[PATCH v5 33/37] KVM: arm64: Add POE save/restore for AT emulation fast-path

[Joey Gouly]

On Wed, Oct 23, 2024 at 03:53:41PM +0100, Marc Zyngier wrote:
> Just like the other extensions affecting address translation,
> we must save/restore POE so that an out-of-context translation
> context can be restored and used with the AT instructions.
> 
> Signed-off-by: Marc Zyngier <maz at kernel.org>

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

> ---
>  arch/arm64/kvm/at.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
> index de7109111e404..ef1643faedeb4 100644
> --- a/arch/arm64/kvm/at.c
> +++ b/arch/arm64/kvm/at.c
> @@ -440,6 +440,8 @@ struct mmu_config {
>  	u64	tcr2;
>  	u64	pir;
>  	u64	pire0;
> +	u64	por_el0;
> +	u64	por_el1;
>  	u64	sctlr;
>  	u64	vttbr;
>  	u64	vtcr;
> @@ -458,6 +460,10 @@ static void __mmu_config_save(struct mmu_config *config)
>  			config->pir	= read_sysreg_el1(SYS_PIR);
>  			config->pire0	= read_sysreg_el1(SYS_PIRE0);
>  		}
> +		if (system_supports_poe()) {
> +			config->por_el1	= read_sysreg_el1(SYS_POR);
> +			config->por_el0	= read_sysreg_s(SYS_POR_EL0);
> +		}
>  	}
>  	config->sctlr	= read_sysreg_el1(SYS_SCTLR);
>  	config->vttbr	= read_sysreg(vttbr_el2);
> @@ -485,6 +491,10 @@ static void __mmu_config_restore(struct mmu_config *config)
>  			write_sysreg_el1(config->pir, SYS_PIR);
>  			write_sysreg_el1(config->pire0, SYS_PIRE0);
>  		}
> +		if (system_supports_poe()) {
> +			write_sysreg_el1(config->por_el1, SYS_POR);
> +			write_sysreg_s(config->por_el0, SYS_POR_EL0);
> +		}
>  	}
>  	write_sysreg_el1(config->sctlr,	SYS_SCTLR);
>  	write_sysreg(config->vttbr,	vttbr_el2);
> @@ -1105,6 +1115,10 @@ static u64 __kvm_at_s1e01_fast(struct kvm_vcpu *vcpu, u32 op, u64 vaddr)
>  			write_sysreg_el1(vcpu_read_sys_reg(vcpu, PIR_EL1), SYS_PIR);
>  			write_sysreg_el1(vcpu_read_sys_reg(vcpu, PIRE0_EL1), SYS_PIRE0);
>  		}
> +		if (kvm_has_s1poe(vcpu->kvm)) {
> +			write_sysreg_el1(vcpu_read_sys_reg(vcpu, POR_EL1), SYS_POR);
> +			write_sysreg_s(vcpu_read_sys_reg(vcpu, POR_EL0), SYS_POR_EL0);
> +		}
>  	}
>  	write_sysreg_el1(vcpu_read_sys_reg(vcpu, SCTLR_EL1),	SYS_SCTLR);
>  	__load_stage2(mmu, mmu->arch);
> -- 
> 2.39.2
>