On 2018年04月12日 11:37, Michael S. Tsirkin wrote:
Yeah, we are still using the existing IOTLB update messages
to send the IOTLB messages to backend. The only difference
is that, QEMU won't wait for the queries before sending the
IOTLB update messages.
Yes, my question is not very clear. I mean why must need a new feature bit?
It looks to me qemu code can work without this.
Generally we avoid adding new messages without a protocol feature bit.
While careful analysis might sometimes prove it's not a strict
requirement, it's just overall a clean and robust approach.
Right but the looks like the patch does not introduce any new type of
In this case remote needs to know that it will send these messages.
Ok, if some backend does not expect qemu will send without any query
from itself, I agree we need a new bit.
But it looks more like a workaround for buggy backend, at least vhost
kernel does not need to know about this.