[PATCH net] netdevsim: Fix physical port index

At present when a netdevsim device is added, the first physical
port will have an index of 1.  This behavior differ from what any
real hardware driver would do, which would start the index at 0.

When using netdevsim to test the devlink-port interface this
behavior becomes a problem because the provided data is incorrect.

Example:
$ sudo modprobe netdevsim
$ sudo sh -c 'echo "10 1" > /sys/bus/netdevsim/new_device'
$ sudo sh -c 'echo 4 > /sys/class/net/eni10np1/device/sriov_numvfs'
$ sudo devlink dev eswitch set netdevsim/netdevsim10 mode switchdev
$ devlink port show
netdevsim/netdevsim10/0: type eth netdev eni10np1 flavour physical port 1
netdevsim/netdevsim10/128: type eth netdev eni10npf0vf0 flavour pcivf pfnum 0 vfnum 0
netdevsim/netdevsim10/129: type eth netdev eni10npf0vf1 flavour pcivf pfnum 0 vfnum 1
netdevsim/netdevsim10/130: type eth netdev eni10npf0vf2 flavour pcivf pfnum 0 vfnum 2
netdevsim/netdevsim10/131: type eth netdev eni10npf0vf3 flavour pcivf pfnum 0 vfnum 3

With this patch applied you would instead get:
$ sudo modprobe netdevsim
$ sudo sh -c 'echo "10 1" > /sys/bus/netdevsim/new_device'
$ sudo sh -c 'echo 4 > /sys/class/net/eni10np0/device/sriov_numvfs'
$ sudo devlink dev eswitch set netdevsim/netdevsim10 mode switchdev
$ devlink port show
netdevsim/netdevsim10/0: type eth netdev eni10np0 flavour physical port 0
netdevsim/netdevsim10/128: type eth netdev eni10npf0vf0 flavour pcivf pfnum 0 vfnum 0
netdevsim/netdevsim10/129: type eth netdev eni10npf0vf1 flavour pcivf pfnum 0 vfnum 1
netdevsim/netdevsim10/130: type eth netdev eni10npf0vf2 flavour pcivf pfnum 0 vfnum 2
netdevsim/netdevsim10/131: type eth netdev eni10npf0vf3 flavour pcivf pfnum 0 vfnum 3

The above more accurately resembles what a real system would look
like.

Fixes: 8320d1459127 ("netdevsim: implement dev probe/remove skeleton with port initialization")
Signed-off-by: Frode Nordahl <redacted>
---
 drivers/net/netdevsim/dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 54345c096a16..8045852cf0fe 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c

@@ -1371,7 +1371,7 @@ static int __nsim_dev_port_add(struct nsim_dev *nsim_dev, enum nsim_dev_port_typ
 	devlink_port = &nsim_dev_port->devlink_port;
 	if (nsim_dev_port_is_pf(nsim_dev_port)) {
 		attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
-		attrs.phys.port_number = port_index + 1;
+		attrs.phys.port_number = port_index;
 	} else {
 		attrs.flavour = DEVLINK_PORT_FLAVOUR_PCI_VF;
 		attrs.pci_vf.pf = 0;

-- 
2.32.0