ixgbe: Support 4 queue RSS on VFs with 1 or 2 queue RSS on PF

Instead of limiting the VFs if we don't use 4 queues for RSS in the PF we
can instead just limit the RSS queues used to a power of 2.  By doing this
we can support use cases where VFs are using more queues than the PF is
currently using and can support RSS if so desired.

The only limitation on this is that we cannot support 3 queues of RSS in
the PF or VF.  In either of these cases we should fall back to 2 queues in
order to be able to use the power of 2 masking provided by the psrtype
register.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c

@@ -515,15 +515,16 @@ static bool ixgbe_set_sriov_queues(struct ixgbe_adapter *adapter)
 	vmdq_i = min_t(u16, IXGBE_MAX_VMDQ_INDICES, vmdq_i);
 
 	/* 64 pool mode with 2 queues per pool */
-	if ((vmdq_i > 32) || (rss_i < 4) || (vmdq_i > 16 && pools)) {
+	if ((vmdq_i > 32) || (vmdq_i > 16 && pools)) {
 		vmdq_m = IXGBE_82599_VMDQ_2Q_MASK;
 		rss_m = IXGBE_RSS_2Q_MASK;
 		rss_i = min_t(u16, rss_i, 2);
-	/* 32 pool mode with 4 queues per pool */
+	/* 32 pool mode with up to 4 queues per pool */
 	} else {
 		vmdq_m = IXGBE_82599_VMDQ_4Q_MASK;
 		rss_m = IXGBE_RSS_4Q_MASK;
-		rss_i = 4;
+		/* We can support 4, 2, or 1 queues */
+		rss_i = (rss_i > 3) ? 4 : (rss_i > 1) ? 2 : 1;
 	}
 
 #ifdef IXGBE_FCOE

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -3248,7 +3248,8 @@ static void ixgbe_setup_mtqc(struct ixgbe_adapter *adapter)
 			mtqc |= IXGBE_MTQC_RT_ENA | IXGBE_MTQC_8TC_8TQ;
 		else if (tcs > 1)
 			mtqc |= IXGBE_MTQC_RT_ENA | IXGBE_MTQC_4TC_4TQ;
-		else if (adapter->ring_feature[RING_F_RSS].indices == 4)
+		else if (adapter->ring_feature[RING_F_VMDQ].mask ==
+			 IXGBE_82599_VMDQ_4Q_MASK)
 			mtqc |= IXGBE_MTQC_32VF;
 		else
 			mtqc |= IXGBE_MTQC_64VF;
@@ -3475,12 +3476,12 @@ static void ixgbe_setup_reta(struct ixgbe_adapter *adapter)
 	u32 reta_entries = ixgbe_rss_indir_tbl_entries(adapter);
 	u16 rss_i = adapter->ring_feature[RING_F_RSS].indices;
 
-	/* Program table for at least 2 queues w/ SR-IOV so that VFs can
+	/* Program table for at least 4 queues w/ SR-IOV so that VFs can
 	 * make full use of any rings they may have.  We will use the
 	 * PSRTYPE register to control how many rings we use within the PF.
 	 */
-	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) && (rss_i < 2))
-		rss_i = 2;
+	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) && (rss_i < 4))
+		rss_i = 4;
 
 	/* Fill out hash function seeds */
 	for (i = 0; i < 10; i++)
@@ -3544,7 +3545,8 @@ static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
 				mrqc = IXGBE_MRQC_VMDQRT8TCEN;	/* 8 TCs */
 			else if (tcs > 1)
 				mrqc = IXGBE_MRQC_VMDQRT4TCEN;	/* 4 TCs */
-			else if (adapter->ring_feature[RING_F_RSS].indices == 4)
+			else if (adapter->ring_feature[RING_F_VMDQ].mask ==
+				 IXGBE_82599_VMDQ_4Q_MASK)
 				mrqc = IXGBE_MRQC_VMDQRSS32EN;
 			else
 				mrqc = IXGBE_MRQC_VMDQRSS64EN;