Hanging when testing Venus Driver with "stuck in ring seqno wait with iter at"

I'm working on getting the Venus driver to work inside QEMU guests, but when I tested `vkcube` in a Linux guest with `VN_DEBUG=init`, I got `stuck in ring seqno wait with iter at {i}` with updating i at exponentially increasing intervals. Taking a cursor glance at the code, it seems that this is due to: the cs encoder's buffer list being empty, or the buffers having a reported size of 0. Is this a potential bug in venus, or is there something I have to implement on the QEMU side? The version of venus I'm testing is 23.0.2.