zircon/vdso/vmo.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library zx;

@transport("Syscall")
protocol Vmo {

    /// ## Summary
    ///
    /// Create a VM object.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_create(uint64_t size, uint32_t options, zx_handle_t* out);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_create()` creates a new, zero-filled, [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO), which represents a container of zero to
    /// *size* bytes of memory managed by the operating system.
    ///
    /// The size of the VMO will be rounded up to the next system page size boundary,
    /// as reported by [`zx_system_get_page_size()`]. Use [`zx_vmo_get_size()`] to
    /// return the current size of the VMO.
    ///
    /// The content size of the VMO will be initialized to the given (unrounded) size.
    /// Use [`zx_object_get_property()`] with **ZX_PROP_VMO_CONTENT_SIZE** to read the
    /// content size of the VMO. Use [`zx_object_set_property()`] with
    /// **ZX_PROP_VMO_CONTENT_SIZE** to set the content size of the VMO without
    /// actually resizing the VMO.
    ///
    /// One handle is returned on success, representing an object with the requested
    /// size.
    ///
    /// The following rights will be set on the handle by default:
    ///
    ///   - **ZX_RIGHT_DUPLICATE** - The handle may be duplicated.
    ///
    ///   - **ZX_RIGHT_TRANSFER** - The handle may be transferred to another process.
    ///
    ///   - **ZX_RIGHT_READ** - May be read from or mapped with read permissions.
    ///
    ///   - **ZX_RIGHT_WRITE** - May be written to or mapped with write permissions.
    ///
    ///   - **ZX_RIGHT_MAP** - May be mapped.
    ///
    ///   - **ZX_RIGHT_GET_PROPERTY** - May get its properties using [`zx_object_get_property()`].
    ///
    ///   - **ZX_RIGHT_SET_PROPERTY** - May set its properties using [`zx_object_set_property()`].
    ///
    ///   - **ZX_RIGHT_RESIZE** - May be resized. Only set if the **ZX_VMO_RESIZABLE** option was specified.
    ///
    /// The *options* field can be 0 or a combination of:
    ///
    ///   - **ZX_VMO_RESIZABLE** to create a VMO that can change size. Children of a non-resizable VMO can
    ///     be resized.
    ///
    ///   - **ZX_VMO_DISCARDABLE** to create a VMO that the kernel can discard pages from under memory
    ///     pressure. Use [`zx_vmo_op_range()`] with **ZX_VMO_OP_LOCK** to lock discardable VMOs when in
    ///     use, and unlock them when done with **ZX_VMO_OP_UNLOCK** making them eligible for reclamation by
    ///     the kernel. A newly created discardable VMO is initially unlocked.
    ///
    /// The **ZX_VMO_ZERO_CHILDREN** signal is active on a newly created VMO. It becomes
    /// inactive whenever a child of the VMO is created and becomes active again when
    /// all children have been destroyed and no mappings of those children into address
    /// spaces exist.
    ///
    /// ## Rights
    ///
    /// Caller job policy must allow **ZX_POL_NEW_VMO**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_create()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_INVALID_ARGS**  *out* is an invalid pointer or NULL or *options* is
    /// any value other than 0.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure due to lack of memory.
    /// There is no good way for userspace to handle this (unlikely) error.
    /// In a future build this error will no longer occur.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  Requested size is too large.
    ///
    /// ## See also
    ///
    ///  - [`zx_system_get_page_size()`]
    ///  - [`zx_vmar_map()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_replace_as_executable()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_object_get_property()`]: object_get_property.md
    /// [`zx_object_set_property()`]: object_set_property.md
    /// [`zx_system_get_page_size()`]: system_get_page_size.md
    /// [`zx_vmar_map()`]: vmar_map.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_replace_as_executable()`]: vmo_replace_as_executable.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    Create(struct {
        size uint64;
        options uint32;
    }) -> (resource struct {
        out Handle:VMO;
    }) error Status;

    // TODO(scottmg): This syscall is very weird, it's currently:
    //    (handle, buffer, offset, buffer_size)
    // rather than:
    //    (handle, buffer, buffer_size, offset)
    // which means the vector<byte> buffer won't work. Unfortunately offset and
    // buffer_size have the same underlying type, so moving them will be
    // error-prone.
    /// ## Summary
    ///
    /// Read bytes from the VMO.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_read(zx_handle_t handle,
    ///                         void* buffer,
    ///                         uint64_t offset,
    ///                         size_t buffer_size);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_read()` attempts to read exactly *buffer_size* bytes from a [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO) at *offset*.
    ///
    /// *buffer* pointer to a user buffer to read bytes into.
    ///
    /// *buffer_size* number of bytes to attempt to read. *buffer* buffer should be large
    /// enough for at least this many bytes.
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_READ**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_read()` returns **ZX_OK** on success, and exactly *buffer_size* bytes will
    /// have been written to *buffer*.
    /// In the event of failure, a negative error value is returned, and the number of
    /// bytes written to *buffer* is undefined.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.
    ///
    /// **ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.
