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 29 typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *); 30 31 static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) 32 { 33 int ret; 34 35 ret = kvm_psci_call(vcpu); 36 if (ret < 0) { 37 kvm_inject_undefined(vcpu); 38 return 1; 39 } 40 41 return ret; 42 } 43 44 static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) 45 { 46 kvm_inject_undefined(vcpu); 47 return 1; 48 } 49 50 /** 51 * kvm_handle_wfx - handle a wait-for-interrupts or wait-for-event 52 * instruction executed by a guest 53 * 54 * @vcpu: the vcpu pointer 55 * 56 * WFE: Yield the CPU and come back to this vcpu when the scheduler 57 * decides to. 58 * WFI: Simply call kvm_vcpu_block(), which will halt execution of 59 * world-switches and schedule other host processes until there is an 60 * incoming IRQ or FIQ to the VM. 61 */ 62 static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) 63 { 64 if (kvm_vcpu_get_hsr(vcpu) & ESR_EL2_EC_WFI_ISS_WFE) 65 kvm_vcpu_on_spin(vcpu); 66 else 67 kvm_vcpu_block(vcpu); 68 69 return 1; 70 } 71 72 static exit_handle_fn arm_exit_handlers[] = { 73 [ESR_EL2_EC_WFI] = kvm_handle_wfx, 74 [ESR_EL2_EC_CP15_32] = kvm_handle_cp15_32, 75 [ESR_EL2_EC_CP15_64] = kvm_handle_cp15_64, 76 [ESR_EL2_EC_CP14_MR] = kvm_handle_cp14_access, 77 [ESR_EL2_EC_CP14_LS] = kvm_handle_cp14_load_store, 78 [ESR_EL2_EC_CP14_64] = kvm_handle_cp14_access, 79 [ESR_EL2_EC_HVC32] = handle_hvc, 80 [ESR_EL2_EC_SMC32] = handle_smc, 81 [ESR_EL2_EC_HVC64] = handle_hvc, 82 [ESR_EL2_EC_SMC64] = handle_smc, 83 [ESR_EL2_EC_SYS64] = kvm_handle_sys_reg, 84 [ESR_EL2_EC_IABT] = kvm_handle_guest_abort, 85 [ESR_EL2_EC_DABT] = kvm_handle_guest_abort, 86 }; 87 88 static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu) 89 { 90 u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu); 91 92 if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers) || 93 !arm_exit_handlers[hsr_ec]) { 94 kvm_err("Unknown exception class: hsr: %#08x\n", 95 (unsigned int)kvm_vcpu_get_hsr(vcpu)); 96 BUG(); 97 } 98 99 return arm_exit_handlers[hsr_ec]; 100 } 101 102 /* 103 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on 104 * proper exit to userspace. 105 */ 106 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, 107 int exception_index) 108 { 109 exit_handle_fn exit_handler; 110 111 switch (exception_index) { 112 case ARM_EXCEPTION_IRQ: 113 return 1; 114 case ARM_EXCEPTION_TRAP: 115 /* 116 * See ARM ARM B1.14.1: "Hyp traps on instructions 117 * that fail their condition code check" 118 */ 119 if (!kvm_condition_valid(vcpu)) { 120 kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); 121 return 1; 122 } 123 124 exit_handler = kvm_get_exit_handler(vcpu); 125 126 return exit_handler(vcpu, run); 127 default: 128 kvm_pr_unimpl("Unsupported exception type: %d", 129 exception_index); 130 run->exit_reason = KVM_EXIT_INTERNAL_ERROR; 131 return 0; 132 } 133 } 134