Re: [Qemu-arm] [Qemu-devel] [PATCH RFC 1/1] arm64: add an option to turn on/off vpmu support

[Peter Maydell]

On 1 August 2016 at 14:08, Andrew Jones <address@hidden> wrote:
> Peter had a good suggestion for this. We need to wrap the property
> addition in an arm_feature check like the has_el3 property. That will
> remove it from all cpu types that don't support it. Then there's no
> need for the enable_pmu && !has_pmu check as the has_pmu part is covered
> very early with the feature flag in arm_cpu_post_init(). Peter also
> suggested we keep the 'has_pmu' name, rather than change it to
> 'enable_pmu'. On that one I would disagree. 'has_pmu' indicates that the
> feature is available at all, which it is to all cpu types that have the
> arm feature, but not all users will want it enabled. 'enable_pmu', which
> matches x86's naming, seems more appropriate for that.

If you create the CPU with pmu=off then it does not have a PMU,
and so has_pmu is false. I don't see any reason for the naming
convention for the PMU to diverge from what we have for EL3
and for the MPU, where the property names and the struct fields
both use 'has'.

thanks
-- PMM