---> You can't use KVM with the vexpress-a15 board. The only Arm guest
machine that will work with KVM is the "virt" board.
ok,I tried -M virt like this :
qemu-system-arm \
-enable-kvm -serial stdio -kernel zImage \
-m 512 -M virt -cpu cortex-a15 \
but I've got the same error : qemu-system-arm: invalid accelerator kvm
On Thu, Aug 10, 2023 at 7:27 PM Mario Marietto <marietto2...@gmail.com>
wrote:
> ---> 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.
>
--
Mario.
