[PATCH v3 29/32] arm64: KVM: 32bit guest fault injection

[Christoffer Dall]

On Mon, Apr 08, 2013 at 05:17:31PM +0100, Marc Zyngier wrote:
> Add fault injection capability for 32bit guests.

looks ok, but seems we are duplicating some functionality here, but I
realize it may not be that easy to share due to different define names
for things like PSR_X_BIT...  Did you look further into this?

> 
> Reviewed-by: Christopher Covington <cov at codeaurora.org>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm64/kvm/inject_fault.c | 79 ++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 78 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
> index 2ff3b78..083cfd5 100644
> --- a/arch/arm64/kvm/inject_fault.c
> +++ b/arch/arm64/kvm/inject_fault.c
> @@ -1,5 +1,5 @@
>  /*
> - * Fault injection for 64bit guests.
> + * Fault injection for both 32 and 64bit guests.
>   *
>   * Copyright (C) 2012,2013 - ARM Ltd
>   * Author: Marc Zyngier <marc.zyngier at arm.com>
> @@ -25,6 +25,74 @@
>  #include <asm/kvm_emulate.h>
>  #include <asm/esr.h>
>  
> +static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
> +{
> +	unsigned long cpsr;
> +	unsigned long new_spsr_value = *vcpu_cpsr(vcpu);
> +	bool is_thumb = (new_spsr_value & COMPAT_PSR_T_BIT);
> +	u32 return_offset = (is_thumb) ? 4 : 0;
> +	u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
> +
> +	cpsr = mode | COMPAT_PSR_I_BIT;
> +
> +	if (sctlr & (1 << 30))
> +		cpsr |= COMPAT_PSR_T_BIT;
> +	if (sctlr & (1 << 25))
> +		cpsr |= COMPAT_PSR_E_BIT;
> +
> +	*vcpu_cpsr(vcpu) = cpsr;
> +
> +	/* Note: These now point to the banked copies */
> +	*vcpu_spsr(vcpu) = new_spsr_value;
> +	*vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
> +
> +	/* Branch to exception vector */
> +	if (sctlr & (1 << 13))
> +		vect_offset += 0xffff0000;
> +	else /* always have security exceptions */
> +		vect_offset += vcpu_cp15(vcpu, c12_VBAR);
> +
> +	*vcpu_pc(vcpu) = vect_offset;
> +}
> +
> +static void inject_undef32(struct kvm_vcpu *vcpu)
> +{
> +	prepare_fault32(vcpu, COMPAT_PSR_MODE_UND, 4);
> +}
> +
> +/*
> + * Modelled after TakeDataAbortException() and TakePrefetchAbortException
> + * pseudocode.
> + */
> +static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt,
> +			 unsigned long addr)
> +{
> +	u32 vect_offset;
> +	u32 *far, *fsr;
> +	bool is_lpae;
> +
> +	if (is_pabt) {
> +		vect_offset = 12;
> +		far = &vcpu_cp15(vcpu, c6_IFAR);
> +		fsr = &vcpu_cp15(vcpu, c5_IFSR);
> +	} else { /* !iabt */
> +		vect_offset = 16;
> +		far = &vcpu_cp15(vcpu, c6_DFAR);
> +		fsr = &vcpu_cp15(vcpu, c5_DFSR);
> +	}
> +
> +	prepare_fault32(vcpu, COMPAT_PSR_MODE_ABT | COMPAT_PSR_A_BIT, vect_offset);
> +
> +	*far = addr;
> +
> +	/* Give the guest an IMPLEMENTATION DEFINED exception */
> +	is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31);
> +	if (is_lpae)
> +		*fsr = 1 << 9 | 0x34;
> +	else
> +		*fsr = 0x14;
> +}
> +
>  static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
>  {
>  	unsigned long cpsr = *vcpu_cpsr(vcpu);
> @@ -90,6 +158,9 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
>   */
>  void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
>  {
> +	if (!(vcpu->arch.hcr_el2 & HCR_RW))
> +		inject_abt32(vcpu, false, addr);
> +
>  	inject_abt64(vcpu, false, addr);
>  }
>  
> @@ -103,6 +174,9 @@ void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
>   */
>  void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
>  {
> +	if (!(vcpu->arch.hcr_el2 & HCR_RW))
> +		inject_abt32(vcpu, true, addr);
> +
>  	inject_abt64(vcpu, true, addr);
>  }
>  
> @@ -114,5 +188,8 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
>   */
>  void kvm_inject_undefined(struct kvm_vcpu *vcpu)
>  {
> +	if (!(vcpu->arch.hcr_el2 & HCR_RW))
> +		inject_undef32(vcpu);
> +
>  	inject_undef64(vcpu);
>  }
> -- 
> 1.8.1.4
> 
> 
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