VMWare / Vbox / HYPER-V Virtual Bios and Chipset

jimbo45 · 07 Apr 2021

Hi folks

Does anybody here know of the specifications of the VMWare and Vbox virtual Bios and the emulation chipset they use. It must be pretty universal as the paravirtualised hardware works on most devices without issue -- i.e you can copy / move VM's more or less at will between different devices and host hardware (including CPU and GPU differences) -- assuming not using physical passthru of real HOST devices and other hardware.

On KVM/QEMU the BIOS is in the public domain so not a problem. SEABIOS for standard MBR and TIANOCORE for the EFI BIOS (also there's a secure boot option too).

I'd also be interested in the same for HYPER-V although Windows being quite strictly proprietary that might be under various "NDA's" so only give legal answers if you are in the know on that one.

Cheers
jimbo

Hopachi · 07 Apr 2021

I'll only add some brief info on what I know.

VirtualBox emulates ICH9 or PIIX3 chipset.
I didn't find much documentation about those but there is some in the manual to begin with and gets elaborated on the Vbox forum at some topics. The choice of chipset depends on selected guest since it must be supported by OS.
Chapter 3. Configuring Virtual Machines (chapter 3.5.1)
BIOS / EFI implementation must be open source but I'm no expert and I didn't dug in the sources to check. Though you can.
All settings can be changed in the VM file with .vbox extension which uses XML and so it's pretty much the closest 'structural' match to KVM / libvirt where XML is also used.

VMWare uses Phoenix BIOS, pretty much tailor-made for the hypervisor. I don't know much on this one so I'll see if someone else has more facts / data on this.

Hyper-V hides most of the boot stuff and VMs are stored in an own special format. I'm also curious about this one.