates that at least one of the attributes of the notifier
+ * is not supported (flag/range) by the IOMMU memory region. In case of error
+ * the error object must be created.
+ *
+ * @mr: the memory region to observe
+ * @n: the IOMMUNotifier to be added; the notify callback receives a
+ *     pointer to an #IOMMUTLBEntry as the opaque value; the pointer
+ *     ceases to be valid on exit from the notifier.
+ * @errp: pointer to Error*, to store an error if it happens.
+ */
+int memory_region_register_iommu_notifier(MemoryRegion *mr,
+                                          IOMMUNotifier *n, Error **errp);
+
+/**
+ * memory_region_iommu_replay: replay existing IOMMU translations to
+ * a notifier with the minimum page granularity returned by
+ * mr->iommu_ops->get_page_size().
+ *
+ * Note: this is not related to record-and-replay functionality.
+ *
+ * @iommu_mr: the memory region to observe
+ * @n: the notifier to which to replay iommu mappings
+ */
+void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n);
+
+/**
+ * memory_region_unregister_iommu_notifier: unregister a notifier for
+ * changes to IOMMU translation entries.
+ *
+ * @mr: the memory region which was observed and for which notify_stopped()
+ *      needs to be called
+ * @n: the notifier to be removed.
+ */
+void memory_region_unregister_iommu_notifier(MemoryRegion *mr,
+                                             IOMMUNotifier *n);
+
+/**
+ * memory_region_iommu_get_attr: return an IOMMU attr if get_attr() is
+ * defined on the IOMMU.
+ *
+ * Returns 0 on success, or a negative errno otherwise. In particular,
+ * -EINVAL indicates that the IOMMU does not support the requested
+ * attribute.
+ *
+ * @iommu_mr: the memory region
+ * @attr: the requested attribute
+ * @data: a pointer to the requested attribute data
+ */
+int memory_region_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
+                                 enum IOMMUMemoryRegionAttr attr,
+                                 void *data);
+
+/**
+ * memory_region_iommu_attrs_to_index: return the IOMMU index to
+ * use for translations with the given memory transaction attributes.
+ *
+ * @iommu_mr: the memory region
+ * @attrs: the memory transaction attributes
+ */
+int memory_region_iommu_attrs_to_index(IOMMUMemoryRegion *iommu_mr,
+                                       MemTxAttrs attrs);
+
+/**
+ * memory_region_iommu_num_indexes: return the total number of IOMMU
+ * indexes that this IOMMU supports.
+ *
+ * @iommu_mr: the memory region
+ */
+int memory_region_iommu_num_indexes(IOMMUMemoryRegion *iommu_mr);
+
+/**
+ * memory_region_name: get a memory region's name
+ *
+ * Returns the string that was used to initialize the memory region.
+ *
+ * @mr: the memory region being queried
+ */
+const char *memory_region_name(const MemoryRegion *mr);
+
+/**
+ * memory_region_is_logging: return whether a memory region is logging writes
+ *
+ * Returns %true if the memory region is logging writes for the given client
+ *
+ * @mr: the memory region being queried
+ * @client: the client being queried
+ */
+bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
+
+/**
+ * memory_region_get_dirty_log_mask: return the clients for which a
+ * memory region is logging writes.
+ *
+ * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
+ * are the bit indices.
+ *
+ * @mr: the memory region being queried
+ */
+uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
+
+/**
+ * memory_region_is_rom: check whether a memory region is ROM
+ *
+ * Returns %true if a memory region is read-only memory.
+ *
+ * @mr: the memory region being queried
+ */
+static inline bool memory_region_is_rom(MemoryRegion *mr)
+{
+    return mr->ram && mr->readonly;
+}
+
+/**
+ * memory_region_is_nonvolatile: check whether a memory region is non-volatile
+ *
+ * Returns %true is a memory region is non-volatile memory.
+ *
+ * @mr: the memory region being queried
+ */
+static inline bool memory_region_is_nonvolatile(MemoryRegion *mr)
+{
+    return mr->nonvolatile;
+}
+
+/**
+ * memory_region_get_fd: Get a file descriptor backing a RAM memory region.
+ *
+ * Returns a file descriptor backing a file-based RAM memory region,
+ * or -1 if the region is not a file-based RAM memory region.
+ *
+ * @mr: the RAM or alias memory region being queried.
+ */
+int memory_region_get_fd(MemoryRegion *mr);
+
+/**
+ * memory_region_from_host: Convert a pointer into a RAM memory region
+ * and an offset within it.
+ *
+ * Given a host pointer inside a RAM memory region (created with
+ * memory_region_init_ram() or memory_region_init_ram_ptr()), return
+ * the MemoryRegion and the offset within it.
+ *
+ * Use with care; by the time this function returns, the returned pointer is
+ * not protected by RCU anymore.  If the caller is not within an RCU critical
+ * section and does not hold the BQL, it must have other means of
+ * protecting the pointer, such as a reference to the region that includes
+ * the incoming ram_addr_t.
+ *
+ * @ptr: the host pointer to be converted
+ * @offset: the offset within memory region
+ */
+MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
+
+/**
+ * memory_region_get_ram_ptr: Get a pointer into a RAM memory region.
+ *
+ * Returns a host pointer to a RAM memory region (created with
+ * memory_region_init_ram() or memory_region_init_ram_ptr()).
+ *
+ * Use with care; by the time this function returns, the returned pointer is
+ * not protected by RCU anymore.  If the caller is not within an RCU critical
+ * section and does not hold the BQL, it must have other means of
+ * protecting the pointer, such as a reference to the region that includes
+ * the incoming ram_addr_t.
+ *
+ * @mr: the memory region being queried.
+ */
+void *memory_region_get_ram_ptr(MemoryRegion *mr);
+
+/* memory_region_ram_resize: Resize a RAM region.
+ *
+ * Resizing RAM while migrating can result in the migration being canceled.
+ * Care has to be taken if the guest might have already detected the memory.
+ *
+ * @mr: a memory region created with @memory_region_init_resizeable_ram.
