On Monday 13 March 2006 19:12, Zachary Amsden wrote: > Fairly straightforward code motion of MSR / TSC / PMC accessors > to the sub-arch level. Note that rdmsr/wrmsr_safe functions are > not moved; Linux relies on the fault behavior here in the event > that certain MSRs are not supported on hardware, and combining > this with a VMI wrapper is overly complicated. The instructions > are virtualizable with trap and emulate, not on critical code > paths, and only used as part of the MSR /proc device, which is > highly sketchy to use inside a virtual machine, but must be > allowed as part of the compile, since it is useful on native. I'm not aware of any MSR access being on a critical code path on a 32bit kernel. And I don't think it's a good idea to virtualize the TSC without CPU support. Why would you want to do any of this? -Andi
