Name

VK_EXT_nested_command_buffer - device extension

VK_EXT_nested_command_buffer

Name String

VK_EXT_nested_command_buffer

Extension Type

Device extension

Registered Extension Number

452

Revision

1

Ratification Status

Not ratified

Extension and Version Dependencies

VK_KHR_get_physical_device_properties2

Contact

• Piers Daniell @pdaniell-nv%0A*Here describe the issue or question you have about the VK_EXT_nested_command_buffer extension*

Other Extension Metadata

Last Modified Date

2023-09-18

Contributors

• Daniel Story, Nintendo
• Peter Kohaut, NVIDIA
• Shahbaz Youssefi, Google
• Slawomir Grajewski, Intel
• Stu Smith, AMD

Description

With core Vulkan it is not legal to call cmdExecuteCommands when recording a secondary command buffer. This extension relaxes that restriction, allowing secondary command buffers to execute other secondary command buffers.

New Structures

• Extending PhysicalDeviceFeatures2, DeviceCreateInfo:

  • PhysicalDeviceNestedCommandBufferFeaturesEXT

• Extending PhysicalDeviceProperties2:

  • PhysicalDeviceNestedCommandBufferPropertiesEXT

New Enum Constants

• EXT_NESTED_COMMAND_BUFFER_EXTENSION_NAME

• EXT_NESTED_COMMAND_BUFFER_SPEC_VERSION

• Extending RenderingFlagBits:

  • RENDERING_CONTENTS_INLINE_BIT_EXT

• Extending StructureType:

  • STRUCTURE_TYPE_PHYSICAL_DEVICE_NESTED_COMMAND_BUFFER_FEATURES_EXT
  • STRUCTURE_TYPE_PHYSICAL_DEVICE_NESTED_COMMAND_BUFFER_PROPERTIES_EXT

• Extending SubpassContents:

  • SUBPASS_CONTENTS_INLINE_AND_SECONDARY_COMMAND_BUFFERS_EXT

Issues

1) The Command Buffer Levels property for the Vulkan commands comes from the cmdbufferlevel attribute in vk.xml for the command, and it is currently not possible to modify this attribute based on whether an extension is enabled. For this extension we want the cmdbufferlevel attribute for vkCmdExecuteCommands to be primary,secondary when this extension is enabled and primary otherwise.

RESOLVED: The cmdbufferlevel attribute for cmdExecuteCommands has been changed to primary,secondary and a new VUID added to prohibit recording this command in a secondary command buffer unless this extension is enabled.

Version History

• Revision 1, 2023-09-18 (Piers Daniell)

  • Internal revisions

See Also

PhysicalDeviceNestedCommandBufferFeaturesEXT, PhysicalDeviceNestedCommandBufferPropertiesEXT

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.