Hello Michael, Michael Tokarev [2020-05-26 12:10 +0300]: > > | $ admin@debian:~$ qemu-system-x86_64 -nographic > > | Could not allocate dynamic translator buffer > > This is something.. wrong.
Heh, yes -- it also doesn't have much Google juice; there are some existing bugzilla.redhat.com reports from 2011, but that doesn't seem relevant any more. > This happens during early init state, before qemu tries to run > any guest code, before even initializing virtual CPUs. > > By default the command above definitely works just fine here. > Do you have some init/conf file which is read by qemu at > startup, something in /etc/qemu/qemu.conf maybe? No, we don't do any config file customization. This is essentially a dist-upgraded buster cloud image with installing some packages: https://github.com/cockpit-project/bots/blob/master/images/scripts/debian.setup However, the difference may be that I tested this already within a VM, i. e. the command above would use nested virtualization (although not nested virt -- but curiously it *does* succeed with -enable-kvm, i. e. nested KVM works fine). I reproduced this directly on a minimal VM: curl -O https://cloud.debian.org/images/cloud/bullseye/daily/20200526-275/debian-11-nocloud-amd64-daily-20200526-275.qcow2 qemu-system-x86_64 -enable-kvm -nographic -m 1024 -drive file=debian-11-nocloud-amd64-daily-20200526-275.qcow2,if=virtio -snapshot -net nic,model=virtio -net user,hostfwd=tcp::22000-:22 then log in as root (no password): # apt update && apt install -y --no-install-recommends qemu-system-x86 (skipping recomends as otherwise it pulls in half of a desktop) # qemu-system-x86_64 -nographic Could not allocate dynamic translator buffer This seems to be related to memory -- if I launch the (outside) VM with `-m 2048`, it works. Our default VMs in CI have 1 GiB RAM, which may explain why you don't see this on real iron. The memory of the inner VM doesn't seem to matter: # free -h total used free shared buff/cache available Mem: 985Mi 53Mi 537Mi 0.0Ki 394Mi 792Mi # qemu-system-x86_64 -nographic -m 256 Could not allocate dynamic translator buffer > > libvirt version did not change (6.0.0-6), but QEMU updated from 4.2 to 5.0. > > I'll send a bug against libvirt, [...] > > I don't think this has anything to do with libvirt. As long > as qemu fails at startup libvirt obviously can't run it > properly. Right, but I was thinking that maybe QEMU 5.0 has some deliberate change and libvirt now needs to call its detection scripts with -enable-kvm or so -- just pure speculation, and mentioning how I got here. Thanks, Martin
