fuchsia.hardware.goldfish

PROTOCOLS

AddressSpaceChildDriver

Defined in fuchsia.hardware.goldfish/goldfish_address_space.fidl

AllocateBlock

Allocates goldfish address space of given size.

Request

Name	Type
`size`	`uint64`

Response

Name	Type
`res`	`zx/status`
`paddr`	`uint64`
`vmo`	`handle<vmo>?`

ClaimSharedBlock

Claim a region at [offset, offset + size) that is a subregion of a larger region managed by hardware. It is possible to share the same regions across different connections, but within a connection, we require the claimed regions to be disjoint. Otherwise, `ZX_ERROR_INVALID_ARGS1 is returned.

Request

Name	Type
`offset`	`uint64`
`size`	`uint64`

Response

Name	Type
`res`	`zx/status`
`vmo`	`handle<vmo>?`

DeallocateBlock

Free goldfish address space associated with given ID.

Request

Name	Type
`paddr`	`uint64`

Response

Name	Type
`res`	`zx/status`

Ping

Ping (General notification for child drivers)

Request

Name	Type
`ping`	`AddressSpaceChildDriverPingMessage`

Response

Name	Type
`res`	`zx/status`
`ping`	`AddressSpaceChildDriverPingMessage`

UnclaimSharedBlock

Unclaim a hardware-shared region. This must correspond to an existing claimed region in the current connection. Otherwise, ZX_ERROR_INVALID_ARGS is returned.

Request

Name	Type
`offset`	`uint64`

Response

Name	Type
`res`	`zx/status`

AddressSpaceDevice

Defined in fuchsia.hardware.goldfish/goldfish_address_space.fidl

State The driver consists of three main pieces of state:

A PCI BAR that clients can suballocate into. This is used for mapping coherent memory from the hardware, such as for Vulkan HOST_COHERENT memory, or for any other buffer owned by the hardware such as video codec buffers. This also includes a mapping where each connection of the driver is associated with one or more mappings.

The next two pieces of state are for child driver connections.

A set of context handles, one per driver connection that the client establishes. This is used to support higher-level/VMM-defined (child) drivers. Each such driver is considered a "child" driver of goldfish address space.
A set of command pages, one per connection. This is used as a shared device/host memory to support the "Ping" command. The "Ping" command is used to run the child driver logic, driven by the app. There is a protocol to permanently associate a particular goldfish address space driver connection with a particular type of child driver, discussed next.

OpenChildDriver

Request

Name	Type
`type`	`AddressSpaceChildDriverType`
`req`	`request<AddressSpaceChildDriver>`

ControlDevice

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Interface for the Goldfish control driver providing color buffers and data buffers.

CreateBuffer2

Create shared data buffer. Buffer is automatically freed when all references to vmo have been closed. Fails if VMO is not associated with goldfish heap memory.

Arguments Refer to CreateBuffer2Params for input arguments.

Return value Error: - ZX_ERR_ALREADY_EXISTS if a buffer or color buffer has already been created for this VMO. - ZX_ERR_INVALID_ARGS if arguments are invalid. (see CreateBuffer2Params)

 `hw_address_page_offset`:
     Memory page offset of the buffer's hardware-mapped memory.
     For buffers with HOST_VISIBLE memory property bits, this
     value is a non-negative integer in [0, 4095]. For
     non-HOST_VISIBLE memory, this value is negative.

Request

Name	Type
`vmo`	`handle<vmo>`
`create_params`	`CreateBuffer2Params`

Response

Name	Type
`result`	`ControlDevice_CreateBuffer2_Result`

CreateColorBuffer2

Create shared color buffer. Color buffer is automatically freed when all references to vmo have been closed. Fails if VMO is not associated with goldfish heap memory.

Arguments Refer to CreateColorBuffer2Params for input arguments.

Return value res: ZX_ERR_ALREADY_EXISTS if a buffer or color buffer has already been created for this VMO. ZX_ERR_INVALID_ARGS if arguments are invalid. (see CreateColorBuffer2Params) Otherwise returns ZX_OK. hw_address_page_offset: memory page offset of the buffer's hardware-mapped memory. For color buffers with HOST_VISIBLE memory property bits, this value is a non-negative integer in [0, 4095]. For non-HOST_VISIBLE memory or failed allocation, this value is negative.

Request

Name	Type
`vmo`	`handle<vmo>`
`create_params`	`CreateColorBuffer2Params`

Response

Name	Type
`res`	`zx/status`
`hw_address_page_offset`	`int32`

GetBufferHandle

Get a buffer handle for VMO and the type of the handle. Fails if VMO is not associated with neither a color buffer nor a buffer.

