Re: [Qemu-devel] [RFC v1 06/25] memory: MemoryRegion: Add container and addr props

[Peter Crosthwaite]

On Fri, May 16, 2014 at 11:53 AM, Peter Crosthwaite
<address@hidden> wrote:
> Expose the already existing .parent and .addr fields as QOM properties.
> Setting the address will cause the memory subregion adding to happen if
> it has not already. If the memory region is already contained, then
> change it's address as per the established memory_region_set_address()
> semantics.
>
> Signed-off-by: Peter Crosthwaite <address@hidden>
> ---
>
>  memory.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
>
> diff --git a/memory.c b/memory.c
> index a37fdd2..4a70920 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -16,6 +16,7 @@
>  #include "exec/memory.h"
>  #include "exec/address-spaces.h"
>  #include "exec/ioport.h"
> +#include "qapi/visitor.h"
>  #include "qemu/bitops.h"
>  #include "qom/object.h"
>  #include "trace.h"
> @@ -844,6 +845,49 @@ void memory_region_init(MemoryRegion *mr,
>      mr->name = g_strdup(name);
>  }
>
> +static void do_memory_region_add_subregion_common(MemoryRegion *subregion);
> +
> +static void memory_region_get_addr(Object *obj, Visitor *v, void *opaque,
> +                                   const char *name, Error **errp)
> +{
> +    MemoryRegion *mr = MEMORY_REGION(obj);
> +    Error *local_err = NULL;
> +    uint64_t value = mr->addr;
> +
> +    visit_type_uint64(v, &value, name, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +    }
> +}
> +
> +static void memory_region_set_addr(Object *obj, Visitor *v, void *opaque,
> +                                   const char *name, Error **errp)
> +{
> +    MemoryRegion *mr = MEMORY_REGION(obj);
> +    Error *local_err = NULL;
> +    uint64_t value;
> +
> +    visit_type_uint64(v, &value, name, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    /* In an ideal world we wait until both the parent and address is set in
> +     * either order, then call do_memory_region_add_subregion_common()
> +     * from the latter property setter. However, as parent is just a dumb 
> link
> +     * we only support setting from the address setter. We therefore assert
> +     * here that the two props are set in correct order.
> +     */

So I have a fix on this. I just rolled my own link property with
object_property_add (and a few callbacks) rather than use
object_property_add_link. The memory_region_add_subregion then happens
from the link setter.

Regards,
Peter