238 lines
6.5 KiB
C
238 lines
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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#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 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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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_read_sys_reg(vcpu, VBAR_EL1) + exc_offset + type;
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}
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/*
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* When an exception is taken, most PSTATE fields are left unchanged in the
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* handler. However, some are explicitly overridden (e.g. M[4:0]). Luckily all
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* of the inherited bits have the same position in the AArch64/AArch32 SPSR_ELx
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* layouts, so we don't need to shuffle these for exceptions from AArch32 EL0.
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*
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* For the SPSR_ELx layout for AArch64, see ARM DDI 0487E.a page C5-429.
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* For the SPSR_ELx layout for AArch32, see ARM DDI 0487E.a page C5-426.
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*
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* Here we manipulate the fields in order of the AArch64 SPSR_ELx layout, from
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* MSB to LSB.
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*/
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static unsigned long get_except64_pstate(struct kvm_vcpu *vcpu)
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{
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unsigned long sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
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unsigned long old, new;
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old = *vcpu_cpsr(vcpu);
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new = 0;
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new |= (old & PSR_N_BIT);
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new |= (old & PSR_Z_BIT);
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new |= (old & PSR_C_BIT);
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new |= (old & PSR_V_BIT);
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// TODO: TCO (if/when ARMv8.5-MemTag is exposed to guests)
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new |= (old & PSR_DIT_BIT);
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// PSTATE.UAO is set to zero upon any exception to AArch64
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// See ARM DDI 0487E.a, page D5-2579.
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// PSTATE.PAN is unchanged unless SCTLR_ELx.SPAN == 0b0
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// SCTLR_ELx.SPAN is RES1 when ARMv8.1-PAN is not implemented
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// See ARM DDI 0487E.a, page D5-2578.
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new |= (old & PSR_PAN_BIT);
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if (!(sctlr & SCTLR_EL1_SPAN))
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new |= PSR_PAN_BIT;
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// PSTATE.SS is set to zero upon any exception to AArch64
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// See ARM DDI 0487E.a, page D2-2452.
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// PSTATE.IL is set to zero upon any exception to AArch64
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// See ARM DDI 0487E.a, page D1-2306.
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// PSTATE.SSBS is set to SCTLR_ELx.DSSBS upon any exception to AArch64
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// See ARM DDI 0487E.a, page D13-3258
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if (sctlr & SCTLR_ELx_DSSBS)
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new |= PSR_SSBS_BIT;
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// PSTATE.BTYPE is set to zero upon any exception to AArch64
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// See ARM DDI 0487E.a, pages D1-2293 to D1-2294.
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new |= PSR_D_BIT;
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new |= PSR_A_BIT;
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new |= PSR_I_BIT;
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new |= PSR_F_BIT;
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new |= PSR_MODE_EL1h;
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return new;
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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 = vcpu_mode_is_32bit(vcpu);
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u32 esr = 0;
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vcpu_write_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) = get_except64_pstate(vcpu);
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vcpu_write_spsr(vcpu, cpsr);
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vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
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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 << ESR_ELx_EC_SHIFT;
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vcpu_write_sys_reg(vcpu, esr | ESR_ELx_FSC_EXTABT, ESR_EL1);
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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_write_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) = get_except64_pstate(vcpu);
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vcpu_write_spsr(vcpu, cpsr);
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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_write_sys_reg(vcpu, esr, ESR_EL1);
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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_el1_is_32bit(vcpu))
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kvm_inject_dabt32(vcpu, 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_el1_is_32bit(vcpu))
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kvm_inject_pabt32(vcpu, 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_el1_is_32bit(vcpu))
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kvm_inject_undef32(vcpu);
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else
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inject_undef64(vcpu);
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}
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void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr)
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{
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vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
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*vcpu_hcr(vcpu) |= HCR_VSE;
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}
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/**
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* kvm_inject_vabt - inject an async abort / SError into the guest
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* @vcpu: The VCPU to receive the exception
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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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* Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with
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* the remaining ISS all-zeros so that this error is not interpreted as an
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* uncategorized RAS error. Without the RAS Extensions we can't specify an ESR
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* value, so the CPU generates an imp-def value.
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*/
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void kvm_inject_vabt(struct kvm_vcpu *vcpu)
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{
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kvm_set_sei_esr(vcpu, ESR_ELx_ISV);
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}
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