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 /* Load the format arguments into x1-7 */ 78 mov x6, x3 79 get_vcpu_ptr x7, x3 80 81 mrs x3, esr_el2 82 mrs x4, far_el2 83 mrs x5, hpfar_el2 84 85 /* Prepare and exit to the host's panic funciton. */ 86 mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ 87 PSR_MODE_EL1h) 88 msr spsr_el2, lr 89 ldr lr, =panic 90 msr elr_el2, lr 91 92 /* 93 * Set the panic format string and enter the host, conditionally 94 * restoring the host context. 95 */ 96 cmp x0, xzr 97 ldr x0, =__hyp_panic_string 98 b.eq __host_enter_without_restoring 99 b __host_enter_for_panic 100SYM_FUNC_END(__hyp_do_panic) 101 102.macro host_el1_sync_vect 103 .align 7 104.L__vect_start\@: 105 stp x0, x1, [sp, #-16]! 106 mrs x0, esr_el2 107 lsr x0, x0, #ESR_ELx_EC_SHIFT 108 cmp x0, #ESR_ELx_EC_HVC64 109 b.ne __host_exit 110 111 ldp x0, x1, [sp] // Don't fixup the stack yet 112 113 /* Check for a stub HVC call */ 114 cmp x0, #HVC_STUB_HCALL_NR 115 b.hs __host_exit 116 117 add sp, sp, #16 118 /* 119 * Compute the idmap address of __kvm_handle_stub_hvc and 120 * jump there. Since we use kimage_voffset, do not use the 121 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead 122 * (by loading it from the constant pool). 123 * 124 * Preserve x0-x4, which may contain stub parameters. 125 */ 126 ldr x5, =__kvm_handle_stub_hvc 127 kimg_pa x5, x6 128 br x5 129.L__vect_end\@: 130.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) 131 .error "host_el1_sync_vect larger than vector entry" 132.endif 133.endm 134 135.macro invalid_host_el2_vect 136 .align 7 137 /* If a guest is loaded, panic out of it. */ 138 stp x0, x1, [sp, #-16]! 139 get_loaded_vcpu x0, x1 140 cbnz x0, __guest_exit_panic 141 add sp, sp, #16 142 143 /* 144 * The panic may not be clean if the exception is taken before the host 145 * context has been saved by __host_exit or after the hyp context has 146 * been partially clobbered by __host_enter. 147 */ 148 b hyp_panic 149.endm 150 151.macro invalid_host_el1_vect 152 .align 7 153 mov x0, xzr /* restore_host = false */ 154 mrs x1, spsr_el2 155 mrs x2, elr_el2 156 mrs x3, par_el1 157 b __hyp_do_panic 158.endm 159 160/* 161 * The host vector does not use an ESB instruction in order to avoid consuming 162 * SErrors that should only be consumed by the host. Guest entry is deferred by 163 * __guest_enter if there are any pending asynchronous exceptions so hyp will 164 * always return to the host without having consumerd host SErrors. 165 * 166 * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the 167 * host knows about the EL2 vectors already, and there is no point in hiding 168 * them. 169 */ 170 .align 11 171SYM_CODE_START(__kvm_hyp_host_vector) 172 invalid_host_el2_vect // Synchronous EL2t 173 invalid_host_el2_vect // IRQ EL2t 174 invalid_host_el2_vect // FIQ EL2t 175 invalid_host_el2_vect // Error EL2t 176 177 invalid_host_el2_vect // Synchronous EL2h 178 invalid_host_el2_vect // IRQ EL2h 179 invalid_host_el2_vect // FIQ EL2h 180 invalid_host_el2_vect // Error EL2h 181 182 host_el1_sync_vect // Synchronous 64-bit EL1 183 invalid_host_el1_vect // IRQ 64-bit EL1 184 invalid_host_el1_vect // FIQ 64-bit EL1 185 invalid_host_el1_vect // Error 64-bit EL1 186 187 invalid_host_el1_vect // Synchronous 32-bit EL1 188 invalid_host_el1_vect // IRQ 32-bit EL1 189 invalid_host_el1_vect // FIQ 32-bit EL1 190 invalid_host_el1_vect // Error 32-bit EL1 191SYM_CODE_END(__kvm_hyp_host_vector) 192 193/* 194 * Forward SMC with arguments in struct kvm_cpu_context, and 195 * store the result into the same struct. Assumes SMCCC 1.2 or older. 196 * 197 * x0: struct kvm_cpu_context* 198 */ 199SYM_CODE_START(__kvm_hyp_host_forward_smc) 200 /* 201 * Use x18 to keep the pointer to the host context because 202 * x18 is callee-saved in SMCCC but not in AAPCS64. 203 */ 204 mov x18, x0 205 206 ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 207 ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 208 ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 209 ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 210 ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 211 ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 212 ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 213 ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 214 ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 215 216 smc #0 217 218 stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 219 stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 220 stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 221 stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 222 stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 223 stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 224 stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 225 stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 226 stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 227 228 ret 229SYM_CODE_END(__kvm_hyp_host_forward_smc) 230