---> You can't use KVM with the vexpress-a15 board. The only Arm guest machine that will work with KVM is the "virt" board.
point 1) On the virtual open systems website they used the vexpress-a15 board. You can read by yourself what they say : The guests that we will create later will be based on the Versatile Express QEMU machine model. For we will use a different kernel branch specific to that platform: $ git checkout origin/kvm-vexpress-3.9$ curl http://www.virtualopensystems.com/downloads/guides/kvm_on_chromebook/guest-config > .config$ ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- make zImage dtbs -j4 Then we can append the dtb file to the kernel image with: $ cat arch/arm/boot/dts/rtsm_ve-cortex_a15x1.dtb >> arch/arm/boot/zImage That way we only need to handle one file. Make sure to copy *arch/arm/boot/zImage* for later usage. point 2) On the devuan 4 host os that I have installed I'm using kernel 5.4,that's lower than 5.7,so the qemu support for it should be there. point 3) if I use the "virt" board,does the KVM acceleration work ? thanks. On Thu, Aug 10, 2023 at 7:07 PM Peter Maydell <peter.mayd...@linaro.org> wrote: > On Thu, 10 Aug 2023 at 17:52, Mario Marietto <marietto2...@gmail.com> > wrote: > > > I conducted some further experiments : > > > > In this example I've used qemu 5.2.0 installed by default by the devuan > 4 : > > > > > > qemu-system-arm \ > > -enable-kvm -serial stdio -kernel zImage \ > > -m 512 -M vexpress-a15 -cpu cortex-a15 \ > > -drive > file=/mnt/fisso/bhyve/img/Linux/ubuntu2210.img,id=virtio-blk,if=none \ > > -device virtio-blk,drive=virtio-blk,transport=virtio-mmio.0 \ > > -device > virtio-net,transport=virtio-mmio.1,netdev=net0,mac="52:54:00:12:34:55" \ > > -netdev type=user,id=net0 \ > > -append "earlyprintk=ttyAMA0 console=ttyAMA0 mem=512M \ > > virtio_mmio.device=1M@0x4e000000:74:0 \ > > virtio_mmio.device=1M@0x4e100000:75:1 \ > > root=/dev/vda rw ip=dhcp --no-log" > > > > qemu-system-arm: invalid accelerator kvm. > > You can't use KVM with the vexpress-a15 board. The only > Arm guest machine that will work with KVM is the "virt" > board. > > Further, it looks like your host CPU is 32-bit. QEMU 5.2 > dropped support for running KVM on 32-bit hosts, because this > support was dropped from host kernels in kernel version 5.7. > > Basically, 32-bit hosts are just too small to do anything > sensible with virtual machines, which is why the kernel > (and in turn QEMU) dropped that support. If you want > to play around with Arm virtualization, use a 64-bit host. > (64-bit hosts can still use KVM to virtualize 32-bit > guests if you want 32-bit guests.) > > thanks > -- PMM > -- Mario.
