From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4286F3C991 for ; Tue, 24 Feb 2026 15:28:06 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 217EF40649; Tue, 24 Feb 2026 16:27:56 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id E085840288 for ; Tue, 24 Feb 2026 16:27:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1771946874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=kf9vgG1BM+EJSPmBJ/JIlCewNVgbMt6JelSsa3EQkrs=; b=gcraWa1NdIhyArTQO6V1u5PCO7sQJoRph5lfRe3WHqN6kl1weay6t4YD+vQJqm9qpWG0aB 8MbUVUwGTo21qF0pk70jw6vW/KJFv/EOPYxzG2JXLvhT4Trov8q7m1Scy2nBO5Z2x8z0PE w/mtGQFBgbSlR95343t+uOC8cAMn5+M= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-56-lfKBc09JNCW35_7b0McBKw-1; Tue, 24 Feb 2026 10:27:53 -0500 X-MC-Unique: lfKBc09JNCW35_7b0McBKw-1 X-Mimecast-MFC-AGG-ID: lfKBc09JNCW35_7b0McBKw_1771946871 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EA1861800451; Tue, 24 Feb 2026 15:27:50 +0000 (UTC) Received: from dmarchan.lan (unknown [10.44.32.223]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8A47E1800370; Tue, 24 Feb 2026 15:27:49 +0000 (UTC) From: David Marchand To: dev@dpdk.org Cc: ktraynor@redhat.com, Stephen Hemminger Subject: [PATCH] net/tap: defer qdisc initialisation for rte_flow Date: Tue, 24 Feb 2026 16:27:44 +0100 Message-ID: <20260224152744.3860285-1-david.marchand@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Bc6O1cmpFda_8vgMTTR9W6aGvYjAWKIyh98XRk1J3Cw_1771946871 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org qdisc setup is required when using a remote_iface or when creating rte_flow rules. Otherwise, many applications don't care about it. Let's postpone the qdisc init to when it is really needed, that will avoid spewing ERR logs for nothing. Signed-off-by: David Marchand --- drivers/net/tap/rte_eth_tap.c | 32 +++++--------------------------- drivers/net/tap/rte_eth_tap.h | 1 + drivers/net/tap/tap_flow.c | 26 ++++++++++++++++++++++++++ drivers/net/tap/tap_flow.h | 2 ++ 4 files changed, 34 insertions(+), 27 deletions(-) diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c index 7a8a98cddb..71fb0a74fa 100644 --- a/drivers/net/tap/rte_eth_tap.c +++ b/drivers/net/tap/rte_eth_tap.c @@ -2122,26 +2122,14 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, const char *tap_name, pmd->persist = persist; #ifdef HAVE_TCA_FLOWER - /* - * Set up everything related to rte_flow: - * - mandatory QDISCs - * - rte_flow actual/implicit lists - * - implicit rules - */ - if (qdisc_create_multiq(pmd->nlsk_fd, pmd->if_index) < 0) { - TAP_LOG(ERR, "%s: failed to create multiq qdisc.", - pmd->name); - goto disable_rte_flow; - } - if (qdisc_create_ingress(pmd->nlsk_fd, pmd->if_index) < 0) { - TAP_LOG(ERR, "%s: failed to create ingress qdisc.", - pmd->name); - goto disable_rte_flow; - } - LIST_INIT(&pmd->flows); if (strlen(remote_iface)) { + if (tap_flow_init(pmd) < 0) { + TAP_LOG(ERR, "Remote feature requires flow support."); + goto error_exit; + } + pmd->remote_if_index = if_nametoindex(remote_iface); if (!pmd->remote_if_index) { TAP_LOG(ERR, "%s: failed to get %s if_index.", @@ -2196,16 +2184,6 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, const char *tap_name, rte_eth_dev_probing_finish(dev); return 0; -disable_rte_flow: - TAP_LOG(ERR, " Disabling rte flow support: %s(%d)", - strerror(errno), errno); - if (strlen(remote_iface)) { - TAP_LOG(ERR, "Remote feature requires flow support."); - goto error_exit; - } - rte_eth_dev_probing_finish(dev); - return 0; - #ifdef HAVE_TCA_FLOWER error_remote: TAP_LOG(ERR, " Can't set up remote feature: %s(%d)", diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h index 218ee1b811..59d61582cc 100644 --- a/drivers/net/tap/rte_eth_tap.h +++ b/drivers/net/tap/rte_eth_tap.h @@ -79,6 +79,7 @@ struct pmd_internals { int nlsk_fd; /* Netlink socket fd */ #ifdef HAVE_TCA_FLOWER + int flow_init; /* 1 if qdiscs were created */ int flow_isolate; /* 1 if flow isolation is enabled */ struct tap_rss *rss; /* BPF program */ diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c index 9d4ef27a8a..8877cef3ff 100644 --- a/drivers/net/tap/tap_flow.c +++ b/drivers/net/tap/tap_flow.c @@ -1235,6 +1235,12 @@ tap_flow_create(struct rte_eth_dev *dev, struct tap_nlmsg *msg = NULL; int err; + if (pmd->flow_init == 0 && tap_flow_init(pmd) < 0) { + rte_flow_error_set(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE, + NULL, + "can't create rule, qdisc not initialized"); + goto fail; + } if (!pmd->if_index) { rte_flow_error_set(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE, NULL, @@ -1875,6 +1881,26 @@ static int rss_add_actions(struct rte_flow *flow, struct pmd_internals *pmd, } #endif +int +tap_flow_init(struct pmd_internals *pmd) +{ + if (qdisc_create_multiq(pmd->nlsk_fd, pmd->if_index) < 0) { + TAP_LOG(ERR, "%s: failed to create multiq qdisc.", + pmd->name); + return -1; + } + + if (qdisc_create_ingress(pmd->nlsk_fd, pmd->if_index) < 0) { + TAP_LOG(ERR, "%s: failed to create ingress qdisc.", + pmd->name); + return -1; + } + + pmd->flow_init = 1; + + return 0; +} + /** * Get rte_flow operations. * diff --git a/drivers/net/tap/tap_flow.h b/drivers/net/tap/tap_flow.h index 8b19347a93..49e7e04050 100644 --- a/drivers/net/tap/tap_flow.h +++ b/drivers/net/tap/tap_flow.h @@ -45,6 +45,8 @@ enum implicit_rule_index { TAP_REMOTE_MAX_IDX, }; +int tap_flow_init(struct pmd_internals *pmd); + int tap_dev_flow_ops_get(struct rte_eth_dev *dev, const struct rte_flow_ops **ops); int tap_flow_flush(struct rte_eth_dev *dev, struct rte_flow_error *error); -- 2.53.0