[libvirt] [PATCHv3 10/12] qemu: conf: Add support for memory device cold(un)plug

John Ferlan jferlan at redhat.com
Fri Mar 20 11:40:21 UTC 2015


>>> I have tested your series with our qemu memory hot remove patch series,
>>> here would be a possible error.
>>>
>>> When hotplug a memory device, its size has been aligned. So the
>>> compare for
>>> size here would fail possiblely.
>>>
>> hmm.. Not sure that's necessary - although Peter can make the final
>> determination... Commit id '57b215a' doesn't modify each def->mems[i]
>> entry in qemuDomainAlignMemorySizes, rather it gets a value from
>> virDomainDefSetMemoryInitial and then does the rounding.
>>
>> If the stored def->mems[i]->size value is/was modified, then I'd agree,
>> but it doesn't appear to be that way.
>>
>> If there is a rounding of the value - then please just point it out
> 
> Yes, the stored def->mems[i]->size value was modified.
> If you assign the size 524287 KiB, the stored value will be 524288.
> 
> Thanks,
> Zhu
> 

Ah - found it - patch 9 has:

+    /* Align memory module sizes */
+    for (i = 0; i < def->nmems; i++)
+        qemuDomainMemoryDeviceAlignSize(def->mems[i]);
+

Which I missed on my first foray through this. Once I cscope'd on
VIR_ROUND_UP() instead of ->size, it became apparent

So yes, it seems the to be compared size needs a likewise adjustment.

John




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