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 3D287CD343F for ; Fri, 15 May 2026 23:20:04 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 9611240672; Sat, 16 May 2026 01:19:48 +0200 (CEST) Received: from mail-qv1-f73.google.com (mail-qv1-f73.google.com [209.85.219.73]) by mails.dpdk.org (Postfix) with ESMTP id A97AF40655 for ; Sat, 16 May 2026 01:19:44 +0200 (CEST) Received: by mail-qv1-f73.google.com with SMTP id 6a1803df08f44-8b640ede74bso7156906d6.1 for ; Fri, 15 May 2026 16:19:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778887184; x=1779491984; darn=dpdk.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=lw+jRbXohwvIgfORfo8oYdv3I0Nd8hCkGydAj9wmrR8=; b=tqjlF230s8AHW4Mz/bhJfywkjzftOeplvWkaR4Gu5/33tp1QD0fqbovY6zTLhsiDQb RnWiyjhoodt28MJukxhrTRNhm2/vIoxrNuvGvSG6fmf7JFw2EonrjaFEcmJo4eJAEQny MNlMz+qbVDl5kzbYBiSUQpXoR0p5yHd8oi4hIKRqd0eSiE7D0n9h42zX/9Nas2/EgVD6 Cprw+WgbJkExeNHuEXHUj0gqdOjevezk4zvSMPMLYkSvvqiulaFzT2yoaALLZNxjgFJ2 Xn3QbuYkWmNlammkCJqDP+2Oiyocatc6NZNTvRRW7o0UQ04p6TV7SuOF8ltCVJgPMgXT NVEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778887184; x=1779491984; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=lw+jRbXohwvIgfORfo8oYdv3I0Nd8hCkGydAj9wmrR8=; b=Ofgwfje0Qdmk4YGeltkPl0wL1m8755t2GNXGV/Uz57du8EjWJ6SkqhfHFXhrmwM8DG eTWHWguCF3MtgOidRWYUHuNUw2Pg9QHLFrLkDGa6wrzaysrZMMTGzcLMvnXhH1GuumzT Xurn600muWDXWUSvcBrWCnjnxpcCMhnqA1cLkwKzC+ZedVLd6xn/yfE8iYsIflvRp4Sq yxXFoXlIoM9nuxDWEDps3HrZ5iOafSEhoBlul2vAC2RDF4gG7JZ6aKsHyU91jYb497LZ zGkUW+3ZXBfNVc6yTUXE5XAM4gaI4v9TQ1UAsKsg4K5J/IWil01+gRAtBKNzaC/mJOlP mpUg== X-Gm-Message-State: AOJu0YzIGWhvyhRtP0jw6QetwF4tRdFQW6a5CxxnB3ZOa0mPeLLhj14g HGiBi+4jg4e9RNAhkIAKsaQHRtadt80Y+4dsP+FOu5sV1oQAYAVPCO36gN+AMKaMWrrknPrZpTB nmecCPA== X-Received: from qvvr20.prod.google.com ([2002:a05:6214:1254:b0:8bb:f102:30a4]) (user=blasko job=prod-delivery.src-stubby-dispatcher) by 2002:a0c:e087:0:b0:8c2:bbef:cccc with SMTP id 6a1803df08f44-8ca0f6a86aamr95431506d6.31.1778887183873; Fri, 15 May 2026 16:19:43 -0700 (PDT) Date: Fri, 15 May 2026 23:19:33 +0000 In-Reply-To: <20260515231936.3296603-1-blasko@google.com> Mime-Version: 1.0 References: <20260511224354.872997-1-blasko@google.com> <20260515231936.3296603-1-blasko@google.com> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260515231936.3296603-5-blasko@google.com> Subject: [PATCH v2 4/6] net/gve: add periodic NIC clock synchronization From: Mark Blasko To: stephen@networkplumber.org Cc: dev@dpdk.org, Mark Blasko , Joshua Washington , "Jasper Tran O'Leary" Content-Type: text/plain; charset="UTF-8" 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 Introduce a mechanism to periodically fetch the NIC hardware timestamp using the GVE_ADMINQ_REPORT_NIC_TIMESTAMP AdminQ command. The synchronization runs every 250ms using rte_alarm. If the read fails, the alarm is still rescheduled. After 7 