Re: [Qemu-devel] [RFC QEMU PATCH 1/8] nvdimm: do not initialize label_data if label_size is zero

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Oct 10, 2016 at 08:34:16AM +0800, Haozhong Zhang wrote:
> When memory-backend-xen is used, the label_data pointer can not be got
> via memory_region_get_ram_ptr(). We will use other functions to get

Could you explain why it cannot be retrieved via that way?

> label_data once we introduce NVDIMM label support to Xen.

Is this an particular patch in this series that does that?
You may want to enumerate which one it is.

> 
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
> ---
> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> ---
>  hw/mem/nvdimm.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/mem/nvdimm.c b/hw/mem/nvdimm.c
> index 7895805..d25993b 100644
> --- a/hw/mem/nvdimm.c
> +++ b/hw/mem/nvdimm.c
> @@ -87,7 +87,9 @@ static void nvdimm_realize(PCDIMMDevice *dimm, Error **errp)
>      align = memory_region_get_alignment(mr);
>  
>      pmem_size = size - nvdimm->label_size;
> -    nvdimm->label_data = memory_region_get_ram_ptr(mr) + pmem_size;
> +    if (nvdimm->label_size) {
> +        nvdimm->label_data = memory_region_get_ram_ptr(mr) + pmem_size;
> +    }
>      pmem_size = QEMU_ALIGN_DOWN(pmem_size, align);
>  
>      if (size <= nvdimm->label_size || !pmem_size) {
> -- 
> 2.10.1
>