So. ok. If I understood correctly : In my system the
file kvm.h is missing. I should install the kernel headers file if I
want it. I could do this if the kernel in use was 6.1,but I'm forced to
use 5.4. I can't install the kernel headers for the kernel 5.4 on top of
debian bookworm. Or at least,at the moment I don't know how to do this.
I'm not sure that the kernel headers for the 5.4 kernel are present
between the packages. Or maybe I can build it from scratch or I can find
it somewhere ? Even in this case, I'm not sure that they will work on a
system that has been compiled on top of a 6.x kernel.
I think that I should re-compile libvirt and QEMU on top of the 5.4
kernel and for this reason I should use an older version of Debian,maybe
8 or 9. Maybe later,I can upgrade the userland from 8/9 to 12,keeping
intact the same kernel. What do you think ? Do you see a shorter
solution ? for sure I don't like to reinstall and recompile everything
on an older version of Linux.
On Wed, Aug 30, 2023 at 11:19 AM Mario Marietto <marietto2008@xxxxxxxxx> wrote:
ok. I've copied this file :/home/marietto/Desktop/Dati/virt/qemu-v5.1.0/linux-headers/linux/kvm.hto this directory :/usr/include/linuxthe previous error is gone,but it still doesn't work :# virsh domcapabilities --machine virt --emulatorbin /usr/local/bin/qemu-system-armerror: failed to get emulator capabilitieserror: KVM is not supported on this platform: Function not implementedthis time there isn't any specific error :(On Wed, Aug 30, 2023 at 11:11 AM Mario Marietto <marietto2008@xxxxxxxxx> wrote:Ok. thanks. Yes,I'm obliged to use a kernel minor than 5.7 and I've chosen 5.4. These are the places where I've found the kvm.h file that I need./home/marietto/Desktop/Dati/virt/qemu-v5.1.0/include/sysemu/kvm.h/home/marietto/Desktop/Dati/virt/qemu-v5.1.0/linux-headers/asm-arm/kvm.h/home/marietto/Desktop/Dati/virt/qemu-v5.1.0/linux-headers/linux/kvm.h/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/tools/include/uapi/linux/kvm.h
/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/tools/arch/arm/include/uapi/asm/kvm.h
/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/include/uapi/linux/kvm.h
/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/include/config/kvm.h
/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/include/trace/events/kvm.h
/home/marietto/Desktop/Dati/200/Si/linux-5.4.244/arch/arm/include/uapi/asm/kvm.hBasically it seems that I can get it from the qemu 5.1 or from the kernel 5.4 source code files. Can you tell me what's the correct one ? You talked about linux-headers,so it might be this :/home/marietto/Desktop/Dati/virt/qemu-v5.1.0/linux-headers/linux/kvm.h?where should I copy it ? to /usr/include/linux is the right place ?thanks.On Wed, Aug 30, 2023 at 9:46 AM Daniel P. Berrangé <berrange@xxxxxxxxxx> wrote:On Tue, Aug 29, 2023 at 09:22:35PM +0200, Mario Marietto wrote:
> Hello.
>
> I'm running Debian bookworm on my ARM Chromebook,model "xe303c12" and
> I've recompiled the kernel (5.4) to enable KVM,so now my system sounds like
> this :
That's surely not the default kernel that comes with Debian bookworm,
as that 5.4 version is many years old.
IIUC the standard bookworm kernel will be 6.4
> root@chromarietto:~# virsh domcapabilities --machine virt
> --emulatorbin /usr/local/bin/qemu-system-arm
>
> 2023-08-29 10:17:59.110+0000: 1763: error : virHostCPUGetKVMMaxVCPUs:1228 :
> KVM is not supported on this platform: Function not implemented ;
> error: failed to get emulator capabilities
> error: KVM is not supported on this platform: Function not implemented
This shows libvirt was built against a kernel that lacks the
kvm.h header file.
This is expected for armv7 as support for KVM on 32-bit arm was
deleted in the 5.7 kernel. I expect libvirt was built against
the kernel headers from Debian's default 6.4 kernel and thus
lacks KVM support.
Your booting of the old 5.4 kernel doesn't solve this - you
would actually need to build libvirt (and QEMU) against this
outdated kernel too.
With regards,
Daniel
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--Mario.
--Mario.
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Mario.
