// Copyright (c) 2016-2018 Khronos Group. This work is licensed under a
// Creative Commons Attribution 4.0 International License; see
// http://creativecommons.org/licenses/by/4.0/

include::meta/VK_KHX_device_group.txt[]

*Last Modified Date*::
    2017-05-19
*IP Status*::
    No known IP claims.
*Contributors*::
  - Jeff Bolz, NVIDIA
  - Tobias Hector, Imagination Technologies

This extension provides functionality to use a logical device that consists
of multiple physical devices, as created with the
`<<VK_KHX_device_group_creation>>` extension.
A device group can allocate memory across the subdevices, bind memory from
one subdevice to a resource on another subdevice, record command buffers
where some work executes on an arbitrary subset of the subdevices, and
potentially present a swapchain image from one or more subdevices.

=== New Object Types

None.

=== New Enum Constants

  * Extending elink:VkStructureType:
  ** ename:VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_FLAGS_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_RENDER_PASS_BEGIN_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_COMMAND_BUFFER_BEGIN_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_SUBMIT_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_BIND_SPARSE_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_PRESENT_CAPABILITIES_KHX
  ** ename:VK_STRUCTURE_TYPE_IMAGE_SWAPCHAIN_CREATE_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_SWAPCHAIN_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_ACQUIRE_NEXT_IMAGE_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_PRESENT_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_DEVICE_GROUP_SWAPCHAIN_CREATE_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_BIND_BUFFER_MEMORY_DEVICE_GROUP_INFO_KHX
  ** ename:VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_DEVICE_GROUP_INFO_KHX
  * Extending elink:VkImageCreateFlagBits
  ** ename:VK_IMAGE_CREATE_BIND_SFR_BIT_KHX
  * Extending elink:VkPipelineCreateFlagBits
  ** ename:VK_PIPELINE_CREATE_VIEW_INDEX_FROM_DEVICE_INDEX_BIT_KHX
  ** ename:VK_PIPELINE_CREATE_DISPATCH_BASE_KHX
  * Extending elink:VkDependencyFlagBits
  ** ename:VK_DEPENDENCY_DEVICE_GROUP_BIT_KHX
  * Extending elink:VkSwapchainCreateFlagBitsKHR
  ** ename:VK_SWAPCHAIN_CREATE_BIND_SFR_BIT_KHX

=== New Enums

  * slink:VkPeerMemoryFeatureFlagBitsKHX
  * slink:VkMemoryAllocateFlagBitsKHX
  * slink:VkDeviceGroupPresentModeFlagBitsKHX

=== New Structures

  * slink:VkMemoryAllocateFlagsInfoKHX
  * slink:VkDeviceGroupRenderPassBeginInfoKHX
  * slink:VkDeviceGroupCommandBufferBeginInfoKHX
  * slink:VkDeviceGroupSubmitInfoKHX
  * slink:VkDeviceGroupBindSparseInfoKHX
  * slink:VkDeviceGroupPresentCapabilitiesKHX
  * slink:VkImageSwapchainCreateInfoKHX
  * slink:VkBindImageMemorySwapchainInfoKHX
  * slink:VkAcquireNextImageInfoKHX
  * slink:VkDeviceGroupPresentInfoKHX
  * slink:VkDeviceGroupSwapchainCreateInfoKHX
  * slink:VkBindBufferMemoryDeviceGroupInfoKHX
  * slink:VkBindImageMemoryDeviceGroupInfoKHX

=== New Functions

  * flink:vkGetDeviceGroupPeerMemoryFeaturesKHX
  * flink:vkCmdSetDeviceMaskKHX
  * flink:vkGetDeviceGroupPresentCapabilitiesKHX
  * flink:vkGetDeviceGroupSurfacePresentModesKHX
  * flink:vkAcquireNextImage2KHX
  * flink:vkCmdDispatchBaseKHX
  * flink:vkGetPhysicalDevicePresentRectanglesKHX

=== New Built-In Variables

  * <<interfaces-builtin-variables-deviceindex,code:DeviceIndex>>

=== New SPIR-V Capabilities

  * <<spirvenv-capabilities-table-devicegroup,code:DeviceGroup>>

=== Issues

None.

=== Examples

TODO

=== Version History

 * Revision 2, 2017-05-19 (Tobias Hector)
   - Removed extended memory bind functions to VK_KHR_bind_memory2, added
     dependency on that extension, and device-group-specific structs for
     those functions.
 * Revision 1, 2016-10-19 (Jeff Bolz)
   - Internal revisions