On 03/30/15 01:04, Alexander Duyck wrote:

On 03/29/2015 09:11 AM, Vlad Zolotarov wrote:

quoted

For 82599 and x540 VFs and PF share the same RSS Key. Therefore we will return
the same RSS key for all VFs.

Support for other devices will be added later.

Signed-off-by: Vlad Zolotarov <redacted>
---
New in v9:
    - Reduce the support to 82599 and x540 devices only.
    - Get rid of registers access in GET_VF_RSS_KEY flow:
       - Get the RSS HASH Key value from the PF's adapter->rss_key[].

New in v5:
    - Use a newly added netdev op to allow/prevent the RSS Hash Key querying on a per-VF
      basis.

New in v3:
    - Added a support for x550 devices.

New in v1 (compared to RFC):
    - Use "if-else" statement instead of a "switch-case" for a single option case
      (in ixgbe_get_vf_rss_key()).
---
  drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h   |  1 +
  drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 25 +++++++++++++++++++++++++
  2 files changed, 26 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
index 3522f53..b1e4703 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h

@@ -100,6 +100,7 @@ enum ixgbe_pfvf_api_rev {
  
  /* mailbox API, version 1.2 VF requests */
  #define IXGBE_VF_GET_RETA	0x0a	/* VF request for RETA */
+#define IXGBE_VF_GET_RSS_KEY	0x0b	/* get RSS key */
  
  /* length of permanent address message returned from PF */
  #define IXGBE_VF_PERMADDR_MSG_LEN 4

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
index 8424e7f..4d87458 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c

@@ -996,6 +996,28 @@ static int ixgbe_get_vf_reta(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
  	return 0;
  }
  
+static int ixgbe_get_vf_rss_key(struct ixgbe_adapter *adapter,
+				u32 *msgbuf, u32 vf)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
+	u32 *rss_key = &msgbuf[1];
+
+	/* verify the PF is supporting the correct API */
+	if (!adapter->vfinfo[vf].rss_query_enabled ||
+	    (adapter->vfinfo[vf].vf_api != ixgbe_mbox_api_12))
+		return -EPERM;
+
+	/* Read the RSS KEY.
+	 * We only support 82599 and x540 devices at the moment.
+	 */
+	if (hw->mac.type >= ixgbe_mac_X550)
+		return -1;
+

The return should be not supported, not -1 since that is too ambiguous.

By the way, this (-1) didn't come from nowhere - I looked at other 
functions in this file (e.g. ixgbe_get_vf_queues() and 
ixgbe_negotiate_vf_api()) and they are returning
this "ambiguous" (-1) just fine in the situations where -EOPNOTSUPP and 
-EINVAL (correspondingly) would be much more appropriate.
So, I went and checked who was the guy who added this terrible 
"ambiguity" and, surprise-surprise!!!, it was mister Alexander Duyck! :D 
In both (!!!) cases! Bang-bang!!! :D Of course it was "two years ago" 
Alex but still... ;)

Anyway, since we fight the ambiguity now I think u, guys, would like to 
send a cleanup follow-up patches that would adjust your "ambiguous code" 
with the new "super-clear styling" we are introducing in this patches... ;)

quoted

+	memcpy(rss_key, adapter->rss_key, sizeof(adapter->rss_key));
+
+	return 0;
+}
+
  static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf)
  {
  	u32 mbx_size = IXGBE_VFMAILBOX_SIZE;

@@ -1055,6 +1077,9 @@ static int ixgbe_rcv_msg_from_vf(struct ixgbe_adapter *adapter, u32 vf)
  	case IXGBE_VF_GET_RETA:
  		retval = ixgbe_get_vf_reta(adapter, msgbuf, vf);
  		break;
+	case IXGBE_VF_GET_RSS_KEY:
+		retval = ixgbe_get_vf_rss_key(adapter, msgbuf, vf);
+		break;
  	default:
  		e_err(drv, "Unhandled Msg %8.8x\n", msgbuf[0]);
  		retval = IXGBE_ERR_MBX;