Re: [PATCH v2 3/3] qom: Link multiple numa nodes to device using a new object

[Ankit Agrawal]

>> An admin can provide the range of nodes using numa-node-start and
>> numa-node-count and link it to a device by providing its id. The following
>> sample creates 8 nodes and link them to the device dev0:
>> 
>>         -numa node,nodeid=2 \
>>         -numa node,nodeid=3 \
>>         -numa node,nodeid=4 \
>>         -numa node,nodeid=5 \
>>         -numa node,nodeid=6 \
>>         -numa node,nodeid=7 \
>>         -numa node,nodeid=8 \
>>         -numa node,nodeid=9 \
>>         -device 
>> vfio-pci-nohotplug,host=0009:01:00.0,bus=pcie.0,addr=04.0,rombar=0,id=dev0 \
>>         -object 
>> nvidia-acpi-generic-initiator,id=gi0,device=dev0,numa-node-start=2,numa-node-count=8
>>  
>
> If you go this way, use an array of references to the numa nodes instead of a 
> start and number.
> There is no obvious reason why they should be contiguous that I can see.

Right.

> I think it is simpler the other way around though - so have the numa nodes 
> point at the
> vfio-pci-nohotplug device. 
>
> Why not something like
> -numa node,gi=dev0 \
> -numa node,gi=dev0 \

That could be one way to do this vs the other suggestion on this thread to 
provide
a node list through the acpi-generic-initiator object.

Just that the Qemu init numa nodes before the vfio-pci device, which could 
affect
our ability to fail in case the user provides the wrong vfio-pci id.

I am fine with both approach. Will implement the node list option if there 
aren't
any strong opinion.

>> If you go this way, use an array of references to the numa nodes instead of 
>> a start and number.
>> There is no obvious reason why they should be contiguous that I can see.
>
> Yup, I was looking for other places we allow a list syntax, I only
> found fds=a:b:...:z, which is also used for vhostfds=.  I didn't find a
> property beyond the string type to hold this though.

Maybe something like 'node=1-3,8-10'?

> Right, a uint16List should do.

Sure, thanks.