| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* |
| 2 | * (not much of an) Emulation layer for 32bit guests. |
| 3 | * |
| 4 | * Copyright (C) 2012,2013 - ARM Ltd |
| 5 | * Author: Marc Zyngier <marc.zyngier@arm.com> |
| 6 | * |
| 7 | * based on arch/arm/kvm/emulate.c |
| 8 | * Copyright (C) 2012 - Virtual Open Systems and Columbia University |
| 9 | * Author: Christoffer Dall <c.dall@virtualopensystems.com> |
| 10 | * |
| 11 | * This program is free software: you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 as |
| 13 | * published by the Free Software Foundation. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 22 | */ |
| 23 | |
| 24 | #include <linux/kvm_host.h> |
| 25 | #include <asm/kvm_emulate.h> |
| 26 | #include <asm/kvm_hyp.h> |
| 27 | |
| 28 | /* |
| 29 | * Table taken from ARMv8 ARM DDI0487B-B, table G1-10. |
| 30 | */ |
| 31 | static const u8 return_offsets[8][2] = { |
| 32 | [0] = { 0, 0 }, /* Reset, unused */ |
| 33 | [1] = { 4, 2 }, /* Undefined */ |
| 34 | [2] = { 0, 0 }, /* SVC, unused */ |
| 35 | [3] = { 4, 4 }, /* Prefetch abort */ |
| 36 | [4] = { 8, 8 }, /* Data abort */ |
| 37 | [5] = { 0, 0 }, /* HVC, unused */ |
| 38 | [6] = { 4, 4 }, /* IRQ, unused */ |
| 39 | [7] = { 4, 4 }, /* FIQ, unused */ |
| 40 | }; |
| 41 | |
| 42 | static void prepare_fault32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset) |
| 43 | { |
| 44 | unsigned long cpsr; |
| 45 | unsigned long new_spsr_value = *vcpu_cpsr(vcpu); |
| 46 | bool is_thumb = (new_spsr_value & PSR_AA32_T_BIT); |
| 47 | u32 return_offset = return_offsets[vect_offset >> 2][is_thumb]; |
| 48 | u32 sctlr = vcpu_cp15(vcpu, c1_SCTLR); |
| 49 | |
| 50 | cpsr = mode | PSR_AA32_I_BIT; |
| 51 | |
| 52 | if (sctlr & (1 << 30)) |
| 53 | cpsr |= PSR_AA32_T_BIT; |
| 54 | if (sctlr & (1 << 25)) |
| 55 | cpsr |= PSR_AA32_E_BIT; |
| 56 | |
| 57 | *vcpu_cpsr(vcpu) = cpsr; |
| 58 | |
| 59 | /* Note: These now point to the banked copies */ |
| 60 | vcpu_write_spsr(vcpu, new_spsr_value); |
| 61 | *vcpu_reg32(vcpu, 14) = *vcpu_pc(vcpu) + return_offset; |
| 62 | |
| 63 | /* Branch to exception vector */ |
| 64 | if (sctlr & (1 << 13)) |
| 65 | vect_offset += 0xffff0000; |
| 66 | else /* always have security exceptions */ |
| 67 | vect_offset += vcpu_cp15(vcpu, c12_VBAR); |
| 68 | |
| 69 | *vcpu_pc(vcpu) = vect_offset; |
| 70 | } |
| 71 | |
| 72 | void kvm_inject_undef32(struct kvm_vcpu *vcpu) |
| 73 | { |
| 74 | prepare_fault32(vcpu, PSR_AA32_MODE_UND, 4); |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * Modelled after TakeDataAbortException() and TakePrefetchAbortException |
| 79 | * pseudocode. |
| 80 | */ |
| 81 | static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, |
| 82 | unsigned long addr) |
| 83 | { |
| 84 | u32 vect_offset; |
| 85 | u32 *far, *fsr; |
| 86 | bool is_lpae; |
| 87 | |
| 88 | if (is_pabt) { |
| 89 | vect_offset = 12; |
| 90 | far = &vcpu_cp15(vcpu, c6_IFAR); |
| 91 | fsr = &vcpu_cp15(vcpu, c5_IFSR); |
| 92 | } else { /* !iabt */ |
| 93 | vect_offset = 16; |
| 94 | far = &vcpu_cp15(vcpu, c6_DFAR); |
| 95 | fsr = &vcpu_cp15(vcpu, c5_DFSR); |
| 96 | } |
| 97 | |
| 98 | prepare_fault32(vcpu, PSR_AA32_MODE_ABT | PSR_AA32_A_BIT, vect_offset); |
| 99 | |
| 100 | *far = addr; |
| 101 | |
| 102 | /* Give the guest an IMPLEMENTATION DEFINED exception */ |
| 103 | is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); |
| 104 | if (is_lpae) |
| 105 | *fsr = 1 << 9 | 0x34; |
| 106 | else |
| 107 | *fsr = 0x14; |
| 108 | } |
| 109 | |
| 110 | void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr) |
| 111 | { |
| 112 | inject_abt32(vcpu, false, addr); |
| 113 | } |
| 114 | |
| 115 | void kvm_inject_pabt32(struct kvm_vcpu *vcpu, unsigned long addr) |
| 116 | { |
| 117 | inject_abt32(vcpu, true, addr); |
| 118 | } |