On 12/19/2017 2:53 PM, Stephen Hemminger wrote:
On Tue, 19 Dec 2017 14:37:50 -0800
"Samudrala, Sridhar" <sridhar.samudrala@xxxxxxxxx> wrote:
On 12/19/2017 11:46 AM, Stephen Hemminger wrote:
On Tue, 19 Dec 2017 11:42:33 -0800
"Samudrala, Sridhar" <sridhar.samudrala@xxxxxxxxx> wrote:
On 12/19/2017 10:41 AM, Stephen Hemminger wrote:
On Tue, 19 Dec 2017 13:21:17 -0500 (EST)
David Miller <davem@xxxxxxxxxxxxx> wrote:
From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Date: Tue, 19 Dec 2017 09:55:48 -0800
could be 10ms, just enough to let udev do its renaming
Please, move to some kind of notification or event based handling of
this problem.
No delay is safe, what if userspace gets swapped out or whatever
else might make userspace stall unexpectedly?
The plan is to remove the delay and do the naming in the kernel.
This was suggested by Lennart since udev is only doing naming policy
because kernel names were not repeatable.
This makes the VF show up as "ethN_vf" on Hyper-V which is user friendly.
Patch is pending.
Do we really need to delay the setup until the name is changed?
Can't we call dev_set_mtu() and dev_open() until dev_change_name() is done?
Thanks
Sridhar
You can call dev_set_mtu, but when dev_open is done the device name
can not be changed by userspace.
I did a quick test to remove the delay and also the dev_open() call and
i don't see
any issues with virtio taking over the VF datapath.
Only the netdev_info() messages may show old device name.
Any specific scenario where we need to explicitly call VF's dev_open()
in the VF setup process?
I tried i40evf driver loaded after virtio_net AND virtio_net loading
after i40evf.
It happens with hotplug. It is possible on Hyper-V to hotplug SR-IOV on
and off while guest is running. If SR-IOV is disabled in host then the
VF device is removed (hotplug) and the inverse. If the master device is
up then the VF device should be brought up by the master device.
Even with KVM, we need to hot unplug SR-IOV device on the source host
and plug it
back on the destination host to enable live migration. It all works for
me even without
the dev_open() of the lower device from the VF setup routine. Will send
out a v2 version
of this patch without the delayed VF setup after some more testing next
week.
Thanks
Sridhar
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