ixgbevf: Add support for VF API negotiation

This change makes it so that the VF can support the PF/VF API negotiation
protocol.  Specifically in this case we are adding support for API 1.0
which will mean that the VF is capable of cleaning up buffers that span
multiple descriptors without triggering an error.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -76,12 +76,29 @@
 /* bits 23:16 are used for exra info for certain messages */
 #define IXGBE_VT_MSGINFO_MASK     (0xFF << IXGBE_VT_MSGINFO_SHIFT)
 
+/* definitions to support mailbox API version negotiation */
+
+/*
+ * each element denotes a version of the API; existing numbers may not
+ * change; any additions must go at the end
+ */
+enum ixgbe_pfvf_api_rev {
+	ixgbe_mbox_api_10,	/* API version 1.0, linux/freebsd VF driver */
+	ixgbe_mbox_api_20,	/* API version 2.0, solaris Phase1 VF driver */
+	/* This value should always be last */
+	ixgbe_mbox_api_unknown,	/* indicates that API version is not known */
+};
+
+/* mailbox API, legacy requests */
 #define IXGBE_VF_RESET            0x01 /* VF requests reset */
 #define IXGBE_VF_SET_MAC_ADDR     0x02 /* VF requests PF to set MAC addr */
 #define IXGBE_VF_SET_MULTICAST    0x03 /* VF requests PF to set MC addr */
 #define IXGBE_VF_SET_VLAN         0x04 /* VF requests PF to set VLAN */
-#define IXGBE_VF_SET_LPE          0x05 /* VF requests PF to set VMOLR.LPE */
-#define IXGBE_VF_SET_MACVLAN      0x06 /* VF requests PF for unicast filter */
+
+/* mailbox API, version 1.0 VF requests */
+#define IXGBE_VF_SET_LPE	0x05 /* VF requests PF to set VMOLR.LPE */
+#define IXGBE_VF_SET_MACVLAN	0x06 /* VF requests PF for unicast filter */
+#define IXGBE_VF_API_NEGOTIATE	0x08 /* negotiate API version */
 
 /* length of permanent address message returned from PF */
 #define IXGBE_VF_PERMADDR_MSG_LEN 4