    ///
    /// **ZX_ERR_ACCESS_DENIED**  *handle* does not have the **ZX_RIGHT_READ** right.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *buffer* is an invalid pointer or NULL.
    ///
    /// **ZX_ERR_NOT_FOUND** *buffer* address does not map to address in address space.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  *offset* + *buffer_size* is greater than the size of
    ///                          the VMO.
    ///
    /// **ZX_ERR_BAD_STATE**  VMO has been marked uncached and is not directly readable, or the VMO is
    /// backed by a pager and the pager or the VMO is in a bad state preventing requested pages from being
    /// populated.
    ///
    /// **ZX_ERR_IO** The VMO is backed by a pager and the pager encountered an I/O error while reading in
    /// the requested pages.
    ///
    /// **ZX_ERR_IO_DATA_INTEGRITY** The VMO is backed by a pager and the contents that were read in by the
    /// pager are corrupted.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_set_cache_policy()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_set_cache_policy()`]: vmo_set_cache_policy.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    @blocking
    Read(resource struct {
        handle Handle:VMO;
        @out
        @voidptr
        buffer experimental_pointer<byte>;
        offset uint64;
        buffer_size usize64;
    }) -> () error Status;

    // TODO(scottmg): Same problem as Read() above.
    /// ## Summary
    ///
    /// Write bytes to the VMO.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_write(zx_handle_t handle,
    ///                          const void* buffer,
    ///                          uint64_t offset,
    ///                          size_t buffer_size);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_write()` attempts to write exactly *buffer_size* bytes to a [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO) at *offset*.
    ///
    /// *buffer* pointer to a user buffer to write bytes from.
    ///
    /// *buffer_size* number of bytes to attempt to write.
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_write()` returns **ZX_OK** on success, and exactly *buffer_size* bytes will
    /// have been written from *buffer*.
    /// In the event of failure, a negative error value is returned, and the number of
    /// bytes written from *buffer* is undefined.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.
    ///
    /// **ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.
    ///
    /// **ZX_ERR_ACCESS_DENIED**  *handle* does not have the **ZX_RIGHT_WRITE** right.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *buffer* is an invalid pointer or NULL.
    ///
    /// **ZX_ERR_NOT_FOUND** *buffer* address does not map to address in address space.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure to allocate system memory to complete write.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  *offset* + *buffer_size* is greater than the size of
    ///                          the VMO.
    ///
    /// **ZX_ERR_BAD_STATE**  VMO has been marked uncached and is not directly writable.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_set_cache_policy()`]
    ///  - [`zx_vmo_set_size()`]
    ///
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_set_cache_policy()`]: vmo_set_cache_policy.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    @blocking
    Write(resource struct {
        handle Handle:VMO;
        @voidptr
        buffer experimental_pointer<byte>;
        offset uint64;
        buffer_size usize64;
    }) -> () error Status;

    // TODO(fxbug.dev/32803): No rights required?
    /// ## SUMMARY
    ///
    /// Read the current size of a VMO object.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_get_size(zx_handle_t handle, uint64_t* size);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_get_size()` returns the current size of the [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO). The size
    /// specified when creating a VMO (e.g. with [`zx_vmo_create()`]), and when
    /// resizing a VMO with [`zx_vmo_set_size()`] will be rounded up to the next
    /// system page size boundary. So the value returned by `zx_vmo_get_size()`
    /// will always be page-aligned.
    ///
    /// ## Rights
    ///
    /// TODO(fxbug.dev/32253)
    ///
    /// ## Return value
    ///
    /// `zx_vmo_get_size()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.
    ///
    /// **ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *size* is an invalid pointer or NULL.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    /// Read the current size of a VMO object.
    GetSize(resource struct {
        handle Handle:VMO;
    }) -> (struct {
        size uint64;
    }) error Status;

    /// ## SUMMARY
    ///
    /// Resize a VMO object.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_set_size(zx_handle_t handle, uint64_t size);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_set_size()` sets the new size of a [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO).
    ///
    /// The size will be rounded up to the next page size boundary.
    /// Subsequent calls to [`zx_vmo_get_size()`] will return the rounded up size.
    ///
    /// The content size of the VMO will be set to the given (unrounded) size.
    /// Use [`zx_object_get_property()`] with **ZX_PROP_VMO_CONTENT_SIZE** to read the
    /// content size of the VMO. Use [`zx_object_set_property()`] with
    /// **ZX_PROP_VMO_CONTENT_SIZE** to set the content size of the VMO without
    /// actually resizing the VMO.
    ///
    /// The data in the VMO between the given size and the end of the VMO (i.e., the next page boundary)
    /// will be overwritten with zeros.
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE** and **ZX_RIGHT_RESIZE**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_set_size()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.
    ///
    /// **ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.
    ///
    /// **ZX_ERR_ACCESS_DENIED**  *handle* does not have the **ZX_RIGHT_WRITE** or **ZX_RIGHT_RESIZE** right.
    ///
    /// **ZX_ERR_UNAVAILABLE** The VMO was not created with **ZX_VMO_RESIZABLE**
    /// or **ZX_VMO_CHILD_RESIZABLE**.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  Requested size is too large.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure due to lack of system memory.