+ * @newsize: the new size the region
+ * @errp: pointer to Error*, to store an error if it happens.
+ */
+void memory_region_ram_resize(MemoryRegion *mr, ram_addr_t newsize,
+                              Error **errp);
+
+/**
+ * memory_region_msync: Synchronize selected address range of
+ * a memory mapped region
+ *
+ * @mr: the memory region to be msync
+ * @addr: the initial address of the range to be sync
+ * @size: the size of the range to be sync
+ */
+void memory_region_msync(MemoryRegion *mr, hwaddr addr, hwaddr size);
+
+/**
+ * memory_region_writeback: Trigger cache writeback for
+ * selected address range
+ *
+ * @mr: the memory region to be updated
+ * @addr: the initial address of the range to be written back
+ * @size: the size of the range to be written back
+ */
+void memory_region_writeback(MemoryRegion *mr, hwaddr addr, hwaddr size);
+
+/**
+ * memory_region_set_log: Turn dirty logging on or off for a region.
+ *
+ * Turns dirty logging on or off for a specified client (display, migration).
+ * Only meaningful for RAM regions.
+ *
+ * @mr: the memory region being updated.
+ * @log: whether dirty logging is to be enabled or disabled.
+ * @client: the user of the logging information; %DIRTY_MEMORY_VGA only.
+ */
+void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client);
+
+/**
+ * memory_region_set_dirty: Mark a range of bytes as dirty in a memory region.
+ *
+ * Marks a range of bytes as dirty, after it has been dirtied outside
+ * guest code.
+ *
+ * @mr: the memory region being dirtied.
+ * @addr: the address (relative to the start of the region) being dirtied.
+ * @size: size of the range being dirtied.
+ */
+void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr,
+                             hwaddr size);
+
+/**
+ * memory_region_clear_dirty_bitmap - clear dirty bitmap for memory range
+ *
+ * This function is called when the caller wants to clear the remote
+ * dirty bitmap of a memory range within the memory region.  This can
+ * be used by e.g. KVM to manually clear dirty log when
+ * KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is declared support by the host
+ * kernel.
+ *
+ * @mr:     the memory region to clear the dirty log upon
+ * @start:  start address offset within the memory region
+ * @len:    length of the memory region to clear dirty bitmap
+ */
+void memory_region_clear_dirty_bitmap(MemoryRegion *mr, hwaddr start,
+                                      hwaddr len);
+
+/**
+ * memory_region_snapshot_and_clear_dirty: Get a snapshot of the dirty
+ *                                         bitmap and clear it.
+ *
+ * Creates a snapshot of the dirty bitmap, clears the dirty bitmap and
+ * returns the snapshot.  The snapshot can then be used to query dirty
+ * status, using memory_region_snapshot_get_dirty.  Snapshotting allows
+ * querying the same page multiple times, which is especially useful for
+ * display updates where the scanlines often are not page aligned.
+ *
+ * The dirty bitmap region which gets copied into the snapshot (and
+ * cleared afterwards) can be larger than requested.  The boundaries
+ * are rounded up/down so complete bitmap longs (covering 64 pages on
+ * 64bit hosts) can be copied over into the bitmap snapshot.  Which
+ * isn't a problem for display updates as the extra pages are outside
+ * the visible area, and in case the visible area changes a full
+ * display redraw is due anyway.  Should other use cases for this
+ * function emerge we might have to revisit this implementation
+ * detail.
+ *
+ * Use g_free to release DirtyBitmapSnapshot.
+ *
+ * @mr: the memory region being queried.
+ * @addr: the address (relative to the start of the region) being queried.
+ * @size: the size of the range being queried.
+ * @client: the user of the logging information; typically %DIRTY_MEMORY_VGA.
+ */
+DirtyBitmapSnapshot *memory_region_snapshot_and_clear_dirty(MemoryRegion *mr,
+                                                            hwaddr addr,
+                                                            hwaddr size,
+                                                            unsigned client);
+
+/**
+ * memory_region_snapshot_get_dirty: Check whether a range of bytes is dirty
+ *                                   in the specified dirty bitmap snapshot.
+ *
+ * @mr: the memory region being queried.
+ * @snap: the dirty bitmap snapshot
+ * @addr: the address (relative to the start of the region) being queried.
+ * @size: the size of the range being queried.
+ */
+bool memory_region_snapshot_get_dirty(MemoryRegion *mr,
+                                      DirtyBitmapSnapshot *snap,
+                                      hwaddr addr, hwaddr size);
+
+/**
+ * memory_region_reset_dirty: Mark a range of pages as clean, for a specified
+ *                            client.
+ *
+ * Marks a range of pages as no longer dirty.
+ *
+ * @mr: the region being updated.
+ * @addr: the start of the subrange being cleaned.
+ * @size: the size of the subrange being cleaned.
+ * @client: the user of the logging information; %DIRTY_MEMORY_MIGRATION or
+ *          %DIRTY_MEMORY_VGA.
+ */
+void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr,
+                               hwaddr size, unsigned client);
+
+/**
+ * memory_region_flush_rom_device: Mark a range of pages dirty and invalidate
+ *                                 TBs (for self-modifying code).
+ *
+ * The MemoryRegionOps->write() callback of a ROM device must use this function
+ * to mark byte ranges that have been modified internally, such as by directly
+ * accessing the memory returned by memory_region_get_ram_ptr().
+ *
+ * This function marks the range dirty and invalidates TBs so that TCG can
+ * detect self-modifying code.
+ *
+ * @mr: the region being flushed.
+ * @addr: the start, relative to the start of the region, of the range being
+ *        flushed.
+ * @size: the size, in bytes, of the range being flushed.
+ */
+void memory_region_flush_rom_device(MemoryRegion *mr, hwaddr addr, hwaddr size);
+
+/**
+ * memory_region_set_readonly: Turn a memory region read-only (or read-write)
+ *
+ * Allows a memory region to be marked as read-only (turning it into a ROM).
+ * only useful on RAM regions.
+ *
+ * @mr: the region being updated.
+ * @readonly: whether the region is to be ROM or RAM.
