forked from Minki/linux
8fc153cda9
At the moment, our fault injection is pretty limited. We always
generate a SYNC exception into EL1, as if the fault was actually
from EL1h, no matter how it was generated.
This is obviously wrong, as EL0 can generate faults of its own
(not to mention the pretty-much unused EL1t mode).
This patch fixes it by implementing section D1.10.2 of the ARMv8 ARM,
and in particular table D1-7 ("Vector offsets from vector table base
address"), which describes which vector to use depending on the source
exception level and type (synchronous, IRQ, FIQ or SError).
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
236 lines
6.1 KiB
C
236 lines
6.1 KiB
C
/*
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* Fault injection for both 32 and 64bit guests.
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*
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* Copyright (C) 2012,2013 - ARM Ltd
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*
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* Based on arch/arm/kvm/emulate.c
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* Copyright (C) 2012 - Virtual Open Systems and Columbia University
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* Author: Christoffer Dall <c.dall@virtualopensystems.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/kvm_host.h>
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#include <asm/kvm_emulate.h>
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#include <asm/esr.h>
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#define PSTATE_FAULT_BITS_64 (PSR_MODE_EL1h | PSR_A_BIT | PSR_F_BIT | \
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PSR_I_BIT | PSR_D_BIT)
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#define CURRENT_EL_SP_EL0_VECTOR 0x0
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#define CURRENT_EL_SP_ELx_VECTOR 0x200
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#define LOWER_EL_AArch64_VECTOR 0x400
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#define LOWER_EL_AArch32_VECTOR 0x600
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static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
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{
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unsigned long cpsr;
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unsigned long new_spsr_value = *vcpu_cpsr(vcpu);
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bool is_thumb = (new_spsr_value & COMPAT_PSR_T_BIT);
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u32 return_offset = (is_thumb) ? 4 : 0;
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u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR);
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cpsr = mode | COMPAT_PSR_I_BIT;
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if (sctlr & (1 << 30))
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cpsr |= COMPAT_PSR_T_BIT;
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if (sctlr & (1 << 25))
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cpsr |= COMPAT_PSR_E_BIT;
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*vcpu_cpsr(vcpu) = cpsr;
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/* Note: These now point to the banked copies */
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*vcpu_spsr(vcpu) = new_spsr_value;
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*vcpu_reg32(vcpu, 14) = *vcpu_pc(vcpu) + return_offset;
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/* Branch to exception vector */
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if (sctlr & (1 << 13))
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vect_offset += 0xffff0000;
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else /* always have security exceptions */
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vect_offset += vcpu_cp15(vcpu, c12_VBAR);
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*vcpu_pc(vcpu) = vect_offset;
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}
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static void inject_undef32(struct kvm_vcpu *vcpu)
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{
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prepare_fault32(vcpu, COMPAT_PSR_MODE_UND, 4);
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}
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/*
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* Modelled after TakeDataAbortException() and TakePrefetchAbortException
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* pseudocode.
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*/
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static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt,
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unsigned long addr)
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{
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u32 vect_offset;
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u32 *far, *fsr;
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bool is_lpae;
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if (is_pabt) {
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vect_offset = 12;
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far = &vcpu_cp15(vcpu, c6_IFAR);
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fsr = &vcpu_cp15(vcpu, c5_IFSR);
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} else { /* !iabt */
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vect_offset = 16;
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far = &vcpu_cp15(vcpu, c6_DFAR);
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fsr = &vcpu_cp15(vcpu, c5_DFSR);
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}
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prepare_fault32(vcpu, COMPAT_PSR_MODE_ABT | COMPAT_PSR_A_BIT, vect_offset);
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*far = addr;
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/* Give the guest an IMPLEMENTATION DEFINED exception */
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is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31);
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if (is_lpae)
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*fsr = 1 << 9 | 0x34;
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else
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*fsr = 0x14;
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}
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enum exception_type {
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except_type_sync = 0,
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except_type_irq = 0x80,
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except_type_fiq = 0x100,
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except_type_serror = 0x180,
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};
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static u64 get_except_vector(struct kvm_vcpu *vcpu, enum exception_type type)
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{
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u64 exc_offset;
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switch (*vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT)) {
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case PSR_MODE_EL1t:
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exc_offset = CURRENT_EL_SP_EL0_VECTOR;
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break;
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case PSR_MODE_EL1h:
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exc_offset = CURRENT_EL_SP_ELx_VECTOR;
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break;
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case PSR_MODE_EL0t:
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exc_offset = LOWER_EL_AArch64_VECTOR;
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break;
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default:
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exc_offset = LOWER_EL_AArch32_VECTOR;
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}
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return vcpu_sys_reg(vcpu, VBAR_EL1) + exc_offset + type;
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}
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static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr)
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{
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unsigned long cpsr = *vcpu_cpsr(vcpu);
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bool is_aarch32;
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u32 esr = 0;
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is_aarch32 = vcpu_mode_is_32bit(vcpu);
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*vcpu_spsr(vcpu) = cpsr;
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*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);
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*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
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*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
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vcpu_sys_reg(vcpu, FAR_EL1) = addr;
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/*
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* Build an {i,d}abort, depending on the level and the
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* instruction set. Report an external synchronous abort.