    ///
    /// **ZX_ERR_BAD_STATE**  Requested size would discard pinned pages.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_object_get_property()`]: object_get_property.md
    /// [`zx_object_set_property()`]: object_set_property.md
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_write()`]: vmo_write.md
    SetSize(resource struct {
        handle Handle:VMO;
        size uint64;
    }) -> () error Status;

    /// ## SUMMARY
    ///
    /// Perform an operation on a range of a VMO.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_op_range(zx_handle_t handle,
    ///                             uint32_t op,
    ///                             uint64_t offset,
    ///                             uint64_t size,
    ///                             void* buffer,
    ///                             size_t buffer_size);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_op_range()` performs cache and memory operations against pages held by the [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO).
    ///
    /// *offset* byte offset specifying the starting location for *op* in the VMO's held memory.
    ///
    /// *size* length, in bytes, to perform the operation on.
    ///
    /// *op* the operation to perform:
    ///
    /// *buffer* and *buffer_size* may be required or unused depending on the *op* as described below.
    ///
    /// **ZX_VMO_OP_COMMIT** - Commit *size* bytes worth of pages starting at byte *offset* for the VMO.
    /// More information can be found in the [vm object documentation](/docs/reference/kernel_objects/vm_object.md).
    /// Requires the **ZX_RIGHT_WRITE** right.
    ///
    /// **ZX_VMO_OP_DECOMMIT** - Release a range of pages previously committed to the VMO from *offset*
    /// to *offset*+*size*, which resets that range's bytes to 0. Requires the **ZX_RIGHT_WRITE** right.
    /// This is only supported for vmos created from [`zx_vmo_create()`], which do not have non-slice
    /// children, and for slice children of such vmos. Provided range must be page aligned.
    ///
    /// **ZX_VMO_OP_ZERO** - Resets the range of bytes in the VMO from *offset* to *offset*+*size* to
    /// 0. This is semantically equivalent to writing 0's with
    /// [`zx_vmo_write()`](/docs/reference/syscalls/vmo_write.md), except that it is able to be done more
    /// efficiently and save memory by de-duping to shared zero pages. Requires the **ZX_RIGHT_WRITE** right.
    ///
    /// **ZX_VMO_OP_LOCK** - Locks a range of pages in a discardable VMO, preventing them from being
    /// discarded by the kernel. Guaranteed to successfully lock the VMO and return **ZX_OK** if the
    /// arguments are valid.  *buffer* should point to a `zx_vmo_lock_state_t` struct, and *buffer_size*
    /// should accommodate the struct. Returns information about the locked and previously discarded ranges
    /// in *buffer*, so that clients can reinitialize discarded contents if needed.
    ///
    /// The entire VMO should be locked at once, so *offset* should be 0 and *size* should be the current
    /// size of the VMO (the page-aligned size as would be returned by [`zx_vmo_get_size()`]). Requires the
    /// **ZX_RIGHT_READ** or **ZX_RIGHT_WRITE** right. Note that locking itself does not commit any pages in
    /// the VMO; it just marks the state of the VMO as “undiscardable” by the kernel.
    ///
    /// *buffer* should be a pointer of type `zx_info_lock_state_t`.
    ///
    /// ```c
    /// typedef struct zx_vmo_lock_state {
    ///   // |offset| and |size| track the locked range, and will be set to the |offset|
    ///   // and |size| arguments passed in if the ZX_VMO_OP_LOCK is successful.
    ///   uint64_t offset;
    ///   uint64_t size;
    ///   // |discarded_offset| and |discarded_size| track the discarded range prior to
    ///   // the lock operation. This is the maximal range within the locked range that
    ///   // contains discarded pages; not all pages within this range might have been
    ///   // discarded. Both |discarded_offset| and |discarded_size| will be set to 0 if
    ///   // the range was not discarded.
    ///   uint64_t discarded_offset;
    ///   uint64_t discarded_size;
    /// } zx_vmo_lock_state_t;
    /// ```
    ///
    /// **ZX_VMO_OP_TRY_LOCK** - Locks a range of pages in a discardable VMO, preventing them from being
    /// discarded by the kernel. Will only succeed if the range has not already been discarded by the
    /// kernel, and will fail with **ZX_ERR_UNAVAILABLE** otherwise. This operation is meant as a
    /// lightweight alternative to **ZX_VMO_OP_LOCK** for trying to lock the VMO without having to set up
    /// the *buffer* argument. It also affords clients the choice to not take any action following failure
    /// to lock the VMO; clients must use **ZX_VMO_OP_LOCK** if they wish to lock the VMO again.
    ///
    /// The entire VMO should be locked at once, so *offset* should be 0 and *size* should be the current
    /// size of the VMO (the page-aligned size as would be returned by [`zx_vmo_get_size()`]). Requires the
    /// **ZX_RIGHT_READ** or **ZX_RIGHT_WRITE** right. Note that locking itself does not commit any pages in
    /// the VMO; it just marks the state of the VMO as “undiscardable” by the kernel.