+ */
+void memory_region_set_readonly(MemoryRegion *mr, bool readonly);
+
+/**
+ * memory_region_set_nonvolatile: Turn a memory region non-volatile
+ *
+ * Allows a memory region to be marked as non-volatile.
+ * only useful on RAM regions.
+ *
+ * @mr: the region being updated.
+ * @nonvolatile: whether the region is to be non-volatile.
+ */
+void memory_region_set_nonvolatile(MemoryRegion *mr, bool nonvolatile);
+
+/**
+ * memory_region_rom_device_set_romd: enable/disable ROMD mode
+ *
+ * Allows a ROM device (initialized with memory_region_init_rom_device() to
+ * set to ROMD mode (default) or MMIO mode.  When it is in ROMD mode, the
+ * device is mapped to guest memory and satisfies read access directly.
+ * When in MMIO mode, reads are forwarded to the #MemoryRegion.read function.
+ * Writes are always handled by the #MemoryRegion.write function.
+ *
+ * @mr: the memory region to be updated
+ * @romd_mode: %true to put the region into ROMD mode
+ */
+void memory_region_rom_device_set_romd(MemoryRegion *mr, bool romd_mode);
+
+/**
+ * memory_region_set_coalescing: Enable memory coalescing for the region.
+ *
+ * Enabled writes to a region to be queued for later processing. MMIO ->write
+ * callbacks may be delayed until a non-coalesced MMIO is issued.
+ * Only useful for IO regions.  Roughly similar to write-combining hardware.
+ *
+ * @mr: the memory region to be write coalesced
+ */
+void memory_region_set_coalescing(MemoryRegion *mr);
+
+/**
+ * memory_region_add_coalescing: Enable memory coalescing for a sub-range of
+ *                               a region.
+ *
+ * Like memory_region_set_coalescing(), but works on a sub-range of a region.
+ * Multiple calls can be issued coalesced disjoint ranges.
+ *
+ * @mr: the memory region to be updated.
+ * @offset: the start of the range within the region to be coalesced.
+ * @size: the size of the subrange to be coalesced.
+ */
+void memory_region_add_coalescing(MemoryRegion *mr,
+                                  hwaddr offset,
+                                  uint64_t size);
+
+/**
+ * memory_region_clear_coalescing: Disable MMIO coalescing for the region.
+ *
+ * Disables any coalescing caused by memory_region_set_coalescing() or
+ * memory_region_add_coalescing().  Roughly equivalent to uncacheble memory
+ * hardware.
+ *
+ * @mr: the memory region to be updated.
+ */
+void memory_region_clear_coalescing(MemoryRegion *mr);
+
+/**
+ * memory_region_set_flush_coalesced: Enforce memory coalescing flush before
+ *                                    accesses.
+ *
+ * Ensure that pending coalesced MMIO request are flushed before the memory
+ * region is accessed. This property is automatically enabled for all regions
+ * passed to memory_region_set_coalescing() and memory_region_add_coalescing().
+ *
+ * @mr: the memory region to be updated.
+ */
+void memory_region_set_flush_coalesced(MemoryRegion *mr);
+
+/**
+ * memory_region_clear_flush_coalesced: Disable memory coalescing flush before
+ *                                      accesses.
+ *
+ * Clear the automatic coalesced MMIO flushing enabled via
+ * memory_region_set_flush_coalesced. Note that this service has no effect on
+ * memory regions that have MMIO coalescing enabled for themselves. For them,
+ * automatic flushing will stop once coalescing is disabled.
+ *
+ * @mr: the memory region to be updated.
+ */
+void memory_region_clear_flush_coalesced(MemoryRegion *mr);
+
+/**
+ * memory_region_add_eventfd: Request an eventfd to be triggered when a word
+ *                            is written to a location.
+ *
+ * Marks a word in an IO region (initialized with memory_region_init_io())
+ * as a trigger for an eventfd event.  The I/O callback will not be called.
+ * The caller must be prepared to handle failure (that is, take the required
+ * action if the callback _is_ called).
+ *
+ * @mr: the memory region being updated.
+ * @addr: the address within @mr that is to be monitored
+ * @size: the size of the access to trigger the eventfd
+ * @match_data: whether to match against @data, instead of just @addr
+ * @data: the data to match against the guest write
+ * @e: event notifier to be triggered when @addr, @size, and @data all match.
+ **/
+void memory_region_add_eventfd(MemoryRegion *mr,
+                               hwaddr addr,
+                               unsigned size,
+                               bool match_data,
+                               uint64_t data,
+                               EventNotifier *e);
+
+/**
+ * memory_region_del_eventfd: Cancel an eventfd.
+ *
+ * Cancels an eventfd trigger requested by a previous
+ * memory_region_add_eventfd() call.
+ *
+ * @mr: the memory region being updated.
+ * @addr: the address within @mr that is to be monitored
+ * @size: the size of the access to trigger the eventfd
+ * @match_data: whether to match against @data, instead of just @addr
+ * @data: the data to match against the guest write
+ * @e: event notifier to be triggered when @addr, @size, and @data all match.
+ */
+void memory_region_del_eventfd(MemoryRegion *mr,
+                               hwaddr addr,
+                               unsigned size,
+                               bool match_data,
+                               uint64_t data,
+                               EventNotifier *e);
+
+/**
+ * memory_region_add_subregion: Add a subregion to a container.
+ *
+ * Adds a subregion at @offset.  The subregion may not overlap with other
+ * subregions (except for those explicitly marked as overlapping).  A region
+ * may only be added once as a subregion (unless removed with
+ * memory_region_del_subregion()); use memory_region_init_alias() if you
+ * want a region to be a subregion in multiple locations.
+ *
+ * @mr: the region to contain the new subregion; must be a container
+ *      initialized with memory_region_init().
+ * @offset: the offset relative to @mr where @subregion is added.
+ * @subregion: the subregion to be added.
+ */
+void memory_region_add_subregion(MemoryRegion *mr,
+                                 hwaddr offset,
+                                 MemoryRegion *subregion);
+/**
+ * memory_region_add_subregion_overlap: Add a subregion to a container
+ *                                      with overlap.
