>> > Does it mean that this requires maintaining a new guest driver >> > different from the existing one on bare metal? >> >> No, the VM would use the same Nvidia open source driver that is used by the >> bare metal. (https://github.com/NVIDIA/open-gpu-kernel-modules). > > because this driver already supports two ways of accessing the aperture: > one via the firmware table, the other using this fake BAR2? Yes, exactly. The driver supports both ways. An absence of ACPI DSD device property describing the device memory (that happens for the virtualization case) when Qemu does not expose them via VM ACPI) provides an indication to the driver that it needs to use the fake BAR (and determine the memory properties from it); use the memory region otherwise.