On 4/3/17, 5:27 AM, "[email protected] on behalf of Przemyslaw
Lal" <[email protected] on behalf of [email protected]>
wrote:
In current implementation port_id is used as an ifindex for all netdev-dpdk
interfaces.
For physical DPDK interfaces using port_id as ifindex causes that '0' is
set as
ifindex for 'dpdk0' interface, '1' for 'dpdk1' and so on. For the DPDK vHost
interfaces ifindexes are not even assigned (0 is used by default) due to the
fact that vHost ports don't use port_id field from the DPDK library.
This causes multiple negative side-effects. First of all 0 is an invalid
ifindex value. The other issue is possible overlapping of 'dpdkX' interfaces
ifindex values with the ifindexes of kernel space interfaces which may cause
problems in any external tools that use those values. Neither 'dpdk0', nor
any
DPDK vHost interfaces are visible in sFlow collector tools, as all
interfaces
with ifindexes smaller than 1 are ignored.
Proposed solution to these issues is to calculate a hash of interface's name
and use calculated value as an ifindex. This way interfaces keep their
ifindexes during OVS-DPDK restarts, ports re-initialization events, etc.,
show
up in sFlow collectors and meet RFC 2863 specification regarding re-using
ifindex values by the same virtual interfaces and maximum ifindex value.
Signed-off-by: Przemyslaw Lal <[email protected]>
---
lib/netdev-dpdk.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index ddc651b..687b0a5 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -2215,7 +2215,11 @@ netdev_dpdk_get_ifindex(const struct netdev *netdev)
int ifindex;
ovs_mutex_lock(&dev->mutex);
- ifindex = dev->port_id;
+ /* Calculate hash from the netdev name. Ensure that ifindex is a 24-bit
+ * postive integer to meet RFC 2863 recommendations.
+ */
+ uint32_t h = hash_string(netdev->name, 0);
+ ifindex = (int)(h % 0xfffffe + 1);
If user configuration was supported, enforcing uniqueness would be the
responsibility of the user.
One minor question:
I know other ifindex implementations do not limit to 24 bits, so I checked RFC
2863.
What section is the 24 bit limit recommendation mentioned in RFC 2863; I missed
it.
ovs_mutex_unlock(&dev->mutex);
return ifindex;
--
1.9.1
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