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