docs/wind: update Versal VxWorks MSI-X setup

Document the GICv3 ITS components needed for e1000e MSI-X and shell/network component updates for the symbol table error.

Signed-off-by: shivkd <shiveshkd@gmail.com>

Author: shivkd

docs/wind/vxworks_xlnx-versal-virt.rst

@@ -1,6 +1,6 @@
-=========================================
-VxWorks 24.03 on xlnx-versal-virt machine
-=========================================
+====================================================
+VxWorks 24.03 and 26.03 on xlnx-versal-virt machine
+====================================================
 
 This document contains steps to build a basic VxWorks project for the QEMU xlnx-versal-virt machine.
 
@@ -135,3 +135,34 @@ virtio-net-pci NIC
      -device virtio-net-pci,disable-legacy=on,netdev=net0,mac=00:00:e8:01:02:04 \
      -append "virtioNet(0,0)host:vxWorks h=10.0.2.2 e=10.0.2.15:ffffff00 g=10.0.2.2 u=target pw=vxTarget f=0x1"
 
+MSI-X support with an attached PCIe NIC
+```````````````````````````````````````
+When testing the xlnx-versal-virt machine with an attached PCIe NIC, such
+as QEMU's e1000e device, the VxWorks image must include the Arm GICv3 ITS
+driver.
+
+.. code::
+    $ vxprj component add DRV_INTCTLR_FDT_ARM_GIC_V3_ITS
+
+The DRV_INTCTLR_FDT_ARM_GIC_V3_ITS component also adds the required
+DRV_INTCTLR_ARM_GIC_V3_ITS component. This is required for PCIe MSI-X
+interrupt support on the xlnx-versal-virt machine.
+
+To avoid the network symbol table error:
+
+.. code::
+    Error opening /host.host/vxWorks.sym: status = 0x290010
+
+remove the network symbol table component:
+
+.. code::
+    $ vxprj component remove INCLUDE_NET_SYM_TBL
+
+Then add the following shell components if missing:
+
+.. code::
+    $ vxprj component add INCLUDE_SHELL_INTERP_C
+    $ vxprj component add INCLUDE_SHELL_INTERP_CMD
+    $ vxprj component add INCLUDE_SHELL_VI_MODE
+    $ vxprj component add INCLUDE_STOP_MODE_AGENT_END
+