Re: [PATCH v8 6/9] ethdev: add common devargs parser

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Doherty, Declan
> Sent: Thursday, April 26, 2018 11:41 AM
> To: dev@dpdk.org
> Cc: Adrien Mazarguil <adrien.mazarguil@6wind.com>; Yigit, Ferruh <ferruh.yigit@intel.com>; Thomas Monjalon <thomas@monjalon.net>;
> Shahaf Shuler <shahafs@mellanox.com>; Ananyev, Konstantin <konstantin.ananyev@intel.com>; Horton, Remy <remy.horton@intel.com>;
> Doherty, Declan <declan.doherty@intel.com>
> Subject: [dpdk-dev][PATCH v8 6/9] ethdev: add common devargs parser
> 
> From: Remy Horton <remy.horton@intel.com>
> 
> Introduces a new structure, rte_eth_devargs, to support generic
> ethdev arguments common across NET PMDs, with a new API
> rte_eth_devargs_parse API to support PMD parsing these arguments. The
> patch add support for a representor argument  passed with passed with
> the EAL -w option. The representor parameter allows the user to specify
> which representor ports to initialise on a device.
> 
> The argument supports passing a single representor port, a list of
> port values or a range of port values.
> 
> -w BDF,representor=1  # create representor port 1 on pci device BDF
> -w BDF,representor=[1,2,5,6,10] # create representor ports in list
> -w BDF,representor=[0-31] # create representor ports in range
> 
> Signed-off-by: Remy Horton <remy.horton@intel.com>
> Signed-off-by: Declan Doherty <declan.doherty@intel.com>
> ---
>  doc/guides/prog_guide/poll_mode_drv.rst |  19 ++++
>  lib/Makefile                            |   1 +
>  lib/librte_ether/rte_ethdev.c           | 182 ++++++++++++++++++++++++++++++++
>  lib/librte_ether/rte_ethdev_driver.h    |  30 ++++++
>  lib/librte_ether/rte_ethdev_version.map |   1 +
>  5 files changed, 233 insertions(+)
> 
> diff --git a/doc/guides/prog_guide/poll_mode_drv.rst b/doc/guides/prog_guide/poll_mode_drv.rst
> index e5d01874e..09a93baec 100644
> --- a/doc/guides/prog_guide/poll_mode_drv.rst
> +++ b/doc/guides/prog_guide/poll_mode_drv.rst
> @@ -345,6 +345,25 @@ Ethernet Device API
> 
>  The Ethernet device API exported by the Ethernet PMDs is described in the *DPDK API Reference*.
> 
> +Ethernet Device Standard Device Arguments
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +Standard Ethernet device arguments allow for a set of commonly used arguments/
> +parameters which are applicable to all Ethernet devices to be available to for
> +specification of specific device and for passing common configuration
> +parameters to those ports.
> +
> +* ``representor`` for a device which supports the creation of representor ports
> +  this argument allows user to specify which switch ports to enable port
> +  representors for.::
> +
> +   -w BDBF,representor=0
> +   -w BDBF,representor=[0,4,6,9]
> +   -w BDBF,representor=[0-31]
> +
> +Note: PMDs are not required to support the standard device arguments and users
> +should consult the relevant PMD documentation to see support devargs.
> +
>  Extended Statistics API
>  ~~~~~~~~~~~~~~~~~~~~~~~
> 
> diff --git a/lib/Makefile b/lib/Makefile
> index 965be6c8d..536775e59 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -21,6 +21,7 @@ DEPDIRS-librte_cmdline := librte_eal
>  DIRS-$(CONFIG_RTE_LIBRTE_ETHER) += librte_ether
>  DEPDIRS-librte_ether := librte_net librte_eal librte_mempool librte_ring
>  DEPDIRS-librte_ether += librte_mbuf
> +DEPDIRS-librte_ether += librte_kvargs
>  DIRS-$(CONFIG_RTE_LIBRTE_BBDEV) += librte_bbdev
>  DEPDIRS-librte_bbdev := librte_eal librte_mempool librte_mbuf
>  DIRS-$(CONFIG_RTE_LIBRTE_CRYPTODEV) += librte_cryptodev
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 621f8af7f..cb85d8bb7 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -34,6 +34,7 @@
>  #include <rte_errno.h>
>  #include <rte_spinlock.h>
>  #include <rte_string_fns.h>
> ++#include <rte_kvargs.h>
> 
>  #include "rte_ether.h"
>  #include "rte_ethdev.h"
> @@ -4101,6 +4102,187 @@ rte_eth_dev_pool_ops_supported(uint16_t port_id, const char *pool)
>  	return (*dev->dev_ops->pool_ops_supported)(dev, pool);
>  }
> 
> +typedef int (*rte_eth_devargs_callback_t)(char *str, void *data);
> +
> +static int
> +rte_eth_devargs_tokenise(struct rte_kvargs *arglist, const char *str_in)
> +{

