Re: [Qemu-devel] [PATCH 0/2] introduce "accel=best"

[Daniel P. Berrange]

On Tue, Oct 04, 2016 at 02:00:46PM +0200, Andrew Jones wrote:
> On Tue, Oct 04, 2016 at 01:30:46PM +0200, Laurent Vivier wrote:
> > This series introduces a new parameter to "accel" to
> > ask to use the best one.
> > 
> > This allows to remove ugly "kvm accelerator not found"
> > from the "make check" logs.
> > 
> > Laurent Vivier (2):
> >   accel: allows to select the "best" accelerator
> >   tests: use accel=best instead of accel=kvm:tcg
> > 
> >  accel.c                  | 58 
> > ++++++++++++++++++++++++++++++++++++++++--------
> >  include/sysemu/accel.h   |  1 +
> >  kvm-all.c                |  1 +
> >  qemu-options.hx          |  4 +++-
> >  qtest.c                  |  1 +
> >  tests/bios-tables-test.c |  2 +-
> >  tests/postcopy-test.c    |  8 +++----
> >  xen-common.c             |  1 +
> >  8 files changed, 61 insertions(+), 15 deletions(-)
> 
> How about probing the host for KVM in the tests. When it's
> available, then only emit accel=kvm. When it's not (and
> it's OK to fallback to tcg), then emit only accel=tcg.
> That's what we do in kvm-unit-tests.

Arguably unit tests should not have any dependancy on the host hardware,
and should be using accel=tcg exclusively, so that they have stable and
predictable behaviour for all developers. Only functional / integration
tests should have dependancies on host hardware/OS, so where accel=kvm
would be appropriate.

Regards,
Daniel
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