[PATCH net-next V2 2/2] intel: ixgbevf: Support Windows hosts (Hyper-V)

["K. Y. Srinivasan" <kys@microsoft.com>]

On Hyper-V, the VF/PF communication is a via software mediated path
as opposed to the hardware mailbox. Make the necessary
adjustments to support Hyper-V.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
	V2: Addressed most of the comments from
	    Alexander Duyck <alexander.duyck@gmail.com>
	    and Rustad, Mark D <mark.d.rustad@intel.com>.

 drivers/net/ethernet/intel/ixgbevf/ixgbevf.h      |   12 ++
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |   16 ++-
 drivers/net/ethernet/intel/ixgbevf/mbx.c          |   12 ++
 drivers/net/ethernet/intel/ixgbevf/vf.c           |  201 +++++++++++++++++++++
 4 files changed, 237 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index 5ac60ee..3296d27 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -460,9 +460,13 @@ enum ixbgevf_state_t {
 
 enum ixgbevf_boards {
 	board_82599_vf,
+	board_82599_vf_hv,
 	board_X540_vf,
+	board_X540_vf_hv,
 	board_X550_vf,
+	board_X550_vf_hv,
 	board_X550EM_x_vf,
+	board_X550EM_x_vf_hv,
 };
 
 enum ixgbevf_xcast_modes {
@@ -477,6 +481,13 @@ extern const struct ixgbevf_info ixgbevf_X550_vf_info;
 extern const struct ixgbevf_info ixgbevf_X550EM_x_vf_info;
 extern const struct ixgbe_mbx_operations ixgbevf_mbx_ops;
 
+
+extern const struct ixgbevf_info ixgbevf_82599_vf_hv_info;
+extern const struct ixgbevf_info ixgbevf_X540_vf_hv_info;
+extern const struct ixgbevf_info ixgbevf_X550_vf_hv_info;
+extern const struct ixgbevf_info ixgbevf_X550EM_x_vf_hv_info;
+extern const struct ixgbe_mbx_operations ixgbevf_hv_mbx_ops;
+
 /* needed by ethtool.c */
 extern const char ixgbevf_driver_name[];
 extern const char ixgbevf_driver_version[];
@@ -494,6 +505,7 @@ void ixgbevf_free_rx_resources(struct ixgbevf_ring *);
 void ixgbevf_free_tx_resources(struct ixgbevf_ring *);
 void ixgbevf_update_stats(struct ixgbevf_adapter *adapter);
 int ethtool_ioctl(struct ifreq *ifr);
+bool ixgbevf_on_hyperv(struct ixgbe_hw *hw);
 
 extern void ixgbevf_write_eitr(struct ixgbevf_q_vector *q_vector);
 
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 007cbe0..c761d80 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -62,10 +62,14 @@ static char ixgbevf_copyright[] =
 	"Copyright (c) 2009 - 2015 Intel Corporation.";
 
 static const struct ixgbevf_info *ixgbevf_info_tbl[] = {
-	[board_82599_vf] = &ixgbevf_82599_vf_info,
-	[board_X540_vf]  = &ixgbevf_X540_vf_info,
-	[board_X550_vf]  = &ixgbevf_X550_vf_info,
-	[board_X550EM_x_vf] = &ixgbevf_X550EM_x_vf_info,
+	[board_82599_vf]	= &ixgbevf_82599_vf_info,
+	[board_82599_vf_hv]	= &ixgbevf_82599_vf_hv_info,
+	[board_X540_vf]		= &ixgbevf_X540_vf_info,
+	[board_X540_vf_hv]	= &ixgbevf_X540_vf_hv_info,
+	[board_X550_vf]		= &ixgbevf_X550_vf_info,
+	[board_X550_vf_hv]	= &ixgbevf_X550_vf_hv_info,
+	[board_X550EM_x_vf]	= &ixgbevf_X550EM_x_vf_info,
+	[board_X550EM_x_vf_hv]	= &ixgbevf_X550EM_x_vf_hv_info,
 };
 
