cloud-hypervisor/docs/riscv.md
abm-77 40055595ff docs: Update riscv docs for developing in QEMU VM
Since there are not a wide availability of RISC-V boards available at
the moment, it is easiest to develop with a QEMU virtual machine. I had
a hard time setting one up, but with the assistance of Ruoqing, I was
able to get one running. These are the steps I took to do so.

Signed-off-by: abm-77 <andrewmiller77@protonmail.com>
2025-05-03 11:11:05 +00:00

168 lines
4.2 KiB
Markdown

# How to build and test Cloud Hypervisor on riscv64
This document introduces how to build and test Cloud Hypervisor on `riscv64`.
All instructions here are tested with Ubuntu 24.04.2 as the host OS.
## Hardware requirements
- riscv64 servers (recommended) or development boards equipped with the AIA
(Advance Interrupt Architecture) interrupt controller.
## Getting started
We create a folder to build and run Cloud Hypervisor at `$HOME/cloud-hypervisor`
```console
export CLOUDH=$HOME/cloud-hypervisor
mkdir $CLOUDH
```
## Prerequisites
You need to install some prerequisite packages to build and test Cloud Hypervisor.
### Tools
```console
# Install rust tool chain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# Install the tools used for building guest kernel, EDK2 and converting guest disk
sudo apt-get update
sudo apt-get install git build-essential m4 bison flex uuid-dev qemu-utils
```
### Building Cloud Hypervisor
```console
pushd $CLOUDH
git clone https://github.com/cloud-hypervisor/cloud-hypervisor.git
cd cloud-hypervisor
cargo build
popd
```
### Disk image
Download the Ubuntu cloud image and convert the image type.
```console
pushd $CLOUDH
wget https://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-riscv64.img
qemu-img convert -p -f qcow2 -O raw jammy-server-cloudimg-riscv64.img jammy-server-cloudimg-riscv64.raw
popd
```
## Direct-kernel booting
### Building kernel
```console
pushd $CLOUDH
git clone --depth 1 "https://github.com/cloud-hypervisor/linux.git" -b ch-6.12.8
cd linux
make ch_defconfig
make -j `nproc`
popd
```
### Booting the guest VM
```console
pushd $CLOUDH
sudo $CLOUDH/cloud-hypervisor/target/debug/cloud-hypervisor \
--kernel $CLOUDH/linux/arch/riscv64/boot/Image \
--disk path=jammy-server-cloudimg-riscv64.raw \
--cmdline "console=hvc0 root=/dev/vda rw" \
--cpus boot=1 \
--memory size=1024M \
--seccomp false \
--log-file boot.log -vv
popd
```
## Virtualized Development Setup
Since there are few RISC-V development boards on the market and not
many details about the AIA interrupt controller featured in product listings,
QEMU is a popular and viable choice for creating a RISC-V development environment.
Below are the steps used to create a QEMU virtual machine that can be used for
cloud-hypervisor RISC-V development:
### Install Dependencies
```console
sudo apt update
sudo apt install opensbi qemu-system-misc u-boot-qemu
```
### Download and Build QEMU (>=v9.2.0)
Older versions of QEMU may not have support for the AIA
interrupt controller.
```console
wget https://download.qemu.org/qemu-10.0.0.tar.xz
tar xvJf qemu-10.0.0.tar.xz
cd qemu-10.0.0
./configure --target-list=riscv64-softmmu
make -j $(nproc)
sudo make install
```
### Download Ubuntu Server Image
At the time of writing, the best results have been seen with
the Ubuntu 24.10 (Oracular) server image. Ex:
```console
wget https://cdimage.ubuntu.com/releases/oracular/release/ubuntu-24.10-preinstalled-server-riscv64.img.xz
xz -dk ubuntu-24.10-preinstalled-server-riscv64.img.xz
```
### (Optional) Resize Disk
If you would like a larger disk, you can resize it now.
```console
qemu-img resize -f raw <ubuntu-image> +5G
```
### Boot VM
Note the inclusion of the AIA interrupt controller in the
invocation.
```console
qemu-system-riscv64 \
-machine virt,aia=aplic-imsic \
-nographic -m 1G -smp 8 \
-kernel /usr/lib/u-boot/qemu-riscv64_smode/uboot.elf \
-device virtio-rng-pci \
-device virtio-net-device,netdev=eth0 -netdev user,id=eth0 \
-drive file=<ubuntu-image>,format=raw,if=virtio
```
### Install KVM Kernel Module Within VM
KVM is not enabled within the VM by default, so we must enable
it manually.
```console
sudo modprobe kvm
```
From this point, you can continue with the above steps from the beginning.
### Sources
https://risc-v-getting-started-guide.readthedocs.io/en/latest/linux-qemu.html
https://canonical-ubuntu-boards.readthedocs-hosted.com/en/latest/how-to/qemu-riscv/#using-the-live-server-image
https://www.qemu.org/docs/master/specs/riscv-aia.html
## Known limitations
- Direct kernel boot only
- `64-bit Linux` guest OS only
- For more details, see
[here](https://github.com/cloud-hypervisor/cloud-hypervisor/issues/6978).