From patchwork Wed Oct 23 08:51:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 13846712 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5AD8FD2E028 for ; Wed, 23 Oct 2024 08:52:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t3X5t-0000db-1Z; Wed, 23 Oct 2024 04:51:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t3X5r-0000dF-TV for qemu-devel@nongnu.org; Wed, 23 Oct 2024 04:51:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t3X5q-00083n-ET for qemu-devel@nongnu.org; Wed, 23 Oct 2024 04:51:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729673494; 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: in-reply-to:in-reply-to:references:references; bh=dsTsmOfDyavmsVDGwb88r2xES8RbPpv2JJlAjl9MVRw=; b=TWG2VGtPyPvAnx4kUcl1qnKg/bDgqn22D6sKrnFCT2j8tPbu9rw8KEOAsNBloP3YWGBP2j 4/e5Kjz5yunahw7kz/uPrYHRzv5uqbe7QPudbXQvsel2pmwtdzIdLUE/h/0wpJkd6EuQWp YwLgt25a5xxKOQKma3FI4Jzjct9nTO4= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-638-uFj9bcgmP82BNsCqWMSnmg-1; Wed, 23 Oct 2024 04:51:31 -0400 X-MC-Unique: uFj9bcgmP82BNsCqWMSnmg-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9AE351955DA6; Wed, 23 Oct 2024 08:51:30 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.19]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 665CB1956056; Wed, 23 Oct 2024 08:51:27 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Yuri Benditovich , =?utf-8?q?Daniel_P=2E_Berra?= =?utf-8?q?ng=C3=A9?= , Paolo Bonzini , Andrew Melnychenko , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , =?utf-8?q?Marc?= =?utf-8?q?-Andr=C3=A9_Lureau?= , Jason Wang Subject: [PATCH v3 6/8] hw/net: report errors from failing to use eBPF RSS FDs Date: Wed, 23 Oct 2024 09:51:01 +0100 Message-ID: <20241023085103.1980072-7-berrange@redhat.com> In-Reply-To: <20241023085103.1980072-1-berrange@redhat.com> References: <20241023085103.1980072-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.519, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org If the user/mgmt app passed in a set of pre-opened FDs for eBPF RSS, then it is expecting QEMU to use them. Any failure to do so must be considered a fatal error and propagated back up the stack, otherwise deployment mistakes will not be detectable in a prompt manner. When not using pre-opened FDs, then eBPF RSS is tried on a "best effort" basis only and thus fallback to software RSS is valid. Signed-off-by: Daniel P. Berrangé --- hw/net/virtio-net.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 289fba8152..c08ae55424 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1316,28 +1316,27 @@ static void virtio_net_disable_rss(VirtIONet *n) virtio_net_commit_rss_config(n); } -static bool virtio_net_load_ebpf_fds(VirtIONet *n) +static bool virtio_net_load_ebpf_fds(VirtIONet *n, Error **errp) { int fds[EBPF_RSS_MAX_FDS] = { [0 ... EBPF_RSS_MAX_FDS - 1] = -1}; int ret = true; int i = 0; if (n->nr_ebpf_rss_fds != EBPF_RSS_MAX_FDS) { - warn_report("Expected %d file descriptors but got %d", - EBPF_RSS_MAX_FDS, n->nr_ebpf_rss_fds); - return false; - } + error_setg(errp, "Expected %d file descriptors but got %d", + EBPF_RSS_MAX_FDS, n->nr_ebpf_rss_fds); + return false; + } for (i = 0; i < n->nr_ebpf_rss_fds; i++) { - fds[i] = monitor_fd_param(monitor_cur(), n->ebpf_rss_fds[i], - &error_warn); + fds[i] = monitor_fd_param(monitor_cur(), n->ebpf_rss_fds[i], errp); if (fds[i] < 0) { ret = false; goto exit; } } - ret = ebpf_rss_load_fds(&n->ebpf_rss, fds[0], fds[1], fds[2], fds[3], NULL); + ret = ebpf_rss_load_fds(&n->ebpf_rss, fds[0], fds[1], fds[2], fds[3], errp); exit: if (!ret) { @@ -1349,13 +1348,15 @@ exit: return ret; } -static bool virtio_net_load_ebpf(VirtIONet *n) +static bool virtio_net_load_ebpf(VirtIONet *n, Error **errp) { bool ret = false; if (virtio_net_attach_ebpf_to_backend(n->nic, -1)) { - if (!(n->ebpf_rss_fds && virtio_net_load_ebpf_fds(n))) { - ret = ebpf_rss_load(&n->ebpf_rss, NULL); + if (n->ebpf_rss_fds) { + ret = virtio_net_load_ebpf_fds(n, errp); + } else { + ret = ebpf_rss_load(&n->ebpf_rss, errp); } } @@ -3761,7 +3762,23 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp) net_rx_pkt_init(&n->rx_pkt); if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) { - virtio_net_load_ebpf(n); + Error *err = NULL; + if (!virtio_net_load_ebpf(n, &err)) { + /* + * If user explicitly gave QEMU RSS FDs to use, then + * failing to use them must be considered a fatal + * error. If no RSS FDs were provided, QEMU is trying + * eBPF on a "best effort" basis only, so report a + * warning and allow fallback to software RSS. + */ + if (n->ebpf_rss_fds) { + error_propagate(errp, err); + } else { + warn_report("unable to load eBPF RSS: %s", + error_get_pretty(err)); + error_free(err); + } + } } }