diff mbox series

[v2,iwl-next] ice: allow hot-swapping XDP programs

Message ID 20230613231523.339413-1-maciej.fijalkowski@intel.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [v2,iwl-next] ice: allow hot-swapping XDP programs | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 10 maintainers not CCed: kuba@kernel.org hawk@kernel.org daniel@iogearbox.net jesse.brandeburg@intel.com john.fastabend@gmail.com bpf@vger.kernel.org davem@davemloft.net pabeni@redhat.com ast@kernel.org edumazet@google.com
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 25 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Maciej Fijalkowski June 13, 2023, 11:15 p.m. UTC
Currently ice driver's .ndo_bpf callback brings interface down and up
independently of XDP resources' presence. This is only needed when
either these resources have to be configured or removed. It means that
if one is switching XDP programs on-the-fly with running traffic,
packets will be dropped.

To avoid this, compare early on ice_xdp_setup_prog() state of incoming
bpf_prog pointer vs the bpf_prog pointer that is already assigned to
VSI. Do the swap in case VSI has bpf_prog and incoming one are non-NULL.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---

v1->v2:
- fix missing brace (sigh)

 drivers/net/ethernet/intel/ice/ice_main.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index a1f7c8edc22f..dba1f7709e8b 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -2924,6 +2924,12 @@  ice_xdp_setup_prog(struct ice_vsi *vsi, struct bpf_prog *prog,
 		}
 	}
 
+	/* hot swap progs and avoid toggling link */
+	if (ice_is_xdp_ena_vsi(vsi) == !!prog) {
+		ice_vsi_assign_bpf_prog(vsi, prog);
+		return 0;
+	}
+
 	/* need to stop netdev while setting up the program for Rx rings */
 	if (if_running && !test_and_set_bit(ICE_VSI_DOWN, vsi->state)) {
 		ret = ice_down(vsi);
@@ -2956,13 +2962,6 @@  ice_xdp_setup_prog(struct ice_vsi *vsi, struct bpf_prog *prog,
 		xdp_ring_err = ice_realloc_zc_buf(vsi, false);
 		if (xdp_ring_err)
 			NL_SET_ERR_MSG_MOD(extack, "Freeing XDP Rx resources failed");
-	} else {
-		/* safe to call even when prog == vsi->xdp_prog as
-		 * dev_xdp_install in net/core/dev.c incremented prog's
-		 * refcount so corresponding bpf_prog_put won't cause
-		 * underflow
-		 */
-		ice_vsi_assign_bpf_prog(vsi, prog);
 	}
 
 	if (if_running)