ixgbevf: Reduce size of maximum rx buffer

There's no need to support up to 15k buffers since the HW is limited to
9.5k in SR-IOV mode.  Instead, allocate buffers that fit and align inside
of a 32K memory buffer.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/ixgbevf/ixgbevf.h

@@ -101,10 +101,10 @@ struct ixgbevf_ring {
 
 /* Supported Rx Buffer Sizes */
 #define IXGBEVF_RXBUFFER_256   256    /* Used for packet split */
-#define IXGBEVF_RXBUFFER_3K    3072
-#define IXGBEVF_RXBUFFER_7K    7168
-#define IXGBEVF_RXBUFFER_15K   15360
-#define IXGBEVF_MAX_RXBUFFER   16384  /* largest size for single descriptor */
+#define IXGBEVF_RXBUFFER_2K    2048
+#define IXGBEVF_RXBUFFER_4K    4096
+#define IXGBEVF_RXBUFFER_8K    8192
+#define IXGBEVF_RXBUFFER_10K   10240
 
 #define IXGBEVF_RX_HDR_SIZE IXGBEVF_RXBUFFER_256