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 25 #include <asm/esr.h> 26 #include <asm/kvm_coproc.h> 27 #include <asm/kvm_emulate.h> 28 #include <asm/kvm_mmu.h> 29 #include <asm/kvm_psci.h> 30 31 #define CREATE_TRACE_POINTS 32 #include "trace.h" 33 34 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *); 35 36 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) 37 { 38 int ret; 39 40 trace_kvm_hvc_arm64(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0), 41 kvm_vcpu_hvc_get_imm(vcpu)); 42 43 ret = kvm_psci_call(vcpu); 44 if (ret < 0) { 45 kvm_inject_undefined(vcpu); 46 return 1; 47 } 48 49 return ret; 50 } 51 52 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) 53 { 54 kvm_inject_undefined(vcpu); 55 return 1; 56 } 57 58 /** 59 * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event 60 * instruction executed by a guest 61 * 62 * @vcpu: the vcpu pointer 63 * 64 * WFE: Yield the CPU and come back to this vcpu when the scheduler 65 * decides to. 66 * WFI: Simply call kvm_vcpu_block(), which will halt execution of 67 * world-switches and schedule other host processes until there is an 68 * incoming IRQ or FIQ to the VM. 69 */ 70 static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) 71 { 72 if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { 73 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); 74 kvm_vcpu_on_spin(vcpu); 75 } else { 76 trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false); 77 kvm_vcpu_block(vcpu); 78 } 79 80 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); 81 82 return 1; 83 } 84 85 static exit_handle_fn arm_exit_handlers[] = { 86 [ESR_ELx_EC_WFx] = kvm_handle_wfx, 87 [ESR_ELx_EC_CP15_32] = kvm_handle_cp15_32, 88 [ESR_ELx_EC_CP15_64] = kvm_handle_cp15_64, 89 [ESR_ELx_EC_CP14_MR] = kvm_handle_cp14_32, 90 [ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store, 91 [ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64, 92 [ESR_ELx_EC_HVC32] = handle_hvc, 93 [ESR_ELx_EC_SMC32] = handle_smc, 94 [ESR_ELx_EC_HVC64] = handle_hvc, 95 [ESR_ELx_EC_SMC64] = handle_smc, 96 [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg, 97 [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, 98 [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, 99 }; 100 101 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu) 102 { 103 u32 hsr = kvm_vcpu_get_hsr(vcpu); 104 u8 hsr_ec = hsr >> ESR_ELx_EC_SHIFT; 105 106 if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) || 107 !arm_exit_handlers[hsr_ec]) { 108 kvm_err("Unknown exception class: hsr: %#08x -- %s\n", 109 hsr, esr_get_class_string(hsr)); 110 BUG(); 111 } 112 113 return arm_exit_handlers[hsr_ec]; 114 } 115 116 /* 117 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on 118 * proper exit to userspace. 119 */ 120 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, 121 int exception_index) 122 { 123 exit_handle_fn exit_handler; 124 125 switch (exception_index) { 126 case ARM_EXCEPTION_IRQ: 127 return 1; 128 case ARM_EXCEPTION_TRAP: 129 /* 130 * See ARM ARM B1.14.1: "Hyp traps on instructions 131 * that fail their condition code check" 132 */ 133 if (!kvm_condition_valid(vcpu)) { 134 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); 135 return 1; 136 } 137 138 exit_handler = kvm_get_exit_handler(vcpu); 139 140 return exit_handler(vcpu, run); 141 default: 142 kvm_pr_unimpl("Unsupported exception type: %d", 143 exception_index); 144 run->exit_reason = KVM_EXIT_INTERNAL_ERROR; 145 return 0; 146 } 147 } 148