 /* ixgbevf_pci_tbl - PCI Device ID Table
@@ -78,9 +82,13 @@ static const struct ixgbevf_info *ixgbevf_info_tbl[] = {
  */
 static const struct pci_device_id ixgbevf_pci_tbl[] = {
 	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_82599_VF), board_82599_vf },
+	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_82599_VF_HV), board_82599_vf_hv },
 	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X540_VF), board_X540_vf },
+	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X540_VF_HV), board_X540_vf_hv },
 	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X550_VF), board_X550_vf },
+	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X550_VF_HV), board_X550_vf_hv },
 	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X550EM_X_VF), board_X550EM_x_vf },
+	{PCI_VDEVICE(INTEL, IXGBE_DEV_ID_X550EM_X_VF_HV), board_X550EM_x_vf_hv},
 	/* required last entry */
 	{0, }
 };
diff --git a/drivers/net/ethernet/intel/ixgbevf/mbx.c b/drivers/net/ethernet/intel/ixgbevf/mbx.c
index dc68fea..298a0da 100644
--- a/drivers/net/ethernet/intel/ixgbevf/mbx.c
+++ b/drivers/net/ethernet/intel/ixgbevf/mbx.c
@@ -346,3 +346,15 @@ const struct ixgbe_mbx_operations ixgbevf_mbx_ops = {
 	.check_for_rst	= ixgbevf_check_for_rst_vf,
 };
 
+/**
+ * Mailbox operations when running on Hyper-V.
+ * On Hyper-V, PF/VF communiction is not through the
+ * hardware mailbox; this communication is through
+ * a software mediated path.
+ * Most mail box operations are noop while running on
+ * Hyper-V.
+ */
+const struct ixgbe_mbx_operations ixgbevf_hv_mbx_ops = {
+	.init_params	= ixgbevf_init_mbx_params_vf,
+	.check_for_rst	= ixgbevf_check_for_rst_vf,
+};
diff --git a/drivers/net/ethernet/intel/ixgbevf/vf.c b/drivers/net/ethernet/intel/ixgbevf/vf.c
index 4d613a4..1ec13c1 100644
--- a/drivers/net/ethernet/intel/ixgbevf/vf.c
+++ b/drivers/net/ethernet/intel/ixgbevf/vf.c
@@ -27,6 +27,13 @@
 #include "vf.h"
 #include "ixgbevf.h"
 
+/*
+ * On Hyper-V, to reset, we need to read from this offset
+ * from the PCI config space. This is the mechanism used on
+ * Hyper-V to support PF/VF communication.
+ */
+#define IXGBE_HV_RESET_OFFSET           0x201
+
 /**
  *  ixgbevf_start_hw_vf - Prepare hardware for Tx/Rx
  *  @hw: pointer to hardware structure
@@ -126,6 +133,23 @@ static s32 ixgbevf_reset_hw_vf(struct ixgbe_hw *hw)
 }
 
 /**
+ * Hyper-V variant; the VF/PF communication is through the PCI
+ * config space.
+ */
+static s32 ixgbevf_hv_reset_hw_vf(struct ixgbe_hw *hw)
+{
+	struct ixgbevf_adapter *adapter = hw->back;
+	int i;
+
+	for (i = 0; i < 6; i++)
+		pci_read_config_byte(adapter->pdev,
+				     (i + IXGBE_HV_RESET_OFFSET),
+				     &hw->mac.perm_addr[i]);
+
+	return 0;
+}
+
+/**
  *  ixgbevf_stop_hw_vf - Generic stop Tx/Rx units
  *  @hw: pointer to hardware structure
  *
@@ -258,6 +282,11 @@ static s32 ixgbevf_set_uc_addr_vf(struct ixgbe_hw *hw, u32 index, u8 *addr)
 	return ret_val;
 }
 
+static s32 ixgbevf_hv_set_uc_addr_vf(struct ixgbe_hw *hw, u32 index, u8 *addr)
+{
+	return -EOPNOTSUPP;
+}
+
 /**
  * ixgbevf_get_reta_locked - get the RSS redirection table (RETA) contents.
  * @adapter: pointer to the port handle
@@ -416,6 +445,26 @@ static s32 ixgbevf_set_rar_vf(struct ixgbe_hw *hw, u32 index, u8 *addr,
 	return ret_val;
 }
 
+/**
+ *  ixgbevf_hv_set_rar_vf - set device MAC address Hyper-V variant
+ *  @hw: pointer to hardware structure
+ *  @index: Receive address register to write
+ *  @addr: Address to put into receive address register
+ *  @vmdq: Unused in this implementation
+ *
+ * We don't really allow setting the device MAC address. However,
+ * if the address being set is the permanent MAC address we will
+ * permit that.
+ **/
+static s32 ixgbevf_hv_set_rar_vf(struct ixgbe_hw *hw, u32 index, u8 *addr,
+				 u32 vmdq)
+{
+	if (ether_addr_equal(addr, hw->mac.perm_addr))
+		return 0;
+
+	return -EOPNOTSUPP;
+}
+
 static void ixgbevf_write_msg_read_ack(struct ixgbe_hw *hw,
 				       u32 *msg, u16 size)
 {
@@ -473,6 +522,15 @@ static s32 ixgbevf_update_mc_addr_list_vf(struct ixgbe_hw *hw,
 }
 
