On 23.10.23 13:13, David Hildenbrand wrote:
When running with "dynamic-memslots=off", we enter virtio_mem_activate_memslots_to_plug() to return immediately again because "vmem->dynamic_memslots == false". However, the compiler might not optimize out calculating start_idx+end_idx, where we divide by vmem->memslot_size. In such a configuration, the memslot size is 0 and we'll get a division by zero:(qemu) qom-set vmem0 requested-size 3G (qemu) q35.sh: line 38: 622940 Floating point exception(core dumped) The same is true for virtio_mem_deactivate_unplugged_memslots(), however we never really reach that code without a prior virtio_mem_activate_memslots_to_plug() call. Let's fix it by simply calling these functions only with "dynamic-memslots=on". This was found when using a debug build of QEMU. Reprted-by: Mario Casquero <mcasq...@redhat.com> Fixes: 177f9b1ee464 ("virtio-mem: Expose device memory dynamically via multiple memslots if enabled") Cc: Michael S. Tsirkin <m...@redhat.com> Cc: Maciej S. Szmigiero <maciej.szmigi...@oracle.com> Signed-off-by: David Hildenbrand <da...@redhat.com> ---
Queued to https://github.com/davidhildenbrand/qemu.git mem-next -- Cheers, David / dhildenb
