Re: [PATCH v2] KVM: kvm_io_bus_unregister_dev() should never fail

[Cornelia Huck]

On Fri, 24 Mar 2017 07:33:01 -0300
Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote:

> Still dislike the "unregister all bus devices" as that renders the guest
> unuseable. Can't you fail gracefully? Say force qemu error.

The callers are probably too varied to find a common way to do that
(multiply with different user space tools).

At least for some cases, the guest will be terminated in the near
future anyway: For example, on s390 a NULL bus will cause an error to
be propagated through KVM_RUN on the next guest->host virtio
notification, which will cause qemu to terminate the guest.

This situation is not ideal, but this is probably the most reasonable
approach.