| Message ID | 20191207144618.14124-3-i.maximets@ovn.org |
|---|---|
| State | Accepted |
| Delegated to: | Ilya Maximets |
| Headers | show |
| Series | dpif-netdev: Avoid infinite re-addition of misconfigured ports. | expand |
On Sat, Dec 07, 2019 at 03:46:17PM +0100, Ilya Maximets wrote: > 'bpf_set_link_xdp_fd' generates netlink event regardless of actual > changes it does, so if-notifier will receive link update even if > there was no XDP program previously loaded on the interface. > > OVS tries to remove XDP program if device configuration was not > successful triggering if-notifier that triggers bridge reconfiguration > and another attempt to add failed port. And so on in the infinite > loop. > > This patch avoids the issue by not removing XDP program if it wasn't > loaded. Since loading of the XDP program is one of the last steps > of port configuration, this should help to avoid infinite re-addition > for most types of misconfiguration. > > Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Thanks! this also fixes the issue reported from Eelco about infinite loop when enable loading XDP program at https://patchwork.ozlabs.org/patch/1199734/ Acked-by: William Tu <u9012063@gmail.com> > --- > lib/netdev-afxdp.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/lib/netdev-afxdp.c b/lib/netdev-afxdp.c > index ca2dfd005..bdabf97f4 100644 > --- a/lib/netdev-afxdp.c > +++ b/lib/netdev-afxdp.c > @@ -710,6 +710,19 @@ static void > xsk_remove_xdp_program(uint32_t ifindex, enum afxdp_mode mode) > { > uint32_t flags = xdp_modes[mode].xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST; > + uint32_t ret, prog_id = 0; > + > + /* Check whether XDP program is loaded. */ > + ret = bpf_get_link_xdp_id(ifindex, &prog_id, flags); > + if (ret) { > + VLOG_ERR("Failed to get XDP prog id (%s)", ovs_strerror(errno)); > + return; > + } > + > + if (!prog_id) { > + VLOG_INFO("No XDP program is loaded at ifindex %d", ifindex); > + return; > + } > > bpf_set_link_xdp_fd(ifindex, -1, flags); > } > -- > 2.17.1 >
diff --git a/lib/netdev-afxdp.c b/lib/netdev-afxdp.c index ca2dfd005..bdabf97f4 100644 --- a/lib/netdev-afxdp.c +++ b/lib/netdev-afxdp.c @@ -710,6 +710,19 @@ static void xsk_remove_xdp_program(uint32_t ifindex, enum afxdp_mode mode) { uint32_t flags = xdp_modes[mode].xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST; + uint32_t ret, prog_id = 0; + + /* Check whether XDP program is loaded. */ + ret = bpf_get_link_xdp_id(ifindex, &prog_id, flags); + if (ret) { + VLOG_ERR("Failed to get XDP prog id (%s)", ovs_strerror(errno)); + return; + } + + if (!prog_id) { + VLOG_INFO("No XDP program is loaded at ifindex %d", ifindex); + return; + } bpf_set_link_xdp_fd(ifindex, -1, flags); }
'bpf_set_link_xdp_fd' generates netlink event regardless of actual changes it does, so if-notifier will receive link update even if there was no XDP program previously loaded on the interface. OVS tries to remove XDP program if device configuration was not successful triggering if-notifier that triggers bridge reconfiguration and another attempt to add failed port. And so on in the infinite loop. This patch avoids the issue by not removing XDP program if it wasn't loaded. Since loading of the XDP program is one of the last steps of port configuration, this should help to avoid infinite re-addition for most types of misconfiguration. Signed-off-by: Ilya Maximets <i.maximets@ovn.org> --- lib/netdev-afxdp.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)