consecutive failures, the timestamp is marked as stale, indicating to the RX path that reconstructed timestamps may be unreliable. Atomics exist because of the potential for async callers (introduced here) and async callers (introduced later in the RX datapath) accessing the cached state. Signed-off-by: Mark Blasko Reviewed-by: Joshua Washington Reviewed-by: Jasper Tran O'Leary --- v2: - Removed redundant void* casts. - Handled alarm reschedule failures by marking timestamp stale. - Added transient error logging on memzone allocation failure. --- drivers/net/gve/gve_ethdev.c | 106 +++++++++++++++++++++++++++++++++++ drivers/net/gve/gve_ethdev.h | 9 +++ 2 files changed, 115 insertions(+) diff --git a/drivers/net/gve/gve_ethdev.c b/drivers/net/gve/gve_ethdev.c index a9e2063dda..ee21fb3ec4 100644 --- a/drivers/net/gve/gve_ethdev.c +++ b/drivers/net/gve/gve_ethdev.c @@ -452,6 +452,86 @@ gve_dev_start(struct rte_eth_dev *dev) return 0; } +static void +gve_read_nic_clock(void *arg) +{ + struct gve_priv *priv = arg; + uint32_t fails; + uint64_t ts; + int err; + + if (!priv || !priv->nic_ts_report_mz) + return; + + memset(priv->nic_ts_report, 0, sizeof(struct gve_nic_ts_report)); + + err = gve_adminq_report_nic_timestamp(priv, priv->nic_ts_report_mz->iova); + if (err == 0) { + ts = be64_to_cpu(priv->nic_ts_report->nic_timestamp); + rte_atomic_store_explicit(&priv->last_read_nic_timestamp, ts, + rte_memory_order_relaxed); + PMD_DRV_LOG(DEBUG, "Fetched NIC Timestamp: %" PRIu64, ts); + rte_atomic_store_explicit(&priv->nic_ts_read_fails, 0, + rte_memory_order_relaxed); + rte_atomic_store_explicit(&priv->nic_ts_stale, 0, + rte_memory_order_release); + } else { + PMD_DRV_LOG(ERR, "Failed to read NIC clock, AQ err: %d", err); + fails = rte_atomic_fetch_add_explicit(&priv->nic_ts_read_fails, 1, + rte_memory_order_relaxed) + 1; + if (fails >= GVE_NIC_CLOCK_READ_MAX_FAILS) { + if (!rte_atomic_load_explicit(&priv->nic_ts_stale, + rte_memory_order_relaxed)) + PMD_DRV_LOG(ERR, + "NIC timestamping marked as stale after %u consecutive failures", + GVE_NIC_CLOCK_READ_MAX_FAILS); + rte_atomic_store_explicit(&priv->nic_ts_stale, 1, + rte_memory_order_release); + } + } + + /* Reschedule the alarm for the next interval */ + if (priv->nic_ts_report_mz) { + err = rte_eal_alarm_set(GVE_NIC_CLOCK_READ_PERIOD_MS * 1000, + gve_read_nic_clock, priv); + if (err < 0) { + PMD_DRV_LOG(ERR, "Failed to reschedule NIC clock read alarm, ret=%d", err); + rte_atomic_store_explicit(&priv->nic_ts_stale, 1, + rte_memory_order_release); + } + } +} + +static int +gve_alloc_nic_ts_report(struct gve_priv *priv) +{ + char z_name[RTE_MEMZONE_NAMESIZE]; + + snprintf(z_name, sizeof(z_name), "gve_%s_nic_ts_report", + priv->pci_dev->device.name); + priv->nic_ts_report_mz = rte_memzone_reserve_aligned(z_name, + sizeof(struct