Avi Kivity wrote: > Dong, Eddie wrote: >>>> I don't know if the patch was still needed now, since it was posted >>>> long ago(I don't know which issue it solved). I'd like to post a >>>> revert patch if necessary. >>>> >>> I believe the patch is still necessary, since we still need to >>> guarantee that a vcpu's tsc is monotonous. I think there are three >>> issues to be addressed: >>> >>> 1. The majority of intel machines don't need the offset adjustment >>> since they already have a constant rate tsc that is synchronized on >>> all cpus. I think this is indicated by X86_FEATURE_CONSTANT_TSC >>> (though I'm not 100% certain if it means that the rate is the same >>> for all cpus, Thomas can you clarify?) >>> >> >> So why not make the TSC_OFFSET adjustment conditional? >> > > Yes, that's what I meant. We just need to be sure that this is what > X86_FEATURE_CONSTANT_TSC means.
I changed tsc offset adjustment to only allow forward adjustment. Since hosts with synced tsc never require positive adjustment, they should now have better quality tsc. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
