On Fri, Jun 03, 2022 at 03:38:08PM +0200, Cornelia Huck wrote: > On Fri, Jun 03 2022, Andrew Jones <drjones@xxxxxxxxxx> wrote: > > > On Fri, Jun 03, 2022 at 02:21:10PM +0200, Cornelia Huck wrote: > >> On Fri, Jun 03 2022, Andrew Jones <drjones@xxxxxxxxxx> wrote: > >> > >> > The max cpu type is a better default cpu type for running tests > >> > with TCG as it provides the maximum possible feature set. Also, > >> > the max cpu type was introduced in QEMU v2.12, so we should be > >> > safe to switch to it at this point. > >> > > >> > There's also a 32-bit arm max cpu type, but we leave the default > >> > as cortex-a15, because compilation requires we specify for which > >> > processor we want to compile and there's no such thing as a 'max'. > >> > > >> > Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx> > >> > --- > >> > configure | 2 +- > >> > 1 file changed, 1 insertion(+), 1 deletion(-) > >> > > >> > diff --git a/configure b/configure > >> > index 5b7daac3c6e8..1474dde2c70d 100755 > >> > --- a/configure > >> > +++ b/configure > >> > @@ -223,7 +223,7 @@ fi > >> > [ -z "$processor" ] && processor="$arch" > >> > > >> > if [ "$processor" = "arm64" ]; then > >> > - processor="cortex-a57" > >> > + processor="max" > >> > elif [ "$processor" = "arm" ]; then > >> > processor="cortex-a15" > >> > fi > >> > >> This looks correct, but the "processor" usage is confusing, as it seems > >> to cover two different things: > >> > >> - what processor to compile for; this is what configure help claims > >> "processor" is used for, but it only seems to have that effect on > >> 32-bit arm > >> - which cpu model to use for tcg on 32-bit and 64-bit arm (other archs > >> don't seem to care) > >> > >> So, I wonder whether it would be less confusing to drop setting > >> "processor" for arm64, and set the cpu models for tcg in arm/run (if > >> none have been specified)? > >> > > > > Good observation, Conny. So, I should probably leave configure alone, > > cortex-a57 is a reasonable processor to compile for, max is based off > > that. > > Yes, it would be reasonable; however, I only see Makefile.arm put it > into CFLAGS, not Makefile.arm64, unless I'm missing something here. But > it doesn't hurt, either. You're not missing anything, but I'd rather leave it set to something than nothing. > > > Then, I can select max in arm/run for both arm and arm64 tests > > instead of using processor there. > > Unless you want to be able to override this via -processor= > explicitly... although I doubt that this is in common use. > If we want to give users the ability to override the CPU QEMU uses, then I think I'd rather they do it with an environment variable like they do the QEMU version and accelerator. While changing to the max cpu in arm/run I could also start checking a new variable (QEMU_CPU). Thanks, drew
