Re: [PATCH v5 12/37] KVM: arm64: Sanitise TCR2_EL2

Joey Gouly
2024-10-24T10:21:50Z

On Wed, Oct 23, 2024 at 03:53:20PM +0100, Marc Zyngier wrote:
> TCR2_EL2 is a bag of control bits, all of which are only valid if
> certain features are present, and RES0 otherwise.
>
> Describe these constraints and register them with the masking
> infrastructure.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/kvm/nested.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
> index b20b3bfb9caec..b4b3ec88399b3 100644
> --- a/arch/arm64/kvm/nested.c
> +++ b/arch/arm64/kvm/nested.c
> @@ -1179,6 +1179,28 @@ int kvm_init_nv_sysregs(struct kvm *kvm)
> res0 |= ~(res0 | res1);
> set_sysreg_masks(kvm, HAFGRTR_EL2, res0, res1);
>
> + /* TCR2_EL2 */
> + res0 = TCR2_EL2_RES0;
> + res1 = TCR2_EL2_RES1;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, D128, IMP))
> + res0 |= (TCR2_EL2_DisCH0 | TCR2_EL2_DisCH1 | TCR2_EL2_D128);
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, MEC, IMP))
> + res0 |= TCR2_EL2_AMEC1 | TCR2_EL2_AMEC0;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, HAFDBS, HAFT))
> + res0 |= TCR2_EL2_HAFT;
> + if (!kvm_has_feat(kvm, ID_AA64PFR1_EL1, THE, IMP))
> + res0 |= TCR2_EL2_PTTWI | TCR2_EL2_PnCH;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, AIE, IMP))
> + res0 |= TCR2_EL2_AIE;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1POE, IMP))
> + res0 |= TCR2_EL2_POE | TCR2_EL2_E0POE;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1PIE, IMP))
> + res0 |= TCR2_EL2_PIE;
> + if (!kvm_has_feat(kvm, ID_AA64MMFR1_EL1, VH, IMP))
> + res0 |= (TCR2_EL2_E0POE | TCR2_EL2_D128 |
> + TCR2_EL2_AMEC1 | TCR2_EL2_DisCH0 | TCR2_EL2_DisCH1);
> + set_sysreg_masks(kvm, TCR2_EL2, res0, res1);
> +
> /* SCTLR_EL1 */
> res0 = SCTLR_EL1_RES0;
> res1 = SCTLR_EL1_RES1;

Reviewed-by: Joey Gouly <joey.gouly@arm.com>