+ *
+ * Adds a subregion at @offset.  The subregion may overlap with other
+ * subregions.  Conflicts are resolved by having a higher @priority hide a
+ * lower @priority. Subregions without priority are taken as @priority 0.
+ * A region may only be added once as a subregion (unless removed with
+ * memory_region_del_subregion()); use memory_region_init_alias() if you
+ * want a region to be a subregion in multiple locations.
+ *
+ * @mr: the region to contain the new subregion; must be a container
+ *      initialized with memory_region_init().
+ * @offset: the offset relative to @mr where @subregion is added.
+ * @subregion: the subregion to be added.
+ * @priority: used for resolving overlaps; highest priority wins.
+ */
+void memory_region_add_subregion_overlap(MemoryRegion *mr,
+                                         hwaddr offset,
+                                         MemoryRegion *subregion,
+                                         int priority);
+
+/**
+ * memory_region_get_ram_addr: Get the ram address associated with a memory
+ *                             region
+ *
+ * @mr: the region to be queried
+ */
+ram_addr_t memory_region_get_ram_addr(MemoryRegion *mr);
+
+uint64_t memory_region_get_alignment(const MemoryRegion *mr);
+/**
+ * memory_region_del_subregion: Remove a subregion.
+ *
+ * Removes a subregion from its container.
+ *
+ * @mr: the container to be updated.
+ * @subregion: the region being removed; must be a current subregion of @mr.
+ */
+void memory_region_del_subregion(MemoryRegion *mr,
+                                 MemoryRegion *subregion);
+
+/*
+ * memory_region_set_enabled: dynamically enable or disable a region
+ *
+ * Enables or disables a memory region.  A disabled memory region
+ * ignores all accesses to itself and its subregions.  It does not
+ * obscure sibling subregions with lower priority - it simply behaves as
+ * if it was removed from the hierarchy.
+ *
+ * Regions default to being enabled.
+ *
+ * @mr: the region to be updated
+ * @enabled: whether to enable or disable the region
+ */
+void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
+
+/*
+ * memory_region_set_address: dynamically update the address of a region
+ *
+ * Dynamically updates the address of a region, relative to its container.
+ * May be used on regions are currently part of a memory hierarchy.
+ *
+ * @mr: the region to be updated
+ * @addr: new address, relative to container region
+ */
+void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
+
+/*
+ * memory_region_set_size: dynamically update the size of a region.
+ *
+ * Dynamically updates the size of a region.
+ *
+ * @mr: the region to be updated
+ * @size: used size of the region.
+ */
+void memory_region_set_size(MemoryRegion *mr, uint64_t size);
+
+/*
+ * memory_region_set_alias_offset: dynamically update a memory alias's offset
+ *
+ * Dynamically updates the offset into the target region that an alias points
+ * to, as if the fourth argument to memory_region_init_alias() has changed.
+ *
+ * @mr: the #MemoryRegion to be updated; should be an alias.
+ * @offset: the new offset into the target memory region
+ */
+void memory_region_set_alias_offset(MemoryRegion *mr,
+                                    hwaddr offset);
+
+/*
+ * memory_region_set_unmergeable: Set a memory region unmergeable
+ *
+ * Mark a memory region unmergeable, resulting in the memory region (or
+ * everything contained in a memory region container) not getting merged when
+ * simplifying the address space and notifying memory listeners. Consequently,
+ * memory listeners will never get notified about ranges that are larger than
+ * the original memory regions.
+ *
+ * This is primarily useful when multiple aliases to a RAM memory region are
+ * mapped into a memory region container, and updates (e.g., enable/disable or
+ * map/unmap) of individual memory region aliases are not supposed to affect
+ * other memory regions in the same container.
+ *
+ * @mr: the #MemoryRegion to be updated
+ * @unmergeable: whether to mark the #MemoryRegion unmergeable
+ */
+void memory_region_set_unmergeable(MemoryRegion *mr, bool unmergeable);
+
+/**
+ * memory_region_present: checks if an address relative to a @container
+ * translates into #MemoryRegion within @container
+ *
+ * Answer whether a #MemoryRegion within @container covers the address
+ * @addr.
+ *
+ * @container: a #MemoryRegion within which @addr is a relative address
+ * @addr: the area within @container to be searched
+ */
+bool memory_region_present(MemoryRegion *container, hwaddr addr);
+
+/**
+ * memory_region_is_mapped: returns true if #MemoryRegion is mapped
+ * into another memory region, which does not necessarily imply that it is
+ * mapped into an address space.
+ *
+ * @mr: a #MemoryRegion which should be checked if it's mapped
+ */
+bool memory_region_is_mapped(MemoryRegion *mr);
+
+/**
+ * memory_region_get_ram_discard_manager: get the #RamDiscardManager for a
+ * #MemoryRegion
+ *
+ * The #RamDiscardManager cannot change while a memory region is mapped.
+ *
+ * @mr: the #MemoryRegion
+ */
+RamDiscardManager *memory_region_get_ram_discard_manager(MemoryRegion *mr);
+
+/**
+ * memory_region_has_ram_discard_manager: check whether a #MemoryRegion has a
+ * #RamDiscardManager assigned
+ *
+ * @mr: the #MemoryRegion
+ */
+static inline bool memory_region_has_ram_discard_manager(MemoryRegion *mr)
+{
+    return !!memory_region_get_ram_discard_manager(mr);
+}
+
+/**
+ * memory_region_set_ram_discard_manager: set the #RamDiscardManager for a
+ * #MemoryRegion
+ *
+ * This function must not be called for a mapped #MemoryRegion, a #MemoryRegion
+ * that does not cover RAM, or a #MemoryRegion that already has a
+ * #RamDiscardManager assigned.
+ *
+ * @mr: the #MemoryRegion
+ * @rdm: #RamDiscardManager to set
+ */
+void memory_region_set_ram_discard_manager(MemoryRegion *mr,
+                                           RamDiscardManager *rdm);
+
+/**
+ * memory_region_find: translate an address/size relative to a
+ * MemoryRegion into a #MemoryRegionSection.
