Re: [PATCH v2] migration: Support gtree migration

[Daniel P . Berrangé]

On Thu, Oct 03, 2019 at 04:54:31PM +0200, Eric Auger wrote:
> Introduce support for GTree migration. A custom save/restore
> is implemented. Each item is made of a key and a data. For that
> reason, 2 VMSD objects are passed into the GTree VMStateField.
> 
> When putting the items, the tree is traversed in sorted order by
> g_tree_foreach.
> 
> On the get() path, gtrees must be allocated using the proper
> key compare, key destroy and value destroy. This can be done
> externally of automatically. If done automatically, the set of
> functions must be stored within the VMStateField in a new opaque
> pointer.
> 
> Automatic allocation is needed for complex state save/restore.
> For instance the virtio-iommu uses a gtree of domain and each
> domain has a gtree of mappings.
> 
> Special care was taken about direct key (ie. when the key is not
> a pointer to an object but is directly a value).
> 
> Tests are added to test save/dump of structs containing gtrees
> including the virtio-iommu domain/mappings scenario.
> 
> Signed-off-by: Eric Auger <address@hidden>
> 
> ---
> 
> diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c
> index bee658a1b2..06c4663de6 100644
> --- a/migration/vmstate-types.c
> +++ b/migration/vmstate-types.c
> @@ -17,6 +17,7 @@
>  #include "qemu/error-report.h"
>  #include "qemu/queue.h"
>  #include "trace.h"
> +#include <glib.h>

Not required, everything in QEMU includes this already.


Regards,
Daniel
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