    ///
    /// **ZX_VMO_OP_UNLOCK** - Unlocks a range of pages in a discardable VMO, indicating that the kernel is
    /// free to discard them under memory pressure. Unlocked pages that have not been discarded yet will be
    /// counted as committed pages.
    ///
    /// The entire VMO should be unlocked at once, so *offset* should be 0 and *size* should be the current
    /// size of the VMO (the page-aligned size as would be returned by [`zx_vmo_get_size()`]). Requires the
    /// **ZX_RIGHT_READ** or **ZX_RIGHT_WRITE** right.
    ///
    /// **ZX_VMO_OP_CACHE_SYNC** - Synchronize instruction caches with data caches, so previous writes are
    /// visible to instruction fetches.
    /// Requires the **ZX_RIGHT_READ** right.
    ///
    /// **ZX_VMO_OP_CACHE_INVALIDATE** - Performs a cache invalidation operation so that future reads see
    /// external changes to main memory. Note, this operation is only available when
    /// `kernel.enable-debugging-syscalls` is true. When debugging syscalls are not enabled, this operation
    /// will fail with **ZX_ERR_NOT_SUPPORTED**
    /// Requires the **ZX_RIGHT_WRITE** right.
    ///
    /// **ZX_VMO_OP_CACHE_CLEAN** - Clean (write back) data caches, so previous writes are visible in main
    /// memory.
    /// Requires the **ZX_RIGHT_READ** right.
    ///
    /// **ZX_VMO_OP_CACHE_CLEAN_INVALIDATE** - Performs cache clean and invalidate operations together.
    /// Requires the **ZX_RIGHT_READ** right.
    ///
    /// **ZX_VMO_OP_DONT_NEED** - Hints that pages in the specified range are not needed anymore and should
    /// be considered for memory reclamation. Intended to be used with VMOs created with
    /// [`zx_pager_create_vmo()`](/docs/reference/syscalls/pager_create_vmo.md); trivially succeeds for
    /// other VMOs.
    ///
    /// This only applies to pages in the given range that are already committed, i.e. no new pages will be
    /// committed as a result of this op. If required, *offset* will be rounded down to the previous page
    /// boundary and *offset*+*size* will be rounded up to the next page boundary.
    ///
    /// **ZX_VMO_OP_ALWAYS_NEED** - Hints that pages in the specified range are important and should be
    /// protected from memory reclamation. The kernel may decide to override this hint when the system is
    /// under extreme memory pressure. This hint also does not prevent pages from being freed by means other
    /// than memory reclamation (e.g. a decommit, VMO resize, or VMO destruction). Intended to be used with
    /// VMOs created with [`zx_pager_create_vmo()`](/docs/reference/syscalls/pager_create_vmo.md); trivially
    /// succeeds for other VMOs.
    ///
    /// This may commit pages in the given range where applicable, e.g. if the VMO is directly backed by a
    /// pager, its pages will be committed, or in the case of a clone, pages in the parent that are visible
    /// to the clone will be committed. If required, *offset* will be rounded down to the previous page
    /// boundary and *offset*+*size* will be rounded up to the next page boundary.
    ///
    /// ## Rights
    ///
    /// If *op* is **ZX_VMO_OP_COMMIT**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE**.
    ///
    /// If *op* is **ZX_VMO_OP_DECOMMIT**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE**.
    ///
    /// If *op* is **ZX_VMO_OP_CACHE_SYNC**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_READ**.
    ///
    /// If *op* is **ZX_VMO_OP_CACHE_INVALIDATE**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE**.
    ///
    /// If *op* is **ZX_VMO_OP_CACHE_CLEAN**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_READ**.
    ///
    /// If *op* is **ZX_VMO_OP_CACHE_CLEAN_INVALIDATE**, *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_READ**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_op_range()` returns **ZX_OK** on success. In the event of failure, a negative error
    /// value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  An invalid memory range specified by *offset* and *size*.
    ///
    /// **ZX_ERR_NO_MEMORY**  Allocations to commit pages for **ZX_VMO_OP_COMMIT** or **ZX_VMO_OP_ZERO**
    /// failed.
    ///
    /// **ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.
    ///
    /// **ZX_ERR_ACCESS_DENIED**  *handle* does not have sufficient rights to perform the operation.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *buffer* is an invalid pointer (if required by the operation), *op* is not
    /// a valid operation, *size* is zero and *op* is a cache operation, or *op* was **ZX_VMO_OP_DECOMMIT**
    /// and range was not page aligned.
    ///
    /// **ZX_ERR_NOT_SUPPORTED**  *op* was **ZX_VMO_OP_LOCK**, **ZX_VMO_OP_TRY_LOCK** or
    /// **ZX_VMO_OP_UNLOCK** and the VMO is not discardable, or *op* was **ZX_VMO_OP_DECOMMIT** and the
    /// underlying VMO does not allow decommiting, or *op* was **ZX_VMO_OP_CACHE_INVALIDATE** and
    /// `kernel.enable-debugging-syscalls` is false.
