| Message ID | 20210622162616.eadk2u5hmf4ru5jd@linutronix.de (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [RFC] ixgbe: Consider xsk pool's frame size for MTU size | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 6 of 6 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 1 this patch: 1 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 39 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 1 this patch: 1 |
| netdev/header_inline | success | Link |
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 2ac5b82676f3b..d250c20a941e9 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -6723,6 +6723,23 @@ static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter) ixgbe_free_rx_resources(adapter->rx_ring[i]); } +static int ixgbe_validate_frame_size(unsigned int frame_size, + struct ixgbe_ring *ring) +{ + struct xsk_buff_pool *xsk_pool; + unsigned int buf_len; + + xsk_pool = ring->xsk_pool; + if (xsk_pool) + buf_len = xsk_pool_get_rx_frame_size(xsk_pool); + else + buf_len = ixgbe_rx_bufsz(ring); + + if (frame_size > buf_len) + return -EINVAL; + return 0; +} + /** * ixgbe_change_mtu - Change the Maximum Transfer Unit * @netdev: network interface device structure @@ -6742,7 +6759,7 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu) for (i = 0; i < adapter->num_rx_queues; i++) { struct ixgbe_ring *ring = adapter->rx_ring[i]; - if (new_frame_size > ixgbe_rx_bufsz(ring)) { + if (ixgbe_validate_frame_size(new_frame_size, ring)) { e_warn(probe, "Requested MTU size is not supported with XDP\n"); return -EINVAL; } @@ -10127,7 +10144,7 @@ static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog) if (ring_is_rsc_enabled(ring)) return -EINVAL; - if (frame_size > ixgbe_rx_bufsz(ring)) + if (ixgbe_validate_frame_size(frame_size, ring)) return -EINVAL; }
The driver has to a ensure that a network packet is not using more than one page for its data if a XDP program is used. This results in an upper limit of 1500 bytes. This can be increased a little if the MTU was programmed to 1514..3072 bytes before loading the XDP program. By setting this increased MTU size the driver will set the __IXGBE_RX_3K_BUFFER flag which in turn will allow to use 3KiB as the upper limit. This looks like a hack and the upper limit is could increased further. If the user configured a memory pool then PAGE_SIZE is used as BSIZEPKT and RLPML is set to pool's memory size as is the card's maximum frame size. The result is that a MTU of 3520 bytes can be programmed and every packet is stored a single page. If a RX ring has a pool assigned use its size while comparing for the maximal MTU size. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- According to my traces incoming packets with a size 70 or 3520 bytes all end up in one page. There is currently only one ring/RX-queue. I'm not sure if it is reasonable to assume to have one RX-queue with xsk_pool and one without. drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 21 +++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)