On 03/27/2018 04:01 PM, Tan, Jianfeng wrote:
On 3/27/2018 7:28 PM, Maxime Coquelin wrote:
On 03/27/2018 11:42 AM, Tan, Jianfeng wrote:
On 3/27/2018 5:24 PM, Chen, Junjie J wrote:
On 3/28/2018 12:05 AM, Junjie Chen wrote:
when creating vdev dynamically, vhost pmd driver start directly
without checking TX/RX queues ready or not, and thus cause
segmentation fault when vhost library accessing queues. This patch
add flag to check whether queues setup or not, and add driver start
call into dev_start to allow user start it after setting up queue.
The issue is clear now. But this patch just puts the situation
before below
fix:
"it doesn't create the actual datagram socket until you call
.dev_start()."
No, if the queue exist, the datagram socket still get created in
vhost_create
API, since the vhost_driver_register still exist in vhost_create.
The queue can never be created, as it's still not probed.
I think we need to separate this into two cases:
Statically create vdev, the datagram recreate logical is still
there since queues are exist already, this patch doesn't change
anything.
Dynamic create vdev, as you pointed out, queue can never be
created, while this should be not valid since In normal process of
creating vdev dynamically, we always need to config queues. Correct
me if I'm wrong.
My point is, either vdev is created statically or dynamically, when
probe(), queues are not setup yet definitely, then *the unix socket
will not be created* until we set up the queues and do dev_start().
If the unix socket is not created, then VM cannot connect to it.
FYI, I think I reproduced such an issue with the vdev statically created
in the past, while doing some experiments. I didn't went further into
the analysis at that time, but it looks like the issue Junjie is trying
to address with this patch for dynamically created vdev.
Yes, I have noticed that this issue mostly happens at dynamic case. Just
try to suggest a proper way to fix. Please check if my suggestion in
another email makes sense.
Yes, it makes sense, that's the right thing to do I think.
Thanks,
Maxime
Thanks,
Jianfeng
Cheers,
Maxime
