[dpdk-dev] [PATCH v3 06/11] net/failsafe: add flexible device definition

Discussion:

Gaetan Rivet

2017-05-24 15:20:04 UTC

Add the "exec" device type.
The parameters given to this type of device will be executed in a shell.
The output of this command is then used as a definition for a device.

That command can be re-interpreted if the related device is not
plugged-in. It allows for a device definition to react to system
changes (e.g. changing PCI bus for a given device).

Signed-off-by: Gaetan Rivet <***@6wind.com>
Acked-by: Olga Shern <***@mellanox.com>
---
doc/guides/nics/fail_safe.rst | 20 +++++++
drivers/net/failsafe/failsafe_args.c | 99 +++++++++++++++++++++++++++++++++
drivers/net/failsafe/failsafe_ether.c | 7 +++
drivers/net/failsafe/failsafe_private.h | 4 ++
4 files changed, 130 insertions(+)

diff --git a/doc/guides/nics/fail_safe.rst b/doc/guides/nics/fail_safe.rst
index c04891a..1b6e110 100644
--- a/doc/guides/nics/fail_safe.rst
+++ b/doc/guides/nics/fail_safe.rst
@@ -91,6 +91,19 @@ Fail-safe command line parameters
additional sub-device parameters if need be. They will be passed on to the
sub-device.

+- **exec(<shell command>)** parameter
+
+ This parameter allows the user to provide a command to the fail-safe PMD to
+ execute and define a sub-device.
+ It is done within a regular shell context.
+ The first line of its output is read by the fail-safe PMD and otherwise
+ interpreted as if passed by the regular **dev** parameter.
+ Any other line is discarded.
+ If the command fail or output an incorrect string, the sub-device is not
+ initialized.
+ All commas within the ``shell command`` are replaced by spaces before
+ executing the command. This helps using scripts to specify devices.
+
- **mac** parameter [MAC address]

This parameter allows the user to set a default MAC address to the fail-safe
@@ -126,6 +139,13 @@ This section shows some example of using **testpmd** with a fail-safe PMD.
--vdev='net_failsafe0,mac=de:ad:be:ef:01:02,dev(84:00.0),dev(net_ring0,nodeaction=r1:0:CREATE)' -- \
-i

+#. Start testpmd using a flexible device definition
+
+ .. code-block:: console
+
+ $RTE_TARGET/build/app/testpmd -c 0xff -n 4 --no-pci \
+ --vdev='net_failsafe0,exec(echo 84:00.0)' -- -i
+
Using the Fail-safe PMD from an application
-------------------------------------------

diff --git a/drivers/net/failsafe/failsafe_args.c b/drivers/net/failsafe/failsafe_args.c
index 8f334aa..c723ca3 100644
--- a/drivers/net/failsafe/failsafe_args.c
+++ b/drivers/net/failsafe/failsafe_args.c
@@ -30,6 +30,8 @@
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+
+#include <assert.h>
#include <string.h>
#include <errno.h>

@@ -96,6 +98,75 @@ fs_parse_device(struct sub_device *sdev, char *args)
return 0;
}

+static void
+fs_sanitize_cmdline(char *args)
+{
+ size_t len;
+
+ len = strnlen(args, DEVARGS_MAXLEN);
+ args[len - 1] = '\0';
+}
+
+static int
+fs_execute_cmd(struct sub_device *sdev, char *cmdline)
+{
+ FILE *fp;
+ /* store possible newline as well */
+ char output[DEVARGS_MAXLEN + 1];
+ size_t len;
+ int old_err;
+ int ret;
+
+ assert(cmdline != NULL || sdev->cmdline != NULL);
+ if (sdev->cmdline == NULL) {
+ char *new_str;
+ size_t i;
+
+ len = strlen(cmdline) + 1;
+ new_str = rte_realloc(sdev->cmdline, len,
+ RTE_CACHE_LINE_SIZE);
+ if (new_str == NULL) {
+ ERROR("Command line allocation failed");
+ return -ENOMEM;
+ }
+ sdev->cmdline = new_str;
+ snprintf(sdev->cmdline, len, "%s", cmdline);
+ /* Replace all commas in the command line by spaces */
+ for (i = 0; i < len; i++)
+ if (sdev->cmdline[i] == ',')
+ sdev->cmdline[i] = ' ';
+ }
+ DEBUG("'%s'", sdev->cmdline);
+ old_err = errno;
+ fp = popen(sdev->cmdline, "r");
+ if (fp == NULL) {
+ ret = errno;
+ ERROR("popen: %s", strerror(errno));
+ errno = old_err;
+ return ret;
+ }
+ /* We only read one line */
+ if (fgets(output, sizeof(output) - 1, fp) == NULL) {
+ DEBUG("Could not read command output");
+ return -ENODEV;
+ }
+ fs_sanitize_cmdline(output);
+ ret = fs_parse_device(sdev, output);
+ if (ret) {
+ ERROR("Parsing device '%s' failed", output);
+ goto ret_pclose;
+ }
+ret_pclose:
+ ret = pclose(fp);
+ if (ret) {
+ ret = errno;
+ ERROR("pclose: %s", strerror(errno));
+ errno = old_err;
+ return ret;
+ }
+ return ret;
+}
+
static int
fs_parse_device_param(struct rte_eth_dev *dev, const char *param,
uint8_t head)
@@ -130,6 +201,14 @@ fs_parse_device_param(struct rte_eth_dev *dev, const char *param,
ret = fs_parse_device(sdev, args);
if (ret)
goto free_args;
+ } else if (strncmp(param, "exec", 4) == 0) {
+ ret = fs_execute_cmd(sdev, args);
+ if (ret == -ENODEV) {
+ DEBUG("Reading device info from command line failed");
+ ret = 0;
+ }
+ if (ret)
+ goto free_args;
} else {
ERROR("Unrecognized device type: %.*s", (int)b, param);
return -EINVAL;
@@ -331,6 +410,8 @@ failsafe_args_free(struct rte_eth_dev *dev)
uint8_t i;

FOREACH_SUBDEV(sdev, i, dev) {
+ rte_free(sdev->cmdline);
+ sdev->cmdline = NULL;
free(sdev->devargs.args);
sdev->devargs.args = NULL;
}
@@ -361,3 +442,21 @@ failsafe_args_count_subdevice(struct rte_eth_dev *dev,
return fs_parse_sub_devices(fs_count_device,
dev, params);
}
+
+int
+failsafe_args_parse_subs(struct rte_eth_dev *dev)
+{
+ struct sub_device *sdev;
+ uint8_t i;
+ int ret = 0;
+
+ FOREACH_SUBDEV(sdev, i, dev) {
+ if (sdev->state >= DEV_PARSED)
+ continue;
+ if (sdev->cmdline)
+ ret = fs_execute_cmd(sdev, sdev->cmdline);
+ if (ret == 0)
+ sdev->state = DEV_PARSED;
+ }
+ return 0;
+}
diff --git a/drivers/net/failsafe/failsafe_ether.c b/drivers/net/failsafe/failsafe_ether.c
index 7910952..2a1535e 100644
--- a/drivers/net/failsafe/failsafe_ether.c
+++ b/drivers/net/failsafe/failsafe_ether.c
@@ -188,6 +188,13 @@ failsafe_eth_dev_state_sync(struct rte_eth_dev *dev)
int ret;
uint8_t i;

+ if (PRIV(dev)->state < DEV_PARSED)
+ return 0;
+
+ ret = failsafe_args_parse_subs(dev);
+ if (ret)
+ return ret;
+
if (PRIV(dev)->state < DEV_PROBED)
return 0;
ret = failsafe_eal_init(dev);
diff --git a/drivers/net/failsafe/failsafe_private.h b/drivers/net/failsafe/failsafe_private.h
index 8fb72fe..554d7a3 100644
--- a/drivers/net/failsafe/failsafe_private.h
+++ b/drivers/net/failsafe/failsafe_private.h
@@ -44,6 +44,7 @@
#define PMD_FAILSAFE_PLUG_IN_POLL_KVARG "hotplug_poll"
#define PMD_FAILSAFE_PARAM_STRING \
"dev(<ifc>)," \
+ "exec(<shell command>)," \
"mac=mac_addr," \
"hotplug_poll=u64" \
""
@@ -87,6 +88,8 @@ struct sub_device {
struct rte_eth_dev *edev;
/* Device state machine */
enum dev_state state;
+ /* Some device are defined as a command line */
+ char *cmdline;
};

struct fs_priv {
@@ -135,6 +138,7 @@ uint16_t failsafe_tx_burst(void *txq,
int failsafe_args_parse(struct rte_eth_dev *dev, const char *params);
void failsafe_args_free(struct rte_eth_dev *dev);
int failsafe_args_count_subdevice(struct rte_eth_dev *dev, const char *params);
+int failsafe_args_parse_subs(struct rte_eth_dev *dev);

/* EAL */

--
2.1.4

Gaetan Rivet

2017-05-24 15:20:06 UTC