+ *
+ * Locates the first #MemoryRegion within @mr that overlaps the range
+ * given by @addr and @size.
+ *
+ * Returns a #MemoryRegionSection that describes a contiguous overlap.
+ * It will have the following characteristics:
+ * - @size = 0 iff no overlap was found
+ * - @mr is non-%NULL iff an overlap was found
+ *
+ * Remember that in the return value the @offset_within_region is
+ * relative to the returned region (in the .@mr field), not to the
+ * @mr argument.
+ *
+ * Similarly, the .@offset_within_address_space is relative to the
+ * address space that contains both regions, the passed and the
+ * returned one.  However, in the special case where the @mr argument
+ * has no container (and thus is the root of the address space), the
+ * following will hold:
+ * - @offset_within_address_space >= @addr
+ * - @offset_within_address_space + .@size <= @addr + @size
+ *
+ * @mr: a MemoryRegion within which @addr is a relative address
+ * @addr: start of the area within @as to be searched
+ * @size: size of the area to be searched
+ */
+MemoryRegionSection memory_region_find(MemoryRegion *mr,
+                                       hwaddr addr, uint64_t size);
+
+/**
+ * memory_global_dirty_log_sync: synchronize the dirty log for all memory
+ *
+ * Synchronizes the dirty page log for all address spaces.
+ *
+ * @last_stage: whether this is the last stage of live migration
+ */
+void memory_global_dirty_log_sync(bool last_stage);
+
+/**
+ * memory_global_after_dirty_log_sync: synchronize the dirty log for all memory
+ *
+ * Synchronizes the vCPUs with a thread that is reading the dirty bitmap.
+ * This function must be called after the dirty log bitmap is cleared, and
+ * before dirty guest memory pages are read.  If you are using
+ * #DirtyBitmapSnapshot, memory_region_snapshot_and_clear_dirty() takes
+ * care of doing this.
+ */
+void memory_global_after_dirty_log_sync(void);
+
+/**
+ * memory_region_transaction_begin: Start a transaction.
+ *
+ * During a transaction, changes will be accumulated and made visible
+ * only when the transaction ends (is committed).
+ */
+void memory_region_transaction_begin(void);
+
+/**
+ * memory_region_transaction_commit: Commit a transaction and make changes
+ *                                   visible to the guest.
+ */
+void memory_region_transaction_commit(void);
+
+/**
+ * memory_listener_register: register callbacks to be called when memory
+ *                           sections are mapped or unmapped into an address
+ *                           space
+ *
+ * @listener: an object containing the callbacks to be called
+ * @filter: if non-%NULL, only regions in this address space will be observed
+ */
+void memory_listener_register(MemoryListener *listener, AddressSpace *filter);
+
+/**
+ * memory_listener_unregister: undo the effect of memory_listener_register()
+ *
+ * @listener: an object containing the callbacks to be removed
+ */
+void memory_listener_unregister(MemoryListener *listener);
+
+/**
+ * memory_global_dirty_log_start: begin dirty logging for all regions
+ *
+ * @flags: purpose of starting dirty log, migration or dirty rate
+ * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
+ */
+bool memory_global_dirty_log_start(unsigned int flags, Error **errp);
+
+/**
+ * memory_global_dirty_log_stop: end dirty logging for all regions
+ *
+ * @flags: purpose of stopping dirty log, migration or dirty rate
+ */
+void memory_global_dirty_log_stop(unsigned int flags);
+
+void mtree_info(bool flatview, bool dispatch_tree, bool owner, bool disabled);
+
+bool memory_region_access_valid(MemoryRegion *mr, hwaddr addr,
+                                unsigned size, bool is_write,
+                                MemTxAttrs attrs);
+
+/**
+ * memory_region_dispatch_read: perform a read directly to the specified
+ * MemoryRegion.
+ *
+ * @mr: #MemoryRegion to access
+ * @addr: address within that region
+ * @pval: pointer to uint64_t which the data is written to
+ * @op: size, sign, and endianness of the memory operation
+ * @attrs: memory transaction attributes to use for the access
+ */
+MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
+                                        hwaddr addr,
+                                        uint64_t *pval,
+                                        MemOp op,
+                                        MemTxAttrs attrs);
+/**
+ * memory_region_dispatch_write: perform a write directly to the specified
+ * MemoryRegion.
+ *
+ * @mr: #MemoryRegion to access
+ * @addr: address within that region
+ * @data: data to write
+ * @op: size, sign, and endianness of the memory operation
+ * @attrs: memory transaction attributes to use for the access
+ */
+MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
+                                         hwaddr addr,
+                                         uint64_t data,
+                                         MemOp op,
+                                         MemTxAttrs attrs);
+
+/**
+ * address_space_init: initializes an address space
+ *
+ * @as: an uninitialized #AddressSpace
+ * @root: a #MemoryRegion that routes addresses for the address space
+ * @name: an address space name.  The name is only used for debugging
+ *        output.
+ */
+void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
+
+/**
+ * address_space_destroy: destroy an address space
+ *
+ * Releases all resources associated with an address space.  After an address space
+ * is destroyed, its root memory region (given by address_space_init()) may be destroyed
+ * as well.
+ *
+ * @as: address space to be destroyed
+ */
+void address_space_destroy(AddressSpace *as);
+
+/**
+ * address_space_remove_listeners: unregister all listeners of an address space
+ *
+ * Removes all callbacks previously registered with memory_listener_register()
+ * for @as.
+ *
+ * @as: an initialized #AddressSpace
+ */
+void address_space_remove_listeners(AddressSpace *as);
+
+/**
+ * address_space_rw: read from or write to an address space.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @attrs: memory transaction attributes
+ * @buf: buffer with the data transferred
+ * @len: the number of bytes to read or write
+ * @is_write: indicates the transfer direction
+ */
+MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
+                             MemTxAttrs attrs, void *buf,
+                             hwaddr len, bool is_write);
+
+/**
+ * address_space_write: write to address space.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @attrs: memory transaction attributes
+ * @buf: buffer with the data transferred
+ * @len: the number of bytes to write
+ */
+MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
+                                MemTxAttrs attrs,
+                                const void *buf, hwaddr len);
+
+/**
+ * address_space_write_rom: write to address space, including ROM.
