linux/arch/arm/kvm/emulate.c
Christoffer Dall 00536ec476 KVM: arm/arm64: Prepare to handle deferred save/restore of SPSR_EL1
SPSR_EL1 is not used by a VHE host kernel and can be deferred, but we
need to rework the accesses to this register to access the latest value
depending on whether or not guest system registers are loaded on the CPU
or only reside in memory.

The handling of accessing the various banked SPSRs for 32-bit VMs is a
bit clunky, but this will be improved in following patches which will
first prepare and subsequently implement deferred save/restore of the
32-bit registers, including the 32-bit SPSRs.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:17 +00:00

179 lines
5.3 KiB
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, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/mm.h>
#include <linux/kvm_host.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_emulate.h>
#include <asm/opcodes.h>
#include <trace/events/kvm.h>
#include "trace.h"
#define VCPU_NR_MODES 6
#define VCPU_REG_OFFSET_USR 0
#define VCPU_REG_OFFSET_FIQ 1
#define VCPU_REG_OFFSET_IRQ 2
#define VCPU_REG_OFFSET_SVC 3
#define VCPU_REG_OFFSET_ABT 4
#define VCPU_REG_OFFSET_UND 5
#define REG_OFFSET(_reg) \
(offsetof(struct kvm_regs, _reg) / sizeof(u32))
#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs.uregs[_num])
static const unsigned long vcpu_reg_offsets[VCPU_NR_MODES][15] = {
/* USR/SYS Registers */
[VCPU_REG_OFFSET_USR] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12), USR_REG_OFFSET(13), USR_REG_OFFSET(14),
},
/* FIQ Registers */
[VCPU_REG_OFFSET_FIQ] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7),
REG_OFFSET(fiq_regs[0]), /* r8 */
REG_OFFSET(fiq_regs[1]), /* r9 */
REG_OFFSET(fiq_regs[2]), /* r10 */
REG_OFFSET(fiq_regs[3]), /* r11 */
REG_OFFSET(fiq_regs[4]), /* r12 */
REG_OFFSET(fiq_regs[5]), /* r13 */
REG_OFFSET(fiq_regs[6]), /* r14 */
},
/* IRQ Registers */
[VCPU_REG_OFFSET_IRQ] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
REG_OFFSET(irq_regs[0]), /* r13 */
REG_OFFSET(irq_regs[1]), /* r14 */
},
/* SVC Registers */
[VCPU_REG_OFFSET_SVC] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
REG_OFFSET(svc_regs[0]), /* r13 */
REG_OFFSET(svc_regs[1]), /* r14 */
},
/* ABT Registers */
[VCPU_REG_OFFSET_ABT] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
REG_OFFSET(abt_regs[0]), /* r13 */
REG_OFFSET(abt_regs[1]), /* r14 */
},
/* UND Registers */
[VCPU_REG_OFFSET_UND] = {
USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
USR_REG_OFFSET(12),
REG_OFFSET(und_regs[0]), /* r13 */
REG_OFFSET(und_regs[1]), /* r14 */
},
};
/*
* Return a pointer to the register number valid in the current mode of
* the virtual CPU.
*/
unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num)
{
unsigned long *reg_array = (unsigned long *)&vcpu->arch.ctxt.gp_regs;
unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK;
switch (mode) {
case USR_MODE...SVC_MODE:
mode &= ~MODE32_BIT; /* 0 ... 3 */
break;
case ABT_MODE:
mode = VCPU_REG_OFFSET_ABT;
break;
case UND_MODE:
mode = VCPU_REG_OFFSET_UND;
break;
case SYSTEM_MODE:
mode = VCPU_REG_OFFSET_USR;
break;
default:
BUG();
}
return reg_array + vcpu_reg_offsets[mode][reg_num];
}
/*
* Return the SPSR for the current mode of the virtual CPU.
*/
unsigned long *__vcpu_spsr(struct kvm_vcpu *vcpu)
{
unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK;
switch (mode) {
case SVC_MODE:
return &vcpu->arch.ctxt.gp_regs.KVM_ARM_SVC_spsr;
case ABT_MODE:
return &vcpu->arch.ctxt.gp_regs.KVM_ARM_ABT_spsr;
case UND_MODE:
return &vcpu->arch.ctxt.gp_regs.KVM_ARM_UND_spsr;
case IRQ_MODE:
return &vcpu->arch.ctxt.gp_regs.KVM_ARM_IRQ_spsr;
case FIQ_MODE:
return &vcpu->arch.ctxt.gp_regs.KVM_ARM_FIQ_spsr;
default:
BUG();
}
}
/******************************************************************************
* Inject exceptions into the guest
*/
/**
* 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.
*/
void kvm_inject_vabt(struct kvm_vcpu *vcpu)
{
*vcpu_hcr(vcpu) |= HCR_VA;
}