On Thu, Dec 15, Vitaly Kuznetsov wrote: > We actually need to read the reply and empty the message slot to make > unload happen. And reading on a different CPU may not work, see: > > http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2016-December/097330.html Does the following sentences mean the vmbus_signal_eom in vmbus_wait_for_unload is a noop because the wrmsrl() is expected to happen on the other cpu instead of the current cpu? ... - When we read the message we need to clear the slot and signal the fact to the hypervisor. In case there are more messages to this CPU pending the hypervisor will deliver the next message. The signaling is done by writing to an MSR so this can only be done on the appropriate CPU. ... Olaf