A queue rebuild regenerates the RSS indirection table from the driver default, so a table the user installed with "ethtool -X" is silently replaced by any reconfiguration that rebuilds the queues.
Carry it over instead when the queue count is unchanged: the entries are queue indices, so they stay meaningful. A driver-generated table is still regenerated, and a table that cannot be honoured for the new queue count is reported to the core as lost - but only once the new set is actually live, so a failed reconfiguration does not clear IFF_RXFH_CONFIGURED on a port that kept its old queues. Signed-off-by: Long Li <[email protected]> --- drivers/net/ethernet/microsoft/mana/mana_en.c | 78 +++++++++++++++++-- include/net/mana/mana.h | 7 ++ 2 files changed, 80 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 7c43c2f9043ba591b58e4ee2211cf37da9fead36..6e77b59cfcf907f7e584625273972bf185501d20 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -3496,6 +3496,38 @@ static void mana_rss_table_init(struct mana_port_context *apc) ethtool_rxfh_indir_default(i, apc->num_queues); } +/* Whether @apc's indirection table can be carried to a set of @num_queues, + * rather than rebuilt from the driver default. + * + * Only a user table ("ethtool -X") is kept; a driver one is rebuilt to spread + * over the new count. ethtool_check_max_channel() already refuses a reduction + * that leaves a user table pointing past the last queue, so the bounds check + * below only guards rebuild paths that bypass ethtool. + * + * @lost reports a table that cannot be carried instead of calling + * ethtool_rxfh_indir_lost() here, since the swap may still fail and leave the + * port on queues where the table still applies. False when none was set. + */ +static bool mana_rss_table_keep(struct mana_port_context *apc, + unsigned int num_queues, bool *lost) +{ + u32 i; + + *lost = false; + + if (!netif_is_rxfh_configured(apc->ndev)) + return false; + + for (i = 0; i < apc->indir_table_sz; i++) { + if (apc->indir_table[i] >= num_queues) { + *lost = true; + return false; + } + } + + return true; +} + int mana_disable_vport_rx(struct mana_port_context *apc) { return mana_cfg_vport_steering(apc, TRI_STATE_FALSE, false, false, @@ -3766,6 +3798,7 @@ int mana_alloc_queues(struct net_device *ndev) { struct mana_port_context *apc = netdev_priv(ndev); struct gdma_dev *gd = apc->ac->gdma_dev; + bool indir_lost; int err; err = mana_create_vport(apc, ndev); @@ -3811,7 +3844,18 @@ int mana_alloc_queues(struct net_device *ndev) goto destroy_rxq; } - mana_rss_table_init(apc); + /* Keep a user-configured RSS table across a rebuild; the entries are + * queue indices, so they stay meaningful as long as the queue count + * is unchanged. Only a driver-generated table is regenerated here. + * + * Nothing to roll back to here, so report the loss as soon as it is + * decided and keep the table and the core's view of it in step. + */ + if (!mana_rss_table_keep(apc, apc->num_queues, &indir_lost)) { + if (indir_lost) + ethtool_rxfh_indir_lost(ndev); + mana_rss_table_init(apc); + } err = mana_config_rss(apc, TRI_STATE_TRUE, true, true); if (err) { @@ -4068,11 +4112,15 @@ static void mana_qset_snapshot(const struct mana_port_context *ctx, out->priv_flags = ctx->priv_flags; out->mtu = ctx->configured_mtu; out->bpf_prog = ctx->bpf_prog; + + /* A set taken from a live context has nothing pending; the builders + * set this after snapshotting if they had to drop the user's table. + */ + out->rxfh_indir_lost = false; } -/* Install @qset's fields onto @ctx. The vport (port_handle, - * vport_use_count) and the port-level debugfs dir are deliberately not - * touched: they outlive any individual queue set. +/* The vport (port_handle, vport_use_count) and the port-level debugfs dir are + * not touched: they outlive any individual queue set. */ static void mana_qset_install(struct mana_port_context *ctx, const struct mana_qset *qset) @@ -4150,6 +4198,7 @@ int mana_alloc_qset(struct mana_port_context *apc, struct mana_qset *out) { struct net_device *ndev = scratch->ndev; + bool indir_lost; int err; ASSERT_RTNL(); @@ -4193,9 +4242,19 @@ int mana_alloc_qset(struct mana_port_context *apc, if (err) goto cleanup_rxq; - mana_rss_table_init(scratch); + /* Carry a user-configured RSS table over to the new set. The entries + * are queue indices, so mana_config_rss() in mana_publish_qset() maps + * them onto the new set's RX objects. A driver-generated table is + * rebuilt instead, so it covers every queue of the new set. + */ + if (mana_rss_table_keep(apc, num_queues, &indir_lost)) + memcpy(scratch->indir_table, apc->indir_table, + apc->indir_table_sz * sizeof(*apc->indir_table)); + else + mana_rss_table_init(scratch); mana_qset_snapshot(scratch, out); + out->rxfh_indir_lost = indir_lost; return 0; cleanup_rxq: @@ -4407,6 +4466,15 @@ int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq, if (carrier_ok) netif_carrier_on(ndev); + /* The set that could not carry the user's indirection table is the one + * serving traffic now, so the table really is gone. Reporting it here + * rather than while the set was being built keeps a failed swap from + * clearing IFF_RXFH_CONFIGURED on a port that kept its old queues, and + * with them a table that is still valid and still programmed. + */ + if (newq->rxfh_indir_lost) + ethtool_rxfh_indir_lost(ndev); + return 0; rollback: diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index 619c66f3c6192dd2988a1bba73e991df2a773923..0d7375adeb5366bbbb99a7faa931a8830f71ef10 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -731,6 +731,13 @@ struct mana_qset { */ int mtu; struct bpf_prog *bpf_prog; + + /* The user's RSS indirection table could not be carried onto this set, + * so a default one was generated for it. mana_publish_qset() tells the + * core once this set is live; until then the port is still running on + * a set where the user's table applies. + */ + bool rxfh_indir_lost; }; netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev); -- 2.43.0
