[PATCH v4 27/40] KVM: arm64: Prepare to handle deferred save/restore of ELR_EL1

[Marc Zyngier]

On Thu, 15 Feb 2018 21:03:19 +0000,
Christoffer Dall wrote:
> 
> ELR_EL1 is not used by a VHE host kernel and can be deferred, but we
> need to rework the accesses to this register to access the latest value
> depending on whether or not guest system registers are loaded on the CPU
> or only reside in memory.
> 
> Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
> ---
> 
> Notes:
>     Changes since v2:
>      - New patch (deferred register handling has been reworked)
> 
>  arch/arm64/include/asm/kvm_emulate.h | 18 +++++++++++++++++-
>  arch/arm64/kvm/inject_fault.c        |  4 ++--
>  2 files changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index 47c2406755fa..9cb13b23c7a1 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -90,11 +90,27 @@ static inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
>  	return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;
>  }
>  
> -static inline unsigned long *vcpu_elr_el1(const struct kvm_vcpu *vcpu)
> +static inline unsigned long *__vcpu_elr_el1(const struct kvm_vcpu *vcpu)
>  {
>  	return (unsigned long *)&vcpu_gp_regs(vcpu)->elr_el1;
>  }
>  
> +static inline unsigned long vcpu_read_elr_el1(const struct kvm_vcpu *vcpu)
> +{
> +	if (vcpu->arch.sysregs_loaded_on_cpu)
> +		return read_sysreg_el1(elr);
> +	else
> +		return *__vcpu_elr_el1(vcpu);
> +}
> +
> +static inline void vcpu_write_elr_el1(const struct kvm_vcpu *vcpu, unsigned long v)
> +{
> +	if (vcpu->arch.sysregs_loaded_on_cpu)
> +		write_sysreg_el1(v, elr);
> +	else
> +		*__vcpu_elr_el1(vcpu) = v;
> +}
> +
>  static inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
>  {
>  	return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pstate;
> diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
> index 8dda1edae727..cc13b6f5ad11 100644
> --- a/arch/arm64/kvm/inject_fault.c
> +++ b/arch/arm64/kvm/inject_fault.c
> @@ -67,7 +67,7 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr
>  	bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
>  	u32 esr = 0;
>  
> -	*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);
> +	vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu));
>  	*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
>  
>  	*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
> @@ -102,7 +102,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
>  	unsigned long cpsr = *vcpu_cpsr(vcpu);
>  	u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
>  
> -	*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);
> +	vcpu_write_elr_el1(vcpu, *vcpu_pc(vcpu));
>  	*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
>  
>  	*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
> -- 
> 2.14.2
> 

Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>

	M.

-- 
Jazz is not dead, it just smell funny.