R-Car/Virtualization

Virtualization on Renesas R-Car Platforms

Prerequisites

• QEMU (e.g. "apt-get install qemu-system-arm"),
• A guest image, e.g. "openwrt-arm64-qemu-virt.Image" from OpenWRT.

Running QEMU

$ qemu-system-aarch64 -m 1024 -cpu cortex-a57 -M virt -nographic -kernel openwrt-arm64-qemu-virt.Image

and press <ENTER> to enjoy your new ARM64 system!

Using KVM

When using an arm64 platform as the host system, guest performance can be improved drastically by making use of the Kernel-based Virtual Machine (KVM).

Host Kernel Configuration

Make sure your host kernel has the following options enabled:

CONFIG_VIRTUALIZATION=y
CONFIG_KVM=y

"renesas_defconfig" should be fine.

Firmware Support

To use KVM, the firmware on your board must start Linux in hypervisor (EL2 / HYP) mode.

If your host kernel prints:

CPU: All CPU(s) started at EL2
...
kvm [1]: Hyp mode initialized successfully

during boot up, everything is fine, and you can skip the next section.

If your host kernel prints:

CPU: All CPU(s) started at EL1
...
kvm [1]: HYP mode not available

during bootup, HYP mode is not available, and KVM cannot be used, unless you first replace the firmware of your board with a version that supports HYP mode.

Enabling HYP Support

To build your own ARM Trusted Firmware with hypervisor mode support:

$ git clone git@github.com:renesas-rcar/arm-trusted-firmware.git
$ cd arm-trusted-firmware
$ make CROSS_COMPILE=aarch64-linux-gnu- PLAT=rcar RCAR_DRAM_SPLIT=3 RCAR_BL33_EXECUTION_EL=1 LSI=H3 # or LSI=M3 

Replace the BL2 and BL31 binaries in your firmware package by the generated "build/rcar/release/bl2.srec" and "build/rcar/release/bl31.srec", and follow your normal firmware upgrade procedure.

Running QEMU with KVM

$ qemu-system-aarch64 -enable-kvm -m 1024 -cpu cortex-a57 -M virt -nographic -kernel openwrt-arm64-qemu-virt.Image

and press <ENTER> to enjoy a faster new ARM64 system!

Note that the above command requires running on a Cortex-A57 CPU core. When running on a Cortex-A53 CPU core in a big.LITTLE configuration, the command will fail with:

kvm_init_vcpu failed: Invalid argument

Just retry, or force your luck by disabling all Cortex-A53 cores:

echo 0 > /sys/devices/system/cpu/cpuN/online

for all "cpuN" representing Cortex-A53 cores.