Hi Mark, On Wed, Nov 16, 2016 at 05:45:44PM +0000, Mark Rutland wrote: > On Wed, Nov 16, 2016 at 03:38:36PM +0100, Andrew Jones wrote: > > ARMv7-A isn't exactly the same as ARMv8-A32 (AArch32). This > > function allows unit tests to make the distinction. > > > > Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx> > > > > --- > > I'm actually unsure if there's a feature bit or not that I could > > probe instead. It'd be nice if somebody can confirm. Thanks, drew > > > +/* > > + * ARMv7-A isn't exactly the same as ARMv8-A32 (AArch32). This > > + * function allows unit tests to make the distinction. > > + */ > > What do you want this for, specifically? > > Since the CPUID registers were introduced, the architecture goes to > great lengths to not expose a version, and trying to guess from software > is a losing battle. > > So I don't think we should try to distinguish ARMv8-A AArch32 from > ARMv7-A. We should test individual features, or if that's not possible, > group them in the same bucket. Perhaps I was too quick to look for a general way to approach the first place I saw the need, which is check_cntr(read_pmccntr()); if (is_aarch64()) check_cntr(read_pmccntr64()); Is PMCCNTR the only "weird" difference? Thanks, drew > > Thanks, > Mark. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html