/usr/libexec/qemu-kvm -enable-kvm -boot order=cd,once=dc -vga cirrus -m 4096 -drive file=~/23815135.img,if=virtio -usbdevice tablet -net nic,macaddr=DE:AD:BE:EF:D4:AB -netdev bridge,br=br0,id=net0 qemu-kvm: -usbdevice tablet: '-usbdevice' is deprecated, please use '-device usb-...' instead access denied by acl file qemu-kvm: bridge helper failed [root@CentOS-82-64-minimal 23815135]# /usr/libexec/qemu-kvm -enable-kvm -boot order=cd,once=dc -vga cirrus -........

Now older versions of qemu-kvm didn't throw this error say if you just had "-video cirrus" when starting qemu-kvm. But newer versions do care. And this probably only applies to you if you are running from bash/terminal with remote kvm images. What you need to do is remove the "-video" part and just add -vnc :5 eg. this would fix the error: qemu-system-x86_64 -enable-kvm -boot order=cd,once=dc -m 1024 -drive........

You may have noticed if you are running QEMU/KVMmanually that in Windows the the position of the physical mouse does not match where the mouse is positioned within Windows. There is an easy command to pass to qemu-kvm or qemu-system (whatever you call your binary): -usbdevice tablet The above flag will fix your mouse pointing problems whether you are running Windows 95, 98, NT, XP 2000, 2003, Vista, 7, 8 10 or Server 2000, 2003, 2008, 2012, 2016 or 2........