Attaching or detaching an XDP program changes the RX buffer layout - full pages with headroom rather than page fragments - so it rebuilds the queues. Convert mana_xdp_set() to pre-allocate and swap, completing the removal of detach/attach from the reconfiguration paths.
The program becomes part of the queue-set configuration, so it is swapped atomically with the queues it was built for and restored by the rollback path. Program references follow the same swap, so attaching no longer leaves the queues briefly running without one. Signed-off-by: Long Li <[email protected]> --- .../net/ethernet/microsoft/mana/mana_bpf.c | 68 ++++++++++--------- drivers/net/ethernet/microsoft/mana/mana_en.c | 18 +++-- .../ethernet/microsoft/mana/mana_ethtool.c | 11 +-- include/net/mana/mana.h | 9 ++- 4 files changed, 58 insertions(+), 48 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c b/drivers/net/ethernet/microsoft/mana/mana_bpf.c index e16ce2a0715839594a5837288c1d4c1de412e7fb..d2093625956bbef30d0d6c63121de8363b633489 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c +++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c @@ -175,10 +175,17 @@ void mana_chn_setxdp(struct mana_port_context *apc, struct bpf_prog *prog) bpf_prog_put(old_prog); } +/* Attaching or detaching XDP changes the RX buffer layout (full pages vs + * fragments), so the RX queues are rebuilt. The swap helpers handle + * refcounting: mana_publish_qset() attaches the program to the new queues, + * mana_free_qset() drops the old set's references. + */ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, struct netlink_ext_ack *extack) { struct mana_port_context *apc = netdev_priv(ndev); + struct mana_port_context *scratch; + struct mana_qset newq, oldq; struct bpf_prog *old_prog; struct gdma_context *gc; int err; @@ -198,46 +205,46 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, return -EOPNOTSUPP; } - /* One refcnt of the prog is hold by the caller already, so - * don't increase refcnt for this one. - */ - apc->bpf_prog = prog; - if (apc->port_is_up) { - /* Re-create rxq's after xdp prog was loaded or unloaded. - * Ex: re create rxq's to switch from full pages to smaller - * size page fragments when xdp prog is unloaded and - * vice-versa. - */ - - /* Pre-allocate buffers to prevent failure in mana_attach */ - err = mana_pre_alloc_rxbufs(apc, ndev->mtu, apc->num_queues); - if (err) { + scratch = mana_qset_scratch_alloc(apc); + if (!scratch) { NL_SET_ERR_MSG_MOD(extack, - "XDP: Insufficient memory for tx/rx re-config"); - return err; + "XDP: Insufficient memory for re-config"); + return -ENOMEM; } - err = mana_detach(ndev, false); + err = mana_alloc_qset(apc, scratch, apc->num_queues, + apc->rx_queue_size, apc->tx_queue_size, + apc->priv_flags, apc->configured_mtu, + prog, &newq); if (err) { - netdev_err(ndev, - "mana_detach failed at xdp set: %d\n", err); NL_SET_ERR_MSG_MOD(extack, - "XDP: Re-config failed at detach"); - goto err_dealloc_rxbuffs; + "XDP: Re-config failed at alloc"); + mana_qset_scratch_free(scratch); + return err; } - err = mana_attach(ndev); + err = mana_publish_qset(apc, &newq, &oldq); if (err) { - netdev_err(ndev, - "mana_attach failed at xdp set: %d\n", err); NL_SET_ERR_MSG_MOD(extack, - "XDP: Re-config failed at attach"); - goto err_dealloc_rxbuffs; + "XDP: Re-config failed at publish"); + mana_free_qset(scratch, &newq); + /* After the cleanup above: closing destroys the EQ pool + * those queues' CQs were attached to. + */ + mana_publish_close_if_needed(apc); + mana_qset_scratch_free(scratch); + return err; } - mana_chn_setxdp(apc, prog); - mana_pre_dealloc_rxbufs(apc); + mana_free_qset(scratch, &oldq); + mana_qset_scratch_free(scratch); + } else { + /* No queues to rebuild; mana_open() will size the RX buffers + * for this program. One refcnt is held by the caller already, + * so don't take another. + */ + apc->bpf_prog = prog; } if (old_prog) @@ -250,11 +257,6 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, ndev->max_mtu = gc->adapter_mtu - ETH_HLEN; return 0; - -err_dealloc_rxbuffs: - apc->bpf_prog = old_prog; - mana_pre_dealloc_rxbufs(apc); - return err; } int mana_bpf(struct net_device *ndev, struct netdev_bpf *bpf) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 2c5aa5e5d1a114e1492b99b5213bb532153d1147..af2fdd5e876eb100cfafb00f2eb0ad7aa9a165c7 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -940,9 +940,9 @@ static int mana_change_mtu(struct net_device *ndev, int new_mtu) if (!scratch) return -ENOMEM; - err = mana_alloc_qset(mpc, scratch, mpc->num_queues, - mpc->rx_queue_size, mpc->tx_queue_size, - mpc->priv_flags, new_mtu, &newq); + err = mana_alloc_qset(mpc, scratch, mpc->num_queues, mpc->rx_queue_size, + mpc->tx_queue_size, mpc->priv_flags, new_mtu, + mpc->bpf_prog, &newq); if (err) goto free_scratch; /* current qset and ndev->mtu untouched */ @@ -4022,6 +4022,7 @@ static void mana_qset_snapshot(const struct mana_port_context *ctx, out->tx_queue_size = ctx->tx_queue_size; out->priv_flags = ctx->priv_flags; out->mtu = ctx->configured_mtu; + out->bpf_prog = ctx->bpf_prog; } /* Install @qset's fields onto @ctx. The vport (port_handle, @@ -4042,6 +4043,7 @@ static void mana_qset_install(struct mana_port_context *ctx, ctx->tx_queue_size = qset->tx_queue_size; ctx->priv_flags = qset->priv_flags; ctx->configured_mtu = qset->mtu; + ctx->bpf_prog = qset->bpf_prog; } /** @@ -4100,7 +4102,8 @@ void mana_qset_scratch_free(struct mana_port_context *scratch) int mana_alloc_qset(struct mana_port_context *apc, struct mana_port_context *scratch, unsigned int num_queues, unsigned int rx_queue_size, unsigned int tx_queue_size, - u32 priv_flags, int mtu, struct mana_qset *out) + u32 priv_flags, int mtu, struct bpf_prog *bpf_prog, + struct mana_qset *out) { struct net_device *ndev = scratch->ndev; int err; @@ -4112,11 +4115,12 @@ int mana_alloc_qset(struct mana_port_context *apc, scratch->tx_queue_size = tx_queue_size; scratch->priv_flags = priv_flags; - /* mana_get_rxbuf_cfg() reads this when sizing RX buffers, so the - * new set is built for the requested MTU without disturbing the - * running set. + /* mana_get_rxbuf_cfg() reads both of these when sizing RX buffers, + * so the new set is built for the requested MTU / XDP program + * without disturbing the running set. */ scratch->configured_mtu = mtu; + scratch->bpf_prog = bpf_prog; err = mana_init_port_context(scratch); if (err) diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index d01add523576f97bea7c02dfdab1073cb24cbca1..82bfd22cfe820c17aea66d6d3f6289165bf32894 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -723,7 +723,7 @@ static int mana_set_channels(struct net_device *ndev, err = mana_alloc_qset(apc, scratch, new_count, apc->rx_queue_size, apc->tx_queue_size, apc->priv_flags, - apc->configured_mtu, &newq); + apc->configured_mtu, apc->bpf_prog, &newq); if (err) goto free_scratch; /* current qset untouched, nothing to undo */ @@ -817,7 +817,8 @@ static int mana_set_ringparam(struct net_device *ndev, } err = mana_alloc_qset(apc, scratch, apc->num_queues, new_rx, new_tx, - apc->priv_flags, apc->configured_mtu, &newq); + apc->priv_flags, apc->configured_mtu, + apc->bpf_prog, &newq); if (err) { NL_SET_ERR_MSG_FMT(extack, "failed to change ring params: %d", err); @@ -914,9 +915,9 @@ static int mana_set_priv_flags(struct net_device *ndev, u32 priv_flags) goto clear_flag; } - err = mana_alloc_qset(apc, scratch, apc->num_queues, - apc->rx_queue_size, apc->tx_queue_size, - priv_flags, apc->configured_mtu, &newq); + err = mana_alloc_qset(apc, scratch, apc->num_queues, apc->rx_queue_size, + apc->tx_queue_size, priv_flags, + apc->configured_mtu, apc->bpf_prog, &newq); if (err) goto free_scratch; /* current qset and priv_flags untouched */ diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index 765eb5358e9ca2b9977096631db9aab37cedacfd..61d136736cf6c455a132d7297badf5ab15b4693d 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -722,11 +722,13 @@ struct mana_qset { unsigned int tx_queue_size; u32 priv_flags; - /* MTU the RX buffers of this set were sized for. It feeds - * mana_get_rxbuf_cfg(), so it is part of the queue-set + /* MTU and XDP program the RX buffers of this set were sized for. + * Both feed mana_get_rxbuf_cfg(), so they are part of the queue-set * configuration and must be swapped atomically with the queues. */ int mtu; + struct bpf_prog *bpf_prog; + }; netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev); @@ -748,7 +750,8 @@ void mana_qset_scratch_free(struct mana_port_context *scratch); int mana_alloc_qset(struct mana_port_context *apc, struct mana_port_context *scratch, unsigned int num_queues, unsigned int rx_queue_size, unsigned int tx_queue_size, - u32 priv_flags, int mtu, struct mana_qset *out); + u32 priv_flags, int mtu, struct bpf_prog *bpf_prog, + struct mana_qset *out); int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq, struct mana_qset *out_old); void mana_publish_close_if_needed(struct mana_port_context *apc); -- 2.43.0
