x86: 0.829 graphic: 0.768 architecture: 0.714 kernel: 0.694 semantic: 0.659 network: 0.571 TCG: 0.567 device: 0.523 socket: 0.363 ppc: 0.351 user-level: 0.305 performance: 0.296 register: 0.295 hypervisor: 0.240 vnc: 0.230 peripherals: 0.228 PID: 0.213 virtual: 0.202 boot: 0.199 files: 0.189 mistranslation: 0.183 permissions: 0.172 i386: 0.162 arm: 0.158 debug: 0.149 risc-v: 0.125 VMM: 0.099 assembly: 0.068 KVM: 0.048 qemu-system-aarch64 crashes with assertion failed while running GCC 9 test suite I am using QEMU 4.0.0 on an x86_64 Linux 4.19.0 host, the guest is an Aarch64 linux 5.0.0 system. The same issue occurred on QEMU 3.1.0. While running the GCC 9.1 test suite on the guest system, QEMU crashes with: qemu-system-aarch64: [...]/qemu-4.0.0/tcg/tcg.c:3952: tcg_gen_code: Assertion `s->gen_insn_end_off[num_insns] == off' failed. I am able to reproduce the issue reliably, which is encouraging. The full QEMU command line is: qemu-system-aarch64 -kernel kernel-5.0.0cbl1 -append "root=/dev/vda1 ro init=/sbin/init console=ttyAMA0" -name guest=cbl -drive file=cbl.qcow2,index=0,media=disk,format=qcow2 -drive file=swap.qcow2,index=1,media=disk,format=qcow2 -machine virt -cpu cortex-a57 -smp 4,sockets=1,cores=2,threads=2 -m size=8192 -netdev tap,id=network0,ifname=tapcbl2,script=no,downscript=no -device virtio-net-device,netdev=network0,mac=aa:bb:cc:dd:ee:02 -nographic The specific GCC test that causes QEMU to crash is vldX.c run from advsimd-intrinsics.exp; I can reproduce via "make check-gcc RUNTESTFLAGS=advsimd-intrinsics.exp=vldX.c" If there is anything I can do to further triage the issue, or gain more insight into what is going on, please let me know! I am eager to help however I can. Hi -- this looks rather like bug #1824853, which exists in QEMU 4.0 but which we have fixed in git. Could you try with a build of QEMU from current head-of-git to confirm that it's fixed there ? I'm on it. Will follow up when I have a result. Confirmed, this is a duplicate of 1824853 and is resolved in 68a7b9724fe80bedb85060bde605213ce3f9baec.