 /**
+ * Hyper-V variant - just a stub.
+ */
+static s32 ixgbevf_hv_update_mc_addr_list_vf(struct ixgbe_hw *hw,
+					  struct net_device *netdev)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
  *  ixgbevf_update_xcast_mode - Update Multicast mode
  *  @hw: pointer to the HW structure
  *  @netdev: pointer to net device structure
@@ -513,6 +571,15 @@ static s32 ixgbevf_update_xcast_mode(struct ixgbe_hw *hw,
 }
 
 /**
+ * Hyper-V variant - just a stub.
+ */
+static s32 ixgbevf_hv_update_xcast_mode(struct ixgbe_hw *hw,
+					struct net_device *netdev, int xcast_mode)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
  *  ixgbevf_set_vfta_vf - Set/Unset VLAN filter table address
  *  @hw: pointer to the HW structure
  *  @vlan: 12 bit VLAN ID
@@ -551,6 +618,15 @@ mbx_err:
 }
 
 /**
+ * Hyper-V variant - just a stub.
+ */
+static s32 ixgbevf_hv_set_vfta_vf(struct ixgbe_hw *hw, u32 vlan, u32 vind,
+				  bool vlan_on)
+{
+	return -EOPNOTSUPP;
+}
+
+/**
  *  ixgbevf_setup_mac_link_vf - Setup MAC link settings
  *  @hw: pointer to hardware structure
  *  @speed: Unused in this implementation
@@ -656,6 +732,67 @@ out:
 }
 
 /**
+ * Hyper-V variant; there is no mailbox communication.
+ */
+static s32 ixgbevf_hv_check_mac_link_vf(struct ixgbe_hw *hw,
+					ixgbe_link_speed *speed,
+					bool *link_up,
+					bool autoneg_wait_to_complete)
+{
+	struct ixgbe_mbx_info *mbx = &hw->mbx;
+	struct ixgbe_mac_info *mac = &hw->mac;
+	u32 links_reg;
+
+	/* If we were hit with a reset drop the link */
+	if (!mbx->ops.check_for_rst(hw) || !mbx->timeout)
+		mac->get_link_status = true;
+
+	if (!mac->get_link_status)
+		goto out;
+
+	/* if link status is down no point in checking to see if pf is up */
+	links_reg = IXGBE_READ_REG(hw, IXGBE_VFLINKS);
+	if (!(links_reg & IXGBE_LINKS_UP))
+		goto out;
+
+	/* for SFP+ modules and DA cables on 82599 it can take up to 500usecs
+	 * before the link status is correct
+	 */
+	if (mac->type == ixgbe_mac_82599_vf) {
+		int i;
+
+		for (i = 0; i < 5; i++) {
+			udelay(100);
+			links_reg = IXGBE_READ_REG(hw, IXGBE_VFLINKS);
+
+			if (!(links_reg & IXGBE_LINKS_UP))
+				goto out;
+		}
+	}
+
+	switch (links_reg & IXGBE_LINKS_SPEED_82599) {
+	case IXGBE_LINKS_SPEED_10G_82599:
+		*speed = IXGBE_LINK_SPEED_10GB_FULL;
+		break;
+	case IXGBE_LINKS_SPEED_1G_82599:
+		*speed = IXGBE_LINK_SPEED_1GB_FULL;
+		break;
+	case IXGBE_LINKS_SPEED_100_82599:
+		*speed = IXGBE_LINK_SPEED_100_FULL;
+		break;
+	}
+
+	/* if we passed all the tests above then the link is up and we no
+	 * longer need to check for link
+	 */
+	mac->get_link_status = false;
+
+out:
+	*link_up = !mac->get_link_status;
+	return 0;
+}
+
+/**
  *  ixgbevf_rlpml_set_vf - Set the maximum receive packet length
  *  @hw: pointer to the HW structure
  *  @max_size: value to assign to max frame size
@@ -663,6 +800,18 @@ out:
 void ixgbevf_rlpml_set_vf(struct ixgbe_hw *hw, u16 max_size)
 {
 	u32 msgbuf[2];
+	u32 reg;
+
+	if (ixgbevf_on_hyperv(hw)) {
+		/* If we are on Hyper-V, we implement
+		 * this functionality differently.
+		 */
+		reg =  IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(0));
+		/* CRC == 4 */
+		reg |= ((max_size + 4) | IXGBE_RXDCTL_RLPML_EN);
+		IXGBE_WRITE_REG(hw, IXGBE_VFRXDCTL(0), reg);
+		return;
+	}
 
