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

[Li, Miao]

Hi chenbo

> -----Original Message-----
> From: Xia, Chenbo <chenbo.xia at intel.com>
> Sent: Wednesday, September 15, 2021 4:45 PM
> To: Li, Miao <miao.li at intel.com>; dev at dpdk.org
> Cc: maxime.coquelin at redhat.com
> Subject: RE: [PATCH 1/5] net/virtio: implement rte_power_monitor API
> 
> Hi Miao,
> 
> > -----Original Message-----
> > From: Li, Miao <miao.li at intel.com>
> > Sent: Friday, September 10, 2021 9:06 PM
> > To: dev at dpdk.org
> > Cc: Xia, Chenbo <chenbo.xia at intel.com>; maxime.coquelin at redhat.com;
> > Li, Miao <miao.li at intel.com>
> > Subject: [PATCH 1/5] net/virtio: implement rte_power_monitor API
> >
> > 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 at intel.com>
> > ---
> >  drivers/net/virtio/virtio_ethdev.c | 57
> > ++++++++++++++++++++++++++++++
> >  1 file changed, 57 insertions(+)
> >
> > diff --git a/drivers/net/virtio/virtio_ethdev.c
> > b/drivers/net/virtio/virtio_ethdev.c
> > index e58085a2c9..4ce49936f5 100644
> > --- a/drivers/net/virtio/virtio_ethdev.c
> > +++ b/drivers/net/virtio/virtio_ethdev.c
> > @@ -73,6 +73,8 @@ 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,
> > @@ -975,6 +977,7 @@ 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,
> >  };
> >
> >  /*
> > @@ -1306,6 +1309,60 @@ 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
> > +static int
> > +virtio_packed_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];
> > +
> > +	return (value & m) == v ? -1 : 0;
> > +}
> > +
> > +static int
> > +virtio_split_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];
> > +
> > +	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 = vq->hw;
> > +	if (vq == NULL)
> > +		return -EINVAL;
> > +	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->fn = virtio_packed_monitor_callback;
> > +		pmc->size = sizeof(uint16_t);
> 
> I suggest to use sizeof(desc[vq->vq_used_cons_idx].flags) or sizeof(desc->flags)
> in case the flag type changes.

Thanks for your suggestion. I will fix it in the next version.

> 
> > +	} 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->fn = virtio_split_monitor_callback;
> > +		pmc->size = sizeof(uint16_t);
> 
> Same here.

I will fix it in the next version, too.

Thanks,
Miao

> 
> Thanks,
> Chenbo
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  static int
> >  virtio_vlan_filter_set(struct rte_eth_dev *dev, uint16_t vlan_id, int
> > on)  {
> > --
> > 2.25.1