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Date: Tue, 26 May 2015 15:48:38 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH qemu v7 06/14] spapr_iommu: Introduce
 "enabled" state for TCE table
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To: Alexey Kardashevskiy <aik@ozlabs.ru>, David Gibson <david@gibson.dropbear.id.au>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>, Alex Williamson <alex.williamson@redhat.com>, qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>



On 26/05/2015 15:42, Alexey Kardashevskiy wrote:
> 
> 
> The next patch of this patchset changes:
> spapr_tce_table_do_enable()
>     memory_region_init_iommu(&iommu)
>     memory_region_add_subregion(&root, &iommu)
> 
> spapr_tce_table_disable()
>     memory_region_del_subregion(&root, &iommu)
>     object_unref(&iommu)
> 
> These spapr_tce_xxx are called by request from the guest. &root is a
> container and exists as long as sPAPRTCETable exists.
> 
> Where do I get a leaking child property here?

When you unref iommu and not unparent it.  The next
memory_region_init_iommu creates a second child property, and the first
is gone.

What is different between the various IOMMU regions, so that you cannot
create just one?

Paolo