[PATCH v3 2/2] net/iavf: reuse device alarm for PHC sync

Soumyadeep Hore
2026-04-06T08:51:14Z

Reuse existing iavf device alarm cadence to drive periodic PHC sync
instead of a dedicated PHC alarm callback.

Keep PHC start/stop hooks as pause/resume controls around queue
reconfiguration and device lifecycle paths.

Signed-off-by: Soumyadeep Hore <soumyadeep.hore@intel.com>
---
drivers/net/intel/iavf/iavf.h | 6 ++
drivers/net/intel/iavf/iavf_ethdev.c | 128 +++++++++++++++++++++++++++
drivers/net/intel/iavf/iavf_vchnl.c | 4 +
3 files changed, 138 insertions(+)

diff --git a/drivers/net/intel/iavf/iavf.h b/drivers/net/intel/iavf/iavf.h
index 403c61e2e8..e30fd710f0 100644
--- a/drivers/net/intel/iavf/iavf.h
+++ b/drivers/net/intel/iavf/iavf.h
@@ -76,6 +76,7 @@
#define IAVF_QUEUE_ITR_INTERVAL_MAX 8160 /* 8160 us */

#define IAVF_ALARM_INTERVAL 50000 /* us */
+#define IAVF_PHC_SYNC_ALARM_INTERVAL_US 200000

/* The overhead from MTU to max frame size.
* Considering QinQ packet, the VLAN tag needs to be counted twice.
@@ -383,6 +384,9 @@ struct iavf_adapter {
enum iavf_rx_func_type rx_func_type;
enum iavf_tx_func_type tx_func_type;
uint16_t fdir_ref_cnt;
+ rte_spinlock_t phc_sync_lock;
+ uint16_t phc_sync_ticks;
+ bool phc_sync_paused;
struct iavf_devargs devargs;
bool mac_primary_set;
};
@@ -517,6 +521,8 @@ void iavf_add_del_all_mac_addr(struct iavf_adapter *adapter, bool add);
int iavf_dev_link_update(struct rte_eth_dev *dev,
__rte_unused int wait_to_complete);
void iavf_dev_alarm_handler(void *param);
+void iavf_phc_sync_alarm_start(struct rte_eth_dev *dev);
+void iavf_phc_sync_alarm_stop(struct rte_eth_dev *dev);
int iavf_query_stats(struct iavf_adapter *adapter,
struct virtchnl_eth_stats **pstats);
int iavf_config_promisc(struct iavf_adapter *adapter, bool enable_unicast,
diff --git a/drivers/net/intel/iavf/iavf_ethdev.c b/drivers/net/intel/iavf/iavf_ethdev.c
index 1eca20bc9a..9c9a5a6b47 100644
--- a/drivers/net/intel/iavf/iavf_ethdev.c
+++ b/drivers/net/intel/iavf/iavf_ethdev.c
@@ -21,6 +21,7 @@
#include <rte_pci.h>
#include <rte_alarm.h>
#include <rte_atomic.h>
+#include <rte_cycles.h>
#include <rte_eal.h>
#include <rte_ether.h>
#include <ethdev_driver.h>
@@ -145,6 +146,11 @@ static int iavf_dev_rx_queue_intr_disable(struct rte_eth_dev *dev,
uint16_t queue_id);
static void iavf_dev_interrupt_handler(void *param);
static void iavf_disable_irq0(struct iavf_hw *hw);
+static struct ci_rx_queue *iavf_phc_sync_rxq_get(struct rte_eth_dev *dev);
+static void iavf_phc_sync_update_all_rxq(struct rte_eth_dev *dev,
+ uint64_t phc_time,
+ uint64_t sw_cur_time);
+static bool iavf_phc_sync_alarm_needed(struct rte_eth_dev *dev);
static int iavf_dev_flow_ops_get(struct rte_eth_dev *dev,
const struct rte_flow_ops **ops);
static int iavf_set_mc_addr_list(struct rte_eth_dev *dev,
@@ -1056,6 +1062,8 @@ iavf_dev_start(struct rte_eth_dev *dev)
goto error;
}

+ iavf_phc_sync_alarm_start(dev);
+
return 0;

error:
@@ -1082,6 +1090,8 @@ iavf_dev_stop(struct rte_eth_dev *dev)
if (adapter->stopped == 1)
return 0;

+ iavf_phc_sync_alarm_stop(dev);
+
/* Disable the interrupt for Rx */
rte_intr_efd_disable(intr_handle);
/* Rx interrupt vector mapping free */
@@ -2705,9 +2715,13 @@ void
iavf_dev_alarm_handler(void *param)
{
struct rte_eth_dev *dev = (struct rte_eth_dev *)param;
+ struct iavf_adapter *adapter;
+ const uint16_t phc_sync_ticks_max = RTE_MAX((uint16_t)1,
+ (uint16_t)(IAVF_PHC_SYNC_ALARM_INTERVAL_US / IAVF_ALARM_INTERVAL));
if (dev == NULL || dev->data == NULL || dev->data->dev_private == NULL)
return;

+ adapter = IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
struct iavf_hw *hw = IAVF_DEV_PRIVATE_TO_HW(dev->data->dev_private);
uint32_t icr0;

@@ -2723,10 +2737,121 @@ iavf_dev_alarm_handler(void *param)

iavf_enable_irq0(hw);

