Re: Error : virHostCPUGetKVMMaxVCPUs:1228 : KVM is not supported on this platform: Function not implemented.

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.h Basically 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(a)redhat.com&gt; 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 > -- > |: https://berrange.com -o- > https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- > https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- > https://www.instagram.com/dberrange :| > > -- Mario.