+ *
+ * This function writes to the specified address space, but will
+ * write data to both ROM and RAM. This is used for non-guest
+ * writes like writes from the gdb debug stub or initial loading
+ * of ROM contents.
+ *
+ * Note that portions of the write which attempt to write data to
+ * a device will be silently ignored -- only real RAM and ROM will
+ * be written to.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @attrs: memory transaction attributes
+ * @buf: buffer with the data transferred
+ * @len: the number of bytes to write
+ */
+MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
+                                    MemTxAttrs attrs,
+                                    const void *buf, hwaddr len);
+
+/* address_space_ld*: load from an address space
+ * address_space_st*: store to an address space
+ *
+ * These functions perform a load or store of the byte, word,
+ * longword or quad to the specified address within the AddressSpace.
+ * The _le suffixed functions treat the data as little endian;
+ * _be indicates big endian; no suffix indicates "same endianness
+ * as guest CPU".
+ *
+ * The "guest CPU endianness" accessors are deprecated for use outside
+ * target-* code; devices should be CPU-agnostic and use either the LE
+ * or the BE accessors.
+ *
+ * @as #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @val: data value, for stores
+ * @attrs: memory transaction attributes
+ * @result: location to write the success/failure of the transaction;
+ *   if NULL, this information is discarded
+ */
+
+#define SUFFIX
+#define ARG1         as
+#define ARG1_DECL    AddressSpace *as
+#include "exec/memory_ldst.h.inc"
+
+static inline void stl_phys_notdirty(AddressSpace *as, hwaddr addr, uint32_t val)
+{
+    address_space_stl_notdirty(as, addr, val,
+                               MEMTXATTRS_UNSPECIFIED, NULL);
+}
+
+#define SUFFIX
+#define ARG1         as
+#define ARG1_DECL    AddressSpace *as
+#include "exec/memory_ldst_phys.h.inc"
+
+struct MemoryRegionCache {
+    uint8_t *ptr;
+    hwaddr xlat;
+    hwaddr len;
+    FlatView *fv;
+    MemoryRegionSection mrs;
+    bool is_write;
+};
+
+/* address_space_ld*_cached: load from a cached #MemoryRegion
+ * address_space_st*_cached: store into a cached #MemoryRegion
+ *
+ * These functions perform a load or store of the byte, word,
+ * longword or quad to the specified address.  The address is
+ * a physical address in the AddressSpace, but it must lie within
+ * a #MemoryRegion that was mapped with address_space_cache_init.
+ *
+ * The _le suffixed functions treat the data as little endian;
+ * _be indicates big endian; no suffix indicates "same endianness
+ * as guest CPU".
+ *
+ * The "guest CPU endianness" accessors are deprecated for use outside
+ * target-* code; devices should be CPU-agnostic and use either the LE
+ * or the BE accessors.
+ *
+ * @cache: previously initialized #MemoryRegionCache to be accessed
+ * @addr: address within the address space
+ * @val: data value, for stores
+ * @attrs: memory transaction attributes
+ * @result: location to write the success/failure of the transaction;
+ *   if NULL, this information is discarded
+ */
+
+#define SUFFIX       _cached_slow
+#define ARG1         cache
+#define ARG1_DECL    MemoryRegionCache *cache
+#include "exec/memory_ldst.h.inc"
+
+/* Inline fast path for direct RAM access.  */
+static inline uint8_t address_space_ldub_cached(MemoryRegionCache *cache,
+    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
+{
+    assert(addr < cache->len);
+    if (likely(cache->ptr)) {
+        return ldub_p(cache->ptr + addr);
+    } else {
+        return address_space_ldub_cached_slow(cache, addr, attrs, result);
+    }
+}
+
+static inline void address_space_stb_cached(MemoryRegionCache *cache,
+    hwaddr addr, uint8_t val, MemTxAttrs attrs, MemTxResult *result)
+{
+    assert(addr < cache->len);
+    if (likely(cache->ptr)) {
+        stb_p(cache->ptr + addr, val);
+    } else {
+        address_space_stb_cached_slow(cache, addr, val, attrs, result);
+    }
+}
+
+#define ENDIANNESS
+#include "exec/memory_ldst_cached.h.inc"
+
+#define ENDIANNESS   _le
+#include "exec/memory_ldst_cached.h.inc"
+
+#define ENDIANNESS   _be
+#include "exec/memory_ldst_cached.h.inc"
+
+#define SUFFIX       _cached
+#define ARG1         cache
+#define ARG1_DECL    MemoryRegionCache *cache
+#include "exec/memory_ldst_phys.h.inc"
+
+/* address_space_cache_init: prepare for repeated access to a physical
+ * memory region
+ *
+ * @cache: #MemoryRegionCache to be filled
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @len: length of buffer
+ * @is_write: indicates the transfer direction
+ *
+ * Will only work with RAM, and may map a subset of the requested range by
+ * returning a value that is less than @len.  On failure, return a negative
+ * errno value.
+ *
+ * Because it only works with RAM, this function can be used for
+ * read-modify-write operations.  In this case, is_write should be %true.
+ *
+ * Note that addresses passed to the address_space_*_cached functions
+ * are relative to @addr.
+ */
+int64_t address_space_cache_init(MemoryRegionCache *cache,
+                                 AddressSpace *as,
+                                 hwaddr addr,
+                                 hwaddr len,
+                                 bool is_write);
+
+/**
+ * address_space_cache_init_empty: Initialize empty #MemoryRegionCache
+ *
+ * @cache: The #MemoryRegionCache to operate on.
+ *
+ * Initializes #MemoryRegionCache structure without memory region attached.
+ * Cache initialized this way can only be safely destroyed, but not used.
