Re: [PATCH 03/10] KVM: arm64: Add TCR2_EL2 to the sysreg arrays

[Joey Gouly <joey.gouly@arm.com>]

On Tue, Aug 13, 2024 at 03:47:31PM +0100, Marc Zyngier wrote:
> Add the TCR2_EL2 register to the per-vcpu sysreg register
> array, as well as the sysreg descriptor array.
> 
> Access to this register is conditionned on ID_AA64MMFR3_EL1.TCRX
> being advertised.

s/conditionned/conditional based/

> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  arch/arm64/include/asm/kvm_host.h |  1 +
>  arch/arm64/kvm/sys_regs.c         | 13 +++++++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index a33f5996ca9f..5a9e0ad35580 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -462,6 +462,7 @@ enum vcpu_sysreg {
>  	TTBR0_EL2,	/* Translation Table Base Register 0 (EL2) */
>  	TTBR1_EL2,	/* Translation Table Base Register 1 (EL2) */
>  	TCR_EL2,	/* Translation Control Register (EL2) */
> +	TCR2_EL2,	/* Extended Translation Control Register (EL2) */
>  	SPSR_EL2,	/* EL2 saved program status register */
>  	ELR_EL2,	/* EL2 exception link register */
>  	AFSR0_EL2,	/* Auxiliary Fault Status Register 0 (EL2) */
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 95832881fd66..52250db3c122 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -436,6 +436,18 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
>  	return true;
>  }
>  
> +static bool access_tcr2_el2(struct kvm_vcpu *vcpu,
> +			    struct sys_reg_params *p,
> +			    const struct sys_reg_desc *r)
> +{
> +	if (!kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP)) {
> +		kvm_inject_undefined(vcpu);
> +		return false;
> +	}
> +
> +	return access_rw(vcpu, p, r);
> +}
> +
>  static bool access_actlr(struct kvm_vcpu *vcpu,
>  			 struct sys_reg_params *p,
>  			 const struct sys_reg_desc *r)
> @@ -2783,6 +2795,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	EL2_REG(TTBR0_EL2, access_rw, reset_val, 0),
>  	EL2_REG(TTBR1_EL2, access_rw, reset_val, 0),
>  	EL2_REG(TCR_EL2, access_rw, reset_val, TCR_EL2_RES1),
> +	EL2_REG(TCR2_EL2, access_tcr2_el2, reset_val, TCR2_EL2_RES1),
>  	EL2_REG_VNCR(VTTBR_EL2, reset_val, 0),
>  	EL2_REG_VNCR(VTCR_EL2, reset_val, 0),
>  

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