 	msgbuf[0] = IXGBE_VF_SET_LPE;
 	msgbuf[1] = max_size;
@@ -679,6 +828,15 @@ int ixgbevf_negotiate_api_version(struct ixgbe_hw *hw, int api)
 	int err;
 	u32 msg[3];
 
+	if (ixgbevf_on_hyperv(hw)) {
+		/* Hyper-V only supports api version ixgbe_mbox_api_10
+		 */
+		if (api != ixgbe_mbox_api_10)
+			return IXGBE_ERR_INVALID_ARGUMENT;
+
+		return 0;
+	}
+
 	/* Negotiate the mailbox API version */
 	msg[0] = IXGBE_VF_API_NEGOTIATE;
 	msg[1] = api;
@@ -776,22 +934,65 @@ static const struct ixgbe_mac_operations ixgbevf_mac_ops = {
 	.set_vfta		= ixgbevf_set_vfta_vf,
 };
 
+static const struct ixgbe_mac_operations ixgbevf_hv_mac_ops = {
+	.init_hw		= ixgbevf_init_hw_vf,
+	.reset_hw		= ixgbevf_hv_reset_hw_vf,
+	.start_hw		= ixgbevf_start_hw_vf,
+	.get_mac_addr		= ixgbevf_get_mac_addr_vf,
+	.stop_adapter		= ixgbevf_stop_hw_vf,
+	.setup_link		= ixgbevf_setup_mac_link_vf,
+	.check_link		= ixgbevf_hv_check_mac_link_vf,
+	.set_rar		= ixgbevf_hv_set_rar_vf,
+	.update_mc_addr_list	= ixgbevf_hv_update_mc_addr_list_vf,
+	.update_xcast_mode	= ixgbevf_hv_update_xcast_mode,
+	.set_uc_addr		= ixgbevf_hv_set_uc_addr_vf,
+	.set_vfta		= ixgbevf_hv_set_vfta_vf,
+};
+
 const struct ixgbevf_info ixgbevf_82599_vf_info = {
 	.mac = ixgbe_mac_82599_vf,
 	.mac_ops = &ixgbevf_mac_ops,
 };
 
+const struct ixgbevf_info ixgbevf_82599_vf_hv_info = {
+	.mac = ixgbe_mac_82599_vf,
+	.mac_ops = &ixgbevf_hv_mac_ops,
+};
+
 const struct ixgbevf_info ixgbevf_X540_vf_info = {
 	.mac = ixgbe_mac_X540_vf,
 	.mac_ops = &ixgbevf_mac_ops,
 };
 
+const struct ixgbevf_info ixgbevf_X540_vf_hv_info = {
+	.mac = ixgbe_mac_X540_vf,
+	.mac_ops = &ixgbevf_hv_mac_ops,
+};
+
 const struct ixgbevf_info ixgbevf_X550_vf_info = {
 	.mac = ixgbe_mac_X550_vf,
 	.mac_ops = &ixgbevf_mac_ops,
 };
 
+const struct ixgbevf_info ixgbevf_X550_vf_hv_info = {
+	.mac = ixgbe_mac_X550_vf,
+	.mac_ops = &ixgbevf_hv_mac_ops,
+};
+
 const struct ixgbevf_info ixgbevf_X550EM_x_vf_info = {
 	.mac = ixgbe_mac_X550EM_x_vf,
 	.mac_ops = &ixgbevf_mac_ops,
 };
+
+const struct ixgbevf_info ixgbevf_X550EM_x_vf_hv_info = {
+	.mac = ixgbe_mac_X550EM_x_vf,
+	.mac_ops = &ixgbevf_hv_mac_ops,
+};
+
+bool ixgbevf_on_hyperv(struct ixgbe_hw *hw)
+{
+	if (hw->mbx.ops.check_for_msg == NULL)
+		return true;
+	else
+		return false;
+}
-- 
1.7.4.1