arch/arm/kvm/handle_exit.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/kvm.h>
  20 #include <linux/kvm_host.h>
  21 #include <asm/kvm_emulate.h>
  22 #include <asm/kvm_coproc.h>
  23 #include <asm/kvm_mmu.h>
  24 #include <asm/kvm_psci.h>
  25 #include <trace/events/kvm.h>
  26
  27 #include "trace.h"
  28
  29 #include "trace.h"
  30
  31 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
  32
  33 static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
  34 {
  35         /* SVC called from Hyp mode should never get here */
  36         kvm_debug("SVC called from Hyp mode shouldn't go here\n");
  37         BUG();
  38         return -EINVAL; /* Squash warning */
  39 }
  40
  41 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  42 {
  43         trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
  44                       kvm_vcpu_hvc_get_imm(vcpu));
  45
  46         if (kvm_psci_call(vcpu))
  47                 return 1;
  48
  49         kvm_inject_undefined(vcpu);
  50         return 1;
  51 }
  52
  53 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  54 {
  55         kvm_inject_undefined(vcpu);
  56         return 1;
  57 }
  58
  59 static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
  60 {
  61         /* The hypervisor should never cause aborts */
  62         kvm_err("Prefetch Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
  63                 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
  64         return -EFAULT;
  65 }
  66
  67 static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
  68 {
  69         /* This is either an error in the ws. code or an external abort */
  70         kvm_err("Data Abort taken from Hyp mode at %#08lx (HSR: %#08x)\n",
  71                 kvm_vcpu_get_hfar(vcpu), kvm_vcpu_get_hsr(vcpu));
  72         return -EFAULT;
  73 }
  74
  75 /**
  76  * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest
  77  * @vcpu:       the vcpu pointer
  78  * @run:        the kvm_run structure pointer
  79  *
  80  * Simply sets the wait_for_interrupts flag on the vcpu structure, which will
  81  * halt execution of world-switches and schedule other host processes until
  82  * there is an incoming IRQ or FIQ to the VM.
  83  */
  84 static int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
  85 {
  86         trace_kvm_wfi(*vcpu_pc(vcpu));
  87         kvm_vcpu_block(vcpu);
  88         return 1;
  89 }
  90
  91 static exit_handle_fn arm_exit_handlers[] = {
  92         [HSR_EC_WFI]            = kvm_handle_wfi,
  93         [HSR_EC_CP15_32]        = kvm_handle_cp15_32,
  94         [HSR_EC_CP15_64]        = kvm_handle_cp15_64,
  95         [HSR_EC_CP14_MR]        = kvm_handle_cp14_access,
  96         [HSR_EC_CP14_LS]        = kvm_handle_cp14_load_store,
  97         [HSR_EC_CP14_64]        = kvm_handle_cp14_access,
  98         [HSR_EC_CP_0_13]        = kvm_handle_cp_0_13_access,
  99         [HSR_EC_CP10_ID]        = kvm_handle_cp10_id,
 100         [HSR_EC_SVC_HYP]        = handle_svc_hyp,
 101         [HSR_EC_HVC]            = handle_hvc,
 102         [HSR_EC_SMC]            = handle_smc,
 103         [HSR_EC_IABT]           = kvm_handle_guest_abort,
 104         [HSR_EC_IABT_HYP]       = handle_pabt_hyp,
 105         [HSR_EC_DABT]           = kvm_handle_guest_abort,
 106         [HSR_EC_DABT_HYP]       = handle_dabt_hyp,
 107 };
 108
 109 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
 110 {
 111         u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
 112
 113         if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
 114             !arm_exit_handlers[hsr_ec]) {
 115                 kvm_err("Unknown exception class: hsr: %#08x\n",
 116                         (unsigned int)kvm_vcpu_get_hsr(vcpu));
 117                 BUG();
 118         }
 119
 120         return arm_exit_handlers[hsr_ec];
 121 }
 122
 123 /*
 124  * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
 125  * proper exit to userspace.
 126  */
 127 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 128                        int exception_index)
 129 {
 130         exit_handle_fn exit_handler;
 131
 132         switch (exception_index) {
 133         case ARM_EXCEPTION_IRQ:
 134                 return 1;
 135         case ARM_EXCEPTION_UNDEFINED:
 136                 kvm_err("Undefined exception in Hyp mode at: %#08lx\n",
 137                         kvm_vcpu_get_hyp_pc(vcpu));
 138                 BUG();
 139                 panic("KVM: Hypervisor undefined exception!\n");
 140         case ARM_EXCEPTION_DATA_ABORT:
 141         case ARM_EXCEPTION_PREF_ABORT:
 142         case ARM_EXCEPTION_HVC:
 143                 /*
 144                  * See ARM ARM B1.14.1: "Hyp traps on instructions
 145                  * that fail their condition code check"
 146                  */
 147                 if (!kvm_condition_valid(vcpu)) {
 148                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
 149                         return 1;
 150                 }
 151
 152                 exit_handler = kvm_get_exit_handler(vcpu);
 153
 154                 return exit_handler(vcpu, run);
 155         default:
 156                 kvm_pr_unimpl("Unsupported exception type: %d",
 157                               exception_index);
 158                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 159                 return 0;
 160         }
 161 }