[PATCH kernel] vfio_pci_nvlink2: Do not attempt NPU2 setup on old P8's NPU

[Alexey Kardashevskiy]

On 13/11/2020 16:30, Andrew Donnellan wrote:
> On 13/11/20 4:06 pm, Alexey Kardashevskiy wrote:
>> We execute certain NPU2 setup code (such as mapping an LPID to a device
>> in NPU2) unconditionally if an Nvlink bridge is detected. However this
>> cannot succeed on P8+ machines as the init helpers return an error other
>> than ENODEV which means the device is there is and setup failed so
>> vfio_pci_enable() fails and pass through is not possible.
>>
>> This changes the two NPU2 related init helpers to return -ENODEV if
>> there is no "memory-region" device tree property as this is
>> the distinction between NPU and NPU2.
>>
>> Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] 
>> subdriver")
>> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> 
> Should this be Cc: stable?

This depends on whether P8+ + NVLink was ever a  product (hi Leonardo) 
and had actual customers who still rely on upstream kernels to work as 
after many years only the last week I heard form some Redhat test 
engineer that it does not work. May be cc: stable...


-- 
Alexey