Re: how to keep time of windows pvhvm synchronized with host after resuming

[ANNIE LI <annie.li@oracle.com>]

Sorry for my slow response since vacation in China now. :-)
>
> I had expected arch_set_info_guest() to be called for every vcpu in the
> HVM guest on restore, because boot_vcpu() is called from hvm_load_cpu_ctxt().
arch_set_info_guest is called when vm is booting, but it is not called 
on HVM guest restore.
I will check boot_vcpu() and hvm_load_cpu_ctxt() further.
> Yes, do_settime() updates the master copy of wc_sec and wc_nsec from its
> inputs, and then copies them to all domains' private copies.  So the
> question is:
>   - is the _master_ copy of wc_sec always zero; or
 From my recent logs, wc_sec is not zero, but it always keeps as certain 
unchanged value. In do_settime(...),
Input parameters secs, nsecs and system_time_base change every time when 
calling this function. But wc_secs
keep unchanged although it is calculated from those 3 parameters by: 
(secs * 1000000000ULL) + (u64)nsecs - system_time_base;
Anything wrong here?
>   - is the master copy right and the HVM domain's copy wrong; or
Is update_domain_wallclock_time doing HVM domain's copy? From my log, 
wc_secs of HVM domain's copy is
same as that of master copy.
>   - is the HVM domain's copy right as seen from Xen but
>     wrong as seen from the tools inside the guest?
wc_secs value from tools inside the guest is same as HVM domain's copy.
> (i.e. is wallclock broken, is propagation broken, or are the tools and
> Xen using different layouts for the shared_info page?)
Maybe something wrong, it seems the log printed is not identical with 
what you expected.

Thanks
Annie.