xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: arm/arm64: Unify 32bit fault injection

Browse Source 
Both arm and arm64 implementations are capable of injecting
faults, and yet have completely divergent implementations,
leading to different bugs and reduced maintainability.

Let's elect the arm64 version as the canonical one
and move it into aarch32.c, which is common to both
architectures.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Marc Zyngier
2017-10-29 02:18:09 +00:00
committed by Christoffer Dall
parent 3eb4271b4a
commit 74a64a9816
5 changed files with 131 additions and 218 deletions
Download Patch File Download Diff File Expand all files Collapse all files

139
arch/arm/kvm/emulate.c
View File

@@ -165,145 +165,6 @@ unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu)
* Inject exceptions into the guest
*/
static u32 exc_vector_base(struct kvm_vcpu *vcpu)
{
u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
u32 vbar = vcpu_cp15(vcpu, c12_VBAR);
if (sctlr & SCTLR_V)
return 0xffff0000;
else /* always have security exceptions */
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_cp15(vcpu, 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
*
* It is assumed that this code is called from the VCPU thread and that the
* VCPU therefore is not currently executing guest code.
*
* Modelled after TakeUndefInstrException() pseudocode.
*/
void kvm_inject_undefined(struct kvm_vcpu *vcpu)
{
unsigned long cpsr = *vcpu_cpsr(vcpu);
bool is_thumb = (cpsr & PSR_T_BIT);
u32 vect_offset = 4;
u32 return_offset = (is_thumb) ? 2 : 4;
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;
}
/*
* Modelled after TakeDataAbortException() and TakePrefetchAbortException
* pseudocode.
*/
static void inject_abt(struct kvm_vcpu *vcpu, bool is_pabt, unsigned long addr)
{
unsigned long cpsr = *vcpu_cpsr(vcpu);
bool is_thumb = (cpsr & PSR_T_BIT);
u32 vect_offset;
u32 return_offset = (is_thumb) ? 4 : 0;
bool is_lpae;
kvm_update_psr(vcpu, ABT_MODE);
*vcpu_reg(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
if (is_pabt)
vect_offset = 12;
else
vect_offset = 16;
/* Branch to exception vector */
*vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset;
if (is_pabt) {
/* Set IFAR and IFSR */
vcpu_cp15(vcpu, c6_IFAR) = addr;
is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31);
/* Always give debug fault for now - should give guest a clue */
if (is_lpae)
vcpu_cp15(vcpu, c5_IFSR) = 1 << 9 | 0x22;
else
vcpu_cp15(vcpu, c5_IFSR) = 2;
} else { /* !iabt */
/* Set DFAR and DFSR */
vcpu_cp15(vcpu, c6_DFAR) = addr;
is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31);
/* Always give debug fault for now - should give guest a clue */
if (is_lpae)
vcpu_cp15(vcpu, c5_DFSR) = 1 << 9 | 0x22;
else
vcpu_cp15(vcpu, c5_DFSR) = 2;
}
}
/**
* kvm_inject_dabt - inject a data abort into the guest
* @vcpu: The VCPU to receive the undefined exception
* @addr: The address to report in the DFAR
*
* It is assumed that this code is called from the VCPU thread and that the
* VCPU therefore is not currently executing guest code.
*/
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
{
inject_abt(vcpu, false, addr);
}
/**
* kvm_inject_pabt - inject a prefetch abort into the guest
* @vcpu: The VCPU to receive the undefined exception
* @addr: The address to report in the DFAR
*
* It is assumed that this code is called from the VCPU thread and that the
* VCPU therefore is not currently executing guest code.
*/
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
{
inject_abt(vcpu, true, addr);
}
/**
* kvm_inject_vabt - inject an async abort / SError into the guest
* @vcpu: The VCPU to receive the exception