diff options
Diffstat (limited to 'kernel/arch/arm64/kvm/inject_fault.c')
| -rw-r--r-- | kernel/arch/arm64/kvm/inject_fault.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/kernel/arch/arm64/kvm/inject_fault.c b/kernel/arch/arm64/kvm/inject_fault.c new file mode 100644 index 000000000..f02530e72 --- /dev/null +++ b/kernel/arch/arm64/kvm/inject_fault.c @@ -0,0 +1,203 @@ +/* + * 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 EL1_EXCEPT_SYNC_OFFSET 0x200 + +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); + bool is_aarch32; + u32 esr = 0; + + is_aarch32 = vcpu_mode_is_32bit(vcpu); + + *vcpu_spsr(vcpu) = cpsr; + *vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu); + + *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; + *vcpu_pc(vcpu) = vcpu_sys_reg(vcpu, VBAR_EL1) + EL1_EXCEPT_SYNC_OFFSET; + + 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; + + 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_spsr(vcpu) = cpsr; + *vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu); + + *vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64; + *vcpu_pc(vcpu) = vcpu_sys_reg(vcpu, VBAR_EL1) + EL1_EXCEPT_SYNC_OFFSET; + + /* + * 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); + + 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); + + 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); + + inject_undef64(vcpu); +} |