    ///
    /// **ZX_ERR_UNAVAILABLE** *op* was **ZX_VMO_OP_TRY_LOCK**, the VMO was discardable and the VMO has been
    /// discarded by the kernel.
    ///
    /// **ZX_ERR_BAD_STATE**  *op* was **ZX_VMO_OP_COMMIT**, the VMO is backed by a pager and the pager or
    /// the VMO is in a bad state preventing requested pages from being populated. *op* was
    /// **ZX_VMO_OP_UNLOCK**, the VMO is discardable and the VMO was not previously locked.
    ///
    /// **ZX_ERR_IO** *op* was **ZX_VMO_OP_COMMIT**, the VMO is backed by a pager and the pager encountered
    /// an I/O error while committing the requested pages.
    ///
    /// **ZX_ERR_IO_DATA_INTEGRITY** *op* was **ZX_VMO_OP_COMMIT**, the VMO is backed by a pager and the
    /// contents that were read in by the pager for the pages being committed are corrupted.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_create_child()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_pager_create_vmo()`]: pager_create_vmo.md
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_child()`]: vmo_create_child.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    @blocking
    OpRange(resource struct {
        handle Handle:VMO;
        op uint32;
        offset uint64;
        size uint64;
        @inout
        @voidptr
        buffer vector<byte>:MAX;
    }) -> () error Status;

    /// ## SUMMARY
    ///
    /// Create a child of a VM Object.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_create_child(zx_handle_t handle,
    ///                                 uint32_t options,
    ///                                 uint64_t offset,
    ///                                 uint64_t size,
    ///                                 zx_handle_t* out);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_create_child()` creates a new [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO) a child of an existing vmo. The behavior
    /// of the semantics depends on the type of the child.
    ///
    /// One handle is returned on success, representing an object with the requested
    /// size.
    ///
    /// *options* must contain exactly one of the following flags to specify the
    /// child type:
    ///
    /// - **ZX_VMO_CHILD_SNAPSHOT** -  Create a child that behaves as if an eager copy is performed. When a
    /// write occurs, both the parent and child perform a lazy copy. Lazy copying allows both the child and
    /// the parent to diverge from each other. Any reads from ranges outside of the parent VMO's size
    /// contain zeros, and writes allocate new zero filled pages.
    /// This flag is not supported on:
    ///  - VMOs with pinned regions.
    ///  - VMOs created with or descended from [`zx_vmo_create_physical()`] or
    ///    [`zx_vmo_create_contiguous()`]
    ///  - VMOs backed by a user pager.
    /// For information on VMO syscall interactions with children, see [Notes](#notes).
    ///
    /// ZX_VMO_CHILD_SNAPSHOT creates an immutable VMO when the ZX_VMO_CHILD_NO_WRITE
    /// option is enabled and the ZX_VMO_CHILD_RESIZABLE option is disabled.
    ///
    /// - **ZX_VMO_CHILD_SNAPSHOT_AT_LEAST_ON_WRITE** -  Create a child that behaves with at least copy on
    /// write semantics. Any write operation on the child brings in a copy of the page from the parent,
    /// after which its contents may diverge from the parent. Until a page is written to, and copied, reads
    /// are permitted, although not guaranteed, to return changing values if the parent performs writes.
    /// This flag may not be used for VMOs created with [`zx_vmo_create_physical()`],
    /// [`zx_vmo_create_contiguous()`] or descendants of such VMOs.
    /// For information on VMO syscall interactions with children, see [Notes](#notes).
    ///
    /// - **ZX_VMO_CHILD_SLICE** - Create a slice that has direct read/write access into
    /// a section of the parent. All operations on the slice VMO behave as if they were done on the parent.
    /// A slice differs from a duplicate handle to the parent by allowing access to only a subrange of the
    /// parent VMO, and allowing for the **ZX_VMO_ZERO_CHILDREN** signal to be used. This flag may be used
    /// with VMOs created with [`zx_vmo_create_physical()`] or [`zx_vmo_create_contiguous()`] and their
    /// descendants. This flag may not be used with VMOs created with the **ZX_VMO_RESIZABLE** option.
    ///
    /// - **ZX_VMO_CHILD_REFERENCE** - Create a reference to the VMO. All operations on the reference VMO
    /// behave as if they were done on the parent. A reference always spans the entirety of the parent, and
    /// *offset* and *size* are required to be 0. This is useful for cases where the user wants to keep
    /// track of outstanding references to a VMO, by using the **ZX_VMO_ZERO_CHILDREN** signal. Refer to
    /// [Notes](#notes) for more details on this signal.
    /// This flag may not be used for VMOs created with [`zx_vmo_create_physical()`],
    /// [`zx_vmo_create_contiguous()`] or descendants of such VMOs.
    ///
    /// In addition, *options* can contain zero or more of the following flags to
    /// further specify the child's behavior:
    ///
    /// - **ZX_VMO_CHILD_RESIZABLE** - Create a resizable child VMO. This is incompatible with
    ///                                **ZX_VMO_CHILD_SLICE**.
