On Wed, Sep 12, 2012 at 05:42:58PM +0200, Jan Kiszka wrote:
> On 2012-09-12 17:06, Gleb Natapov wrote:
> >>>> Are there other issues with reinjection that people are aware of? Does
> >>>> anything seem obviously wrong with the above?
> >>>
> >>> We should take the chance and design everything in a way that the HPET
> >>> can finally be (left) enabled.
> >>
> >> I thought the issue with the HPET was access frequency and the cost of
> >> heavy weight exits.
> >>
> >> I don't have concrete data here. I've only heard it second hand. Can
> >> anyone comment more?
> >>
> > There is no any reason whatsoever to emulate HPET for Windows. It will
> > make it slower. Hyper-V does not emulate it. For proper time support in
> > Windows we need to implement relevant part of Hyper-V spec.
>
> There are two reasons to do it nevertheless:
>
> - QEMU is not Hyper-V. We are emulating the HPET already, and we
> expose it by default. So we should do it properly.
>
> - The time drift fix for the RTC is still a hack. Adding a second user
> would force us to finally clean it up.
>
I am not saying we should not emulate HPET in QEMU, I am saying there
is not reason to emulate it for Windows :)
--
Gleb.
