On Fri, 2020-02-07 at 08:12 -0800, Stephen Hemminger wrote: > On Fri, 07 Feb 2020 15:22:23 +0200 > Mohammed Gamal <[email protected]> wrote: > > > On Thu, 2020-02-06 at 16:10 -0800, Stephen Hemminger wrote: > > > If application is using link state interrupt, the correct link > > > state > > > needs to be filled in when device is started. This is similar to > > > how virtio updates link information. > > > > > > Reported-by: Mohammed Gamal <[email protected]> > > > Signed-off-by: Stephen Hemminger <[email protected]> > > > --- > > > This version marked RFT because am in airport without access to a > > > machine to test it. > > > > > > drivers/net/netvsc/hn_ethdev.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/net/netvsc/hn_ethdev.c > > > b/drivers/net/netvsc/hn_ethdev.c > > > index c79f924379fe..564620748daf 100644 > > > --- a/drivers/net/netvsc/hn_ethdev.c > > > +++ b/drivers/net/netvsc/hn_ethdev.c > > > @@ -823,6 +823,10 @@ hn_dev_start(struct rte_eth_dev *dev) > > > if (error) > > > hn_rndis_set_rxfilter(hv, 0); > > > > > > + /* Initialize Link state */ > > > + if (error == 0) > > > + hn_dev_link_update(dev, 0); > > > + > > > return error; > > > } > > > > > > > I tested this and I always get the link status as UP, regardless of > > whether I start the interface on the guest in UP or DOWN state. > > Looking > > at hn_dev_link_update() code, I see that the link status depends on > > the > > NDIS status that the driver gets from the host if my understanding > > is > > correct. > > The question is whether if I use 'ip li set dev $IF_NAME down' on > > the > > guest affects the status the host sees, or would the host set the > > state > > to NDIS_MEDIA_STATE_CONNECTED of the device is physcially connected > > regardless of what the guest tries to do? > > > > Are you confused about admin state vs link state? Admin state is the > up/down state in software, and link state is the (virtual) hardware > link > status. In traditional Linux, admin state is controlled by ip link > set up/down; in DPDK the admin state is implied by whether the DPDK > device is started or stopped. The link state for hardware devices is > determined by whether the hardware link has synchronized with the > switch. > In virtual environments this is synchronized. In Linux link state > is reported as NOCARRIER (IFF_RUNNING). In DPDK it is reported in > via the link info get. > > The device visible to the kernel is the accelerated networking > (Mellanox) > device and is not related directly to the netvsc device. > > To test link up/down is not easy on Azure. You would have to use > Azure CLI > to disconnect the NIC from VM. On native Hyper-V you can test by > setting up a virtual switch with an external network device; then > unplug the network device. > >
I see. Thanks for the explanation. In this case this does work as expected. Tested-by: Mohammed Gamal <[email protected]>
