While there is already Virgl for allowing OpenGL within QEMU, for those making use of the Venus Vulkan driver, the latest additions to Mesa 23.2-devel aim to enhance the Zink support for going that route with OpenGL support.
Juston Li of Google has added support for VK_EXT_non_seamless_cube_map, VK_KHR_shader_clock, VK_EXT_dynamic_rendering_unused_attachments, VK_EXT_fragment_shader_interlock, and a few other extensions. These extensions can allow for more optimal use of the Zink OpenGL-on-Vulkan implementation.
Those making use of the Venus Vulkan driver wanting to find out more details on these Zink-focused additions can see this merge request of the now-merged code into Mesa 23.2. Google for their part works on Venus as part of their Chrome OS efforts.