On 13/02/2015 10:37, Mark Burton wrote:
> the memory barrier is on the cpu requesting the flush isn’t it (not
> on the CPU that is being flushed)?
Oops, I misread Peter's explanation.
In that case, perhaps DMB can be treated in a similar way as WFI, using
cpu->halted. Queueing work on other CPUs can be done with
async_run_on_cpu, which exits the idle loop in qemu_tcg_wait_io_event
(this avoids the deadlocks). Checking that other CPUs have flushed the
TLBs can be done in cpu_has_work ("always return false if cpu->halted ==
true there are outstanding TLB requests").
Paolo
