Re: [Qemu-devel] [PATCH] kvm: Set default accelerator to "kvm" if the host supports it

[Peter Maydell <peter.maydell@linaro.org>]

On 3 October 2012 21:01, Blue Swirl <blauwirbel@gmail.com> wrote:
> On Mon, Oct 1, 2012 at 4:20 PM, Anthony Liguori <anthony@codemonkey.ws> wrote:
>> Jan Kiszka <jan.kiszka@siemens.com> writes:
>>> +        /* The default accelerator depends on the availability of KVM. */
>>> +        p = kvm_configured ? "kvm" : "tcg";
>>>      }

>> Blue/Aurelien, any objections?
>
> No, maybe a message could be printed that says that the default has
> changed, for a few releases.

I've lost track of the conversation, are we currently proposing
the accelerator default to be "kvm" (as per the original patch
you quote here) or "kvm:tcg" ?

I'm not entirely sure which I prefer from an ARM perspective
For some time to come and for a lot of targets (ie any target
CPU except A15), having a default of "kvm" is going to cause
existing working commandlines to stop working. [I expect that
ARM-host qemu binaries will be built with CONFIG_KVM once ARM
KVM support lands, but the same binary will be run on hosts
without virtualization extensions.] On the other hand, perhaps
there just aren't really very many people who run QEMU on
ARM hosts, and so we can ignore them :-)

-- PMM