arch/arm/kvm/emulate.c

   1 /*
   2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   3  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #include <linux/mm.h>
  20 #include <linux/kvm_host.h>
  21 #include <asm/kvm_arm.h>
  22 #include <asm/kvm_emulate.h>
  23 #include <asm/opcodes.h>
  24 #include <trace/events/kvm.h>
  25
  26 #include "trace.h"
  27
  28 #define VCPU_NR_MODES           6
  29 #define VCPU_REG_OFFSET_USR     0
  30 #define VCPU_REG_OFFSET_FIQ     1
  31 #define VCPU_REG_OFFSET_IRQ     2
  32 #define VCPU_REG_OFFSET_SVC     3
  33 #define VCPU_REG_OFFSET_ABT     4
  34 #define VCPU_REG_OFFSET_UND     5
  35 #define REG_OFFSET(_reg) \
  36         (offsetof(struct kvm_regs, _reg) / sizeof(u32))
  37
  38 #define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs.uregs[_num])
  39
  40 static const unsigned long vcpu_reg_offsets[VCPU_NR_MODES][15] = {
  41         /* USR/SYS Registers */
  42         [VCPU_REG_OFFSET_USR] = {
  43                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
  44                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
  45                 USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
  46                 USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
  47                 USR_REG_OFFSET(12), USR_REG_OFFSET(13), USR_REG_OFFSET(14),
  48         },
  49
  50         /* FIQ Registers */
  51         [VCPU_REG_OFFSET_FIQ] = {
  52                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
  53                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
  54                 USR_REG_OFFSET(6), USR_REG_OFFSET(7),
  55                 REG_OFFSET(fiq_regs[0]), /* r8 */
  56                 REG_OFFSET(fiq_regs[1]), /* r9 */
  57                 REG_OFFSET(fiq_regs[2]), /* r10 */
  58                 REG_OFFSET(fiq_regs[3]), /* r11 */
  59                 REG_OFFSET(fiq_regs[4]), /* r12 */
  60                 REG_OFFSET(fiq_regs[5]), /* r13 */
  61                 REG_OFFSET(fiq_regs[6]), /* r14 */
  62         },
  63
  64         /* IRQ Registers */
  65         [VCPU_REG_OFFSET_IRQ] = {
  66                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
  67                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
  68                 USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
  69                 USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
  70                 USR_REG_OFFSET(12),
  71                 REG_OFFSET(irq_regs[0]), /* r13 */
  72                 REG_OFFSET(irq_regs[1]), /* r14 */
  73         },
  74
  75         /* SVC Registers */
  76         [VCPU_REG_OFFSET_SVC] = {
  77                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
  78                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
  79                 USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
  80                 USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
  81                 USR_REG_OFFSET(12),
  82                 REG_OFFSET(svc_regs[0]), /* r13 */
  83                 REG_OFFSET(svc_regs[1]), /* r14 */
  84         },
  85
  86         /* ABT Registers */
  87         [VCPU_REG_OFFSET_ABT] = {
  88                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
  89                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
  90                 USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
  91                 USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
  92                 USR_REG_OFFSET(12),
  93                 REG_OFFSET(abt_regs[0]), /* r13 */
  94                 REG_OFFSET(abt_regs[1]), /* r14 */
  95         },
  96
  97         /* UND Registers */
  98         [VCPU_REG_OFFSET_UND] = {
  99                 USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
 100                 USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
 101                 USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 102                 USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 103                 USR_REG_OFFSET(12),
 104                 REG_OFFSET(und_regs[0]), /* r13 */
 105                 REG_OFFSET(und_regs[1]), /* r14 */
 106         },
 107 };
 108
 109 /*
 110  * Return a pointer to the register number valid in the current mode of
 111  * the virtual CPU.
 112  */
 113 unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num)
 114 {
 115         unsigned long *reg_array = (unsigned long *)&vcpu->arch.ctxt.gp_regs;
 116         unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK;
 117
 118         switch (mode) {
 119         case USR_MODE...SVC_MODE:
 120                 mode &= ~MODE32_BIT; /* 0 ... 3 */
 121                 break;
 122
 123         case ABT_MODE:
 124                 mode = VCPU_REG_OFFSET_ABT;
 125                 break;
 126
 127         case UND_MODE:
 128                 mode = VCPU_REG_OFFSET_UND;
 129                 break;
 130
 131         case SYSTEM_MODE:
 132                 mode = VCPU_REG_OFFSET_USR;
 133                 break;
 134
 135         default:
 136                 BUG();
 137         }
 138
 139         return reg_array + vcpu_reg_offsets[mode][reg_num];
 140 }
 141
 142 /*
 143  * Return the SPSR for the current mode of the virtual CPU.
 144  */
 145 unsigned long *__vcpu_spsr(struct kvm_vcpu *vcpu)
 146 {
 147         unsigned long mode = *vcpu_cpsr(vcpu) & MODE_MASK;
 148         switch (mode) {
 149         case SVC_MODE:
 150                 return &vcpu->arch.ctxt.gp_regs.KVM_ARM_SVC_spsr;
 151         case ABT_MODE:
 152                 return &vcpu->arch.ctxt.gp_regs.KVM_ARM_ABT_spsr;
 153         case UND_MODE:
 154                 return &vcpu->arch.ctxt.gp_regs.KVM_ARM_UND_spsr;
 155         case IRQ_MODE:
 156                 return &vcpu->arch.ctxt.gp_regs.KVM_ARM_IRQ_spsr;
 157         case FIQ_MODE:
 158                 return &vcpu->arch.ctxt.gp_regs.KVM_ARM_FIQ_spsr;
 159         default:
 160                 BUG();
 161         }
 162 }
 163
 164 /******************************************************************************
 165  * Inject exceptions into the guest
 166  */
 167
 168 /**
 169  * kvm_inject_vabt - inject an async abort / SError into the guest
 170  * @vcpu: The VCPU to receive the exception
 171  *
 172  * It is assumed that this code is called from the VCPU thread and that the
 173  * VCPU therefore is not currently executing guest code.
 174  */
 175 void kvm_inject_vabt(struct kvm_vcpu *vcpu)
 176 {
 177         *vcpu_hcr(vcpu) |= HCR_VA;
 178 }