Disabling nested paging may help but Windows 9x still remains an unsupported guest OS in VirtualBox. The bottom line is that this is not a regression and it's not something VirtualBox can fix.
Intel has done such things too, various old operating systems no longer work on current Intel CPUs because they did things that they shouldn't have done, and they're no longer commercially important. You can complain to AMD but they will very likely tell you that this is a bug in Win9x that they have no desire working around. Please note that Windows 9x is known to have serious problems on fast CPUs.Īlso note that the first generation Ryzens had a bug related to VME (Virtual-8086 Mode Extensions) but VirtualBox works around that and AMD fixed that a long ago. But disabling nested paging does a lot, because it hides the TLB management problem referenced above. The method Windows 9x uses to manage page tables does not work (reliably) on AMD Bulldozer and Ryzen CPUs, and it probably only works by accident on other CPUs.ĭisabling the I/O APIC of course does nothing, Windows 9x does not use it. I believe this blog post explains what the problem is. Google for 'windows 98 ryzen crash' and you will see that this is not a problem with VirtualBox, it's a problem with Ryzen CPUs and Windows 9x, or more likely a bug in Windows 9x. Before opening such tickets, please do some due diligence first.
