The backtrace you provided is from a debugging session, likely in a system like QEMU or Virtio-SCSI. It shows the call stack leading up to an error or crash in the `virtio_scsi` component. Here's a breakdown of the key points: 1. **Call Stack Analysis**: - The backtrace starts at `qemu_log_flush`, indicating that logging was involved. - It proceeds through various functions related to Virtio-SCSI and asynchronous I/O (`aio_dispatch_handler`, `aio_dispatch_ready_handlers`, `aio_poll`). - The error occurs in the `virtio_scsi_request_done` function, specifically at line 608 of `hw/scsi/virtio-scsi.c`. 2. **Function Breakdown**: - **`qemu_log_flush`**: This suggests that logging was being used and might have triggered the error. - **`aio_dispatch_handler`**: Indicates that asynchronous I/O operations were being handled. - **`virtio_queue_notify_vq`**: Points to Virtio queue notifications, which are part of the Virtio-SCSI communication mechanism. - **`virtio_scsi_handle_event`**: Shows that a Virtio-SCSI event was being processed. 3. **Error Location**: The error occurs in `virtio_scsi_request_done`, which likely handles the completion of SCSI requests. At line 608, there's an issue with the state or handling of a request. 4. **Potential Causes**: - A null pointer dereference or invalid memory access. - An incorrect state transition in the Virtio-SCSI protocol. - A misconfiguration or mismatch in the Virtio queue setup. 5. **Recommendations**: - Check the implementation of `virtio_scsi_request_done` and ensure that all pointers are valid before accessing them. - Verify that the Virtio queue is properly configured and that notifications are handled correctly. - Look for any missing error handling or state checks in the relevant functions. If you have access to the source code, focusing on line 608 of `hw/scsi/virtio-scsi.c` would be a good starting point. Additionally, checking the surrounding context and ensuring that all variables are properly initialized could help identify the root cause.