Request

Name	Type
`vmo`	`handle<vmo>`

Response

Name	Type
`res`	`zx/status`
`id`	`uint32`
`type`	`BufferHandleType`

Pipe

Defined in fuchsia.hardware.goldfish/goldfish_pipe.fidl

DoCall

Writes count bytes from the IO buffer at specified write offset. Returns ZX_ERR_SHOULD_WAIT if pipe device is not writable.

If it writes to device successfully, it subsequently reads read_count bytes into the IO buffer at specified read_offset. Returns ZX_ERR_SHOULD_WAIT if pipe device is not readable.

Return value actual is the total bytes read from and written to the IO buffer.

The name "DoCall" (instead of "Call") is to avoid collision with LLCPP generated code "class Call" (generated per protocol). We don't want this method attempting to compile as if it were a constructor.

Request

Name	Type
`count`	`uint64`
`offset`	`uint64`
`read_count`	`uint64`
`read_offset`	`uint64`

Response

Name	Type
`res`	`zx/status`
`actual`	`uint64`

GetBuffer

Acquire VMO for IO buffer. Can be called multiple times. Each call returns a new handle to the VMO.

Request

Name	Type

Response

Name	Type
`res`	`zx/status`
`vmo`	`handle<vmo>?`

Read

Attempt to read up to count bytes into IO buffer at specified offset. Returns ZX_ERR_SHOULD_WAIT if pipe device is not readable.

Request

Name	Type
`count`	`uint64`
`offset`	`uint64`

Response

Name	Type
`res`	`zx/status`
`actual`	`uint64`

SetBufferSize

Request new IO buffer size. Can fail if out of memory. Discards contents of existing buffer on success. Leaves existing buffer intact on failure.

Request

Name	Type
`size`	`uint64`

Response

Name	Type
`res`	`zx/status`

SetEvent

Set event used to signal device state. Discards existing event after having transferred device state to the new event.

Request

Name	Type
`event`	`handle<event>`

Write

Writes up to count bytes from the IO buffer at specified offset. Returns ZX_ERR_SHOULD_WAIT if pipe device is not writable.

Request

Name	Type
`count`	`uint64`
`offset`	`uint64`

Response

Name	Type
`res`	`zx/status`
`actual`	`uint64`

PipeDevice

Defined in fuchsia.hardware.goldfish/goldfish_pipe.fidl

Interface for the Goldfish pipe driver.

OpenPipe

Open pipe. A protocol request pipe_request provides an interface to the pipe. Multiple pipes can be opened for a single device. Closing the device connection will also close all pipe connections. TODO(fxbug.dev/6547): Unify device and pipe.

Request

Name	Type
`pipe_request`	`request<Pipe>`

STRUCTS

AddressSpaceChildDriverPingMessage

Defined in fuchsia.hardware.goldfish/goldfish_address_space.fidl

Child driver protocol

By default, creating connection to the driver does not associate any child driver with the connection.

The client opens a child driver via OpenChildDriver, giving the type of the driver as an argument along with a request for the connection. The type of the driver is a number and the number/drivertype mapping is determined/maintained in: https://android.googlesource.com/platform/external/qemu/+/refs/heads/emu-master-dev/android/android-emu/android/emulation/AddressSpaceService.h

In Fuchsia, we currently only support the DEFAULT type, which is used for graphics.

After opening the child driver, the client and hardware communicate via a child driver-specific protocol, with notifications driven by Ping(), each of which writes and reads messages to the hardware that follow this AddressSpaceChildDriverPingMessage struct. Each child driver type will have its own semantics for each field. It's common for child drivers to refer to offset/size plus a metadata field. We also provide extra data fields for other use cases in particular child drivers.

Name	Type	Default
`offset`	`uint64`	No default
`size`	`uint64`	No default
`metadata`	`uint64`	No default
`data0`	`uint64`	No default
`data1`	`uint64`	No default
`data2`	`uint32`	No default
`data3`	`uint32`	No default

ControlDevice_CreateBuffer2_Response

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Name	Type	Description	Default
`hw_address_page_offset`	`int32`		No default

ENUMS

AddressSpaceChildDriverType

Type: uint32

Defined in fuchsia.hardware.goldfish/goldfish_address_space.fidl

Interface for the Goldfish address space driver.

Name	Value	Description
`DEFAULT`	`0`	The `DEFAULT` child driver type is for graphics.

BufferHandleType

Type: uint32

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Name	Value	Description
`INVALID`	`0`
`BUFFER`	`1`
`COLOR_BUFFER`	`2`

ColorBufferFormatType

Type: uint32

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Color buffer formats.

Goldfish control device accepts GL format values as "internalFormat" argument when creating color buffers. All format types should be defined using their format definitions in GL headers.

Name	Value	Description
`LUMINANCE`	`6409`
`RG`	`33319`
`RGBA`	`6408`
`BGRA`	`32993`

TABLES

CreateBuffer2Params

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Input arguments of ControlDevice.CreateBuffer2() method. Includes necessary properties of a Vulkan-backed data buffer.

