From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Date: Wed, 29 Apr 2009 17:38:45 +0000
Subject: Re: [Qemu-devel] [PATCH 4/7] kvm: Add sanity checks to slot management
Message-Id: <49F890A5.8000405@codemonkey.ws>
List-Id: <kvm-ppc.vger.kernel.org>
References: <20090411172025.32383.77687.stgit@mchn012c.ww002.siemens.net>	<20090411172026.32383.7492.stgit@mchn012c.ww002.siemens.net>	<0A1FE637C2C7E148B9573BB60CC630E5210713@zch01exm26.fsl.freescale.net>	<49F82E09.3070702@siemens.com>
	<1241025000.24990.51.camel@slate.austin.ibm.com>
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To: Hollis Blanchard <hollisb@us.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Liu Yu-B13201 <Yu.Liu@freescale.com>, qemu-devel@nongnu.org, kvm-ppc@vger.kernel.org

Hollis Blanchard wrote:
> On Wed, 2009-04-29 at 12:38 +0200, Jan Kiszka wrote:
>   
>> What is the alignment of those regions then? None? And do regions of
>> different types overlap even on the same page? Maybe the check reveals
>> some deeper conflict /wrt KVM. Can you point me to the involved code files?
>>     
>
> These PCI controllers make separate calls to
> cpu_register_physical_memory() for separate callbacks. Reading
> ppce500_pci_init(), for example:
> 0xe0008000 -> CFGADDR (4 bytes)
> 0xe0008004 -> CFGDATA (4 bytes)
> 0xe0008c00 -> other registers
>   

That's goofy.  If the single device owns the entire region, it should 
region the entire region instead of relying on subpage functionality.

If just requires a switch() on the address to dispatch to the 
appropriate functions.  It should be easy enough to fix.

Regards,

Anthony Liguori