Re: Re: Xen-unstable save error

[Michal Novotny <minovotn@redhat.com>]

On 06/22/2010 08:48 AM, Jan Beulich wrote:
>>>> On 22.06.10 at 08:23, Michal Novotny<minovotn@redhat.com>  wrote:
>>>>          
>> Jan, as we were solving this with Keir on the list I was unable to save
>> the HVM guest properly and reverting your c/s 21615 helped and with your
>> patch reverted it was working fine. Any idea why there were so type
>> failures for all the pages of HVM guest?
>>      
> Not really, and I think you will need to find out by instrumenting the
> hypercall implementation (XEN_DOMCTL_getpageframeinfo{2,3}) -
> really, type failures should only happen for grant frames and I/O
> memory pages (as you can see in the code, for the function to
> report XTAB either the MFN must be invalid, must be a Xen frame,
> or it must be impossible to obtain a reference to the page - all of
> which shouldn't hold for the majority of a HVM guest's pages).
>
> Btw., Keir, is it really correct for the type to be returned as zero
> (normal page) when xsm_getpageframeinfo() returns non-zero?
>
> Is there anything special about the guest you're trying to save? That
> patch was tested quite extensively here before submission...
>
> Jan
>    

Nothing special, the guest is RHEL-5 i386 HVM guest with the serial 
console enabled in /boot/grub/grub.conf to be able to access it using 
the `xm console` command. It returns no error printed to the xend.log 
(except when I added the debug output) but the total size of the 'ls 
-alh /path/to/save/file' (after the save) is 54M instead of > 1G (the 
guest memory size).

Michal

-- 
Michal Novotny<minovotn@redhat.com>, RHCE
Virtualization Team (xen userspace), Red Hat