Ordinal Name Type Description

Ordinal	Name	Type	Description
1	`size`	`uint64`	Size of the buffer (unit: byte). This argument is mandatory. `CreateBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `size` is missing.
2	`memory_property`	`uint32`	Memory property flags the buffer should support. Only bits from `fuchsia.hardware.goldfish.MEMORY_PROPERTY_*` are allowed. This argument is mandatory. `CreateBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `memory_property` is missing.
3	`physical_address`	`uint64`	Goldfish address space device allocates a physical memory address for each host-visible buffer. This address is mapped to a corresponding hardware address when that host-visible buffer is created, and is unmapped when the buffer is torn down. This field stores the physical memory address allocated by address space device. If `memory_property` has the bit `MEMORY_PROPERTY_HOST_VISIBLE` set, this argument is mandatory. If `physical_address` is missing, `CreateBuffer2()` returns `ZX_ERR_INVALID_ARGS`. If `memory_property` doesn't have the `MEMORY_PROPERTY_HOST_VISIBLE` bit, this argument is ignored.

size

uint64

Size of the buffer (unit: byte).

This argument is mandatory. CreateBuffer2() method returns ZX_ERR_INVALID_ARGS if size is missing.

memory_property

uint32

Memory property flags the buffer should support. Only bits from fuchsia.hardware.goldfish.MEMORY_PROPERTY_* are allowed.

This argument is mandatory. CreateBuffer2() method returns ZX_ERR_INVALID_ARGS if memory_property is missing.

physical_address

uint64

Goldfish address space device allocates a physical memory address for each host-visible buffer. This address is mapped to a corresponding hardware address when that host-visible buffer is created, and is unmapped when the buffer is torn down.

This field stores the physical memory address allocated by address space device.

If memory_property has the bit MEMORY_PROPERTY_HOST_VISIBLE set, this argument is mandatory. If physical_address is missing, CreateBuffer2() returns ZX_ERR_INVALID_ARGS.

If memory_property doesn't have the MEMORY_PROPERTY_HOST_VISIBLE bit, this argument is ignored.

CreateColorBuffer2Params

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Input arguments of ControlDevice.CreateColorBuffer2() method. Includes necessary properties of a Vulkan-backed color buffer.

Ordinal	Name	Type	Description
1	`width`	`uint32`	Width of the color buffer (unit: pixel). This argument is mandatory. `CreateColorBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `width` is missing.
2	`height`	`uint32`	Height of the color buffer (unit: pixel). This argument is mandatory. `CreateColorBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `height` is missing.
3	`format`	`ColorBufferFormatType`	Color format type of the color buffer. This argument is mandatory. `CreateColorBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `format` is missing.
4	`memory_property`	`uint32`	Memory property flags the color buffer should support. Only bits from `fuchsia.hardware.goldfish.MEMORY_PROPERTY_*` are allowed. This argument is mandatory. `CreateColorBuffer2()` method returns `ZX_ERR_INVALID_ARGS` if `memory_property` is missing.
5	`physical_address`	`uint64`	Goldfish address space device allocates a physical memory address for each host-visible color buffer. This address is mapped to a corresponding hardware address when that host-visible color buffer is created, and is unmapped when the color buffer is torn down. This field stores the physical memory address allocated by address space device. If `memory_property` has the bit `MEMORY_PROPERTY_HOST_VISIBLE` set, this argument is mandatory. If `physical_address` is missing, `CreateColorBuffer2()` returns `ZX_ERR_INVALID_ARGS`. If `memory_property` doesn't have the `MEMORY_PROPERTY_HOST_VISIBLE` bit, this argument is ignored.

UNIONS

ControlDevice_CreateBuffer2_Result

Defined in fuchsia.hardware.goldfish/goldfish_control.fidl

Name	Type	Description
`response`	`ControlDevice_CreateBuffer2_Response`
`err`	`zx/status`

CONSTANTS

Name	Value	Type	Description
MEMORY_PROPERTY_DEVICE_LOCAL	`1`	`uint32`	Memory property flags for color buffers and data buffers. `MEMORY_PROPERTY_DEVICE_LOCAL` corresponds to Vulkan's memory property `VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT`. Memory allocated with this type is the most efficient for device access.
MEMORY_PROPERTY_HOST_VISIBLE	`2`	`uint32`	`MEMORY_PROPERTY_HOST_VISIBLE` corresponds to Vulkan's memory property `VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT`. Memory allocated with this type can be mapped for host access using `vkMapMemory()`.
SIGNAL_HANGUP	`67108864`	`uint32`	Signal that will be active on event handle if the device has been disconnected.
SIGNAL_READABLE	`16777216`	`uint32`	Signal that will be active on event handle if the Read() method will return data.
SIGNAL_WRITABLE	`33554432`	`uint32`	Signal that will be active on event handle if the Write() method will accept data.