Re: [RFC] fix VMX TSC synchronicity

Andi Kleen
2008-01-17T18:56:49Z

> And turning of the TSC bit (for 32-bit guests).

Turning off the TSC bit will break 64bit Linux (it checks
if the cpuid bits have minimum supported features) and you don't know
in advantage if a guest is 32bit or not.

Ok there is a special BIOS call that the kernel issues to tell
the BIOS that it is 64bit -- in theory you could intercept that
one and then disable the TSC bit, but it doesn't sound very clean.

Also that call wasn't in the very first 64bit kernels.

-Andi