WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] HVM Save/Restore status.

To: "Petersson, Mats" <Mats.Petersson@xxxxxxx>, "Tim Deegan" <Tim.Deegan@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] HVM Save/Restore status.
From: "Petersson, Mats" <Mats.Petersson@xxxxxxx>
Date: Wed, 25 Apr 2007 18:15:05 +0200
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, "Woller, Thomas" <thomas.woller@xxxxxxx>
Delivery-date: Wed, 25 Apr 2007 09:13:59 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <907625E08839C4409CE5768403633E0B018E1C5C@xxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AceHQ1NhmcwbUEeuQemQtofsXL8/jAAAMWQgAAIiRHAAAfGQEA==
Thread-topic: [Xen-devel] HVM Save/Restore status.
 

> -----Original Message-----
> From: Petersson, Mats 
> Sent: 25 April 2007 16:18
> To: Petersson, Mats; Tim Deegan
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Woller, Thomas
> Subject: RE: [Xen-devel] HVM Save/Restore status.
> 
>  
> 
> > -----Original Message-----
> > From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx 
> > [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of 
> > Petersson, Mats
> > Sent: 25 April 2007 15:25
> > To: Tim Deegan
> > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Woller, Thomas
> > Subject: RE: [Xen-devel] HVM Save/Restore status.
> > 
> >  
> > 
> > > -----Original Message-----
> > > From: Tim Deegan [mailto:Tim.Deegan@xxxxxxxxxxxxx] 
> > > Sent: 25 April 2007 15:09
> > > To: Petersson, Mats
> > > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Woller, Thomas
> > > Subject: Re: [Xen-devel] HVM Save/Restore status.
> > > 
> > > Hi, 
> > > 
> > > At 12:58 +0200 on 25 Apr (1177505885), Petersson, Mats wrote:
> > > > My "disk-stress" tests have the following status:
> > > > 1. SLES 9.3 using VNC as display has run for over 23 
> > > virtual hours, some
> > > > 40 or so hours since I set off the test without any failures.
> > > 
> > > That's great! 
> > > 
> > > > There's
> > > > one difference between this test and previous ones: I've 
> > > disabled the
> > > > blanking of the screen - there appears to be a problem 
> > > waking the screen
> > > > after some time, not sure why that would be. 
> > > 
> > > What are the symptoms there?  Is the guest still alive?  
> Is qemu-dm
> > > alive?  Does it respond on the network, and just have a 
> > > wedged console?
> > > (Might it be the keyboard + mouse that have got wedged?)
> > 
> > Good question. It turns out (from an attempt to stop the 
> guest nicely
> > when I was going to reboot to have a new Linux-kernel with 
> > debug code in
> > it) that although the guest is still running, I have 
> actually lost at
> > least:
> > - Network. I can't ping the guest or SSH to the guest on the 
> > IP address
> > it used to be when it first got an address from DHCP - 
> presumably, the
> > IP address shouldn't change (it doesn't on other machines 
> that get IP
> > address from the same DHCP server). 
> > - Keyboard. Pressing for example CTRL-C to stop the running 
> > application
> > doesn't work. No other keys appear to have any effect either.
> > 
> > It's unclear to me if any other operations are affected or 
> not. [Time
> > seemed a bit funny too, but that may be my app - I haven't 
> > debugged that
> > yet. It kept cycling around a 2-3 second range around 
> 23h14m18-20s (or
> > some such), where the time comes from "time()" - so perhaps there's
> > something wrong in the "gettimeofday" functionality too.] 
> > 
> > > 
> > > > 2. "Simple-guest" fails to restore on the second restore, 
> > > ending up with
> > > > the guest "killed". Scanning the xend.log, I find "error 
> > > zeroing magic
> > > > pages". Looking further down that path, it seems like it's 
> > > failing to do
> > > > "xc_map_foreign_range"... I'm adding some debug output to try to
> > > > determine where it goes wrong here. 
> > > 
> > > Strange.  Are you doing anything wierd with the ioreq or 
> > > xenstore pages
> > > in the simple guest?  Their PFNs should have been maintained 
> > > across the
> > > first save/restore cycle, and they were mappable the first time...
> > 
> > I'm trying to see what fails and where by printing 
> something at every
> > failure point. So far I've tracked it down to somewhere inside the
> > function direct_remap_pfn_range... Not sure where in this 
> function it
> > goes wrong or where in any of the called functions. As far as 
> > I can see,
> > there's not many things that can go wrong there... 
> 
> Error is 14, which is "EFAULT", which means that the problem 
> appears to be inside the hypercall. 
> 
> I'll see if I can print the different pages involved here. 

So, a few printf later: The first time (which succeds) and the second
time (which fails) is exactly the same frame numbers (1fff, 1ffe, 1ffd).
It fails on the FIRST (I split the "if( ... [0] || ... [1] || ... [2] )"
into separate lines, and print the failure on each with a "[n]" to
indicate which one failed, and it got [0] in the printout. 

--
Mats

> 
> Also, I missed answering the question of what I do with those 
> pages: Nothing. My guest uses about 2MB of the entire 32MB 
> memory range, around 1MB-3MB. 
> 
> --
> Mats
> > 
> > --
> > Mats
> > > 
> > > Cheers,
> > > 
> > > Tim.
> > > 
> > > -- 
> > > Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>, XenSource UK Limited
> > > Registered office c/o EC2Y 5EB, UK; company number 05334508
> > > 
> > > 
> > > 
> > 
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> > 
> > 
> > 



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel