[dpdk-dev] [PATCH v8 1/3] i40e: support floating VEB config

[Bruce Richardson]

On Wed, May 25, 2016 at 01:28:04AM +0800, Zhe Tao wrote:
> Add the new floating related argument option in the devarg.
> Using this parameter, all the samples can decide whether to use legacy 
> VEB/VEPA
> or floating VEB.
> To enable this feature, the user should pass a devargs parameter to the EAL
> like "-w 84:00.0,enable_floating=1", and the application will make sure the 
> PMD
> will use the floating VEB feature for all the VFs created by this PF device.
> 
> Signed-off-by: Zhe Tao 
> ---
>  drivers/net/i40e/i40e_ethdev.c | 44 
> ++
>  drivers/net/i40e/i40e_ethdev.h |  6 ++
>  2 files changed, 50 insertions(+)

I don't think we should ever use the word "floating" in this context without the
word "VEB" on it as well, because it's really meaningless - being an adjective,
it always requires a noun will it. This applies both to cmdline arguments and to
commit messages.

Secondly, these patches really could do with an explanation of what a floating
VEB is and what it can do vs a non-floating VEB. I know that in the second patch
you refer to standards which define VEBs, but:
a) why is that reference not in patch 1?
b) when I tried looking it up the spec requires a login for the IEEE site, and
a google search for "floating VEB" only brings up links to these patches in
patchwork.

Regards,
/Bruce

[dpdk-dev] [PATCH v8 1/3] i40e: support floating VEB config

[Zhe Tao]

Add the new floating related argument option in the devarg.
Using this parameter, all the samples can decide whether to use legacy VEB/VEPA
or floating VEB.
To enable this feature, the user should pass a devargs parameter to the EAL
like "-w 84:00.0,enable_floating=1", and the application will make sure the PMD
will use the floating VEB feature for all the VFs created by this PF device.

Signed-off-by: Zhe Tao 
---
 drivers/net/i40e/i40e_ethdev.c | 44 ++
 drivers/net/i40e/i40e_ethdev.h |  6 ++
 2 files changed, 50 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 24777d5..e558c63 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -750,6 +750,44 @@ i40e_add_tx_flow_control_drop_filter(struct i40e_pf *pf)
  " frames from VSIs.");
 }

+static int i40e_check_floating_handler(__rte_unused const char *key,
+  const char *value,
+  __rte_unused void *opaque)
+{
+   if (strcmp(value, "1"))
+   return -1;
+
+   return 0;
+}
+
+static int
+i40e_check_floating(struct rte_devargs *devargs)
+{
+   struct rte_kvargs *kvlist;
+   const char *floating_key = "enable_floating";
+
+   if (devargs == NULL)
+   return 0;
+
+   kvlist = rte_kvargs_parse(devargs->args, NULL);
+   if (kvlist == NULL)
+   return 0;
+
+   if (!rte_kvargs_count(kvlist, floating_key)) {
+   rte_kvargs_free(kvlist);
+   return 0;
+   }
+   /* Floating is enabled when there's key-value pair: enable_floating=1 */
+   if (rte_kvargs_process(kvlist, floating_key,
+  i40e_check_floating_handler, NULL) < 0) {
+   rte_kvargs_free(kvlist);
+   return 0;
+   }
+   rte_kvargs_free(kvlist);
+
+   return 1;
+}
+
 static int
 eth_i40e_dev_init(struct rte_eth_dev *dev)
 {
@@ -843,6 +881,12 @@ eth_i40e_dev_init(struct rte_eth_dev *dev)
 ((hw->nvm.version >> 4) & 0xff),
 (hw->nvm.version & 0xf), hw->nvm.eetrack);

+   /* Need the special FW version support floating VEB */
+   if (hw->aq.fw_maj_ver >= FLOATING_FW_MAJ) {
+   pf->floating = i40e_check_floating(pci_dev->devargs);
+   } else {
+   pf->floating = false;
+   }
/* Clear PXE mode */
i40e_clear_pxe_mode(hw);

diff --git a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h
index cfd2399..8297c5f 100644
--- a/drivers/net/i40e/i40e_ethdev.h
+++ b/drivers/net/i40e/i40e_ethdev.h
@@ -36,6 +36,7 @@

 #include 
 #include 
+#include 

 #define I40E_VLAN_TAG_SIZE4

@@ -171,6 +172,10 @@ enum i40e_flxpld_layer_idx {
 #define I40E_QUEUE_ITR_INTERVAL_DEFAULT 32 /* 32 us */
 #define I40E_QUEUE_ITR_INTERVAL_MAX 8160 /* 8160 us */

+/* Special FW support this floating VEB feature */
+#define FLOATING_FW_MAJ 5
+#define FLOATING_FW_MIN 0
+
 struct i40e_adapter;

 /**
@@ -450,6 +455,7 @@ struct i40e_pf {
struct i40e_fc_conf fc_conf; /* Flow control conf */
struct i40e_mirror_rule_list mirror_list;
uint16_t nb_mirror_rule;   /* The number of mirror rules */
+   uint16_t floating; /* The flag to use the floating VEB */
 };

 enum pending_msg {
-- 
2.1.4