linux/arch/arm64/kvm/inject_fault.c
James Morse 4715c14bc1 KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2.
Prior to v8.2's RAS Extensions, the HCR_EL2.VSE 'virtual SError' feature
generated an SError with an implementation defined ESR_EL1.ISS, because we
had no mechanism to specify the ESR value.

On Juno this generates an all-zero ESR, the most significant bit 'ISV'
is clear indicating the remainder of the ISS field is invalid.

With the RAS Extensions we have a mechanism to specify this value, and the
most significant bit has a new meaning: 'IDS - Implementation Defined
Syndrome'. An all-zero SError ESR now means: 'RAS error: Uncategorized'
instead of 'no valid ISS'.

Add KVM support for the VSESR_EL2 register to specify an ESR value when
HCR_EL2.VSE generates a virtual SError. Change kvm_inject_vabt() to
specify an implementation-defined value.

We only need to restore the VSESR_EL2 value when HCR_EL2.VSE is set, KVM
save/restores this bit during __{,de}activate_traps() and hardware clears the
bit once the guest has consumed the virtual-SError.

Future patches may add an API (or KVM CAP) to pend a virtual SError with
a specified ESR.

Cc: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-16 15:08:41 +00:00

189 lines
5.3 KiB
C

/*
* 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
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))
kvm_inject_dabt32(vcpu, 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))
kvm_inject_pabt32(vcpu, 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))
kvm_inject_undef32(vcpu);
else
inject_undef64(vcpu);
}
static void pend_guest_serror(struct kvm_vcpu *vcpu, u64 esr)
{
vcpu_set_vsesr(vcpu, esr);
vcpu_set_hcr(vcpu, vcpu_get_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)
{
pend_guest_serror(vcpu, ESR_ELx_ISV);
}