Yes, I had seen some reference to something like that. I think there is also an option to set the cpuid. Unfortunately, these features do not seem to be very well documented. For example, when I search google for "virtualbox synthcpu" I get your mailing list post on the first page of results, even though it was only sent 3 hours ago. However, the mailing list post that you linked to contains:
"By default, Guest OS sees the Host CPU features, and you will need to limit this. All the other hardware is fully abstract. AFAIK This is possible with VirtualBox, but not documented. i.e. to make VirtualBox always pass some kind of generic (old) CPU to guest, such as the old Pentium II chip." Of course, returning a restricted feature set when executing the cpuid instruction might not be the same as raising an illegal instruction exception when the guest OS tries to execute an instruction that the cpuid says it shouldn't be able to execute, but it would be a start if I could figure out how to do this. (And it isn't completely implausible to me that a virtual machine might be able to raise an illegal instruction exception, and thus more or less fully pretend to be an old cpu, but I also wouldn't be surprised if it could not.) If it doesn't take me more than a few minutes (of work -- I don't mind waiting for compilation) maybe I'll try to do this using QEMU tomorrow. But compile might take a really long time. On Sat, Dec 3, 2011 at 11:54 PM, Emil Widmann <emil.widm...@gmail.com>wrote: > > It seems that properties of the host CPU are passed over to the VM > > guest as indicated here, > https://forums.virtualbox.org/viewtopic.php?f=10&t=33954 > > Maybe there is a chance with VirtualBox: I found the following in the > documentation of the VBoxManage command: > VBoxManage --synthcpu on|off: This setting determines whether > VirtualBox will expose a synthetic CPU to the guest to allow live > migration between host systems that differ significantly. > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
