Re: [PATCH] xen: fix initialization of wallclock time for PVHVM on migration

[Keir Fraser <keir.xen@gmail.com>]

On 11/06/2013 15:16, "Jan Beulich" <JBeulich@suse.com> wrote:

>> Would it be OK to call
>> update_domain_wallclock_time unconditionally on
>> hvm_hypercall_page_initialise?
> 
> The primary question is - why is what we have not enough for you?
> In particular I would expect that the call from arch_set_info_guest()
> (for vCPU 0) should do what you want. Or wait, this is covering PV
> only. So yes, with the description change I would then withdraw my
> NACK - apparently no-one really used the shared info wall clock
> time in a HVM guest so far (or it going wrong post-resume wasn't
> noticed).
> 
> I would, however, prefer the if() immediately preceding the patch
> context to be pulled out past the domain_lock()ed region, convert it
> to switch(), and add your code. That was, eventual other post-
> processing for the various map spaces has a consistent, easily
> extensible home.

I apparently made a fix for this to work on initial boot of a 32-bit PVHVM
guest back in September (a change in hvmloader to not zero the wc fields in
shared_info). But I agree I now can't see why it works... But it surely does
as it was tested to do so by Konrad.

A bit more digging required...

 -- Keir