+ */
+static inline void address_space_cache_init_empty(MemoryRegionCache *cache)
+{
+    cache->mrs.mr = NULL;
+    /* There is no real need to initialize fv, but it makes Coverity happy. */
+    cache->fv = NULL;
+}
+
+/**
+ * address_space_cache_invalidate: complete a write to a #MemoryRegionCache
+ *
+ * @cache: The #MemoryRegionCache to operate on.
+ * @addr: The first physical address that was written, relative to the
+ * address that was passed to @address_space_cache_init.
+ * @access_len: The number of bytes that were written starting at @addr.
+ */
+void address_space_cache_invalidate(MemoryRegionCache *cache,
+                                    hwaddr addr,
+                                    hwaddr access_len);
+
+/**
+ * address_space_cache_destroy: free a #MemoryRegionCache
+ *
+ * @cache: The #MemoryRegionCache whose memory should be released.
+ */
+void address_space_cache_destroy(MemoryRegionCache *cache);
+
+/* address_space_get_iotlb_entry: translate an address into an IOTLB
+ * entry. Should be called from an RCU critical section.
+ */
+IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+                                            bool is_write, MemTxAttrs attrs);
+
+/* address_space_translate: translate an address range into an address space
+ * into a MemoryRegion and an address range into that section.  Should be
+ * called from an RCU critical section, to avoid that the last reference
+ * to the returned region disappears after address_space_translate returns.
+ *
+ * @fv: #FlatView to be accessed
+ * @addr: address within that address space
+ * @xlat: pointer to address within the returned memory region section's
+ * #MemoryRegion.
+ * @len: pointer to length
+ * @is_write: indicates the transfer direction
+ * @attrs: memory attributes
+ */
+MemoryRegion *flatview_translate(FlatView *fv,
+                                 hwaddr addr, hwaddr *xlat,
+                                 hwaddr *len, bool is_write,
+                                 MemTxAttrs attrs);
+
+static inline MemoryRegion *address_space_translate(AddressSpace *as,
+                                                    hwaddr addr, hwaddr *xlat,
+                                                    hwaddr *len, bool is_write,
+                                                    MemTxAttrs attrs)
+{
+    return flatview_translate(address_space_to_flatview(as),
+                              addr, xlat, len, is_write, attrs);
+}
+
+/* address_space_access_valid: check for validity of accessing an address
+ * space range
+ *
+ * Check whether memory is assigned to the given address space range, and
+ * access is permitted by any IOMMU regions that are active for the address
+ * space.
+ *
+ * For now, addr and len should be aligned to a page size.  This limitation
+ * will be lifted in the future.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @len: length of the area to be checked
+ * @is_write: indicates the transfer direction
+ * @attrs: memory attributes
+ */
+bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
+                                bool is_write, MemTxAttrs attrs);
+
+/* address_space_map: map a physical memory region into a host virtual address
+ *
+ * May map a subset of the requested range, given by and returned in @plen.
+ * May return %NULL and set *@plen to zero(0), if resources needed to perform
+ * the mapping are exhausted.
+ * Use only for reads OR writes - not for read-modify-write operations.
+ * Use address_space_register_map_client() to know when retrying the map
+ * operation is likely to succeed.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @plen: pointer to length of buffer; updated on return
+ * @is_write: indicates the transfer direction
+ * @attrs: memory attributes
+ */
+void *address_space_map(AddressSpace *as, hwaddr addr,
+                        hwaddr *plen, bool is_write, MemTxAttrs attrs);
+
+/* address_space_unmap: Unmaps a memory region previously mapped by address_space_map()
+ *
+ * Will also mark the memory as dirty if @is_write == %true.  @access_len gives
+ * the amount of memory that was actually read or written by the caller.
+ *
+ * @as: #AddressSpace used
+ * @buffer: host pointer as returned by address_space_map()
+ * @len: buffer length as returned by address_space_map()
+ * @access_len: amount of data actually transferred
+ * @is_write: indicates the transfer direction
+ */
+void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
+                         bool is_write, hwaddr access_len);
+
+/*
+ * address_space_register_map_client: Register a callback to invoke when
+ * resources for address_space_map() are available again.
+ *
+ * address_space_map may fail when there are not enough resources available,
+ * such as when bounce buffer memory would exceed the limit. The callback can
+ * be used to retry the address_space_map operation. Note that the callback
+ * gets automatically removed after firing.
+ *
+ * @as: #AddressSpace to be accessed
+ * @bh: callback to invoke when address_space_map() retry is appropriate
+ */
+void address_space_register_map_client(AddressSpace *as, QEMUBH *bh);
+
+/*
+ * address_space_unregister_map_client: Unregister a callback that has
+ * previously been registered and not fired yet.
+ *
+ * @as: #AddressSpace to be accessed
+ * @bh: callback to unregister
+ */
+void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh);
+
+/* Internal functions, part of the implementation of address_space_read.  */
+MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
+                                    MemTxAttrs attrs, void *buf, hwaddr len);
+MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
+                                   MemTxAttrs attrs, void *buf,
+                                   hwaddr len, hwaddr addr1, hwaddr l,
+                                   MemoryRegion *mr);
+void *qemu_map_ram_ptr(RAMBlock *ram_block, ram_addr_t addr);
+
+/* Internal functions, part of the implementation of address_space_read_cached
+ * and address_space_write_cached.  */
+MemTxResult address_space_read_cached_slow(MemoryRegionCache *cache,
+                                           hwaddr addr, void *buf, hwaddr len);
+MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
+                                            hwaddr addr, const void *buf,
+                                            hwaddr len);
+
+int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr);
+bool prepare_mmio_access(MemoryRegion *mr);
+
+static inline bool memory_region_supports_direct_access(MemoryRegion *mr)
+{
+    /* ROM DEVICE regions only allow direct access if in ROMD mode. */
+    if (memory_region_is_romd(mr)) {
+        return true;
+    }
+    if (!memory_region_is_ram(mr)) {
+        return false;
+    }
+    /*
+     * RAM DEVICE regions can be accessed directly using memcpy, but it might
+     * be MMIO and access using mempy can be wrong (e.g., using instructions not
+     * intended for MMIO access). So we treat this as IO.
