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Date: Sat, 31 Oct 2015 13:52:30 +0300
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
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Subject: Re: [Qemu-devel] [PATCH v6 18/33] dimm: get mapped memory region
 from DIMMDeviceClass->get_memory_region
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To: Xiao Guangrong <guangrong.xiao@linux.intel.com>, pbonzini@redhat.com, imammedo@redhat.com
Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, dan.j.williams@intel.com, rth@twiddle.net

On 30.10.2015 08:56, Xiao Guangrong wrote:
> Curretly, the memory region of backed memory is directly mapped to
> guest's address space, however, it is not true for nvdimm device
>
> This patch let dimm device realize this fact and use
> DIMMDeviceClass->get_memory_region method to get the mapped memory
> region
>
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>   hw/mem/dimm.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/mem/dimm.c b/hw/mem/dimm.c
> index 4a63409..498d380 100644
> --- a/hw/mem/dimm.c
> +++ b/hw/mem/dimm.c
> @@ -377,8 +377,9 @@ static void dimm_get_size(Object *obj, Visitor *v, void *opaque,
>       int64_t value;
>       MemoryRegion *mr;
>       DIMMDevice *dimm = DIMM(obj);
> +    DIMMDeviceClass *ddc = DIMM_GET_CLASS(obj);
>   
> -    mr = host_memory_backend_get_memory(dimm->hostmem, errp);
> +    mr = ddc->get_memory_region(dimm);
>       value = memory_region_size(mr);
>   
>       visit_type_int(v, &value, name, errp);

Isn't it better to add Error** parameter to get_memory_region and not 
mix returning error in errp parameter and aborting through &error_abort?

-- 
Best regards,
Vladimir
* now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.