[v2,03/15] pc-dimm: keep the state of the whole backend memory
diff mbox

Message ID 1463732412-99212-4-git-send-email-guangrong.xiao@linux.intel.com
State New
Headers show

Commit Message

Xiao Guangrong May 20, 2016, 8:20 a.m. UTC
QEMU keeps the state of memory of dimm device during live migration,
however, it is not enough for nvdimm device as its memory does not
contain its label data, so that we should protect the whole backend
memory instead

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
 hw/mem/pc-dimm.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

Comments

Stefan Hajnoczi May 30, 2016, 6:42 p.m. UTC | #1
On Fri, May 20, 2016 at 04:20:00PM +0800, Xiao Guangrong wrote:
> QEMU keeps the state of memory of dimm device during live migration,
> however, it is not enough for nvdimm device as its memory does not
> contain its label data, so that we should protect the whole backend
> memory instead
> 
> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> ---
>  hw/mem/pc-dimm.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
> index 6de2275..72b33ba 100644
> --- a/hw/mem/pc-dimm.c
> +++ b/hw/mem/pc-dimm.c
> @@ -105,9 +105,16 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
>      }
>  
>      memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
> -    vmstate_register_ram(mr, dev);
>      numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node);
>  
> +    /*
> +     * save the state only for @mr is not enough as it does not contain
> +     * the label data of NVDIMM device, so that we keep the state of
> +     * whole hostmem instead.
> +     */
> +    vmstate_register_ram(host_memory_backend_get_memory(dimm->hostmem, errp),
> +                         dev);
> +
>  out:
>      error_propagate(errp, local_err);
>  }

In Patch 1 you introduced a callback to get the guest-visible memory
region.  Instead of mentioning NVDIMM in generic pc-dimm.c code, it
would be cleaner to add another callback to get the vmstate memory
region:

  .get_guest_memory_region() - Patch 1
  .get_vmstate_memory_region() - a new patch in this series
Xiao Guangrong May 31, 2016, 2:04 a.m. UTC | #2
On 05/31/2016 02:42 AM, Stefan Hajnoczi wrote:
> On Fri, May 20, 2016 at 04:20:00PM +0800, Xiao Guangrong wrote:
>> QEMU keeps the state of memory of dimm device during live migration,
>> however, it is not enough for nvdimm device as its memory does not
>> contain its label data, so that we should protect the whole backend
>> memory instead
>>
>> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
>> ---
>>   hw/mem/pc-dimm.c | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
>> index 6de2275..72b33ba 100644
>> --- a/hw/mem/pc-dimm.c
>> +++ b/hw/mem/pc-dimm.c
>> @@ -105,9 +105,16 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
>>       }
>>
>>       memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
>> -    vmstate_register_ram(mr, dev);
>>       numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node);
>>
>> +    /*
>> +     * save the state only for @mr is not enough as it does not contain
>> +     * the label data of NVDIMM device, so that we keep the state of
>> +     * whole hostmem instead.
>> +     */
>> +    vmstate_register_ram(host_memory_backend_get_memory(dimm->hostmem, errp),
>> +                         dev);
>> +
>>   out:
>>       error_propagate(errp, local_err);
>>   }
>
> In Patch 1 you introduced a callback to get the guest-visible memory
> region.  Instead of mentioning NVDIMM in generic pc-dimm.c code, it
> would be cleaner to add another callback to get the vmstate memory
> region:
>
>    .get_guest_memory_region() - Patch 1
>    .get_vmstate_memory_region() - a new patch in this series
>

It is good to me, will do it. Thanks!
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Patch
diff mbox

diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 6de2275..72b33ba 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -105,9 +105,16 @@  void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
     }
 
     memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
-    vmstate_register_ram(mr, dev);
     numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node);
 
+    /*
+     * save the state only for @mr is not enough as it does not contain
+     * the label data of NVDIMM device, so that we keep the state of
+     * whole hostmem instead.
+     */
+    vmstate_register_ram(host_memory_backend_get_memory(dimm->hostmem, errp),
+                         dev);
+
 out:
     error_propagate(errp, local_err);
 }
@@ -116,10 +123,12 @@  void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
                            MemoryRegion *mr)
 {
     PCDIMMDevice *dimm = PC_DIMM(dev);
+    MemoryRegion *hostmem;
 
+    hostmem = host_memory_backend_get_memory(dimm->hostmem, &error_abort);
     numa_unset_mem_node_id(dimm->addr, memory_region_size(mr), dimm->node);
     memory_region_del_subregion(&hpms->mr, mr);
-    vmstate_unregister_ram(mr, dev);
+    vmstate_unregister_ram(hostmem, dev);
 }
 
 static int pc_existing_dimms_capacity_internal(Object *obj, void *opaque)