Re: [PATCH] KVM: arm64: selftests: Request PMU feature in get-reg-list

[Gavin Shan]

On 5/13/21 9:14 PM, Marc Zyngier wrote:
> On 2021-05-13 14:06, Gavin Shan wrote:
> > Since the following commit, PMU registers are hidden from user until
> > it's explicitly requested by feeding feature (KVM_ARM_VCPU_PMU_V3).
> > Otherwise, 74 missing PMU registers are missing as the following
> > log indicates.
> >
> >    11663111cd49 ("KVM: arm64: Hide PMU registers from userspace when
> > not available")
> >
> >    # ./get-reg-list
> >    Number blessed registers:   308
> >    Number registers:           238
> >
> >    There are 74 missing registers.
> >    The following lines are missing registers:
> >
> >           ARM64_SYS_REG(3, 0, 9, 14, 1),
> >     ARM64_SYS_REG(3, 0, 9, 14, 2),
> >              :
> >     ARM64_SYS_REG(3, 3, 14, 15, 7),
> >
> > This fixes the issue of wrongly reported missing PMU registers by
> > requesting it explicitly.
> >
> > Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
> > ---
> >  tools/testing/selftests/kvm/aarch64/get-reg-list.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/tools/testing/selftests/kvm/aarch64/get-reg-list.c
> > b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
> > index 486932164cf2..6c6bdc6f5dc3 100644
> > --- a/tools/testing/selftests/kvm/aarch64/get-reg-list.c
> > +++ b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
> > @@ -314,6 +314,8 @@ static void core_reg_fixup(void)
> >
> >  static void prepare_vcpu_init(struct kvm_vcpu_init *init)
> >  {
> > +    init->features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
> > +
> >      if (reg_list_sve())
> >          init->features[0] |= 1 << KVM_ARM_VCPU_SVE;
> >  }
>
> Please see Andrew's series[1], which actually deals with options.
>
>          M.
>
> [1] https://lore.kernel.org/r/20210507200416.198055-1-drjones@xxxxxxxxxx

Thanks, Marc. Yes, Drew's series already had the fix.
Sorry about the noise and please ignore this.

Thanks,
Gavin