[PATCH] doc: Add information related to network connectivity with qemu.

[David Craven <david@craven.ch>]

* doc/guix.text: Add it.
---
 doc/guix.texi | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/doc/guix.texi b/doc/guix.texi
index 785d6fb..5173ca7 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -11030,6 +11030,45 @@ which may be insufficient for some operations.
 The file name of the qcow2 image.
 @end table
 
+The default @command{run-vm.sh} script that is returned by an invokation of
+@command{guix system vm} does not add a @command{-net user} flag by default.
+To get network access from within the vm add the @code{(dhcp-client-service)}
+to your system definition and start the vm using
+@command{$(guix system vm config.scm) -net user}.  An important caveat of using
+@command{-net user} for networking is that @command{ping} will not work, because
+it uses the ICMP protocol.  You'll have to use a different command to check for
+network connectivity, I'll leave this as an exercise for the reader.
+
+@subsubsection Connecting through ssh
+
+To enable ssh inside a vm you need to add a ssh server like @code{(dropbear-service)}
+or @code{(lsh-service)} to your vm. The @code{(lsh-service}) doesn't currently
+boot unsupervised. It requires you to type some characters to initialize the
+randomness generator. In addition you need to forward the ssh port, 22 by
+default, to the host. You can do this with
+@command{$(guix system vm config.scm) -net user,hostfwd=tcp::10022-:22}. To connect
+to the vm you can run
+@command{ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022}.
+The @command{-p} tells @command{ssh} the port you want to connect to.
+@command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
+every time you modify your @command{config.scm} file and the
+@command{-o StrictHostKeyChecking=no} prevents you from having to allow a
+connection to an unknown host every time you connect.
+
+@subsubsection Using virt-viewer with spice
+
+The default qemu graphical client isn't very nice.  As an alternative you can
+use the @command{remote-viewer} from the @command{virt-viewer} package. To
+connect pass the @command{-spice port=5930,disable-ticketing} flag to
+@command{qemu}. See previous section for further information on how to do this.
+
+Spice also allows you to do some nice stuff like share your clipboard with your
+vm.  To enable that you'll have to in addition pass the following flags to
+@command{qemu}: @command{-device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5}
+@command{-chardev spicevmc,name=vdagent,id=vdagent}
+@command{-device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,name=com.redhat.spice.0}.
+You'll also need to add the @code{(spice-vdagent-service)}.
+
 @node Defining Services
 @subsection Defining Services
 
-- 
2.9.0