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/*
* Fault injection for both 32 and 64bit guests.
*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* Based on arch/arm/kvm/emulate.c
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/esr.h>
#define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \
PSR_I_BIT | PSR_D_BIT)
#define CURRENT_EL_SP_EL0_VECTOR 0x0
#define CURRENT_EL_SP_ELx_VECTOR 0x200
#define LOWER_EL_AArch64_VECTOR 0x400
#define LOWER_EL_AArch32_VECTOR 0x600
/*
* Table taken from ARMv8 ARM DDI0487B-B, table G1-10.
*/
static const u8 return_offsets[8][2] = {
[0] = { 0, 0 }, /* Reset, unused */
[1] = { 4, 2 }, /* Undefined */
[2] = { 0, 0 }, /* SVC, unused */
[3] = { 4, 4 }, /* Prefetch abort */
[4] = { 8, 8 }, /* Data abort */
[5] = { 0, 0 }, /* HVC, unused */
[6] = { 4, 4 }, /* IRQ, unused */
[7] = { 4, 4 }, /* FIQ, unused */
};
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 = return_offsets[vect_offset >> 2][is_thumb];
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_reg32(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;
}
enum exception_type {
except_type_sync = 0,
except_type_irq = 0x80,
except_type_fiq = 0x100,
except_type_serror = 0x180,
};
static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type)
{
u64 exc_offset;
switch (*vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT)) {
case PSR_MODE_EL1t:
exc_offset = CURRENT_EL_SP_EL0_VECTOR;
break;
case PSR_MODE_EL1h:
exc_offset = CURRENT_EL_SP_ELx_VECTOR;
break;
case PSR_MODE_EL0t:
exc_offset = LOWER_EL_AArch64_VECTOR;
break;
default:
exc_offset = LOWER_EL_AArch32_VECTOR;
}
return vcpu_sys_reg(vcpu, VBAR_EL1) + exc_offset + type;
}
static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
{
unsigned long cpsr = *vcpu_cpsr(vcpu);
bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
u32 esr = 0;
*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);
*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
*vcpu_spsr(vcpu) = cpsr;
vcpu_sys_reg(vcpu, FAR_EL1) = addr;
/*
* Build an {i,d}abort, depending on the level and the
* instruction set. Report an external synchronous abort.
*/
if (kvm_vcpu_trap_il_is32bit(vcpu))
esr |= ESR_ELx_IL;
/*
* Here, the guest runs in AArch64 mode when in EL1. If we get
* an AArch32 fault, it means we managed to trap an EL0 fault.
*/
if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
else
esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
if (!is_iabt)
esr |= ESR_ELx_EC_DABT_LOW << ESR_ELx_EC_SHIFT;
vcpu_sys_reg(vcpu, ESR_EL1) = esr | ESR_ELx_FSC_EXTABT;
}
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_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
*vcpu_spsr(vcpu) = cpsr;
/*
* Build an unknown exception, depending on the instruction
* set.
*/
if (kvm_vcpu_trap_il_is32bit(vcpu))
esr |= ESR_ELx_IL;
vcpu_sys_reg(vcpu, ESR_EL1) = esr;
}
/**
* 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)
{
if (!(vcpu->arch.hcr_el2 & HCR_RW))
inject_abt32(vcpu, false, addr);
else
inject_abt64(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)
{
if (!(vcpu->arch.hcr_el2 & HCR_RW))
inject_abt32(vcpu, true, addr);
else
inject_abt64(vcpu, true, addr);
}
/**
* kvm_inject_undefined - inject an undefined instruction into the guest
*
* 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_undefined(struct kvm_vcpu *vcpu)
{
if (!(vcpu->arch.hcr_el2 & HCR_RW))
inject_undef32(vcpu);
else
inject_undef64(vcpu);
}
/**
* kvm_inject_vabt - inject an async abort / SError into the guest
* @vcpu: The VCPU to receive the exception
*
* 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_vabt(struct kvm_vcpu *vcpu)
{
vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) | HCR_VSE);
}
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