nvme-tcp bricks my computer

[Sagi Grimberg]

>> Hi Sagi,
>>
>> I was able to capture a bit more info. Again, because my computer 
>> freezes (i.e. no keyboard or mouse response) I could only take a 
>> picture of the screen (attached). This does say NULL pointer dereference.
>>
>> To answer your questions:
>>
>> Q) Does this happen if you directly connect to a normal nvme controller?
>> A) I still need to try this. All I know is that it doesn't happen when 
>> the controller returns OAES[31]=0.
>>
>> Q) What is your target implementation? Is this the nvme target thatis 
>> built into Linux?
>> A) I work for Dell, and I'm on the same team as Douglas Farley and 
>> Erik Smith, whom I believe you've had discussions with. Dell is 
>> currently developing a Central Discovery Controller (CDC). That's the 
>> target I've been testing with. I need to find different targets I can 
>> test with but working from home makes it a bit difficult. I will check 
>> with my team tomorrow to see if I can connect to a different target.
>>
>> Q) Can you share your kernel config file?
>> Q) Can you run gdb on vmlinux and share what this provides?
>> A) I'll get that tomorrow (both questions).
> 
> For the record, I compiled Fedora 33 kernel and ran it on my VM
> and it doesn't happen. I also modified Linux nvme target to
> report the same limits as your target and still it doesn't happen.
> -- 
> [  162.006049] nvme nvme0: Failed to read smart log (error 24577)
> [  162.006060] nvme nvme0: queue_size 128 > ctrl sqsize 32, clamping down
> [  162.006063] nvme nvme0: sqsize 32 > ctrl maxcmd 31, clamping down
> [  162.006778] nvme nvme0: new ctrl: NQN 
> "nqn.2014-08.org.nvmexpress.discovery", addr 192.168.123.1:8009
> [  162.008939] nvme nvme0: Removing ctrl: NQN 
> "nqn.2014-08.org.nvmexpress.discovery"
> -- 
> 
> So something here seems to be specific to your env.

Hey Martin, any updates with this?