// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_nested.h>
#include <asm/esr.h>
static void pend_sync_exception(struct kvm_vcpu *vcpu)
{
/* If not nesting, EL1 is the only possible exception target */
if (likely(!vcpu_has_nv(vcpu))) {
kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
return;
}
/*
* With NV, we need to pick between EL1 and EL2. Note that we
* never deal with a nesting exception here, hence never
* changing context, and the exception itself can be delayed
* until the next entry.
*/
switch(*vcpu_cpsr(vcpu) & PSR_MODE_MASK) {
case PSR_MODE_EL2h:
case PSR_MODE_EL2t:
kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
break;
case PSR_MODE_EL1h:
case PSR_MODE_EL1t:
kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
break;
case PSR_MODE_EL0t:
if (vcpu_el2_tge_is_set(vcpu))
kvm_pend_exception(vcpu, EXCEPT_AA64_EL2_SYNC);
else
kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
break;
default:
BUG();
}
}
static bool match_target_el(struct kvm_vcpu *vcpu, unsigned long target)
{
return (vcpu_get_flag(vcpu, EXCEPT_MASK) == target);
}
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);
u64 esr = 0;
pend_sync_exception(vcpu);
/*
* 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;
esr |= ESR_ELx_FSC_EXTABT;
if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC))) {
vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
} else {
vcpu_write_sys_reg(vcpu, addr, FAR_EL2);
vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
}
}
static void inject_undef64(struct kvm_vcpu *vcpu)
{
u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
pend_sync_exception(vcpu);
/*
* Build an unknown exception, depending on the instruction
* set.
*/
if (kvm_vcpu_trap_il_is32bit(vcpu))
esr |= ESR_ELx_IL;
if (match_target_el(vcpu, unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC)))
vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
else
vcpu_write_sys_reg(vcpu, esr, ESR_EL2);
}
#define DFSR_FSC_EXTABT_LPAE 0x10
#define DFSR_FSC_EXTABT_nLPAE 0x08
#define DFSR_LPAE BIT(9)
#define TTBCR_EAE BIT(31)
static void inject_undef32(struct kvm_vcpu *vcpu)
{
kvm_pend_exception(vcpu, EXCEPT_AA32_UND);
}
/*
* Modelled after TakeDataAbortException() and TakePrefetchAbortException
* pseudocode.
*/
static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
{
u64 far;
u32 fsr;
/* Give the guest an IMPLEMENTATION DEFINED exception */
if (vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE) {
fsr = DFSR_LPAE | DFSR_FSC_EXTABT_LPAE;
} else {
/* no need to shuffle FS[4] into DFSR[10] as its 0 */
fsr = DFSR_FSC_EXTABT_nLPAE;
}
far = vcpu_read_sys_reg(vcpu, FAR_EL1);
if (is_pabt) {
kvm_pend_exception(vcpu, EXCEPT_AA32_IABT);
far &= GENMASK(31, 0);
far |= (u64)addr << 32;
vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2);
} else { /* !iabt */
kvm_pend_exception(vcpu, EXCEPT_AA32_DABT);
far &= GENMASK(63, 32);
far |= addr;
vcpu_write_sys_reg(vcpu, fsr, ESR_EL1);
}
vcpu_write_sys_reg(vcpu, far, FAR_EL1);
}
/**
* kvm_inject_dabt - inject a data abort into the guest
* @vcpu: The VCPU to receive the data abort
* @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_el1_is_32bit(vcpu))
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 prefetch abort
* @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_el1_is_32bit(vcpu))
inject_abt32(vcpu, true, addr);
else
inject_abt64(vcpu, true, addr);
}
void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
{
unsigned long addr, esr;
addr = kvm_vcpu_get_fault_ipa(vcpu);
addr |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
if (kvm_vcpu_trap_is_iabt(vcpu))
kvm_inject_pabt(vcpu, addr);
else
kvm_inject_dabt(vcpu, addr);
/*
* If AArch64 or LPAE, set FSC to 0 to indicate an Address
* Size Fault at level 0, as if exceeding PARange.
*
* Non-LPAE guests will only get the external abort, as there
* is no way to describe the ASF.
*/
if (vcpu_el1_is_32bit(vcpu) &&
!(vcpu_read_sys_reg(vcpu, TCR_EL1) & TTBCR_EAE))
return;
esr = vcpu_read_sys_reg(vcpu, ESR_EL1);
esr &= ~GENMASK_ULL(5, 0);
vcpu_write_sys_reg(vcpu, esr, ESR_EL1);
}
/**
* kvm_inject_undefined - inject an undefined instruction into the guest
* @vcpu: The vCPU in which to inject 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_undefined(struct kvm_vcpu *vcpu)
{
if (vcpu_el1_is_32bit(vcpu))
inject_undef32(vcpu);
else
inject_undef64(vcpu);
}
void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 esr)
{
vcpu_set_vsesr(vcpu, esr & ESR_ELx_ISS_MASK);
*vcpu_hcr(vcpu) |= HCR_VSE;
}
/**
* 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.
*
* Systems with the RAS Extensions specify an imp-def ESR (ISV/IDS = 1) with
* the remaining ISS all-zeros so that this error is not interpreted as an
* uncategorized RAS error. Without the RAS Extensions we can't specify an ESR
* value, so the CPU generates an imp-def value.
*/
void kvm_inject_vabt(struct kvm_vcpu *vcpu)
{
kvm_set_sei_esr(vcpu, ESR_ELx_ISV);
}