[dpdk-dev] [PATCH v5 2/5] vhost: implement rte_power_monitor API

[Xia, Chenbo]

Hi,

> -----Original Message-----
> From: Li, Miao <miao.li at intel.com>
> Sent: Friday, October 15, 2021 11:12 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 v5 2/5] vhost: implement rte_power_monitor API
> 
> This patch defines rte_vhost_power_monitor_cond which is used to pass
> some information to vhost driver. The information is including the address
> to monitor, the expected value, the mask to extract value read from 'addr',
> the value size of monitor address, the match flag used to distinguish the
> value used to match something or not match something. Vhost driver can use
> these information to fill rte_power_monitor_cond.
> 
> Signed-off-by: Miao Li <miao.li at intel.com>
> ---
>  doc/guides/rel_notes/release_21_11.rst |  4 +++
>  lib/vhost/rte_vhost.h                  | 44 ++++++++++++++++++++++++++
>  lib/vhost/version.map                  |  3 ++
>  lib/vhost/vhost.c                      | 38 ++++++++++++++++++++++
>  4 files changed, 89 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/release_21_11.rst
> b/doc/guides/rel_notes/release_21_11.rst
> index 27dc896703..ad6d256a55 100644
> --- a/doc/guides/rel_notes/release_21_11.rst
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -72,6 +72,10 @@ 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.
> 
> +* **Added power monitor API in vhost library.**
> +
> +  Added an API to support power monitor in vhost library.
> +
>  * **Updated virtio PMD.**
> 
>    Implement rte_power_monitor API in virtio PMD.
> diff --git a/lib/vhost/rte_vhost.h b/lib/vhost/rte_vhost.h
> index fd372d5259..42bda95e96 100644
> --- a/lib/vhost/rte_vhost.h
> +++ b/lib/vhost/rte_vhost.h
> @@ -292,6 +292,33 @@ struct vhost_device_ops {
>  	void *reserved[1]; /**< Reserved for future extension */
>  };
> 
> +/**
> + * Power monitor condition.
> + */
> +struct rte_vhost_power_monitor_cond {
> +	/**< Address to monitor for changes */
> +	volatile void *addr;
> +	/**< If the `mask` is non-zero, location pointed
> +	 *   to by `addr` will be read and masked, then
> +	 *   compared with this value.
> +	 */
> +	uint64_t val;
> +	/**< 64-bit mask to extract value read from `addr` */
> +	uint64_t mask;
> +	/**< Data size (in bytes) that will be read from the
> +	 *   monitored memory location (`addr`). Can be 1, 2,
> +	 *   4, or 8. Supplying any other value will result in
> +	 *   an error.

'Can be ...' part is not necessary, as this value is defined in vhost
lib and currently only has two different values for packed or split.

> +	 */
> +	uint8_t size;
> +	/**< If 1, and masked value that read from 'addr' equals
> +	 *   'val', the driver will skip core sleep. If 0, and

'will' -> 'should'. As it's a suggestion for vhost driver.

> +	 *  masked value that read from 'addr' does not equal 'val',
> +	 *  the driver will skip core sleep.

Ditto.

Thanks,
Chenbo

> +	 */
> +	uint8_t match;
> +};
> +
>  /**
>   * Convert guest physical address to host virtual address
>   *
> @@ -903,6 +930,23 @@ int rte_vhost_vring_call(int vid, uint16_t vring_idx);
>   */
>  uint32_t rte_vhost_rx_queue_count(int vid, uint16_t qid);
> 
> +/**
> + * Get power monitor address of the vhost device
> + *
> + * @param vid
> + *  vhost device ID
> + * @param queue_id
> + *  vhost queue ID
> + * @param pmc
> + *  power monitor condition
> + * @return
> + *  0 on success, -1 on failure
> + */
> +__rte_experimental
> +int
> +rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
> +		struct rte_vhost_power_monitor_cond *pmc);
> +
>  /**
>   * Get log base and log size of the vhost device
>   *
> diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> index 8ebde3f694..c8599ddb97 100644
> --- a/lib/vhost/version.map
> +++ b/lib/vhost/version.map
> @@ -85,4 +85,7 @@ EXPERIMENTAL {
>  	rte_vhost_async_channel_register_thread_unsafe;
>  	rte_vhost_async_channel_unregister_thread_unsafe;
>  	rte_vhost_clear_queue_thread_unsafe;
> +
> +	# added in 21.11
> +	rte_vhost_get_monitor_addr;
>  };
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 9540522dac..36c896c9e2 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -1889,5 +1889,43 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
>  	return ret;
>  }
> 
> +int
> +rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
> +		struct rte_vhost_power_monitor_cond *pmc)
> +{
> +	struct virtio_net *dev = get_device(vid);
> +	struct vhost_virtqueue *vq;
> +
> +	if (dev == NULL)
> +		return -1;
> +	if (queue_id >= VHOST_MAX_VRING)
> +		return -1;
> +
> +	vq = dev->virtqueue[queue_id];
> +	if (vq == NULL)
> +		return -1;
> +
> +	if (vq_is_packed(dev)) {
> +		struct vring_packed_desc *desc;
> +		desc = vq->desc_packed;
> +		pmc->addr = &desc[vq->last_avail_idx].flags;
> +		if (vq->avail_wrap_counter)
> +			pmc->val = VRING_DESC_F_AVAIL;
> +		else
> +			pmc->val = VRING_DESC_F_USED;
> +		pmc->mask = VRING_DESC_F_AVAIL | VRING_DESC_F_USED;
> +		pmc->size = sizeof(desc[vq->last_avail_idx].flags);
> +		pmc->match = 1;
> +	} else {
> +		pmc->addr = &vq->avail->idx;
> +		pmc->val = vq->last_avail_idx & (vq->size - 1);
> +		pmc->mask = vq->size - 1;
> +		pmc->size = sizeof(vq->avail->idx);
> +		pmc->match = 0;
> +	}
> +
> +	return 0;
> +}
> +
>  RTE_LOG_REGISTER_SUFFIX(vhost_config_log_level, config, INFO);
>  RTE_LOG_REGISTER_SUFFIX(vhost_data_log_level, data, WARNING);
> --
> 2.25.1