Re: [PATCH 4/7] KVM: arm64: Handle RASv1p1 registers

[Marc Zyngier <maz@kernel.org>]

On Mon, 21 Jul 2025 11:19:52 +0100,
Marc Zyngier <maz@kernel.org> wrote:
> 
> FEAT_RASv1p1 system registeres are not handled at all so far.
> KVM will give an embarassed warning on the console and inject
> an UNDEF, despite RASv1p1 being exposed to the guest on suitable HW.
> 
> Handle these registers similarly to FEAT_RAS, with the added fun
> that there are *two* way to indicate the presence of FEAT_RASv1p1.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  arch/arm64/kvm/sys_regs.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index aea50870d9f11..9fb2812106cb0 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2695,6 +2695,16 @@ static bool access_ras(struct kvm_vcpu *vcpu,
>  	struct kvm *kvm = vcpu->kvm;
>  
>  	switch(reg_to_encoding(r)) {
> +	case SYS_ERXPFGCDN_EL1:
> +	case SYS_ERXPFGCTL_EL1:
> +	case SYS_ERXPFGF_EL1:
> +		if (!(kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, V1P1) ||
> +		      (kvm_has_feat_enum(kvm, ID_AA64PFR0_EL1, RAS, IMP) &&
> +		       kvm_has_feat(kvm, ID_AA64PFR1_EL1, RAS_frac, RASv1p1)))) {
> +			kvm_inject_undefined(vcpu);
> +			return false;
> +		}
> +		break;
>  	default:
>  		if (!kvm_has_feat(kvm, ID_AA64PFR0_EL1, RAS, IMP)) {
>  			kvm_inject_undefined(vcpu);
> @@ -3058,6 +3068,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	{ SYS_DESC(SYS_ERXCTLR_EL1), access_ras },
>  	{ SYS_DESC(SYS_ERXSTATUS_EL1), access_ras },
>  	{ SYS_DESC(SYS_ERXADDR_EL1), access_ras },
> +	{ SYS_DESC(SYS_ERXPFGF_EL1), access_ras },
> +	{ SYS_DESC(SYS_ERXPFGCTL_EL1), access_ras },
> +	{ SYS_DESC(SYS_ERXPFGCDN_EL1), access_ras },
>  	{ SYS_DESC(SYS_ERXMISC0_EL1), access_ras },
>  	{ SYS_DESC(SYS_ERXMISC1_EL1), access_ras },
>  

This is obviously missing the ERXMISC{2,3}_EL1 registers, which I have
now added as a fixup on top of the current series. I'll squash that
before reposting.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.