Merge master into staging-next

4 files changed, 18 insertions, 8 deletions

diff --git a/nixos/doc/manual/configuration/subversion.chapter.md b/nixos/doc/manual/configuration/subversion.chapter.md
index 84f9c270337..ff870f5c40b 100644
--- a/nixos/doc/manual/configuration/subversion.chapter.md
+++ b/nixos/doc/manual/configuration/subversion.chapter.md
@@ -2,7 +2,7 @@
 
 [Subversion](https://subversion.apache.org/) is a centralized
 version-control system. It can use a [variety of
-protocols](http://svnbook.red-bean.com/en/1.7/svn-book.html#svn.serverconfig.choosing)
+protocols](https://svnbook.red-bean.com/en/1.7/svn-book.html#svn.serverconfig.choosing)
 for communication between client and server.
 
 ## Subversion inside Apache HTTP {#module-services-subversion-apache-httpd}
@@ -14,7 +14,7 @@ for communication.
 
 For more information on the general setup, please refer to the [the
 appropriate section of the Subversion
-book](http://svnbook.red-bean.com/en/1.7/svn-book.html#svn.serverconfig.httpd).
+book](https://svnbook.red-bean.com/en/1.7/svn-book.html#svn.serverconfig.httpd).
 
 To configure, include in `/etc/nixos/configuration.nix` code to activate
 Apache HTTP, setting [](#opt-services.httpd.adminAddr)
diff --git a/nixos/doc/manual/development/running-nixos-tests-interactively.section.md b/nixos/doc/manual/development/running-nixos-tests-interactively.section.md
index a816213f37d..4b8385d7e0d 100644
--- a/nixos/doc/manual/development/running-nixos-tests-interactively.section.md
+++ b/nixos/doc/manual/development/running-nixos-tests-interactively.section.md
@@ -62,7 +62,7 @@ where socat is running.
 If your test has only a single VM, you may use e.g.
 
 ```ShellSession
-$ QEMU_NET_OPTS="hostfwd=tcp:127.0.0.1:2222-127.0.0.1:22" ./result/bin/nixos-test-driver
+$ QEMU_NET_OPTS="hostfwd=tcp:127.0.0.1:2222-:22" ./result/bin/nixos-test-driver
 ```
 
 to port-forward a port in the VM (here `22`) to the host machine (here port `2222`).
@@ -73,6 +73,11 @@ since a single port on the host cannot forward to multiple VMs.
 If the test defines multiple machines, you may opt to _temporarily_ set
 `virtualisation.forwardPorts` in the test definition for debugging.
 
+Such port forwardings connect via the VM's virtual network interface.
+Thus they cannot connect to ports that are only bound to the VM's
+loopback interface (`127.0.0.1`), and the VM's NixOS firewall
+must be configured to allow these connections.
+
 ## Reuse VM state {#sec-nixos-test-reuse-vm-state}
 
 You can re-use the VM states coming from a previous run by setting the
diff --git a/nixos/doc/manual/development/writing-documentation.chapter.md b/nixos/doc/manual/development/writing-documentation.chapter.md
index c07a2618c07..3d9bd318cf3 100644
--- a/nixos/doc/manual/development/writing-documentation.chapter.md
+++ b/nixos/doc/manual/development/writing-documentation.chapter.md
@@ -33,13 +33,13 @@ symlink at `./result/share/doc/nixos/index.html`.
 ## Editing DocBook XML {#sec-writing-docs-editing-docbook-xml}
 
 For general information on how to write in DocBook, see [DocBook 5: The
-Definitive Guide](http://www.docbook.org/tdg5/en/html/docbook.html).
+Definitive Guide](https://tdg.docbook.org/tdg/5.1/).
 
 Emacs nXML Mode is very helpful for editing DocBook XML because it
 validates the document as you write, and precisely locates errors. To
 use it, see [](#sec-emacs-docbook-xml).
 
-[Pandoc](http://pandoc.org) can generate DocBook XML from a multitude of
+[Pandoc](https://pandoc.org/) can generate DocBook XML from a multitude of
 formats, which makes a good starting point. Here is an example of Pandoc
 invocation to convert GitHub-Flavoured MarkDown to DocBook 5 XML:
 
@@ -62,9 +62,9 @@ topic from scratch.
 
 Keep the following guidelines in mind when you create and add a topic:
 
--   The NixOS [`book`](http://www.docbook.org/tdg5/en/html/book.html)
+-   The NixOS [`book`](https://tdg.docbook.org/tdg/5.0/book.html)
     element is in `nixos/doc/manual/manual.xml`. It includes several
-    [`parts`](http://www.docbook.org/tdg5/en/html/book.html) which are in
+    [`parts`](https://tdg.docbook.org/tdg/5.0/book.html) which are in
     subdirectories.
 
 -   Store the topic file in the same directory as the `part` to which it
diff --git a/nixos/doc/manual/installation/changing-config.chapter.md b/nixos/doc/manual/installation/changing-config.chapter.md
index f2ffea9088a..12abf90b718 100644
--- a/nixos/doc/manual/installation/changing-config.chapter.md
+++ b/nixos/doc/manual/installation/changing-config.chapter.md
@@ -89,7 +89,7 @@ guest. For instance, the following will forward host port 2222 to guest
 port 22 (SSH):
 
 ```ShellSession
-$ QEMU_NET_OPTS="hostfwd=tcp:127.0.0.1:2222-127.0.0.1:22" ./result/bin/run-*-vm
+$ QEMU_NET_OPTS="hostfwd=tcp:127.0.0.1:2222-:22" ./result/bin/run-*-vm
 ```
 
 allowing you to log in via SSH (assuming you have set the appropriate
@@ -98,3 +98,8 @@ passwords or SSH authorized keys):
 ```ShellSession
 $ ssh -p 2222 localhost
 ```
+
+Such port forwardings connect via the VM's virtual network interface.
+Thus they cannot connect to ports that are only bound to the VM's
+loopback interface (`127.0.0.1`), and the VM's NixOS firewall
+must be configured to allow these connections.