vmxnet3: add command to allow disabling of offloads

This patch adds a new command to disable certain offloads. This
allows user to specify, using VM configuration, if certain offloads
need to be disabled.
Signed-off-by: Ronak Doshi <ronak.doshi@broadcom.com>
Acked-by: Guolin Yang <guolin.yang@broadcom.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240531193050.4132-4-ronak.doshi@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/vmxnet3/vmxnet3_defs.h

@@ -126,6 +126,7 @@ enum {
 	VMXNET3_CMD_GET_MAX_CAPABILITIES,
 	VMXNET3_CMD_GET_DCR0_REG,
 	VMXNET3_CMD_GET_TSRING_DESC_SIZE,
+	VMXNET3_CMD_GET_DISABLED_OFFLOADS,
 };
 
 /*
@@ -912,4 +913,7 @@ struct Vmxnet3_DriverShared {
 /* when new capability is introduced, update VMXNET3_CAP_MAX */
 #define VMXNET3_CAP_MAX                            VMXNET3_CAP_VERSION_7_MAX
 
+#define VMXNET3_OFFLOAD_TSO         BIT(0)
+#define VMXNET3_OFFLOAD_LRO         BIT(1)
+
 #endif /* _VMXNET3_DEFS_H_ */

drivers/net/vmxnet3/vmxnet3_drv.c

@@ -3645,6 +3645,15 @@ static void
 vmxnet3_declare_features(struct vmxnet3_adapter *adapter)
 {
 	struct net_device *netdev = adapter->netdev;
+	unsigned long flags;
+
+	if (VMXNET3_VERSION_GE_9(adapter)) {
+		spin_lock_irqsave(&adapter->cmd_lock, flags);
+		VMXNET3_WRITE_BAR1_REG(adapter, VMXNET3_REG_CMD,
+				       VMXNET3_CMD_GET_DISABLED_OFFLOADS);
+		adapter->disabledOffloads = VMXNET3_READ_BAR1_REG(adapter, VMXNET3_REG_CMD);
+		spin_unlock_irqrestore(&adapter->cmd_lock, flags);
+	}
 
 	netdev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM |
 		NETIF_F_HW_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
@@ -3662,6 +3671,16 @@ vmxnet3_declare_features(struct vmxnet3_adapter *adapter)
 			NETIF_F_GSO_UDP_TUNNEL_CSUM;
 	}
 
+	if (adapter->disabledOffloads & VMXNET3_OFFLOAD_TSO) {
+		netdev->hw_features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
+		netdev->hw_enc_features &= ~(NETIF_F_TSO | NETIF_F_TSO6);
+	}
+
+	if (adapter->disabledOffloads & VMXNET3_OFFLOAD_LRO) {
+		netdev->hw_features &= ~(NETIF_F_LRO);
+		netdev->hw_enc_features &= ~(NETIF_F_LRO);
+	}
+
 	if (VMXNET3_VERSION_GE_7(adapter)) {
 		unsigned long flags;
 

drivers/net/vmxnet3/vmxnet3_int.h

@@ -454,6 +454,7 @@ struct vmxnet3_adapter {
 	/* Size of buffer in the ts ring */
 	u16     tx_ts_desc_size;
 	u16     rx_ts_desc_size;
+	u32     disabledOffloads;
 };
 
 #define VMXNET3_WRITE_BAR0_REG(adapter, reg, val)  \