    ///
    /// - **ZX_VMO_CHILD_NO_WRITE** - Create a child that cannot be written to. This is incompatible with
    ///                               **ZX_VMO_CHILD_RESIZABLE**.
    ///
    /// *offset* must be page aligned.
    ///
    /// *offset* + *size* may not exceed the range of a 64bit unsigned value.
    ///
    /// Both offset and size may start or extend beyond the original VMO's size.
    ///
    /// The size of the VMO will be rounded up to the next page size boundary.
    ///
    /// The content size of the VMO will be initialized to the given (unrounded) size.
    /// Use [`zx_object_get_property()`] with **ZX_PROP_VMO_CONTENT_SIZE** to read the
    /// content size of the VMO. Use [`zx_object_set_property()`] with
    /// **ZX_PROP_VMO_CONTENT_SIZE** to set the content size of the VMO without
    /// actually resizing the VMO.
    ///
    /// By default the rights of the child handle will be the same as the
    /// original with a few exceptions. See [`zx_vmo_create()`] for a
    /// discussion of the details of each right.
    ///
    /// If *options* includes **ZX_VMO_CHILD_RESIZABLE** then **ZX_RIGHT_RESIZE** will be added.
    ///
    /// For **ZX_VMO_CHILD_REFERENCE**, the **ZX_VMO_CHILD_RESIZABLE** option controls whether the parent
    /// VMO may be resized using the reference handle returned in *out*. The reference will see a resize on
    /// the parent VMO if the parent VMO was resizable, regardless of the presence of
    /// **ZX_VMO_CHILD_RESIZABLE**. However **ZX_VMO_CHILD_RESIZABLE** is only supported if the parent VMO
    /// was resizable, i.e. it is not possible to create a resizable reference of a non-resizable VMO.
    ///
    /// In all cases if **ZX_VMO_NO_WRITE** is set then **ZX_RIGHT_WRITE** will be removed.
    ///
    /// If *options* is **ZX_VMO_CHILD_SNAPSHOT** or **ZX_VMO_CHILD_SNAPSHOT_AT_LEAST_ON_WRITE** and
    /// **ZX_VMO_CHILD_NO_WRITE** is not set then **ZX_RIGHT_WRITE** will be added and **ZX_RIGHT_EXECUTE**
    /// will be removed.
    ///
    /// ## Notes
    ///
    /// Creating a child VMO causes the existing (source) VMO **ZX_VMO_ZERO_CHILDREN** signal
    /// to become inactive. Only when the last child is destroyed and no mappings
    /// of those child into address spaces exist, will **ZX_VMO_ZERO_CHILDREN** become
    /// active again.
    ///
    /// Non-slice child vmos will interact with the VMO syscalls in the following ways:
    ///
    /// - The COMMIT mode of [`zx_vmo_op_range()`] on a child will commit pages into the child that
    ///   have the same content as its parent's corresponding pages. If those pages are supplied by a
    ///   pager, this operation will also commit those pages in the parent. Otherwise, if those pages
    ///   are not committed in the parent, zero-filled pages will be committed directly into
    ///   child, without affecting the parent.
    /// - The DECOMMIT mode of [`zx_vmo_op_range()`] is not supported.
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_DUPLICATE** and have **ZX_RIGHT_READ**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_create_child()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_TYPE**  Input handle is not a VMO.
    ///
    /// **ZX_ERR_ACCESS_DENIED**  Input handle does not have sufficient rights.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *out* is an invalid pointer or NULL
    /// or the offset is not page aligned, or an incompatible combination of *options* was given.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  *offset* + *size* is too large.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure due to lack of memory.
    /// There is no good way for userspace to handle this (unlikely) error.
    /// In a future build this error will no longer occur.
    ///
    /// **ZX_ERR_BAD_STATE**  A COW child could not be created because the vmo has some
    /// pinned pages.
    ///
    /// **ZX_ERR_NOT_SUPPORTED**  Input handle is a discardable VMO, or input handle is
    /// a resizable VMO and *options* contains **ZX_VMO_CHILD_SLICE**.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmar_map()`]
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_object_get_property()`]: object_get_property.md
    /// [`zx_object_set_property()`]: object_set_property.md
    /// [`zx_pager_create_vmo()`]: pager_create_vmo.md
    /// [`zx_vmar_map()`]: vmar_map.md
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_create_contiguous()`]: vmo_create_contiguous.md
    /// [`zx_vmo_create_physical()`]: vmo_create_physical.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    CreateChild(resource struct {
        handle Handle:VMO;
        options uint32;
        offset uint64;
        size uint64;
    }) -> (resource struct {
        out Handle:VMO;
    }) error Status;

    /// ## SUMMARY
    ///
    /// Set the caching policy for pages held by a VMO.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_set_cache_policy(zx_handle_t handle, uint32_t cache_policy);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_set_cache_policy()` sets caching policy for a [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO). Generally used on VMOs
    /// that point directly at physical memory. Such VMOs are generally only handed to
    /// userspace via bus protocol interfaces, so this syscall will typically only be
    /// used by drivers dealing with device memory. This call can also be used on a
    /// regular memory backed VMO with similar limitations and uses.
