Complete-Single-GPU-Passthrough/README.org

* Set up IOMMU
** Enable IOMMU
***** Load /etc/default/grub and append "intel_iommu=on" or "amd_iommu=on" to GRUB_CMDLINE_LINUX_DEFAULT. Also, "iommu=pt".
***** Update grub configuration.
#+BEGIN_SRC bash
  grub-mkconfig -o /boot/grub/grub.cfg
#+END_SRC
** Verify IOMMU is enabled successfully
***** You should see "IOMMU enabled" in output.
#+BEGIN_SRC bash
  dmesg | grep -i -e DMAR -e IOMMU | grep enabled
#+END_SRC
* Set up VM
** Installation
***** Install the required packages.
#+BEGIN_SRC bash
  sudo pacman -S qemu libvirt edk2-ovmf virt-manager dnsmasq ebtables iptables
#+END_SRC
** Starting services
***** Enable and start libvirt service
#+BEGIN_SRC bash
  sudo systemctl enable libvirtd
  sudo systemctl start libvirtd
#+END_SRC
** Start default network
***** This may not be needed. If default network isn't started by default for you, start the network manually.
#+BEGIN_SRC bash
  sudo virsh net-start default
  sudo virsh net-autostart default
#+END_SRC
** Setup Guest OS
***** Launch virt-manager, and start creating guest. On final step, check "Customize before install".
***** > In the "Overview" section, set Chipset to "Q35" and firmware to "UEFI".
***** > In the "CPUs" section, change CPU model to "host-passthrough". You need to type it manually. According to Arch Wiki, this makes sure that the CPU is detected properly. Without it, some applications may complain about your CPU being of an unknown model.
***** > Set Disk Bus of Storage to "virtio".
***** > Set NIC Device Model to "virtio".
***** Now, you can *Begin Installation*. You can continue installing Windows right now or after setting up Passthrough.
** Attach PCI devices
***** Remove devices such as Spice Channel, XQL video adaper, USB tablet, etc.
***** Click on "Add Hardware" and add PCI devices for GPU and HDMI Audio. For NVIDIA GPU, GPU ROM should be patched. See next section.
** NVIDIA GPU Patching
***** Dump GPU VBIOS
Using GPU-Z in Windows is the easiest method of dumping VBIOS. The following command didn't work for me but it's worth trying.
#+BEGIN_SRC bash
  su
  echo 1 > /sys/bus/pci/devices/0000:01:00.0/rom
  cat /sys/bus/pci/devices/0000:01:00.0/rom > vbios.rom
  echo 0 > /sys/bus/pci/devices/0000:01:00.0/rom
#+END_SRC
***** Patch VBIOS file
Use Hex Editor and search string "VIDEO", and remove everything before HEX value *55*. There are bunch of 0s or fs usually..

***** Using Patched VBIOS file
You need to edit configution file of VM.
#+BEGIN_SRC bash
  sudo virsh edit win10
#+END_SRC
Search for *hostdev*. Add
#+BEGIN_SRC xml
  <rom file="path/to/your/patched_vbios.rom"/>
#+END_SRC
before *address* tag.
** Keyboard/mouse Passthrough
You need to modify libvirt configuration.
#+BEGIN_SRC bash
  sudo virsh edit win10
#+END_SRC
Modify first line
#+BEGIN_SRC xml
  <domain type='kvm'>
#+END_SRC
to
#+BEGIN_SRC xml
  <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
#+END_SRC
Find your keyboard and mouse devices. Use the devices having *event* in their name.
#+BEGIN_SRC bash
  ls /dev/input/by-id/
#+END_SRC
Verify you selected the right device by using following command. You should see output on terminal when using that device..
#+BEGIN_SRC bash
  cat /dev/input/by-id/your_device
#+END_SRC
Add devices to the configuration. Replace *MOUSE_NAME* and *KEYBOARD_NAME* with your device id.
#+BEGIN_SRC bash
virsh edit win10
#+END_SRC
#+BEGIN_SRC xml
  <qemu:commandline>
    <qemu:arg value='-object'/>
    <qemu:arg value='input-linux,id=mouse1,evdev=/dev/input/by-id/MOUSE_NAME'/>
    <qemu:arg value='-object'/>
    <qemu:arg value='input-linux,id=kbd1,evdev=/dev/input/by-id/KEYBOARD_NAME,grab_all=on,repeat=on'/>
  </qemu:commandline>
#+END_SRC