> > @@ -336,6 +372,19 @@ int hv_synic_cleanup(unsigned int cpu)
> > if (channel_found && vmbus_connection.conn_state == CONNECTED)
> > return -EBUSY;
> >
> > + if (vmbus_proto_version >= VERSION_WIN10_V4_1) {
> > + /*
> > + * channel_found == false means that any channels that were
> > previously
> > + * assigned to the CPU have been reassigned elsewhere with a
> > call of
> > + * vmbus_send_modifychannel(). Scan the event flags page
> > looking for
> > + * bits that are set and waiting with a timeout for
> > vmbus_chan_sched()
> > + * to process such bits. If bits are still set after this
> > operation
> > + * and VMBus is connected, fail the CPU offlining operation.
> > + */
> > + if (hv_synic_event_pending() && vmbus_connection.conn_state ==
> > CONNECTED)
> > + return -EBUSY;
> > + }
> > +
>
> Perhaps the test for conn_state == CONNECTED could be factored out as
> follows. If we're
> not CONNECTED (i.e., in the panic or kexec path) we should be able to also
> skip the search
> for channels that are bound to the CPU since we will ignore the result anyway.
>
> if (vmbus_connection.conn_state != CONNECTED)
> goto always_cleanup;
>
> if (cpu == VMBUS_CONNECT_CPU)
> return -EBUSY;
>
> [Code to search for channels that are bound to the CPU we're about to
> clean up]
>
> if (channel_found)
> return -EBUSY;
>
> /*
> * channel_found == false means that any channels that were previously
> * assigned to the CPU have been reassigned elsewhere with a call of
> * vmbus_send_modifychannel(). Scan the event flags page looking for
> * bits that are set and waiting with a timeout for vmbus_chan_sched()
> * to process such bits. If bits are still set after this operation
> * and VMBus is connected, fail the CPU offlining operation.
> */
> if (vmbus_proto_version >= VERSION_WIN10_V4_1 &&
> hv_synic_event_pending())
> return -EBUSY;
>
> always_cleanup:
Agreed, applied. Thank you for the suggestion,
Andrea