gve_nic_ts_report), rte_socket_id(), + RTE_MEMZONE_IOVA_CONTIG, PAGE_SIZE); + + if (!priv->nic_ts_report_mz) { + PMD_DRV_LOG(ERR, "Failed to allocate memzone for NIC TS report"); + return -ENOMEM; + } + priv->nic_ts_report = priv->nic_ts_report_mz->addr; + rte_atomic_store_explicit(&priv->nic_ts_read_fails, 0, rte_memory_order_relaxed); + return 0; +} + +static void +gve_free_nic_ts_report(struct gve_priv *priv) +{ + if (priv->nic_ts_report_mz) { + rte_memzone_free(priv->nic_ts_report_mz); + priv->nic_ts_report_mz = NULL; + priv->nic_ts_report = NULL; + } +} + static int gve_dev_stop(struct rte_eth_dev *dev) { @@ -576,6 +656,7 @@ static void gve_teardown_device_resources(struct gve_priv *priv) { int err; + int ret; /* Tell device its resources are being freed */ if (gve_get_device_resources_ok(priv)) { @@ -586,6 +667,13 @@ gve_teardown_device_resources(struct gve_priv *priv) err); } + if (priv->nic_ts_report_mz) { + ret = rte_eal_alarm_cancel(gve_read_nic_clock, priv); + if (ret < 0) + PMD_DRV_LOG(ERR, "Failed to cancel NIC clock sync alarm, ret=%d", ret); + gve_free_nic_ts_report(priv); + } + gve_free_ptype_lut_dqo(priv); gve_free_counter_array(priv); gve_free_irq_db(priv); @@ -1252,6 +1340,23 @@ pci_dev_msix_vec_count(struct rte_pci_device *pdev) return 0; } +static void +gve_setup_nic_timestamp(struct gve_priv *priv) +{ + int err; + + if (!priv->nic_timestamp_supported) + return; + + rte_atomic_store_explicit(&priv->nic_ts_read_fails, 0, rte_memory_order_relaxed); + rte_atomic_store_explicit(&priv->nic_ts_stale, 1, rte_memory_order_relaxed); + err = gve_alloc_nic_ts_report(priv); + if (err == 0) + gve_read_nic_clock(priv); + else + PMD_DRV_LOG(ERR, "Failed to allocate memory for NIC timestamping subsystem. Please reset device to retry."); +} + static int gve_setup_device_resources(struct gve_priv *priv) { @@ -1307,6 +1412,7 @@ gve_setup_device_resources(struct gve_priv *priv) goto free_ptype_lut; } } + gve_setup_nic_timestamp(priv); gve_set_device_resources_ok(priv); diff --git a/drivers/net/gve/gve_ethdev.h b/drivers/net/gve/gve_ethdev.h index b67f82c263..7e6f24e910 100644 --- a/drivers/net/gve/gve_ethdev.h +++ b/drivers/net/gve/gve_ethdev.h @@ -12,6 +12,7 @@ #include #include #include +#include #include "base/gve.h" @@ -39,6 +40,9 @@ #define GVE_RSS_HASH_KEY_SIZE 40 #define GVE_RSS_INDIR_SIZE 128 +#define GVE_NIC_CLOCK_READ_PERIOD_MS 250 +#define GVE_NIC_CLOCK_READ_MAX_FAILS 7 + #define GVE_TX_CKSUM_OFFLOAD_MASK ( \ RTE_MBUF_F_TX_L4_MASK | \ RTE_MBUF_F_TX_TCP_SEG) @@ -359,6 +363,11 @@ struct gve_priv { /* HW Timestamping Fields */ bool nic_timestamp_supported; + const struct rte_memzone *nic_ts_report_mz; + struct gve_nic_ts_report *nic_ts_report; + RTE_ATOMIC(uint64_t) last_read_nic_timestamp; + RTE_ATOMIC(uint32_t) nic_ts_read_fails; + RTE_ATOMIC(uint8_t) nic_ts_stale; }; static inline bool -- 2.54.0.563.g4f69b47b94-goog