Re: [PATCH] arm64/boot: Don't set PMUv3p9 FGT2 bits without PMUv3

[Fuad Tabba]

Hi Anshuman,

On Wed, 30 Sept 2026 at 14:26, Anshuman Khandual
<anshuman.khandual@xxxxxxx> wrote:
>
> On Wed, Sep 30, 2026 at 01:12:12PM +0100, Fuad Tabba wrote:
> > On a CPU with FGT2 and an IMPLEMENTATION DEFINED PMU (PMUVer 0b1111),
> > __init_el2_fgt2 sets the PMUv3p9 bits in HDFGRTR2_EL2 and HDFGWTR2_EL2,
> > which are RES0 there. The macro only checks that PMUVer is at least
> > PMUv3p9, and 0b1111 passes.
>
> Just curious - has this caused any real world problem on IMP defined PMUs ?

Not as far as I know. I found it while auditing these and related bits for pKVM.

Cheers,
/fuad