[xen master] docs: add documentation for generic virtio devices

[patchbot@xxxxxxx]

commit dd54ea500be80f347402d75f3e4e7061e7db78d2
Author:     Viresh Kumar <viresh.kumar@xxxxxxxxxx>
AuthorDate: Wed Dec 14 12:03:38 2022 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Dec 14 12:03:38 2022 +0100

    docs: add documentation for generic virtio devices
    
    This patch updates xl.cfg man page with details of generic Virtio device
    related information.
    
    Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
    Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
    Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
---
 docs/man/xl.cfg.5.pod.in | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
index ec444fb2ba..024bceeb61 100644
--- a/docs/man/xl.cfg.5.pod.in
+++ b/docs/man/xl.cfg.5.pod.in
@@ -1585,6 +1585,39 @@ Set maximum height for pointer device.
 
 =back
 
+=item B<virtio=[ "VIRTIO_DEVICE_STRING", "VIRTIO_DEVICE_STRING", ...]>
+
+Specifies the Virtio devices to be provided to the guest.
+
+Each B<VIRTIO_DEVICE_STRING> is a comma-separated list of C<KEY=VALUE> settings
+from the following list. As a special case, a single comma is allowed in the
+VALUE of the "type" KEY, where the VALUE is set with "virtio,device<N>".
+
+=over 4
+
+=item B<backend=domain-id>
+
+Specifies the backend domain name or id, defaults to dom0.
+
+=item B<type=STRING>
+
+Specifies the compatible string for the specific Virtio device. The same will 
be
+written in the Device Tree compatible property of the Virtio device. For
+example, "type=virtio,device22" for the I2C device, whose device-tree binding 
is
+present here:
+
+L<https://www.kernel.org/doc/Documentation/devicetree/bindings/i2c/i2c-virtio.yaml>
+
+For generic virtio devices, where we don't need to set special or compatible
+properties in the Device Tree, the type field must be set to "virtio,device".
+
+=item B<transport=STRING>
+
+Specifies the transport mechanism for the Virtio device, only "mmio" is
+supported for now.
+
+=back
+
 =item B<tee="STRING">
 
 B<Arm only.> Set TEE type for the guest. TEE is a Trusted Execution
--
generated by git-patchbot for /home/xen/git/xen.git#master