I still think that if you'd like to extend rte_kvarrgs to be able to parse something like: "key=[val1,val2,...,valn]",
you have to make it generic kvargs ability and put it into librte_kvargs, not try to introduce your own new parser here.
Imagine that in addition to your 'port=[val1,val2, ..valn]' devargs string would contain some extra (let say device specific)
parameters.
What would happen, when PMD will try to use rte_kvargs_parse() on such string?
My understanding - it would fail, correct?

As an alternative - as I remember rte_kvargs allows you to have multiple identical key, i.e: "key=val1,key=val2,...,key=valn".
Why not to use that way, if you don't want to introduce extra code in rte_kvargs?

> +	int state;
> +	struct rte_kvargs_pair *pair;
> +	char *letter;
> +
> +	arglist->str = strdup(str_in);
> +	if (arglist->str == NULL)
> +		return -ENOMEM;
> +
> +	letter = arglist->str;
> +	state = 0;
> +	arglist->count = 0;
> +	pair = &arglist->pairs[0];
> +	while (1) {
> +		switch (state) {
> +		case 0: /* Initial */
> +			if (*letter == '=')
> +				return -EINVAL;
> +			else if (*letter == '\0')
> +				return 0;
> +
> +			state = 1;
> +			pair->key = letter;
> +			/* fall-thru */
> +
> +		case 1: /* Parsing key */
> +			if (*letter == '=') {
> +				*letter = '\0';
> +				pair->value = letter + 1;
> +				state = 2;
> +			} else if (*letter == ',' || *letter == '\0')
> +				return -EINVAL;
> +			break;
> +
> +
> +		case 2: /* Parsing value */
> +			if (*letter == '[')
> +				state = 3;
> +			else if (*letter == ',') {
> +				*letter = '\0';
> +				arglist->count++;
> +				pair = &arglist->pairs[arglist->count];
> +				state = 0;
> +			} else if (*letter == '\0') {
> +				letter--;
> +				arglist->count++;
> +				pair = &arglist->pairs[arglist->count];
> +				state = 0;
> +			}
> +			break;
> +
> +		case 3: /* Parsing list */
> +			if (*letter == ']')
> +				state = 2;
> +			else if (*letter == '\0')
> +				return -EINVAL;
> +			break;
> +		}
> +		letter++;
> +	}
> +}
> +
> +static int
> +rte_eth_devargs_parse_list(char *str, rte_eth_devargs_callback_t callback,
> +	void *data)
> +{
> +	char *str_start;
> +	int state;
> +	int result;
> +
> +	if (*str != '[')
> +		/* Single element, not a list */
> +		return callback(str, data);
> +
> +	/* Sanity check, then strip the brackets */
> +	str_start = &str[strlen(str) - 1];
> +	if (*str_start != ']') {
> +		RTE_LOG(ERR, EAL, "(%s): List does not end with ']'", str);
> +		return -EINVAL;
> +	}
> +	str++;
> +	*str_start = '\0';
> +
> +	/* Process list elements */
> +	state = 0;
> +	while (1) {
> +		if (state == 0) {
> +			if (*str == '\0')
> +				break;
> +			if (*str != ',') {
> +				str_start = str;
> +				state = 1;
> +			}
> +		} else if (state == 1) {
> +			if (*str == ',' || *str == '\0') {
> +				if (str > str_start) {
> +					/* Non-empty string fragment */
> +					*str = '\0';
> +					result = callback(str_start, data);
> +					if (result < 0)
> +						return result;
> +				}
> +				state = 0;
> +			}
> +		}
> +		str++;
> +	}
> +	return 0;
> +}
> +
> +static int
> +rte_eth_devargs_process_range(char *str, uint16_t *list, uint16_t *len_list,
> +	const uint16_t max_list)
> +{
> +	uint16_t lo, hi, val;
> +	int result;
> +
> +	result = sscanf(str, "%hu-%hu", &lo, &hi);
> +	if (result == 1) {
> +		if (*len_list >= max_list)
> +			return -ENOMEM;
> +		list[(*len_list)++] = lo;
> +	} else if (result == 2) {
> +		if (lo >= hi || lo > RTE_MAX_ETHPORTS || hi > RTE_MAX_ETHPORTS)

lo > RTE_MAX_ETHPORTS is redundant here.

