Re: [PATCH 1/2] VMware detection support for x86 and x86-64

H. Peter Anvin
2008-09-17T15:39:42Z

Ingo Molnar wrote:
>
> that still leaves the CPUID/MSR method for the virtualizer to announce
> itself.
>

FWIW, it's getting pretty clear with the recent bout of Virtual PC bugs
that we need virtualizer detection, and that a lot of VMs are doing
various idiotic things.

Again, with Virtual PC, it seems that DMI is the preferred detection
method, as disgusting as it is, simply because the alternatives are the
moral equivalent of ad hoc probing for ISA cards (a random I/O port for
VMWare, a random "hopefully unused" opcode for VPC.)

>> I feel It's also unfit to touch the whole PCI or DMI thing before CPU
>> registers and memory are settled. A simple solution here is to only
>> issue a KERN_INFO when we detected mtrr is empty and later, when we
>> can be sure that the OS is not running as a VM, issue a warning. The
>> later part can be done in early_quirks().
>
> ok, we can move the MTRR message further back, to after the early quirks
> phase.

Makes sense to me.

-hpa