    ///
    /// A handle must have the **ZX_RIGHT_MAP** right for this call to be
    /// permitted. Additionally, the VMO must not presently be mapped by any process,
    /// have any children, be a child itself, or have any pinned pages. Having committed
    /// pages is only allowed if transitioning from a cached state, and the pages will be
    /// cleaned and invalidated.
    ///
    /// *cache_policy* cache flags to use:
    ///
    ///   - **ZX_CACHE_POLICY_CACHED** - Use hardware caching. On Aarch64 this corresponds to the Normal
    ///     Memory, Outer Write-back non-transient Read and Write allocate, Inner Write-back non-transient
    ///     Read and Write allocate memory attributes
    ///
    ///   - **ZX_CACHE_POLICY_UNCACHED** - Disable caching. On Aarch64 this corresponds to the Device-nGnRnE
    ///     memory attributes.
    ///
    ///   - **ZX_CACHE_POLICY_UNCACHED_DEVICE** - Disable cache and treat as device memory. This is
    ///     architecture dependent and may be equivalent to **ZX_CACHE_POLICY_UNCACHED** on some
    ///     architectures. On Aarch64 this corresponds to the Device-nGnRE memory attributes.
    ///
    ///   - **ZX_CACHE_POLICY_WRITE_COMBINING** - Uncached with write combining. On Aarch64 this corresponds
    ///     to the Normal memory, uncached memory attributes.
    ///
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_MAP**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_set_cache_policy()` returns **ZX_OK** on success. In the event of
    /// failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_ACCESS_DENIED** Cache policy has been configured for this VMO already and
    /// may not be changed, or *handle* lacks the **ZX_RIGHT_MAP** right.
    ///
    /// **ZX_ERR_BAD_HANDLE** *handle* is not a valid handle.
    ///
    /// **ZX_ERR_INVALID_ARGS** *cache_policy* contains flags outside of the ones listed
    /// above, or *cache_policy* contains an invalid mix of cache policy flags.
    ///
    /// **ZX_ERR_NOT_SUPPORTED** The VMO *handle* corresponds to is not one holding
    /// physical memory.
    ///
    /// **ZX_ERR_BAD_STATE** Cache policy cannot be changed because the VMO is presently
    /// mapped, has children, is a child itself, has pinned pages, or has committed pages
    /// and the VMO is currently not cached.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmo_create()`]
    ///  - [`zx_vmo_get_size()`]
    ///  - [`zx_vmo_op_range()`]
    ///  - [`zx_vmo_read()`]
    ///  - [`zx_vmo_set_size()`]
    ///  - [`zx_vmo_write()`]
    ///
    /// [`zx_vmo_create()`]: vmo_create.md
    /// [`zx_vmo_get_size()`]: vmo_get_size.md
    /// [`zx_vmo_op_range()`]: vmo_op_range.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_set_size()`]: vmo_set_size.md
    /// [`zx_vmo_write()`]: vmo_write.md
    SetCachePolicy(resource struct {
        handle Handle:VMO;
        cache_policy uint32;
    }) -> () error Status;

    // TODO(fxbug.dev/32803): handle: No rights required, ZX_RIGHT_EXECUTE added to dup out
    // TODO(fxbug.dev/32803): vmex == ZX_HANDLE_INVALID also accepted.
    /// ## SUMMARY
    ///
    /// Add execute rights to a VMO.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_replace_as_executable(zx_handle_t handle,
    ///                                          zx_handle_t vmex,
    ///                                          zx_handle_t* out);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_replace_as_executable()` creates a replacement for *handle*, referring
    /// to the same underlying [virtual memory object](/docs/reference/kernel_objects/vm_object.md) (VMO),
    /// adding the right **ZX_RIGHT_EXECUTE**.
    ///
    /// *handle* is always invalidated.
    ///
    /// ## Rights
    ///
    /// *handle* must be of type **ZX_OBJ_TYPE_VMO**.
    ///
    /// *vmex* must have resource kind **ZX_RSRC_KIND_SYSTEM** with base
    /// **ZX_RSRC_SYSTEM_VMEX_BASE**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_replace_as_executable()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZX_ERR_BAD_HANDLE**  *handle* isn't a valid VM object handle, or
    /// *vmex* isn't a valid **ZX_RSRC_KIND_SYSTEM** resource handle with base
    /// **ZX_RSRC_SYSTEM_VMEX_BASE**.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure due to lack of memory.
    /// There is no good way for userspace to handle this (unlikely) error.
    /// In a future build this error will no longer occur.
    ///
    /// ## See also
    ///
    ///  - [`zx_resource_create()`]
    ///  - [`zx_vmar_map()`]
    ///
    /// [`zx_resource_create()`]: resource_create.md
    /// [`zx_vmar_map()`]: vmar_map.md
    ReplaceAsExecutable(resource struct {
        @release
        handle Handle:VMO;
        vmex Handle:RESOURCE;
    }) -> (resource struct {
        out Handle:VMO;
    }) error Status;

    /// ## SUMMARY
    ///
    /// TODO(fxbug.dev/32938)
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_create_contiguous(zx_handle_t bti,
    ///                                      size_t size,
    ///                                      uint32_t alignment_log2,
    ///                                      zx_handle_t* out);
    /// ```
    ///
    /// ## Description
    ///
    /// TODO(fxbug.dev/32938)
    ///
    /// ## Rights
    ///
    /// *bti* must be of type **ZX_OBJ_TYPE_BTI** and have **ZX_RIGHT_MAP**.
