Paolo Bonzini <pbonz...@redhat.com> writes:
> On 07/05/2018 09:56, Markus Armbruster wrote:
>>>>> I'm not that sure anymore about -no-kvm. It can come in handy for
>>>>> distros (*cough* RHEL *cough) that only ship a qemu-kvm binary with
>>>>> default accelerator "-machine accel=kvm:tcg".
>>>>>
>>>>> Yeah, "-accel tcg" is only a few characters later, but it is a
>>>>> relatively recent addition.
>>>>
>>>> 2012 is "relatively recent" in the alternate RHEL universe, perhaps :)
>>>
>>> That was the "-machine accel=tcg", but Paolo was rather talking about
>>> "-accel tcg", which has been added last year. Yes, we've got three (!)
>>> ways of dealing with accelerators now: "-M accel=", "-accel" and
>>> "-enable-kvm + -no-kvm". We're very userfriendly, aren't we? ;-)
>>
>> Ugh. Apparently, vl.c still is a playground without adult supervision.
>
> I'm not sure I get it... "-accel" was added in order to provide
> accelerator options. If anything, "-machine accel" (added back in 2010)
> is the one that makes little sense these days.
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.kon...@greensocs.com>
[AJB: move to -accel tcg,thread=multi|single, defaults]
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
Reviewed-by: Richard Henderson <r...@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.
[*] Replacements generally involve deprecation and a grace period.
