Subject: [PATCH v4 05/21] KVM: ARM64: Add reset and access handlers for PMSELR register

From: [email-masked] (Marc Zyngier)
Date: Mon, 30 Nov 2015 17:56:00 +0000

On Fri, 30 Oct 2015 14:21:47 +0800
Shannon Zhao <[email-masked]> wrote:

> From: Shannon Zhao <[email-masked]>
> 
> Since the reset value of PMSELR_EL0 is UNKNOWN, use reset_unknown for
> its reset handler. As it doesn't need to deal with the acsessing action
> specially, it uses default case to emulate writing and reading PMSELR
> register.
> 
> Add a helper for CP15 registers reset to UNKNOWN.
> 
> Signed-off-by: Shannon Zhao <[email-masked]>
> ---
>  arch/arm64/kvm/sys_regs.c | 5 +++--
>  arch/arm64/kvm/sys_regs.h | 8 ++++++++
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 5b591d6..35d232e 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -707,7 +707,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	  trap_raz_wi },
>  	/* PMSELR_EL0 */
>  	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101),
> -	  trap_raz_wi },
> +	  access_pmu_regs, reset_unknown, PMSELR_EL0 },
>  	/* PMCEID0_EL0 */
>  	{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
>  	  trap_raz_wi },
> @@ -998,7 +998,8 @@ static const struct sys_reg_desc cp15_regs[] = {
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
> -	{ Op1( 0), CRn( 9), CRm(12), Op2( 5), trap_raz_wi },
> +	{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmu_cp15_regs,
> +	  reset_unknown_cp15, c9_PMSELR },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 6), trap_raz_wi },
>  	{ Op1( 0), CRn( 9), CRm(12), Op2( 7), trap_raz_wi },
>  	{ Op1( 0), CRn( 9), CRm(13), Op2( 0), trap_raz_wi },
> diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
> index eaa324e..8afeff7 100644
> --- a/arch/arm64/kvm/sys_regs.h
> +++ b/arch/arm64/kvm/sys_regs.h
> @@ -110,6 +110,14 @@ static inline void reset_unknown(struct kvm_vcpu *vcpu,
>  	vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
>  }
>  
> +static inline void reset_unknown_cp15(struct kvm_vcpu *vcpu,
> +				      const struct sys_reg_desc *r)
> +{
> +	BUG_ON(!r->reg);
> +	BUG_ON(r->reg >= NR_COPRO_REGS);
> +	vcpu_cp15(vcpu, r->reg) = 0xdecafbad;
> +}
> +
>  static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
>  {
>  	BUG_ON(!r->reg);

Same remark here as the one I made earlier. I'm pretty sure we don't
call any CP15 reset because they are all shared with their 64bit
counterparts. The same thing goes for the whole series.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny.