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RE: [Xen-devel] RE: [Xen-changelog] [PAE] Allow pgdirs above 4GB for par

To: "Keir Fraser" <Keir.Fraser@xxxxxxxxxxxx>
Subject: RE: [Xen-devel] RE: [Xen-changelog] [PAE] Allow pgdirs above 4GB for paravirt guests.
From: "Nakajima, Jun" <jun.nakajima@xxxxxxxxx>
Date: Sat, 27 May 2006 09:23:10 -0700
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Thread-topic: [Xen-devel] RE: [Xen-changelog] [PAE] Allow pgdirs above 4GB for paravirt guests.
It's same, but it can be exposing a bug with loading a wrong module.
Without the patch, it should complain like:

Loading scsi_mod.ko module
scsi_mod: version magic '2.6.15-1.2054_FC5smp SMP 686 REGPARM 4KSTACKS
gcc-4.1' should be ' SMP 686 gcc-3.4'
insmod: error inserting '/lib/scsi_mod.ko': -1 Invalid module format

With that patch, it hangs like that:

Loading scsi_mod.ko module

I don't see anything after (XEN). 

A quick debugging tells me that one processor is waiting at
smp_call_function and the other one has a bogus CR3, i.e. all four PDPT
entries are 0. I'll take a look later today if I have time.

Intel Open Source Technology Center 

-----Original Message-----
From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx] 
Sent: Saturday, May 27, 2006 2:05 AM
To: Nakajima, Jun
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] RE: [Xen-changelog] [PAE] Allow pgdirs above
4GB for paravirt guests.

On 26 May 2006, at 23:31, Nakajima, Jun wrote:

> Dom0 hangs with this patch when loading modules. If I back it out, it
> boots fine. I configured dom0 as SMP (and the machine has >4GB).

Is the hang just of domain0, not Xen? What happens if you force 
emulation of writable pagetables (no batching)?

  -- Keir

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