Re: [Qemu-devel] [PATCH qemu] vmstate: Define VARRAY with VMS_ALLOC

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Alexey Kardashevskiy (aik@ozlabs.ru) wrote:
> This allows dynamic allocation for migrating arrays.
> 
> Already existing VMSTATE_VARRAY_UINT32 requires an array to be
> pre-allocated, however there are cases when the size is not known in
> advance and there is no real need to enforce it.
> 
> This defines another variant of VMSTATE_VARRAY_UINT32 with WMS_ALLOC
> flag which tells the receiving side to allocate memory for the array
> before receiving the data.
> 
> The first user of it is the "pseries" machine (POWER8) with
> dynamic DMA windows which existence and size are totally dynamic.

You say totally dynamic, how big do they get out of interest?

Dave

> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> ---
> 
> 
> As David suggested, I am posting it alone (separately from the DDW patchset).
> 
> It would be nice either to get "ack" to get this pulled via the powerpc
> tree or get it pulled to the upstream via some other tree. Thanks!
> 
> 
> 
> ---
>  include/migration/vmstate.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
> index 84ee355..1622638 100644
> --- a/include/migration/vmstate.h
> +++ b/include/migration/vmstate.h
> @@ -386,6 +386,16 @@ extern const VMStateInfo vmstate_info_bitmap;
>      .offset     = vmstate_offset_pointer(_state, _field, _type),     \
>  }
>  
> +#define VMSTATE_VARRAY_UINT32_ALLOC(_field, _state, _field_num, _version, _info, _type) {\
> +    .name       = (stringify(_field)),                               \
> +    .version_id = (_version),                                        \
> +    .num_offset = vmstate_offset_value(_state, _field_num, uint32_t),\
> +    .info       = &(_info),                                          \
> +    .size       = sizeof(_type),                                     \
> +    .flags      = VMS_VARRAY_UINT32|VMS_POINTER|VMS_ALLOC,           \
> +    .offset     = vmstate_offset_pointer(_state, _field, _type),     \
> +}
> +
>  #define VMSTATE_VARRAY_UINT16_UNSAFE(_field, _state, _field_num, _version, _info, _type) {\
>      .name       = (stringify(_field)),                               \
>      .version_id = (_version),                                        \
> -- 
> 2.5.0.rc3
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK