Messages in this thread | | | Date | Sun, 31 Aug 2008 12:27:51 -0700 | From | Arjan van de Ven <> | Subject | Re: [BUG] x86 kenel won't boot under Virtual PC |
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On Sun, 31 Aug 2008 11:47:04 -0700 (PDT) Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > > On Sun, 31 Aug 2008, David Sanders wrote: > > > > I recently discovered that x86 kernels won't boot under Virtual PC. > > What CPU does Virtual PC emulate? As far as Wikipedia is concerned > (not that I'd take it on complete faith) it emulates a 32-bit Intel > Pentium II. > > And that commit makes the kernel use the "P6 nops" for such hardware. > Maybe Virtual PC doesn't support the newer intel nop things? > > Intel docs say that it should be available on any intel CPU that has > CPUID.01H.EAX[11:8] = 0110B or 1111B. That's the "family ID", and > Pentium II should have a family ID of 6 (ie that 0110B case). > > So it sounds like a Virtual PC bug, but I dunno. And maybe we should > just use the legcay nops for anything that isn't modern (ie P4+ or > Core)?
it's probably even a security bug in that I don't see what would be stopping a ring 3 user process from executing these instructions...
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