viewtopic.php?f=33&t=59935#p668661
As the extension to the above discussion, I simply tried recompiling my existing Glide3x guest wrapper with DJGPP GCC and fixed up all the plumbing for DJGPP DPMI implementation.
Update (2019/05/23): Fixed black screen issue when Q2DOS started directly into 3Dfx OpenGL.
Update (2019/05/25): QEMU 3Dfx main thread now includes the latest DJGPP DXE in the prebuilt binaries for guest wrappers.
viewtopic.php?f=24&t=60950#p680830
In theory, this should also work for other DJGPP DOS ports that use MesaFX/OpenGL for 3Dfx, such as QDOS/QWDOS/H2DOS.
With QEMU WHPX acceleration, the game was only a little faster than running in Win9x guest with QEMU TCG on AMD FX8300 CPU. The DJGPP DXE is a Glide3x driver, so at the moment, it will only work with Glide3x wrapper from host and for WIN64 this means only dgVoodoo2. Anyway, this is at least 2X more FPS than running on DOSBox SVN with voodoo chip emulation. Software rendering is very fast on QEMU WHPX acceleration, up to VESA 1024x768, with a decent desktop class CPU, but with different rendering quality.
Update: Attached Mesa-5.0.2 with Glide2x.dxe.