+ rte_spinlock_lock(&adapter->phc_sync_lock);
+ if (!adapter->phc_sync_paused &&
+ iavf_phc_sync_alarm_needed(dev)) {
+ uint16_t phc_sync_ticks =
+ ++adapter->phc_sync_ticks;
+
+ if (phc_sync_ticks >= phc_sync_ticks_max) {
+ struct ci_rx_queue *sync_rxq;
+ uint64_t sw_cur_time;
+
+ adapter->phc_sync_ticks = 0;
+ sync_rxq = iavf_phc_sync_rxq_get(dev);
+ if (sync_rxq != NULL && iavf_get_phc_time(sync_rxq) == 0) {
+ sw_cur_time = rte_get_timer_cycles() /
+ (rte_get_timer_hz() / 1000);
+ iavf_phc_sync_update_all_rxq(dev,
+ sync_rxq->phc_time, sw_cur_time);
+ } else if (sync_rxq != NULL) {
+ PMD_DRV_LOG(ERR, "get physical time failed");
+ }
+ }
+ } else {
+ adapter->phc_sync_ticks = 0;
+ }
+ rte_spinlock_unlock(&adapter->phc_sync_lock);
+
rte_eal_alarm_set(IAVF_ALARM_INTERVAL,
iavf_dev_alarm_handler, dev);
}

+static struct ci_rx_queue *
+iavf_phc_sync_rxq_get(struct rte_eth_dev *dev)
+{
+ struct ci_rx_queue *rxq;
+ uint16_t i;
+
+ for (i = 0; i < dev->data->nb_rx_queues; i++) {
+ rxq = dev->data->rx_queues[i];
+ if (rxq != NULL)
+ return rxq;
+ }
+
+ return NULL;
+}
+
+static void
+iavf_phc_sync_update_all_rxq(struct rte_eth_dev *dev,
+ uint64_t phc_time,
+ uint64_t sw_cur_time)
+{
+ struct ci_rx_queue *rxq;
+ uint16_t i;
+
+ for (i = 0; i < dev->data->nb_rx_queues; i++) {
+ rxq = dev->data->rx_queues[i];
+ if (rxq == NULL)
+ continue;
+
+ rxq->phc_time = phc_time;
+ rxq->hw_time_update = sw_cur_time;
+ }
+}
+
+static bool
+iavf_phc_sync_alarm_needed(struct rte_eth_dev *dev)
+{
+ struct iavf_adapter *adapter;
+
+ adapter = IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+
+ if (adapter->closed || adapter->stopped)
+ return false;
+
+ if (!(dev->data->dev_conf.rxmode.offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP))
+ return false;
+
+ if (dev->data->nb_rx_queues == 0)
+ return false;
+
+ if (iavf_phc_sync_rxq_get(dev) == NULL)
+ return false;
+
+ return true;
+}
+
+void
+iavf_phc_sync_alarm_start(struct rte_eth_dev *dev)
+{
+ struct iavf_adapter *adapter;
+
+ if (!iavf_phc_sync_alarm_needed(dev))
+ return;
+
+ adapter = IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+ rte_spinlock_lock(&adapter->phc_sync_lock);
+ adapter->phc_sync_paused = false;
+ adapter->phc_sync_ticks = 0;
+ rte_spinlock_unlock(&adapter->phc_sync_lock);
+}
+
+void
+iavf_phc_sync_alarm_stop(struct rte_eth_dev *dev)
+{
+ struct iavf_adapter *adapter;
+
+ if (dev == NULL || dev->data == NULL || dev->data->dev_private == NULL)
+ return;
+
+ adapter = IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+ rte_spinlock_lock(&adapter->phc_sync_lock);
+ adapter->phc_sync_paused = true;
+ adapter->phc_sync_ticks = 0;
+ rte_spinlock_unlock(&adapter->phc_sync_lock);
+}
+
static int
iavf_dev_flow_ops_get(struct rte_eth_dev *dev,
const struct rte_flow_ops **ops)
@@ -2808,6 +2933,7 @@ iavf_dev_init(struct rte_eth_dev *eth_dev)
adapter->dev_data = eth_dev->data;
adapter->stopped = 1;
adapter->mac_primary_set = false;
+ rte_spinlock_init(&adapter->phc_sync_lock);

if (iavf_dev_event_handler_init())
goto init_vf_err;
@@ -2912,6 +3038,7 @@ iavf_dev_init(struct rte_eth_dev *eth_dev)
} else {
rte_eal_alarm_cancel(iavf_dev_alarm_handler, eth_dev);
}
+ iavf_phc_sync_alarm_stop(eth_dev);

rte_free(eth_dev->data->mac_addrs);
eth_dev->data->mac_addrs = NULL;
@@ -2986,6 +3113,7 @@ iavf_dev_close(struct rte_eth_dev *dev)
} else {
rte_eal_alarm_cancel(iavf_dev_alarm_handler, dev);
}
+ iavf_phc_sync_alarm_stop(dev);
iavf_disable_irq0(hw);

if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_QOS)
diff --git a/drivers/net/intel/iavf/iavf_vchnl.c b/drivers/net/intel/iavf/iavf_vchnl.c
index 08dd6f2d7f..79ef4cec56 100644
--- a/drivers/net/intel/iavf/iavf_vchnl.c
+++ b/drivers/net/intel/iavf/iavf_vchnl.c
@@ -2133,12 +2133,16 @@ iavf_request_queues(struct rte_eth_dev *dev, uint16_t num)
args.out_size = IAVF_AQ_BUF_SZ;

if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_WB_ON_ITR) {
+ iavf_phc_sync_alarm_stop(dev);
err = iavf_execute_vf_cmd_safe(adapter, &args, 0);
+ iavf_phc_sync_alarm_start(dev);
} else {
+ iavf_phc_sync_alarm_stop(dev);
rte_eal_alarm_cancel(iavf_dev_alarm_handler, dev);
err = iavf_execute_vf_cmd_safe(adapter, &args, 0);
rte_eal_alarm_set(IAVF_ALARM_INTERVAL,
iavf_dev_alarm_handler, dev);
+ iavf_phc_sync_alarm_start(dev);
}

if (err) {
--
2.47.1