Accelerate QEMU virtual machines in Termux with pKVM

infoivonblog.nkfjt@aleeas.com (Ivon Huang) — Tue, 23 Dec 2025 11:00:00 +0800

I discussed the problem of running virtual machines on Android phones with Termux in Termux + QEMU Linux VM. The conclusion: it is slow as hell.

Without KVM, everything depends on software emulation. The result is that you can only run 20-year-old Windows XP systems; modern operating systems are simply too heavy.

Phones equipped with Google Tensor processors introduced pKVM after Android 15, which is the technology supported underneath the AVF framework.

At the moment, except for Android 16’s experimental Debian Linux Terminal, ordinary apps cannot access pKVM. You need root privileges to enable pKVM.

1. Install packages
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With KVM acceleration, you should run a virtual machine of the same architecture. According to Termux developers, using the qemu-system-aarch64-headless package can give you a pKVM-accelerated virtual machine.

Install the following packages. On ARM machines, it is best to enable UEFI.

pkg install qemu-system-aarch64-headless qemu-utils qemu-common ovmf sudo

There is no Virt Manager in the graphical interface, and the Libvirt service probably will not run, so we have to use AVNC to access the virtual machine display.

2. Create a Linux virtual machine in Termux
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Download the Ubuntu ARM ISO and put it in Termux’s home directory
Confirm that KVM exists

sudo ls /dev/kvm

Create a virtual disk

qemu-img create -f qcow2 ubuntu.qcow2 32G

Create files to store UEFI

truncate -s 64m varstore.img

truncate -s 64m efi.img

dd if=$PREFIX/share/qemu/edk2-aarch64-code.fd of=efi.img conv=notrunc

Add a boot script

touch startubuntu.sh

chmod +x startubuntu.sh

vim startubuntu.sh

The contents are as follows

qemu-system-aarch64 -M virt \
-enable-kvm \
-drive if=pflash,format=raw,file="efi.img",readonly \
-drive if=pflash,format=raw,file="varstore.img" \
-smp cpus=2 \
-m 1024 \
-cpu host \
-nographic \
-netdev user,id=n1,hostfwd=tcp::2222-:22 -device virtio-net,netdev=n1 \
-drive file=ubuntu.qcow2 \
-boot d \
-vnc :0 \
-cdrom ubuntu-24.04.3-live-server-arm64.iso

Add sudo when running it.

sudo ./startubuntu.sh

If everything goes smoothly, you can open localhost:59000 in AVNC and see the virtual machine display.

The strange thing is that it can boot without enabling KVM, but once KVM is enabled it hits the qemu-system-aarch64: Failed to put registers after init: Invalid argument error.

If you switch to chroot and run KVM inside it, maybe the success rate will go up?

References
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Why I Like Using Virt Manager + QEMU/KVM, Starting From Baked Spaghetti

infoivonblog.nkfjt@aleeas.com (Ivon Huang) — Mon, 08 Jul 2024 22:00:00 +0800

A side story not mentioned in Linux Leraning History! The QEMU/KVM skill tree.

As of now, common virtualization software on GNU/Linux systems includes:

QEMU/KVM, managed with Virt Manager or GNOME Boxes
Oracle VirtualBox
VMware
Xen

Why do the articles in this site’s “Virtual Machines and Container Technologies” category almost all discuss QEMU/KVM as the virtual machine software? (At least up to now.) This has to start with my obsession with QEMU/KVM.

I am not talented; my understanding of Linux virtualization is only like taking one ladle of water from the river.

1. Baked Spaghetti and QEMU/KVM
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The reason I have been enthusiastic about studying QEMU/KVM virtual machines to this day is that, at first, I wanted to migrate to Linux, but was worried about losing access to Windows functionality.

Before 2022, I had not yet come into contact with the cult-like free software ideology, so naturally I could not let go of Windows. Even though I knew Wine existed, I still hoped to have a virtual machine that could quickly create a Windows environment, so that I could run software when necessary.

(In hindsight: I did not expect that two years later I would go to the computer science department to learn C# programming. The virtual machine saved my life, letting me install Visual Studio and finish assignments.)

I already had some experience operating virtual machines before this, but I did not really understand the principles behind them. I only felt that VirtualBox and VMware were intuitive and easy to use! Systems could be installed whoosh, just like that. QEMU/KVM was unknown territory to me.

I vaguely understood that the greatest weak point of virtual machines was graphics processing capability, so starting in my sophomore year (2020), I began researching GPU passthrough technology.

At the school cafeteria attached to the National Pingtung University dormitory, I ordered baked spaghetti, sat down, took out my phone, and read articles written by “For Possible Sounds”, “CT Wang”, “How to Play LOL on Linux”, “Bird Brother”, and others, beginning my study of how to do GPU passthrough.

During the same period, I tried installing Hackintosh on bare metal. I read articles, went back to the dorm to test it, and actually succeeded! Ah, but I could not handle the audio card kext, so I gave up very quickly.

The shop served the meal in a small bowl. The spaghetti was wrapped in aluminum foil, with a hot baked crust covering the top. When I pierced it with a fork and rolled up tomato noodles with stringy cheese and crust, the crispy, sweet-and-sour feeling in my mouth was truly delicious.

Mamma mia, I simply could not understand what those online articles were writing. What IOMMU, VFIO, nouveau blacklist, what the heck!? Why does everyone introduce GPU passthrough like they are writing a thesis? While reading, I finished the noodles too, so I quit and went to sleep!

Slowly, by 2022, I successfully tried GPU passthrough on Ubuntu for the first time. It was not some sudden enlightenment, but success through repeated trial and error. After all, that was a time when I did not even know how to use vim.

QEMU-KVM on Ivon's Blog

Accelerate QEMU virtual machines in Termux with pKVM

1. Install packages #

2. Create a Linux virtual machine in Termux #

References #

Why I Like Using Virt Manager + QEMU/KVM, Starting From Baked Spaghetti

1. Baked Spaghetti and QEMU/KVM #

1. Install packages
#

2. Create a Linux virtual machine in Termux
#

References
#

1. Baked Spaghetti and QEMU/KVM
#