On Mon, May 20, 2013 at 11:32:27AM +0200, Paolo Bonzini wrote: > Il 20/05/2013 11:25, Gleb Natapov ha scritto: > > So in Hyper-V spec they > > say: > > > > Special value of 0xFFFFFFFF is used to indicate that this facility is no > > longer a reliable source of reference time and the virtual machine must > > fall back to a different source (for example, the virtual PM timer). > > > > May be they really mean "virtual PM timer" here and reference counter is > > not considered as a fall back source, but this is not what we want. > > > > On the other hand in API specification [1] they have: > > > > #define HV_REFERENCE_TSC_SEQUENCE_INVALID (0x00000000) > > > > which is not even documented in hyper-v spec. Actually 0 is specified as > > valid value there. Go figure. > > > > [1] http://msdn.microsoft.com/en-us/library/windows/hardware/ff540244%28v=vs.85%29.aspx > > Ok, if the API document is right then we should use > HV_REFERENCE_TSC_SEQUENCE_INVALID instead of 0, with a comment > explaining why we use 0 and not 0xFFFFFFFF. > Using define is always a good idea no matter if API doc is right or hyper-v spec is, it's just the "decent documentation" part that got me :) Definitely better than nothing and thanks them for that. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
