Re: [PATCH 1/3] KVM: arm64: Make ID_PFR1_EL1.GIC writable

Hey,

On Mon, Oct 13, 2025 at 09:32:05AM +0100, Marc Zyngier wrote:

Similarly to ID_AA64PFR0_EL1.GIC, relax ID_PFR1_EL1.GIC to be writable.

This looks fine to me, although I do wonder if we should just allow userspace to write whatever value it wants to the 32-bit ID registers and be done with it.

Nowhere do we use a 32-bit ID register value as a condition for trap configuration / emulation, so even if the VMM lies to the guest it shouldn't trip up KVM.

Thanks, Oliver