Okay, so I'm trying to classify this QEMU bug report as either 'user-mode' or 'system-mode'. Let me go through the information step by step. First, looking at the issue: it's an assertion failure in virtio-blk. The error message is about `s->dataplane_started` being true when it shouldn't be during a reset. That suggests something went wrong with how the device is being handled after or during initialization. The reproducer uses a script that writes to various I/O ports and memory addresses, which makes me think it's interacting directly with hardware components. The commands like `outl` (output long) are typically used for writing to I/O ports, which in this case would be part of the virtio-blk device. Looking at the stack trace, it starts from `virtio_blk_reset` and goes through several layers related to VirtIO devices and memory handling. The functions involved include `virtio_pci_reset`, `memory_region_write_accessor`, and others that deal with physical memory and I/O operations. These are lower-level components, which suggests system-mode issues. System-mode in QEMU refers to the part that runs as a privileged process, handling hardware emulation, devices, and low-level resources. User-mode would be more about the guest operating system's execution environment without direct device interactions. Given that this issue involves device configuration and I/O operations directly affecting the VirtIO block driver, it seems to involve the lower-level emulation of hardware components. Therefore, this is likely a system-mode related bug. system