+     */
+    return !memory_region_is_ram_device(mr);
+}
+
+static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write,
+                                           MemTxAttrs attrs)
+{
+    if (!memory_region_supports_direct_access(mr)) {
+        return false;
+    }
+    /* Debug access can write to ROM. */
+    if (is_write && !attrs.debug) {
+        return !mr->readonly && !mr->rom_device;
+    }
+    return true;
+}
+
+/**
+ * address_space_read: read from an address space.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).  Called within RCU critical section.
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @attrs: memory transaction attributes
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline __attribute__((__always_inline__))
+MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
+                               MemTxAttrs attrs, void *buf,
+                               hwaddr len)
+{
+    MemTxResult result = MEMTX_OK;
+    hwaddr l, addr1;
+    void *ptr;
+    MemoryRegion *mr;
+    FlatView *fv;
+
+    if (__builtin_constant_p(len)) {
+        if (len) {
+            RCU_READ_LOCK_GUARD();
+            fv = address_space_to_flatview(as);
+            l = len;
+            mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
+            if (len == l && memory_access_is_direct(mr, false, attrs)) {
+                ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
+                memcpy(buf, ptr, len);
+            } else {
+                result = flatview_read_continue(fv, addr, attrs, buf, len,
+                                                addr1, l, mr);
+            }
+        }
+    } else {
+        result = address_space_read_full(as, addr, attrs, buf, len);
+    }
+    return result;
+}
+
+/**
+ * address_space_read_cached: read from a cached RAM region
+ *
+ * @cache: Cached region to be addressed
+ * @addr: address relative to the base of the RAM region
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline MemTxResult
+address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
+                          void *buf, hwaddr len)
+{
+    assert(addr < cache->len && len <= cache->len - addr);
+    fuzz_dma_read_cb(cache->xlat + addr, len, cache->mrs.mr);
+    if (likely(cache->ptr)) {
+        memcpy(buf, cache->ptr + addr, len);
+        return MEMTX_OK;
+    } else {
+        return address_space_read_cached_slow(cache, addr, buf, len);
+    }
+}
+
+/**
+ * address_space_write_cached: write to a cached RAM region
+ *
+ * @cache: Cached region to be addressed
+ * @addr: address relative to the base of the RAM region
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline MemTxResult
+address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
+                           const void *buf, hwaddr len)
+{
+    assert(addr < cache->len && len <= cache->len - addr);
+    if (likely(cache->ptr)) {
+        memcpy(cache->ptr + addr, buf, len);
+        return MEMTX_OK;
+    } else {
+        return address_space_write_cached_slow(cache, addr, buf, len);
+    }
+}
+
+/**
+ * address_space_set: Fill address space with a constant byte.
+ *
+ * Return a MemTxResult indicating whether the operation succeeded
+ * or failed (eg unassigned memory, device rejected the transaction,
+ * IOMMU fault).
+ *
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @c: constant byte to fill the memory
+ * @len: the number of bytes to fill with the constant byte
+ * @attrs: memory transaction attributes
+ */
+MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+                              uint8_t c, hwaddr len, MemTxAttrs attrs);
+
+/*
+ * Inhibit technologies that require discarding of pages in RAM blocks, e.g.,
+ * to manage the actual amount of memory consumed by the VM (then, the memory
+ * provided by RAM blocks might be bigger than the desired memory consumption).
+ * This *must* be set if:
+ * - Discarding parts of a RAM blocks does not result in the change being
+ *   reflected in the VM and the pages getting freed.
+ * - All memory in RAM blocks is pinned or duplicated, invaldiating any previous
+ *   discards blindly.
+ * - Discarding parts of a RAM blocks will result in integrity issues (e.g.,
+ *   encrypted VMs).
+ * Technologies that only temporarily pin the current working set of a
+ * driver are fine, because we don't expect such pages to be discarded
+ * (esp. based on guest action like balloon inflation).
+ *
+ * This is *not* to be used to protect from concurrent discards (esp.,
+ * postcopy).
+ *
+ * Returns 0 if successful. Returns -EBUSY if a technology that relies on
+ * discards to work reliably is active.
+ */
+int ram_block_discard_disable(bool state);
+
+/*
+ * See ram_block_discard_disable(): only disable uncoordinated discards,
+ * keeping coordinated discards (via the RamDiscardManager) enabled.
+ */
+int ram_block_uncoordinated_discard_disable(bool state);
+
+/*
+ * Inhibit technologies that disable discarding of pages in RAM blocks.
+ *
+ * Returns 0 if successful. Returns -EBUSY if discards are already set to
+ * broken.
+ */
+int ram_block_discard_require(bool state);
+
+/*
+ * See ram_block_discard_require(): only inhibit technologies that disable
+ * uncoordinated discarding of pages in RAM blocks, allowing co-existence with
+ * technologies that only inhibit uncoordinated discards (via the
+ * RamDiscardManager).
+ */
+int ram_block_coordinated_discard_require(bool state);
+
+/*
+ * Test if any discarding of memory in ram blocks is disabled.
+ */
+bool ram_block_discard_is_disabled(void);
+
+/*
+ * Test if any discarding of memory in ram blocks is required to work reliably.
+ */
+bool ram_block_discard_is_required(void);
+
+void ram_block_add_cpr_blocker(RAMBlock *rb, Error **errp);
+void ram_block_del_cpr_blocker(RAMBlock *rb);
+
+#endif
diff --git a/include/system/vhost-user-backend.h b/include/system/vhost-user-backend.h
index 327b0b84f1..5ed953cd53 100644
--- a/include/system/vhost-user-backend.h
+++ b/include/system/vhost-user-backend.h
@@ -13,7 +13,7 @@
 #define QEMU_VHOST_USER_BACKEND_H
 
 #include "qom/object.h"
-#include "exec/memory.h"
+#include "system/memory.h"
 #include "qemu/option.h"
 #include "qemu/bitmap.h"
 #include "hw/virtio/vhost.h"