[PATCH v3 5/7] ARM: KVM: don't special case PC when doing an MMIO

[cdall@cs.columbia.edu (Christoffer Dall)]

On Tue, May 14, 2013 at 12:11:38PM +0100, Marc Zyngier wrote:
> Admitedly, reading a MMIO register to load PC is very weird.
> Writing PC to a MMIO register is probably even worse. But
> the architecture doesn't forbid any of these, and injecting
> a Prefetch Abort is the wrong thing to do anyway.
> 
> Remove this check altogether, and let the adventurous guest
> wander into LaLaLand if they feel compelled to do so.
> 
> Reported-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm/include/asm/kvm_emulate.h | 5 -----
>  arch/arm/kvm/mmio.c                | 6 ------
>  2 files changed, 11 deletions(-)
> 
> diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
> index 82b4bab..a464e8d 100644
> --- a/arch/arm/include/asm/kvm_emulate.h
> +++ b/arch/arm/include/asm/kvm_emulate.h
> @@ -65,11 +65,6 @@ static inline bool vcpu_mode_priv(struct kvm_vcpu *vcpu)
>  	return cpsr_mode > USR_MODE;;
>  }
>  
> -static inline bool kvm_vcpu_reg_is_pc(struct kvm_vcpu *vcpu, int reg)
> -{
> -	return reg == 15;
> -}
> -
>  static inline u32 kvm_vcpu_get_hsr(struct kvm_vcpu *vcpu)
>  {
>  	return vcpu->arch.fault.hsr;
> diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
> index 72a12f2..b8e06b7 100644
> --- a/arch/arm/kvm/mmio.c
> +++ b/arch/arm/kvm/mmio.c
> @@ -86,12 +86,6 @@ static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
>  	sign_extend = kvm_vcpu_dabt_issext(vcpu);
>  	rt = kvm_vcpu_dabt_get_rd(vcpu);
>  
> -	if (kvm_vcpu_reg_is_pc(vcpu, rt)) {
> -		/* IO memory trying to read/write pc */
> -		kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
> -		return 1;
> -	}
> -
>  	mmio->is_write = is_write;
>  	mmio->phys_addr = fault_ipa;
>  	mmio->len = len;
> -- 
> 1.8.2.3
> 
> 
Applied, thanks.
-Christoffer