Re: [PATCH 0/6] x86/HVM: RTC/VPT adjustments

[George Dunlap <george.dunlap@eu.citrix.com>]

On 02/05/13 07:58, Jan Beulich wrote:
>>>> On 01.05.13 at 18:15, George Dunlap <george.dunlap@eu.citrix.com> wrote:
>> On 29/04/13 14:42, Jan Beulich wrote:
>>> 1: fix processing of RTC REG_B writes
>>> 2: slightly adjust RTC reset
>>> 3: adjust IRQ (de-)assertion
>>> 4: properly handle RTC periodic timer even when !RTC_PIE
>>> 5: fix legacy PIC check in pt_update_irq()
>>> 6: RTC code must be in line with WAET flags passed by hvmloader
>>>
>>> This fixes the Win2003 boot failure George reported. Roger, since
>>> the first patch is slightly different from what you tested earlier,
>>> could you re-test that patch alone and the full series against
>>> FreeBSD?
>>>
>>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> This series seems to fix the w2k3 issue -- but it looks like a series of
>> "fixes and updates".  I thought we had decided to revert all the RTC
>> changes?
> I always said I'd prefer a partial revert over a full one, if at all
> possible. Of course I'm not intending to enforce this in any way,
> but I'm also not intending to myself revert good fixes (and drop
> further ones, as presented in this series) without need. So my
> proposed solution is this series of patches (which is a partial
> revert in terms of functionality, but not any kind of revert in terms
> of source code) - others can certainly propose other solutions.
> This is even more so now that we know that the reason for the
> observed regression weren't the RTC changes themselves, but
> the expectation of non-spec-conforming emulation behavior by
> the guest.

OK -- well I'll leave it to you and Tim to judge; just let me remind you 
of our primary goals at this point (in order of importance):

1. A bug-free 4.3 release
2. An awesome 4.3 release
3. An on-time 4.3 release

And that for #1, in particular we're worried about bugs that that may 
not be detected until after the release.

If you think this series optimizes those goals from a risk / benefits 
perspective, then I'm OK with it.

  -George