linux/arch/arm64/kvm/handle_exit.c
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   1/*
   2 * Copyright (C) 2012,2013 - ARM Ltd
   3 * Author: Marc Zyngier <marc.zyngier@arm.com>
   4 *
   5 * Derived from arch/arm/kvm/handle_exit.c:
   6 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   7 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22#include <linux/kvm.h>
  23#include <linux/kvm_host.h>
  24#include <asm/kvm_emulate.h>
  25#include <asm/kvm_coproc.h>
  26#include <asm/kvm_mmu.h>
  27#include <asm/kvm_psci.h>
  28
  29typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
  30
  31static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  32{
  33        if (kvm_psci_call(vcpu))
  34                return 1;
  35
  36        kvm_inject_undefined(vcpu);
  37        return 1;
  38}
  39
  40static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
  41{
  42        if (kvm_psci_call(vcpu))
  43                return 1;
  44
  45        kvm_inject_undefined(vcpu);
  46        return 1;
  47}
  48
  49/**
  50 * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest
  51 * @vcpu:       the vcpu pointer
  52 *
  53 * Simply call kvm_vcpu_block(), which will halt execution of
  54 * world-switches and schedule other host processes until there is an
  55 * incoming IRQ or FIQ to the VM.
  56 */
  57static int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
  58{
  59        kvm_vcpu_block(vcpu);
  60        return 1;
  61}
  62
  63static exit_handle_fn arm_exit_handlers[] = {
  64        [ESR_EL2_EC_WFI]        = kvm_handle_wfi,
  65        [ESR_EL2_EC_CP15_32]    = kvm_handle_cp15_32,
  66        [ESR_EL2_EC_CP15_64]    = kvm_handle_cp15_64,
  67        [ESR_EL2_EC_CP14_MR]    = kvm_handle_cp14_access,
  68        [ESR_EL2_EC_CP14_LS]    = kvm_handle_cp14_load_store,
  69        [ESR_EL2_EC_CP14_64]    = kvm_handle_cp14_access,
  70        [ESR_EL2_EC_HVC32]      = handle_hvc,
  71        [ESR_EL2_EC_SMC32]      = handle_smc,
  72        [ESR_EL2_EC_HVC64]      = handle_hvc,
  73        [ESR_EL2_EC_SMC64]      = handle_smc,
  74        [ESR_EL2_EC_SYS64]      = kvm_handle_sys_reg,
  75        [ESR_EL2_EC_IABT]       = kvm_handle_guest_abort,
  76        [ESR_EL2_EC_DABT]       = kvm_handle_guest_abort,
  77};
  78
  79static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
  80{
  81        u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
  82
  83        if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) ||
  84            !arm_exit_handlers[hsr_ec]) {
  85                kvm_err("Unkown exception class: hsr: %#08x\n",
  86                        (unsigned int)kvm_vcpu_get_hsr(vcpu));
  87                BUG();
  88        }
  89
  90        return arm_exit_handlers[hsr_ec];
  91}
  92
  93/*
  94 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
  95 * proper exit to userspace.
  96 */
  97int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
  98                       int exception_index)
  99{
 100        exit_handle_fn exit_handler;
 101
 102        switch (exception_index) {
 103        case ARM_EXCEPTION_IRQ:
 104                return 1;
 105        case ARM_EXCEPTION_TRAP:
 106                /*
 107                 * See ARM ARM B1.14.1: "Hyp traps on instructions
 108                 * that fail their condition code check"
 109                 */
 110                if (!kvm_condition_valid(vcpu)) {
 111                        kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
 112                        return 1;
 113                }
 114
 115                exit_handler = kvm_get_exit_handler(vcpu);
 116
 117                return exit_handler(vcpu, run);
 118        default:
 119                kvm_pr_unimpl("Unsupported exception type: %d",
 120                              exception_index);
 121                run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 122                return 0;
 123        }
 124}
 125