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
  26 #include "trace.h"
  27
  28 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
  29
  30 static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
  31 {
  32         /* SVC called from Hyp mode should never get here */
  33         kvm_debug("SVC called from Hyp mode shouldn't go here\n");
  34         BUG();
  35         return -EINVAL; /* Squash warning */
  36 }
  37
  38 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  39 {
  40         trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
  41                       kvm_vcpu_hvc_get_imm(vcpu));
  42
  43         if (kvm_psci_call(vcpu))
  44                 return 1;
  45
  46         kvm_inject_undefined(vcpu);
  47         return 1;
  48 }
  49
  50 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  51 {
  52         if (kvm_psci_call(vcpu))
  53                 return 1;
  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 static exit_handle_fn arm_exit_handlers[] = {
  76         [HSR_EC_WFI]            = kvm_handle_wfi,
  77         [HSR_EC_CP15_32]        = kvm_handle_cp15_32,
  78         [HSR_EC_CP15_64]        = kvm_handle_cp15_64,
  79         [HSR_EC_CP14_MR]        = kvm_handle_cp14_access,
  80         [HSR_EC_CP14_LS]        = kvm_handle_cp14_load_store,
  81         [HSR_EC_CP14_64]        = kvm_handle_cp14_access,
  82         [HSR_EC_CP_0_13]        = kvm_handle_cp_0_13_access,
  83         [HSR_EC_CP10_ID]        = kvm_handle_cp10_id,
  84         [HSR_EC_SVC_HYP]        = handle_svc_hyp,
  85         [HSR_EC_HVC]            = handle_hvc,
  86         [HSR_EC_SMC]            = handle_smc,
  87         [HSR_EC_IABT]           = kvm_handle_guest_abort,
  88         [HSR_EC_IABT_HYP]       = handle_pabt_hyp,
  89         [HSR_EC_DABT]           = kvm_handle_guest_abort,
  90         [HSR_EC_DABT_HYP]       = handle_dabt_hyp,
  91 };
  92
  93 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
  94 {
  95         u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
  96
  97         if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
  98             !arm_exit_handlers[hsr_ec]) {
  99                 kvm_err("Unkown exception class: hsr: %#08x\n",
 100                         (unsigned int)kvm_vcpu_get_hsr(vcpu));
 101                 BUG();
 102         }
 103
 104         return arm_exit_handlers[hsr_ec];
 105 }
 106
 107 /*
 108  * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
 109  * proper exit to userspace.
 110  */
 111 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 112                        int exception_index)
 113 {
 114         exit_handle_fn exit_handler;
 115
 116         switch (exception_index) {
 117         case ARM_EXCEPTION_IRQ:
 118                 return 1;
 119         case ARM_EXCEPTION_UNDEFINED:
 120                 kvm_err("Undefined exception in Hyp mode at: %#08lx\n",
 121                         kvm_vcpu_get_hyp_pc(vcpu));
 122                 BUG();
 123                 panic("KVM: Hypervisor undefined exception!\n");
 124         case ARM_EXCEPTION_DATA_ABORT:
 125         case ARM_EXCEPTION_PREF_ABORT:
 126         case ARM_EXCEPTION_HVC:
 127                 /*
 128                  * See ARM ARM B1.14.1: "Hyp traps on instructions
 129                  * that fail their condition code check"
 130                  */
 131                 if (!kvm_condition_valid(vcpu)) {
 132                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
 133                         return 1;
 134                 }
 135
 136                 exit_handler = kvm_get_exit_handler(vcpu);
 137
 138                 return exit_handler(vcpu, run);
 139         default:
 140                 kvm_pr_unimpl("Unsupported exception type: %d",
 141                               exception_index);
 142                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 143                 return 0;
 144         }
 145 }