Constant vk_mem_erupt::ffi::VmaMemoryUsage_VMA_MEMORY_USAGE_GPU_ONLY

pub const VmaMemoryUsage_VMA_MEMORY_USAGE_GPU_ONLY: VmaMemoryUsage = 1;

Memory will be used on device only, so fast access from the device is preferred. It usually means device-local GPU (video) memory. No need to be mappable on host. It is roughly equivalent of D3D12_HEAP_TYPE_DEFAULT.

Usage:

• Resources written and read by device, e.g. images used as attachments.
• Resources transferred from host once (immutable) or infrequently and read by device multiple times, e.g. textures to be sampled, vertex buffers, uniform (constant) buffers, and majority of other types of resources used on GPU.

Allocation may still end up in HOST_VISIBLE memory on some implementations. In such case, you are free to map it. You can use #VMA_ALLOCATION_CREATE_MAPPED_BIT with this usage type.