1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Copyright (C) 2020 - Google Inc 4 * Author: Andrew Scull <ascull@google.com> 5 */ 6 7#include <linux/linkage.h> 8 9#include <asm/assembler.h> 10#include <asm/kvm_asm.h> 11#include <asm/kvm_mmu.h> 12 13 .text 14 15SYM_FUNC_START(__host_exit) 16 get_host_ctxt x0, x1 17 18 /* Store the host regs x2 and x3 */ 19 stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] 20 21 /* Retrieve the host regs x0-x1 from the stack */ 22 ldp x2, x3, [sp], #16 // x0, x1 23 24 /* Store the host regs x0-x1 and x4-x17 */ 25 stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] 26 stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] 27 stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] 28 stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] 29 stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] 30 stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] 31 stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] 32 stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] 33 34 /* Store the host regs x18-x29, lr */ 35 save_callee_saved_regs x0 36 37 /* Save the host context pointer in x29 across the function call */ 38 mov x29, x0 39 bl handle_trap 40 41 /* Restore host regs x0-x17 */ 42__host_enter_restore_full: 43 ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] 44 ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] 45 ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] 46 ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] 47 48 /* x0-7 are use for panic arguments */ 49__host_enter_for_panic: 50 ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] 51 ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] 52 ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] 53 ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] 54 ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] 55 56 /* Restore host regs x18-x29, lr */ 57 restore_callee_saved_regs x29 58 59 /* Do not touch any register after this! */ 60__host_enter_without_restoring: 61 eret 62 sb 63SYM_FUNC_END(__host_exit) 64 65/* 66 * void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); 67 */ 68SYM_FUNC_START(__host_enter) 69 mov x29, x0 70 b __host_enter_restore_full 71SYM_FUNC_END(__host_enter) 72 73/* 74 * void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par); 75 */ 76SYM_FUNC_START(__hyp_do_panic) 77 /* Prepare and exit to the host's panic funciton. */ 78 mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ 79 PSR_MODE_EL1h) 80 msr spsr_el2, lr 81 ldr lr, =panic 82 hyp_kimg_va lr, x6 83 msr elr_el2, lr 84 85 /* Set the panic format string. Use the, now free, LR as scratch. */ 86 ldr lr, =__hyp_panic_string 87 hyp_kimg_va lr, x6 88 89 /* Load the format arguments into x1-7. */ 90 mov x6, x3 91 get_vcpu_ptr x7, x3 92 mrs x3, esr_el2 93 mrs x4, far_el2 94 mrs x5, hpfar_el2 95 96 /* Enter the host, conditionally restoring the host context. */ 97 cmp x0, xzr 98 mov x0, lr 99 b.eq __host_enter_without_restoring 100 b __host_enter_for_panic 101SYM_FUNC_END(__hyp_do_panic) 102 103.macro host_el1_sync_vect 104 .align 7 105.L__vect_start\@: 106 stp x0, x1, [sp, #-16]! 107 mrs x0, esr_el2 108 lsr x0, x0, #ESR_ELx_EC_SHIFT 109 cmp x0, #ESR_ELx_EC_HVC64 110 b.ne __host_exit 111 112 ldp x0, x1, [sp] // Don't fixup the stack yet 113 114 /* Check for a stub HVC call */ 115 cmp x0, #HVC_STUB_HCALL_NR 116 b.hs __host_exit 117 118 add sp, sp, #16 119 /* 120 * Compute the idmap address of __kvm_handle_stub_hvc and 121 * jump there. Since we use kimage_voffset, do not use the 122 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead 123 * (by loading it from the constant pool). 124 * 125 * Preserve x0-x4, which may contain stub parameters. 126 */ 127 ldr x5, =__kvm_handle_stub_hvc 128 hyp_pa x5, x6 129 br x5 130.L__vect_end\@: 131.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) 132 .error "host_el1_sync_vect larger than vector entry" 133.endif 134.endm 135 136.macro invalid_host_el2_vect 137 .align 7 138 /* If a guest is loaded, panic out of it. */ 139 stp x0, x1, [sp, #-16]! 140 get_loaded_vcpu x0, x1 141 cbnz x0, __guest_exit_panic 142 add sp, sp, #16 143 144 /* 145 * The panic may not be clean if the exception is taken before the host 146 * context has been saved by __host_exit or after the hyp context has 147 * been partially clobbered by __host_enter. 148 */ 149 b hyp_panic 150.endm 151 152.macro invalid_host_el1_vect 153 .align 7 154 mov x0, xzr /* restore_host = false */ 155 mrs x1, spsr_el2 156 mrs x2, elr_el2 157 mrs x3, par_el1 158 b __hyp_do_panic 159.endm 160 161/* 162 * The host vector does not use an ESB instruction in order to avoid consuming 163 * SErrors that should only be consumed by the host. Guest entry is deferred by 164 * __guest_enter if there are any pending asynchronous exceptions so hyp will 165 * always return to the host without having consumerd host SErrors. 166 * 167 * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the 168 * host knows about the EL2 vectors already, and there is no point in hiding 169 * them. 170 */ 171 .align 11 172SYM_CODE_START(__kvm_hyp_host_vector) 173 invalid_host_el2_vect // Synchronous EL2t 174 invalid_host_el2_vect // IRQ EL2t 175 invalid_host_el2_vect // FIQ EL2t 176 invalid_host_el2_vect // Error EL2t 177 178 invalid_host_el2_vect // Synchronous EL2h 179 invalid_host_el2_vect // IRQ EL2h 180 invalid_host_el2_vect // FIQ EL2h 181 invalid_host_el2_vect // Error EL2h 182 183 host_el1_sync_vect // Synchronous 64-bit EL1 184 invalid_host_el1_vect // IRQ 64-bit EL1 185 invalid_host_el1_vect // FIQ 64-bit EL1 186 invalid_host_el1_vect // Error 64-bit EL1 187 188 invalid_host_el1_vect // Synchronous 32-bit EL1 189 invalid_host_el1_vect // IRQ 32-bit EL1 190 invalid_host_el1_vect // FIQ 32-bit EL1 191 invalid_host_el1_vect // Error 32-bit EL1 192SYM_CODE_END(__kvm_hyp_host_vector) 193 194/* 195 * Forward SMC with arguments in struct kvm_cpu_context, and 196 * store the result into the same struct. Assumes SMCCC 1.2 or older. 197 * 198 * x0: struct kvm_cpu_context* 199 */ 200SYM_CODE_START(__kvm_hyp_host_forward_smc) 201 /* 202 * Use x18 to keep the pointer to the host context because 203 * x18 is callee-saved in SMCCC but not in AAPCS64. 204 */ 205 mov x18, x0 206 207 ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 208 ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 209 ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 210 ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 211 ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 212 ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 213 ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 214 ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 215 ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 216 217 smc #0 218 219 stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 220 stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 221 stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 222 stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 223 stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 224 stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 225 stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 226 stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 227 stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 228 229 ret 230SYM_CODE_END(__kvm_hyp_host_forward_smc) 231