Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e078ef81 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

ARM: KVM: Cleanup exception injection 



David Binderman reported that the exception injection code had a
couple of unused variables lingering around.

Upon examination, it looked like this code could do with an
anticipated spring cleaning, which amounts to deduplicating
the CPSR/SPSR update, and making it look a bit more like
the architecture spec.

The spurious variables are removed in the process.

Reported-by: default avatarDavid Binderman <dcb314@hotmail.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 3ffa75cd

arch/arm/kvm/emulate.c

+38 −36
Original line number Diff line number Diff line
@@ -275,6 +275,40 @@ static u32 exc_vector_base(struct kvm_vcpu *vcpu) 
		return vbar;

}



/*

 * Switch to an exception mode, updating both CPSR and SPSR. Follow

 * the logic described in AArch32.EnterMode() from the ARMv8 ARM.

 */

static void kvm_update_psr(struct kvm_vcpu *vcpu, unsigned long mode)

{

	unsigned long cpsr = *vcpu_cpsr(vcpu);

	u32 sctlr = vcpu->arch.cp15[c1_SCTLR];



	*vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | mode;



	switch (mode) {

	case FIQ_MODE:

		*vcpu_cpsr(vcpu) |= PSR_F_BIT;

		/* Fall through */

	case ABT_MODE:

	case IRQ_MODE:

		*vcpu_cpsr(vcpu) |= PSR_A_BIT;

		/* Fall through */

	default:

		*vcpu_cpsr(vcpu) |= PSR_I_BIT;

	}



	*vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);



	if (sctlr & SCTLR_TE)

		*vcpu_cpsr(vcpu) |= PSR_T_BIT;

	if (sctlr & SCTLR_EE)

		*vcpu_cpsr(vcpu) |= PSR_E_BIT;



	/* Note: These now point to the mode banked copies */

	*vcpu_spsr(vcpu) = cpsr;

}



/**

 * kvm_inject_undefined - inject an undefined exception into the guest

 * @vcpu: The VCPU to receive the undefined exception
@@ -286,29 +320,13 @@ static u32 exc_vector_base(struct kvm_vcpu *vcpu) 
 */

void kvm_inject_undefined(struct kvm_vcpu *vcpu)

{

	unsigned long new_lr_value;

	unsigned long new_spsr_value;

	unsigned long cpsr = *vcpu_cpsr(vcpu);

	u32 sctlr = vcpu->arch.cp15[c1_SCTLR];

	bool is_thumb = (cpsr & PSR_T_BIT);

	u32 vect_offset = 4;

	u32 return_offset = (is_thumb) ? 2 : 4;



	new_spsr_value = cpsr;

	new_lr_value = *vcpu_pc(vcpu) - return_offset;



	*vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | UND_MODE;

	*vcpu_cpsr(vcpu) |= PSR_I_BIT;

	*vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);



	if (sctlr & SCTLR_TE)

		*vcpu_cpsr(vcpu) |= PSR_T_BIT;

	if (sctlr & SCTLR_EE)

		*vcpu_cpsr(vcpu) |= PSR_E_BIT;



	/* Note: These now point to UND banked copies */

	*vcpu_spsr(vcpu) = cpsr;

	*vcpu_reg(vcpu, 14) = new_lr_value;

	kvm_update_psr(vcpu, UND_MODE);

	*vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) - return_offset;



	/* Branch to exception vector */

	*vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset;
@@ -320,30 +338,14 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu) 
 */

static void inject_abt(struct kvm_vcpu *vcpu, bool is_pabt, unsigned long addr)

{

	unsigned long new_lr_value;

	unsigned long new_spsr_value;

	unsigned long cpsr = *vcpu_cpsr(vcpu);

	u32 sctlr = vcpu->arch.cp15[c1_SCTLR];

	bool is_thumb = (cpsr & PSR_T_BIT);

	u32 vect_offset;

	u32 return_offset = (is_thumb) ? 4 : 0;

	bool is_lpae;



	new_spsr_value = cpsr;

	new_lr_value = *vcpu_pc(vcpu) + return_offset;



	*vcpu_cpsr(vcpu) = (cpsr & ~MODE_MASK) | ABT_MODE;

	*vcpu_cpsr(vcpu) |= PSR_I_BIT | PSR_A_BIT;

	*vcpu_cpsr(vcpu) &= ~(PSR_IT_MASK | PSR_J_BIT | PSR_E_BIT | PSR_T_BIT);



	if (sctlr & SCTLR_TE)

		*vcpu_cpsr(vcpu) |= PSR_T_BIT;

	if (sctlr & SCTLR_EE)

		*vcpu_cpsr(vcpu) |= PSR_E_BIT;



	/* Note: These now point to ABT banked copies */

	*vcpu_spsr(vcpu) = cpsr;

	*vcpu_reg(vcpu, 14) = new_lr_value;

	kvm_update_psr(vcpu, ABT_MODE);

	*vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;



	if (is_pabt)

		vect_offset = 12;