Re: [Qemu-devel] [RFC PATCH v1 7/9] cpus: move icount preparation out of tcg_exec_cpu

[Alex Bennée]

Paolo Bonzini <address@hidden> writes:

> On 04/04/2017 12:46, Alex Bennée wrote:
>>> In theory the main-loop should be sequenced before or after vCPU events
>>> because of the BQL. I'm not sure why this is not currently the case.
>>
>> It seems cpu_handle_exception doesn't take the BQL until
>> replay_exception() has done its thing. This is fixable but the function
>> is a mess so I'm trying to neaten that up first.
>
> Long term neither cpu_handle_exception nor cpu_handle_interrupt need the
> BQL at all.

Well for record/replay they might. Otherwise we end up moving the record
stream on even though a checkpoint might be being written by the
main-loop.

As far as the cc->do_interrupt() stuff is concerned it will be guest
dependant because you could end up in device emulation code down this
path which must be protected by the BQL - the arm_gic code being a good
example.

>
> Paolo


--
Alex Bennée