ixgbe: ensure IPsec VF<->PF compatibility

The VF driver can forward any IPsec flags and such makes the function
is not extendable and prone to backward/forward incompatibility.

If new software runs on VF, it won't know that PF configured something
completely different as it "knows" only XFRM_OFFLOAD_INBOUND flag.

Fixes: eda0333 ("ixgbe: add VF IPsec management")
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Shannon Nelson <snelson@pensando.io>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20220427173152.443102-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: rleon

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

@@ -903,7 +903,8 @@ int ixgbe_ipsec_vf_add_sa(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
 	/* Tx IPsec offload doesn't seem to work on this
 	 * device, so block these requests for now.
 	 */
-	if (!(sam->flags & XFRM_OFFLOAD_INBOUND)) {
+	sam->flags = sam->flags & ~XFRM_OFFLOAD_IPV6;
+	if (sam->flags != XFRM_OFFLOAD_INBOUND) {
 		err = -EOPNOTSUPP;
 		goto err_out;
 	}