2 Oct
2024
2 Oct
'24
6:24 p.m.
On Wed, Oct 02, 2024 at 04:55:25PM +0100, Marc Zyngier wrote:
Marc Zyngier maz@kernel.org wrote:
- if (!kvm_has_gcs(kvm))
kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nGCS_EL0 |HFGxTR_EL2_nGCS_EL1);
Why are you still allowing the GCS instructions when GCS isn't enabled?
Scratch that, they are NOPs when GCS isn't enabled, so there shouldn't be any need for extra traps.
They are, though really they should UNDEF if GCS isn't there (which I had thought was what you were referencing here). Equally we only have traps for a subset of GCS instructions and it's not like there aren't a whole bunch of untrappable extensions anyway so it's not clear it's worth the effort just for that.