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 /** 86 * kvm_handle_guest_debug - handle a debug exception instruction 87 * 88 * @vcpu: the vcpu pointer 89 * @run: access to the kvm_run structure for results 90 * 91 * We route all debug exceptions through the same handler. If both the 92 * guest and host are using the same debug facilities it will be up to 93 * userspace to re-inject the correct exception for guest delivery. 94 * 95 * @return: 0 (while setting run->exit_reason), -1 for error 96 */ 97 static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run) 98 { 99 u32 hsr = kvm_vcpu_get_hsr(vcpu); 100 int ret = 0; 101 102 run->exit_reason = KVM_EXIT_DEBUG; 103 run->debug.arch.hsr = hsr; 104 105 switch (hsr >> ESR_ELx_EC_SHIFT) { 106 case ESR_ELx_EC_WATCHPT_LOW: 107 run->debug.arch.far = vcpu->arch.fault.far_el2; 108 /* fall through */ 109 case ESR_ELx_EC_SOFTSTP_LOW: 110 case ESR_ELx_EC_BREAKPT_LOW: 111 case ESR_ELx_EC_BKPT32: 112 case ESR_ELx_EC_BRK64: 113 break; 114 default: 115 kvm_err("%s: un-handled case hsr: %#08x\n", 116 __func__, (unsigned int) hsr); 117 ret = -1; 118 break; 119 } 120 121 return ret; 122 } 123 124 static exit_handle_fn arm_exit_handlers[] = { 125 [ESR_ELx_EC_WFx] = kvm_handle_wfx, 126 [ESR_ELx_EC_CP15_32] = kvm_handle_cp15_32, 127 [ESR_ELx_EC_CP15_64] = kvm_handle_cp15_64, 128 [ESR_ELx_EC_CP14_MR] = kvm_handle_cp14_32, 129 [ESR_ELx_EC_CP14_LS] = kvm_handle_cp14_load_store, 130 [ESR_ELx_EC_CP14_64] = kvm_handle_cp14_64, 131 [ESR_ELx_EC_HVC32] = handle_hvc, 132 [ESR_ELx_EC_SMC32] = handle_smc, 133 [ESR_ELx_EC_HVC64] = handle_hvc, 134 [ESR_ELx_EC_SMC64] = handle_smc, 135 [ESR_ELx_EC_SYS64] = kvm_handle_sys_reg, 136 [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, 137 [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, 138 [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug, 139 [ESR_ELx_EC_WATCHPT_LOW]= kvm_handle_guest_debug, 140 [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug, 141 [ESR_ELx_EC_BKPT32] = kvm_handle_guest_debug, 142 [ESR_ELx_EC_BRK64] = kvm_handle_guest_debug, 143 }; 144 145 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu) 146 { 147 u32 hsr = kvm_vcpu_get_hsr(vcpu); 148 u8 hsr_ec = hsr >> ESR_ELx_EC_SHIFT; 149 150 if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) || 151 !arm_exit_handlers[hsr_ec]) { 152 kvm_err("Unknown exception class: hsr: %#08x -- %s\n", 153 hsr, esr_get_class_string(hsr)); 154 BUG(); 155 } 156 157 return arm_exit_handlers[hsr_ec]; 158 } 159 160 /* 161 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on 162 * proper exit to userspace. 163 */ 164 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, 165 int exception_index) 166 { 167 exit_handle_fn exit_handler; 168 169 switch (exception_index) { 170 case ARM_EXCEPTION_IRQ: 171 return 1; 172 case ARM_EXCEPTION_TRAP: 173 /* 174 * See ARM ARM B1.14.1: "Hyp traps on instructions 175 * that fail their condition code check" 176 */ 177 if (!kvm_condition_valid(vcpu)) { 178 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); 179 return 1; 180 } 181 182 exit_handler = kvm_get_exit_handler(vcpu); 183 184 return exit_handler(vcpu, run); 185 default: 186 kvm_pr_unimpl("Unsupported exception type: %d", 187 exception_index); 188 run->exit_reason = KVM_EXIT_INTERNAL_ERROR; 189 return 0; 190 } 191 } 192