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

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

On 19/10/2021 5:39 AM, Xia, Chenbo wrote:
>> -----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>


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