On 07.05.2018 19:01, Paolo Bonzini wrote:
On 07/05/2018 18:50, Markus Armbruster wrote:
> Paolo Bonzini <pbonzini(a)redhat.com> writes:
>
>> On 07/05/2018 13:56, Markus Armbruster wrote:
>>> Adding more and more ways to do the same stuff does not improve an
>>> interface. Interface design needs to be *opinionated*. If we decide
>>> -machine accel=tcg isn't a nice interface, by all means create a better
>>> one, but as replacement[*], not as addition.
>>>
>>> Furthermore:
>>>
>>> tcg: add options for enabling MTTCG
>>>
>>> We know there will be cases where MTTCG won't work until additional
work
>>> is done in the front/back ends to support. It will however be useful to
>>> be able to turn it on.
>>>
>>> As a result MTTCG will default to off unless the combination is
>>> supported. However the user can turn it on for the sake of testing.
>>>
>>> Signed-off-by: KONRAD Frederic <fred.konrad(a)greensocs.com>
>>> [AJB: move to -accel tcg,thread=multi|single, defaults]
>>> Signed-off-by: Alex Bennée <alex.bennee(a)linaro.org>
>>> Reviewed-by: Richard Henderson <rth(a)twiddle.net>
>>>
>>> I'm sorry, but this us sub-par. Yes, the commit is also about
"enabling
>>> MTTCG", but it also adds a new way to select accelerators, without ever
>>> spelling that out. It should've been split, and properly described.
>>
>> Perhaps we can deprecate "-M accel" then, and also while we're at
it
>> move kernel_irqchip from -machine to "-accel kvm" where it belongs?
>
> Sounds good to me.
Thomas, here's one for you! :)
I like the idea of deprecating "-machine accel=xxx" - but that will also
be a bigger change, since "-accel" is internally setting the accel
option of the machine again...
Also libvirt is still using "-machine accel=..." as far as I know, so
we've got to make sure that this gets changed there, too...
Thomas