> +			return -EINVAL;
> +		for (val = lo; val <= hi; val++) {
> +			if (*len_list >= max_list)
> +				return -ENOMEM;
> +			list[(*len_list)++] = val;
> +		}
> +	} else
> +		return -EINVAL;
> +	return 0;
> +}
> +
> +
> +static int
> +rte_eth_devargs_parse_representor_ports(char *str, void *data)
> +{
> +	struct rte_eth_devargs *eth_da = data;
> +
> +	return rte_eth_devargs_process_range(str, eth_da->representor_ports,
> +		&eth_da->nb_representor_ports, RTE_MAX_ETHPORTS);
> +}
> +
> +int __rte_experimental
> +rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_da)
> +{
> +	struct rte_kvargs args;
> +	struct rte_kvargs_pair *pair;
> +	unsigned int i;
> +	int result = 0;
> +
> +	memset(eth_da, 0, sizeof(*eth_da));
> +
> +	result = rte_eth_devargs_tokenise(&args, dargs);
> +	if (result < 0)
> +		goto parse_cleanup;
> +
> +	for (i = 0; i < args.count; i++) {
> +		pair = &args.pairs[i];
> +		if (strcmp("representor", pair->key) == 0) {
> +			result = rte_eth_devargs_parse_list(pair->value,
> +				rte_eth_devargs_parse_representor_ports,
> +				eth_da);
> +			if (result < 0)
> +				goto parse_cleanup;
> +		}
> +	}
> +
> +parse_cleanup:
> +	if (args.str)
> +		free(args.str);
> +
> +	return result;
> +}
> +
>  RTE_INIT(ethdev_init_log);
>  static void
>  ethdev_init_log(void)
> diff --git a/lib/librte_ether/rte_ethdev_driver.h b/lib/librte_ether/rte_ethdev_driver.h
> index 8c61ab2f4..492da754a 100644
> --- a/lib/librte_ether/rte_ethdev_driver.h
> +++ b/lib/librte_ether/rte_ethdev_driver.h
> @@ -189,6 +189,36 @@ rte_eth_linkstatus_get(const struct rte_eth_dev *dev,
>  }
> 
> 
> +/** Generic Ethernet device arguments  */
> +struct rte_eth_devargs {
> +	uint16_t ports[RTE_MAX_ETHPORTS];
> +	/** port/s number to enable on a multi-port single function */
> +	uint16_t nb_ports;
> +	/** number of ports in ports field */
> +	uint16_t representor_ports[RTE_MAX_ETHPORTS];
> +	/** representor port/s identifier to enable on device */
> +	uint16_t nb_representor_ports;
> +	/** number of ports in representor port field */
> +};
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * PMD helper function to parse ethdev arguments
> + *
> + * @param devargs
> + *  device arguments
> + * @param eth_devargs
> + *  parsed ethdev specific arguments.
> + *
> + * @return
> + *   Negative errno value on error, 0 on success.
> + */
> +int __rte_experimental
> +rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_devargs);
> +
> +
>  typedef int (*ethdev_init_t)(struct rte_eth_dev *ethdev, void *init_params);
>  typedef int (*ethdev_bus_specific_init)(struct rte_eth_dev *ethdev,
>  	void *bus_specific_init_params);
> diff --git a/lib/librte_ether/rte_ethdev_version.map b/lib/librte_ether/rte_ethdev_version.map
> index c4380aa31..41c3d2699 100644
> --- a/lib/librte_ether/rte_ethdev_version.map
> +++ b/lib/librte_ether/rte_ethdev_version.map
> @@ -206,6 +206,7 @@ DPDK_18.02 {
>  EXPERIMENTAL {
>  	global:
> 
> +	rte_eth_devargs_parse;
>  	rte_eth_dev_count_avail;
>  	rte_eth_dev_count_total;
>  	rte_eth_dev_create;
> --
> 2.14.3