On Sat, 05 Oct 2024 14:08:39 +0100,
Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> On Sat, Oct 05, 2024 at 12:34:20PM +0100, Marc Zyngier wrote:
> > Mark Brown <broonie@xxxxxxxxxx> wrote:
>
> > > + if (!kvm_has_gcs(kvm)) {
> > > + kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nGCS_EL0 |
> > > + HFGxTR_EL2_nGCS_EL1);
> > > + kvm->arch.fgu[HFGITR_GROUP] |= (HFGITR_EL2_nGCSEPP |
> > > + HFGITR_EL2_nGCSSTR_EL1 |
> > > + HFGITR_EL2_nGCSPUSHM_EL1);
>
> > Where is the handling of traps resulting of HFGITR_EL2.nGCSSTR_EL1?
>
> These will trap with an EC of 0x2d which isn't known so I was expecting
> this to get handled in the same way as for example a return of false
> from kvm_hyp_handle_fpsimd() for SVE when unsupported, or for the
> simiarly unknown SME EC, currently. I gather from your comment that
> you're instead expecting to see an explicit exit handler for this EC
> that just injects the UNDEF directly?
Not just inject an UNDEF directly, but also track whether this needs
to be forwarded when the guest's HFGITR_EL2.nGCSSTR_EL1 is 0 while not
being not RES0. Basically following what the pseudocode describes.
M.
--
Without deviation from the norm, progress is not possible.
