[PATCH 1/3] docs: Document Module virtionet

[Andrew Hamilton]

Add documentation for new module virtionet which can be used to provide
network driver support in GRUB in a virtual environment like Qemu.

Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
---
 docs/grub.texi | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/docs/grub.texi b/docs/grub.texi
index 78d47f467..e0002095c 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -4167,6 +4167,7 @@ Modules can be loaded via the @command{insmod} 
(@pxref{insmod}) command.
 * videoinfo_module::
 * videotest_module::
 * videotest_checksum_module::
+* virtionet_module::
 * wrmsr_module::
 * xen_boot_module::
 * xfs_module::
@@ -5861,6 +5862,21 @@ specified width and height.
 This module is intended for performing a functional test of the video
 functions in GRUB by displaying a test image and capturing a checksum.
 
+@node virtionet_module
+@section virtionet
+This module provides network driver support in GRUB for a "virtio" device, such
+as may be available in a virtual environment like Qemu. This driver uses the
+virtio-pci interface, and provides support for PCI IDs: Vendor 1AF4 with
+device ID 1000 (transitional virtio network device) and Vendor 1AF4 with
+device ID 1041 (regular virtio network device). The following is an example of
+parameters that can be passed to Qemu (in this case the "TAP" interface is used
+which probably requires root permissions when launching Qemu:
+@samp{-netdev tap,id=hostnet0,ifname=tap0,script=no,downscript=no -device
+virtio-net-pci,netdev=hostnet0}.
+This module may be useful in cases where the network driver support provided
+by the BIOS / UEFI are not available (such as when BIOS PXE isn't used) or
+when a specific configuration does not have a native network driver available.
+
 @node wrmsr_module
 @section wrmsr
 This module provides support for the @command{wrmsr} command to write to CPU
-- 
2.39.5