Re: [dpdk-dev] [PATCH v7 1/5] net/virtio: implement rte_power_monitor API

[David Hunt <david.hunt@intel.com>]

On 18/10/2021 3:16 PM, Miao Li wrote:
> This patch implements rte_power_monitor API in virtio 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
> virtio_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>
> Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
> ---
>   doc/guides/rel_notes/release_21_11.rst |  4 ++
>   drivers/net/virtio/virtio_ethdev.c     | 56 ++++++++++++++++++++++++++
>   2 files changed, 60 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
> index d5435a64aa..c298844898 100644
> --- a/doc/guides/rel_notes/release_21_11.rst
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -80,6 +80,10 @@ New Features
>     Added macros ETH_RSS_IPV4_CHKSUM and ETH_RSS_L4_CHKSUM, now IPv4 and
>     TCP/UDP/SCTP header checksum field can be used as input set for RSS.
>   
> +* **Updated virtio PMD.**
> +
> +  Implement rte_power_monitor API in virtio PMD.
> +
>   * **Updated af_packet ethdev driver.**
>   
>     * Default VLAN strip behavior was changed. VLAN tag won't be stripped
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index 6aa36b3f39..1227f3f1f4 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -74,6 +74,8 @@ static int virtio_mac_addr_set(struct rte_eth_dev *dev,
>   				struct rte_ether_addr *mac_addr);
>   
>   static int virtio_intr_disable(struct rte_eth_dev *dev);
> +static int virtio_get_monitor_addr(void *rx_queue,
> +				struct rte_power_monitor_cond *pmc);
>   
>   static int virtio_dev_queue_stats_mapping_set(
>   	struct rte_eth_dev *eth_dev,
> @@ -982,6 +984,7 @@ static const struct eth_dev_ops virtio_eth_dev_ops = {
>   	.mac_addr_add            = virtio_mac_addr_add,
>   	.mac_addr_remove         = virtio_mac_addr_remove,
>   	.mac_addr_set            = virtio_mac_addr_set,
> +	.get_monitor_addr        = virtio_get_monitor_addr,
>   };
>   
>   /*
> @@ -1313,6 +1316,59 @@ virtio_mac_addr_set(struct rte_eth_dev *dev, struct rte_ether_addr *mac_addr)
>   	return 0;
>   }
>   
> +#define CLB_VAL_IDX 0
> +#define CLB_MSK_IDX 1
> +#define CLB_MATCH_IDX 2
> +static int
> +virtio_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
> +virtio_get_monitor_addr(void *rx_queue, struct rte_power_monitor_cond *pmc)
> +{
> +	struct virtnet_rx *rxvq = rx_queue;
> +	struct virtqueue *vq = virtnet_rxq_to_vq(rxvq);
> +	struct virtio_hw *hw;
> +
> +	if (vq == NULL)
> +		return -EINVAL;
> +
> +	hw = vq->hw;
> +	if (virtio_with_packed_queue(hw)) {
> +		struct vring_packed_desc *desc;
> +		desc = vq->vq_packed.ring.desc;
> +		pmc->addr = &desc[vq->vq_used_cons_idx].flags;
> +		if (vq->vq_packed.used_wrap_counter)
> +			pmc->opaque[CLB_VAL_IDX] =
> +						VRING_PACKED_DESC_F_AVAIL_USED;
> +		else
> +			pmc->opaque[CLB_VAL_IDX] = 0;
> +		pmc->opaque[CLB_MSK_IDX] = VRING_PACKED_DESC_F_AVAIL_USED;
> +		pmc->opaque[CLB_MATCH_IDX] = 1;
> +		pmc->size = sizeof(desc[vq->vq_used_cons_idx].flags);
> +	} else {
> +		pmc->addr = &vq->vq_split.ring.used->idx;
> +		pmc->opaque[CLB_VAL_IDX] = vq->vq_used_cons_idx
> +					& (vq->vq_nentries - 1);
> +		pmc->opaque[CLB_MSK_IDX] = vq->vq_nentries - 1;
> +		pmc->opaque[CLB_MATCH_IDX] = 0;
> +		pmc->size = sizeof(vq->vq_split.ring.used->idx);
> +	}
> +	pmc->fn = virtio_monitor_callback;
> +
> +	return 0;
> +}
> +
>   static int
>   virtio_vlan_filter_set(struct rte_eth_dev *dev, uint16_t vlan_id, int on)
>   {


LGTM.

Acked-by: David Hunt <david.hunt@intel.com>