[dpdk-dev] [PATCH 0/2] Fix virtio-user multi-process crash.

[Tan, Jianfeng]

Hi Thomas,


On 4/7/2017 4:14 AM, Thomas Monjalon wrote:
> Ping
>
> 2017-03-08 12:40, Thomas Monjalon:
>> 2017-03-02 11:00, Ami Sabo:
>>> The patchset fixes secondary process crash issue when it tries
>>> to access virtio-user pmd (e.g. via rte_eth_rx_burst).
>>>
>>> The crash happens because in virtio_user probing,
>>> eth_dev_attach_secondary is not being called, as it does from
>>> rte_eth_dev_pci_probe. Therefore, the device is not properly
>>> initialized.
>>>
>>> The patchset contains 2 patches:
>>> 1. Export rte_eth_dev_attach_secondary, so non-pci drivers will be
>>> allowed to call it.
>>> 2. Fix the actual bug by calling the function during virtio_user probe.
>> I do not understand why nobody complains for other virtual devices.
>> We should have the same issue with pcap, tap, ring, af_packet, etc.

Yes, none of vdev except ring supports primary/secondary mode.

>> Probably that other drivers are broken in secondary processes.
>> Or should we make a fix to handle every secondary vdev in
>> rte_eth_dev_allocate() ?

Agreed. We can change the rte_eth_dev_allocate() like this:
if (primary)
     allocate();
else
     lookup(name);

Besides, we need each vdev to handle its private. For example, pcap 
should share the selectable unix fd with secondary process; virtio-user 
should share callfds and kickfds; tap should share the fd pointing to 
/dev/tun.

Thanks,
Jianfeng