riscv/bhyve - FreeBSD Wiki

The page is dedicated to riscv "H"-extension[1].

The RISC-V Hypervisor specification virtualizes supervisor-level architecture to efficiently host guest operating systems atop a type-1 or type-2 hypervisor. Virtual machine implementations require the RISC-V Hypervisor specification. The Hypervisor specification will help drive RISC-V adoption in cloud and embedded applications where virtualization is critical, such as in data centers, automotive applications, and industrial control applications.

Code:

userspace part
kernel part

Project Status

Feature	Status	Notes	Owner
spike	supported	working in multi-core	RuslanBukin
qemu	supported	working in multi-core	RuslanBukin
VMID/ASID bits management for stage 2	no support	TODO
MSI interrupts	no support	TODO
u-boot	WIP	u-boot starts up, review	RuslanBukin
PCIe emulation	supported
SMP in host	supported		RuslanBukin
SMP in guest	supported		RuslanBukin
multiple bhyve instances in host	unknown
bhyve SBI implementation ID	done		RuslanBukin
stage 2 pmap	done		RuslanBukin
check if APLIC emulation needs locking to protect structures	added		RuslanBukin
check if we want to trap rdcycle / rdtime and emulate it
SBI RFNC extension support

Hardware

At the moment, no real hardware with H-extension implemented available.

Instructions

Build FreeBSD (VM host)

Apply VMM kernel & userspace patches to your freebsd repository and build it as usual.

Prepare OpenSBI (host)

git clone https://github.com/riscv/opensbi.git
cd opensbi
gmake -j24 CROSS_COMPILE=riscv64-none-elf- PLATFORM=generic

Alternatively,

sudo pkg install opensbi

Fetch guest root fs

fetch https://download.freebsd.org/snapshots/VM-IMAGES/15.0-CURRENT/riscv64/Latest/FreeBSD-15.0-CURRENT-riscv-riscv64-ufs.qcow2.xz
unxz FreeBSD-15.0-CURRENT-riscv-riscv64-ufs.qcow2.xz

QEMU

git clone https://github.com/qemu/qemu
cd qemu
mkdir build && cd build
../configure --target-list=riscv64-softmmu
gmake -j `sysctl -n hw.ncpu`

Run QEMU

Add more storage devices if needed (e.g. VM-host rootfs). In my case I use mdroot, so the only drive in the command line below is guest-rootfs disk.

./qemu-system-riscv64 -nographic \
        -machine virt \
        -cpu 'rv64,h=true' \
        -smp 8 \
        -device virtio-scsi-pci,id=scsi \
        -drive file=FreeBSD-15.0-CURRENT-riscv-riscv64-ufs.qcow2,id=disk,format=qcow2,if=none,cache=writeback -device scsi-hd,drive=disk \
        -m 16G \
        -device virtio-rng-pci \
        -bios /usr/local/share/opensbi/lp64/generic/firmware/fw_jump.elf \
        -kernel /usr/obj/usr/home/br/dev/freebsd/riscv.riscv64/sys/GENERIC/kernel.bin

Bhyve

This has to be run on freebsd that is booted up in QEMU. Ensure you have u-boot.bin on your qemu rootfs.

bhyve -c 8 -m 256 -o bootrom=/usr/local/share/u-boot/u-boot-bhyve-riscv/u-boot.bin -o console=stdio -s 4,virtio-blk,/dev/da0 test