The performance is likely to be atrocious, but the Mesa Lavapipe driver implementing the Vulkan API for CPU-based execution has rolled out support for Vulkan ray-tracing.

Mesa developer Konstantin Seurer managed to implement support for VK_KHR_acceleration_structure, VK_KHR_deferred_host_operations, and VK_KHR_ray_query for Lavapipe. This Lavapipe Vulkan ray-tracing support is based in part on porting code from the emulated ray-tracing worked on for RADV with older Radeon GPUs.

With the merge request that landed this Vulkan ray-tracing support for Lavapipe, Konstantin Seurer shared the screenshot below and wrote "Don't ask about performance":

This (slow) CPU-based Vulkan ray-tracing will be found in Mesa 24.1. Lavapipe joins the Intel ANV and Radeon RADV drivers as the other Mesa Vulkan drivers currently supporting the ray-tracing extensions for Vulkan.