add kvm-on-arch.md

docs/posts/kvm-on-arch.md

@@ -0,0 +1,125 @@
+---
+title: "KVM On Arch"
+date: 2021-10-07
+draft: false
+tags: ["Arch", "linux", "kvm", "virtualmachine"]
+authors: ["trent"]
+post: 24
+---
+date: 2021-10-07
+
+## Introduction
+This is not intended to be a tutorial, but rather a walk-through of
+how I would install
+[libvirt/kvm on Arch Linux](https://wiki.archlinux.org/title/Libvirt){target="_blank"}.
+
+## Packages
+* iptables-nft
+* dnsmasq
+* bridge-utils
+* openbsd-netcat
+* libvirt
+* qemu-headless
+* virt-install
+
+`virt-install` is not needed if connecting remotely with virt-manager,
+but it does provide `virt-clone`.
+
+## Configuration
+* enable libvirtd service
+    * `systemctl enable libvirtd`
+* add user to libvirt group
+    * `usermod -a -G libvirt <user>`
+### environment/bashrc
+```cfg
+# ~/.bashrc
+export LIBVIRT_DEFAULT_URI="qemu:///system"
+```
+reboot the machine
+
+## Network
+The default network is defined in `/etc/libvirt/qemu/networks/default.xml`.
+
+* Start the default network `virsh net-start default`.
+* Permanently enable the default network `virsh net-autostart default`.
+
+## Jump Host With `virt-manager`
+Abstract your jump host in `~/.ssh/config`
+```cfg
+# ~/.ssh/config
+Host jumphost
+        Hostname <ip address>
+        Port 22
+        User <user>
+
+Host kvmhost
+        Hostname <ip address>
+        ProxyJump jumphost
+        Port 22
+        User <user>
+```
+Now you can connect `virt-manager` to <user\>@kvmhost
+
+## Console Access
+Enable serial console on guest.
+`systemctl enable serial-getty@ttyS0.service`
+
+## Nested KVM
+I was going to try to figure out how to permantly set the cpu mode default
+such that all virtualmachines will be capable of nested virtualization,
+but it already is. Perhaps that is the default in `virt-manager` now?
+
+Anyway, in case you want to make sure
+[nested virtualization](https://wiki.archlinux.org/title/KVM#Nested_virtualization){target="_blank"}
+is enabled in the host kernel.
+
+## Clone Ip Address Conflict
+I found a great tutorial
+[for assigning ip addresses](https://bobcares.com/blog/virsh-set-ip-address/){target="_blank"}.
+
+The problem we need to solve here is that virtual machine clones won't necessarily
+solicit a unique ip address, although a clone will have a new `mac address`.
+
+So, you clone a vm:
+
+  * `virt-clone --original arch --name archone --auto-clone`
+
+Get the clone's mac address:
+
+  * `virsh dumpxml archone | grep mac`
+
+### Now assign the clone a dhcp reservation:
+
+  * `virsh net-edit default`
+
+Notice that I tighten up the dhcp range, and add a
+reservation outside the new dhcp range.
+
+```xml
+<network connections='1'>
+  <name>default</name>
+  <uuid>8013c9a5-606f-48a0-a3ec-1cf097e76fb1</uuid>
+  <forward mode='nat'>
+    <nat>
+      <port start='1024' end='65535'/>
+    </nat>
+  </forward>
+  <bridge name='virbr0' stp='on' delay='0'/>
+  <mac address='52:54:00:ef:cb:d2'/>
+  <ip address='192.168.122.1' netmask='255.255.255.0'>
+    <dhcp>
+      <!-- previous dhcp range
+      <range start='192.168.122.2' end='192.168.122.254'/>
+      -->
+      <!-- begin new lines -->
+      <range start='192.168.122.50' end='192.168.122.150'/>
+      <host mac='52:54:00:cd:7d:7f' name='archone' ip='192.168.122.25'/>
+      <!-- end new lines -->
+    </dhcp>
+  </ip>
+</network>
+```
+
+### Restart Default Network
+* `virsh net-destroy default`
+* `virsh net-start default`

mkdocs.yml

@@ -24,6 +24,7 @@ markdown_extensions:
 nav:
   - Home:
     - Home: index.md
+    - "KVM On Arch": posts/kvm-on-arch.md
     - "RaspberryPi LTE-Failover Router With DNS Caching": posts/raspberrypi-lte-failover-router-with-dns-caching.md
     - "Flutter Integration Test Server in Debian 11 Nspawn Container": posts/debian-11-nspawn-flutter-integration-test-server.md
     - "Debian 11 TT-RSS": posts/debian-11-ttrss.md
@@ -61,6 +62,7 @@ nav:
     - FreeCodeCampChallenges: https://trentspalmer.github.io/fcc-challenges/
     - DeviceLayout: https://trentpalmer.work/6a57bbe24d8244289610bf57533d6c6f/
   - Posts:
+    - "KVM On Arch": posts/kvm-on-arch.md
     - "RaspberryPi LTE-Failover Router With DNS Caching": posts/raspberrypi-lte-failover-router-with-dns-caching.md
     - "Flutter Integration Test Server in Debian 11 Nspawn Container": posts/debian-11-nspawn-flutter-integration-test-server.md
     - "Debian 11 TT-RSS": posts/debian-11-ttrss.md