On Thu, Jan 25, 2018 at 06:19:13PM +0800, Wei Wang wrote:
On 01/24/2018 07:40 PM, Stefan Hajnoczi wrote:
On Tue, Jan 23, 2018 at 09:06:49PM +0800, Wei Wang wrote:
On 01/23/2018 07:12 PM, Stefan Hajnoczi wrote:
On Mon, Jan 22, 2018 at 07:09:06PM +0800, Wei Wang wrote:
On 01/19/2018 09:06 PM, Stefan Hajnoczi wrote:
- Suppose in the future there is also a kernel virtio-vhost-user driver as
other PCI devices, can we unbind the kernel driver first, and then bind the
device to the dpdk driver? A normal PCI device should be able to smoothly
switch between the kernel driver and dpdk driver.
It depends what you mean by "smoothly switch".
If you mean whether it's possible to go from a kernel driver to
vfio-pci, then the answer is yes.
But if the kernel driver has an established vhost-user connection then
it will be closed. This is the same as reconnecting with AF_UNIX
vhost-user.
Actually not only the case of switching to testpmd after kernel establishes
the connection, but also for several runs of testpmd. That is, if we run
testpmd, then exit testpmd. I think the second run of testpmd won't work.
The vhost-user master must reconnect and initialize again (SET_FEATURES,
SET_MEM_TABLE, etc). Is your master reconnecting after the AF_UNIX
connection is closed?
Is this an explicit qmp operation to make the master re-connect?
I haven't tested it myself but I'm aware of two modes of operation:
1. -chardev socket,id=chardev0,...,server
-netdev vhost-user,chardev=chardev0
When the vhost-user socket is disconnected the peer needs to
reconnect. In this case no special commands are necessary.
Here we're relying on DPDK librte_vhost's reconnection behavior.
Or
2. -chardev socket,id=chardev0,...,reconnect=3
-netdev vhost-user,chardev=chardev0
When the vhost-user socket is disconnected a new connection attempt
will be made after 3 seconds.
In both cases vhost-user negotiation will resume when the new connection
is established.
Stefan