[dpdk-dev] [PATCH v3 3/5] net/vhost: implement rte_power_monitor API

[Miao Li <miao.li@intel.com>]

This patch implements rte_power_monitor API in vhost PMD to reduce
power consumption when no packet come in. According to current semantics
of power monitor, this commit adds a callback function to decide whether
aborts the sleep by checking current value against the expected value and
vhost_get_monitor_addr to provide address to monitor. When no packet come
in, the value of address will not be changed and the running core will
sleep. Once packets arrive, the value of address will be changed and the
running core will wakeup.

Signed-off-by: Miao Li <miao.li@intel.com>
---
 drivers/net/vhost/rte_eth_vhost.c | 40 +++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index a202931e9a..eabb0b0519 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -1380,6 +1380,45 @@ eth_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	return rte_vhost_rx_queue_count(vq->vid, vq->virtqueue_id);
 }
 
+#define CLB_VAL_IDX 0
+#define CLB_MSK_IDX 1
+#define CLB_MATCH_IDX 2
+static int
+vhost_monitor_callback(const uint64_t value,
+		const uint64_t opaque[RTE_POWER_MONITOR_OPAQUE_SZ])
+{
+	const uint64_t m = opaque[CLB_MSK_IDX];
+	const uint64_t v = opaque[CLB_VAL_IDX];
+	const uint64_t c = opaque[CLB_MATCH_IDX];
+
+	if (c)
+		return (value & m) == v ? -1 : 0;
+	else
+		return (value & m) == v ? 0 : -1;
+}
+
+static int
+vhost_get_monitor_addr(void *rx_queue, struct rte_power_monitor_cond *pmc)
+{
+	struct vhost_queue *vq = rx_queue;
+	struct rte_vhost_power_monitor_cond vhost_pmc;
+	int ret;
+	if (vq == NULL)
+		return -EINVAL;
+	ret = rte_vhost_get_monitor_addr(vq->vid, vq->virtqueue_id,
+			&vhost_pmc);
+	if (ret < 0)
+		return -EINVAL;
+	pmc->addr = vhost_pmc.addr;
+	pmc->opaque[CLB_VAL_IDX] = vhost_pmc.val;
+	pmc->opaque[CLB_MSK_IDX] = vhost_pmc.mask;
+	pmc->opaque[CLB_MATCH_IDX] = vhost_pmc.match;
+	pmc->size = vhost_pmc.size;
+	pmc->fn = vhost_monitor_callback;
+
+	return 0;
+}
+
 static const struct eth_dev_ops ops = {
 	.dev_start = eth_dev_start,
 	.dev_stop = eth_dev_stop,
@@ -1399,6 +1438,7 @@ static const struct eth_dev_ops ops = {
 	.xstats_get_names = vhost_dev_xstats_get_names,
 	.rx_queue_intr_enable = eth_rxq_intr_enable,
 	.rx_queue_intr_disable = eth_rxq_intr_disable,
+	.get_monitor_addr        = vhost_get_monitor_addr,
 };
 
 static int
-- 
2.25.1