vkGetBufferDeviceAddress

To query a 64-bit buffer device address value through which buffer memory can be accessed in a shader, call:

VkDeviceAddress vkGetBufferDeviceAddressKHR(
    VkDevice device,
    const VkBufferDeviceAddressInfo* pInfo);

or the equivalent command

VkDeviceAddress vkGetBufferDeviceAddressEXT(
    VkDevice device,
    const VkBufferDeviceAddressInfo* pInfo);

• device is the logical device that the buffer was created on.
• pInfo is a pointer to a VkBufferDeviceAddressInfo structure specifying the buffer to retrieve an address for.

The 64-bit return value is an address of the start of pInfo→buffer. The address range starting at this value and whose size is the size of the buffer can be used in a shader to access the memory bound to that buffer, using the SPV_KHR_physical_storage_buffer extension or the equivalent SPV_EXT_physical_storage_buffer extension and the PhysicalStorageBuffer storage class. For example, this value can be stored in a uniform buffer, and the shader can read the value from the uniform buffer and use it to do a dependent read/write to this buffer. A value of zero is reserved as a null pointer and must not be returned as a valid buffer device address. All loads, stores, and atomics in a shader through PhysicalStorageBuffer pointers must access addresses in the address range of some buffer.

If the buffer was created with a non-zero value of VkBufferOpaqueCaptureAddressCreateInfo::opaqueCaptureAddress or VkBufferDeviceAddressCreateInfoEXT::deviceAddress, the return value will be the same address that was returned at capture time.

The returned address must satisfy the alignment requirement specified by VkMemoryRequirements::alignment for the buffer in VkBufferDeviceAddressInfo::buffer.

If multiple VkBuffer objects are bound to overlapping ranges of VkDeviceMemory, implementations may return address ranges which overlap. In this case, it is ambiguous which VkBuffer is associated with any given device address. For purposes of valid usage, if multiple VkBuffer objects can be attributed to a device address, a VkBuffer is selected such that valid usage passes, if it exists.