Re: [dpdk-dev] [PATCH v7 3/5] net/vhost: implement rte_power_monitor API

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Li, Miao <miao.li@intel.com>
> Sent: Monday, October 18, 2021 10:17 PM
> To: dev@dpdk.org
> Cc: Xia, Chenbo <chenbo.xia@intel.com>; maxime.coquelin@redhat.com; Li, Miao
> <miao.li@intel.com>
> Subject: [PATCH v7 3/5] net/vhost: implement rte_power_monitor API
> 
> 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>
> ---
>  doc/guides/rel_notes/release_21_11.rst |  4 +++
>  drivers/net/vhost/rte_eth_vhost.c      | 40 ++++++++++++++++++++++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/release_21_11.rst
> b/doc/guides/rel_notes/release_21_11.rst
> index a497674352..f3dc2cf219 100644
> --- a/doc/guides/rel_notes/release_21_11.rst
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -84,6 +84,10 @@ New Features
> 
>    Added an API to support power monitor in vhost library.
> 
> +* **Updated vhost PMD.**
> +
> +  Implement rte_power_monitor API in vhost PMD.
> +
>  * **Updated virtio PMD.**
> 
>    Implement rte_power_monitor API in virtio PMD.
> diff --git a/drivers/net/vhost/rte_eth_vhost.c
> b/drivers/net/vhost/rte_eth_vhost.c
> index 2e24e5f7ff..c9947e4db7 100644
> --- a/drivers/net/vhost/rte_eth_vhost.c
> +++ b/drivers/net/vhost/rte_eth_vhost.c
> @@ -1386,6 +1386,45 @@ 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,
> @@ -1405,6 +1444,7 @@ 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

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>