    ///
    /// ## Return value
    ///
    /// TODO(fxbug.dev/32938)
    ///
    /// ## Errors
    ///
    /// TODO(fxbug.dev/32938)
    ///
    /// ## See also
    ///
    /// TODO(fxbug.dev/32938)
    CreateContiguous(resource struct {
        bti Handle:BTI;
        size usize64;
        alignment_log2 uint32;
    }) -> (resource struct {
        out Handle:VMO;
    }) error Status;

    /// ## SUMMARY
    ///
    /// Create a VM object referring to a specific contiguous range of physical memory.
    ///
    /// ## Declaration
    ///
    /// ```c
    /// #include <zircon/syscalls.h>
    ///
    /// zx_status_t zx_vmo_create_physical(zx_handle_t resource,
    ///                                    zx_paddr_t paddr,
    ///                                    size_t size,
    ///                                    zx_handle_t* out);
    /// ```
    ///
    /// ## Description
    ///
    /// `zx_vmo_create_physical()` creates a new [virtual memory
    /// object](/docs/reference/kernel_objects/vm_object.md) (VMO), which represents the
    /// *size* bytes of physical memory beginning at physical address *paddr*.
    ///
    /// The content size of the VMO will be initialized to the given (unrounded) size.
    /// Use [`zx_object_get_property()`] with **ZX_PROP_VMO_CONTENT_SIZE** to read the
    /// content size of the VMO. Use [`zx_object_set_property()`] with
    /// **ZX_PROP_VMO_CONTENT_SIZE** to set the content size of the VMO without
    /// actually resizing the VMO.
    ///
    /// One handle is returned on success, representing an object with the requested
    /// size.
    ///
    /// The following rights will be set on the handle by default:
    ///
    ///   - **ZX_RIGHT_DUPLICATE** - The handle may be duplicated.
    ///
    ///   - **ZX_RIGHT_TRANSFER** - The handle may be transferred to another process.
    ///
    ///   - **ZX_RIGHT_READ** - May be read from or mapped with read permissions.
    ///
    ///   - **ZX_RIGHT_WRITE** - May be written to or mapped with write permissions.
    ///
    ///   - **ZX_RIGHT_EXECUTE** - May be mapped with execute permissions.
    ///
    ///   - **ZX_RIGHT_MAP** - May be mapped.
    ///
    ///   - **ZX_RIGHT_GET_PROPERTY** - May get its properties using [`zx_object_get_property()`].
    ///
    ///   - **ZX_RIGHT_SET_PROPERTY** - May set its properties using [`zx_object_set_property()`].
    ///
    /// The **ZX_VMO_ZERO_CHILDREN** signal is active on a newly created VMO. It becomes
    /// inactive whenever a child of the VMO is created and becomes active again when
    /// all children have been destroyed and no mappings of those children into address
    /// spaces exist.
    ///
    /// ## Notes
    ///
    /// The VMOs created by this syscall are not usable with [`zx_vmo_read()`] and
    /// [`zx_vmo_write()`].
    ///
    /// ## Rights
    ///
    /// *resource* must have resource kind **ZX_RSRC_KIND_MMIO**.
    ///
    /// ## Return value
    ///
    /// `zx_vmo_create_physical()` returns **ZX_OK** on success. In the event
    /// of failure, a negative error value is returned.
    ///
    /// ## Errors
    ///
    /// **ZER_ERR_WRONG_TYPE** *resource* is not a handle to a Resource object.
    ///
    /// **ZER_ERR_ACCESS_DENIED** *resource* does not grant access to the requested
    /// range of memory.
    ///
    /// **ZX_ERR_INVALID_ARGS**  *out* is an invalid pointer or NULL, or *paddr* or
    /// *size* are not page-aligned.
    ///
    /// **ZX_ERR_NO_MEMORY**  Failure due to lack of memory.
    /// There is no good way for userspace to handle this (unlikely) error.
    /// In a future build this error will no longer occur.
    ///
    /// **ZX_ERR_OUT_OF_RANGE**  Requested size is too large.
    ///
    /// ## See also
    ///
    ///  - [`zx_vmar_map()`]
    ///
    /// [`zx_object_get_property()`]: object_get_property.md
    /// [`zx_object_set_property()`]: object_set_property.md
    /// [`zx_vmar_map()`]: vmar_map.md
    /// [`zx_vmo_read()`]: vmo_read.md
    /// [`zx_vmo_write()`]: vmo_write.md
    CreatePhysical(resource struct {
        resource Handle:RESOURCE;
        paddr Paddr;
        size usize64;
    }) -> (resource struct {
        out Handle:VMO;
    }) error Status;
};