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*/
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if (kvm_vcpu_trap_il_is32bit(vcpu))
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esr |= ESR_ELx_IL;
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/*
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* Here, the guest runs in AArch64 mode when in EL1. If we get
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* an AArch32 fault, it means we managed to trap an EL0 fault.
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*/
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if (is_aarch32 || (cpsr & PSR_MODE_MASK) == PSR_MODE_EL0t)
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esr |= (ESR_ELx_EC_IABT_LOW << ESR_ELx_EC_SHIFT);
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else
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esr |= (ESR_ELx_EC_IABT_CUR << ESR_ELx_EC_SHIFT);
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if (!is_iabt)
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esr |= ESR_ELx_EC_DABT_LOW;
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vcpu_sys_reg(vcpu, ESR_EL1) = esr | ESR_ELx_FSC_EXTABT;
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}
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static void inject_undef64(struct kvm_vcpu *vcpu)
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{
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unsigned long cpsr = *vcpu_cpsr(vcpu);
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u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
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*vcpu_spsr(vcpu) = cpsr;
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*vcpu_elr_el1(vcpu) = *vcpu_pc(vcpu);
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*vcpu_pc(vcpu) = get_except_vector(vcpu, except_type_sync);
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*vcpu_cpsr(vcpu) = PSTATE_FAULT_BITS_64;
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/*
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* Build an unknown exception, depending on the instruction
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* set.
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*/
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if (kvm_vcpu_trap_il_is32bit(vcpu))
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esr |= ESR_ELx_IL;
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vcpu_sys_reg(vcpu, ESR_EL1) = esr;
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}
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/**
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* kvm_inject_dabt - inject a data abort into the guest
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* @vcpu: The VCPU to receive the undefined exception
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* @addr: The address to report in the DFAR
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*
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* It is assumed that this code is called from the VCPU thread and that the
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* VCPU therefore is not currently executing guest code.
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*/
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void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
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{
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if (!(vcpu->arch.hcr_el2 & HCR_RW))
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inject_abt32(vcpu, false, addr);
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else
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inject_abt64(vcpu, false, addr);
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}
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/**
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* kvm_inject_pabt - inject a prefetch abort into the guest
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* @vcpu: The VCPU to receive the undefined exception
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* @addr: The address to report in the DFAR
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*
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* It is assumed that this code is called from the VCPU thread and that the
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* VCPU therefore is not currently executing guest code.
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*/
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void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
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{
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if (!(vcpu->arch.hcr_el2 & HCR_RW))
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inject_abt32(vcpu, true, addr);
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else
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inject_abt64(vcpu, true, addr);
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}
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/**
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* kvm_inject_undefined - inject an undefined instruction into the guest
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*
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* It is assumed that this code is called from the VCPU thread and that the
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* VCPU therefore is not currently executing guest code.
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*/
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void kvm_inject_undefined(struct kvm_vcpu *vcpu)
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{
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if (!(vcpu->arch.hcr_el2 & HCR_RW))
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inject_undef32(vcpu);
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else
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inject_undef64(vcpu);
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}
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