RISC-V Hypervisors

[Anup Patel]

Hi All,

It's a great pleasure to inform everyone that we have RISC-V
hypervisor extension available for QEMU and along with it we
also have Xvisor (a baremetal type-1 hypervisor) working on
QEMU with RISC-V hypervisor extension. Currently, we are able
to boot two Linux RV64 Guests on Xvisor RV64.

This will be very useful to RISC-V CPU designers in validating
their implementation of RISC-V hypervisor extensions.

The QEMU RISC-V hypervisor emulation is done by Alistair and is
available in riscv-hyp-work.next branch at:
https://github.com/alistair23/qemu.git.

At the moment, QEMU RISC-V hypervisor emulation patches are
on QEMU mailing list for review.
(Refer, https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg06064.html)

The Xvisor RISC-V port is done by myself (Anup) and Atish. It
can be found in master branch of Xvisor staging repo at:
https://github.com/avpatel/xvisor-next.git.

For more details on Xvisor, refer
http://xhypervisor.org/
http://xhypervisor.org/index.php?page=news/20150427

The SBI runtime needs to support RISC-V hypervisor extensions.
Particularly, we need to handle trap redirection, misaligned
load/store emulation, and missing CSR emulation differently for
HS-mode and VS-mode. We have extended OpenSBI to support RISC-V
hypervisor extension and it is available in hyp_ext_changes_v1
branch at:
https://github.com/riscv/opensbi.git

We have made great progress in KVM RISC-V (type-2 hypervisor) as
well. Currently, we are debugging KVM RISC-V and KVMTOOL RISC-V
port on QEMU. You can expect RFC patches soon in June/July 2019.

The KVM RISC-V can be found in riscv_kvm_v1 branch at:
https://github.com/avpatel/linux.git

The KVMTOOL RISC-V port can be found in riscv_v1 branch at:
https://github.com/avpatel/kvmtool.git

There is an early work on Xen RISC-V port which is avaliable
in alistair/riscv-port branch at:
https://github.com/alistair23/xen.git

We will be showing a demo of QEMU+OpenSBI+Xvisor+Linux at
up-coming RISC-V Zurich Workshop.
(Refer, https://tmt.knect365.com/risc-v-workshop-zurich/)

Stay tuned for more exciting updates on RISC-V hypervisors.

Regards,
Anup