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(struct kvm_cpu_context *host_ctxt, u64 spsr, 75 * u64 elr, u64 par); 76 */ 77SYM_FUNC_START(__hyp_do_panic) 78 /* Prepare and exit to the host's panic funciton. */ 79 mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ 80 PSR_MODE_EL1h) 81 msr spsr_el2, lr 82 ldr lr, =nvhe_hyp_panic_handler 83 hyp_kimg_va lr, x6 84 msr elr_el2, lr 85 86 mov x29, x0 87 88 /* Load the panic arguments into x0-7 */ 89 mrs x0, esr_el2 90 get_vcpu_ptr x4, x5 91 mrs x5, far_el2 92 mrs x6, hpfar_el2 93 mov x7, xzr // Unused argument 94 95 /* Enter the host, conditionally restoring the host context. */ 96 cbz x29, __host_enter_without_restoring 97 b __host_enter_for_panic 98SYM_FUNC_END(__hyp_do_panic) 99 100.macro host_el1_sync_vect 101 .align 7 102.L__vect_start\@: 103 stp x0, x1, [sp, #-16]! 104 mrs x0, esr_el2 105 lsr x0, x0, #ESR_ELx_EC_SHIFT 106 cmp x0, #ESR_ELx_EC_HVC64 107 b.ne __host_exit 108 109 ldp x0, x1, [sp] // Don't fixup the stack yet 110 111 /* Check for a stub HVC call */ 112 cmp x0, #HVC_STUB_HCALL_NR 113 b.hs __host_exit 114 115 add sp, sp, #16 116 /* 117 * Compute the idmap address of __kvm_handle_stub_hvc and 118 * jump there. Since we use kimage_voffset, do not use the 119 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead 120 * (by loading it from the constant pool). 121 * 122 * Preserve x0-x4, which may contain stub parameters. 123 */ 124 ldr x5, =__kvm_handle_stub_hvc 125 hyp_pa x5, x6 126 br x5 127.L__vect_end\@: 128.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) 129 .error "host_el1_sync_vect larger than vector entry" 130.endif 131.endm 132 133.macro invalid_host_el2_vect 134 .align 7 135 /* If a guest is loaded, panic out of it. */ 136 stp x0, x1, [sp, #-16]! 137 get_loaded_vcpu x0, x1 138 cbnz x0, __guest_exit_panic 139 add sp, sp, #16 140 141 /* 142 * The panic may not be clean if the exception is taken before the host 143 * context has been saved by __host_exit or after the hyp context has 144 * been partially clobbered by __host_enter. 145 */ 146 b hyp_panic 147.endm 148 149.macro invalid_host_el1_vect 150 .align 7 151 mov x0, xzr /* restore_host = false */ 152 mrs x1, spsr_el2 153 mrs x2, elr_el2 154 mrs x3, par_el1 155 b __hyp_do_panic 156.endm 157 158/* 159 * The host vector does not use an ESB instruction in order to avoid consuming 160 * SErrors that should only be consumed by the host. Guest entry is deferred by 161 * __guest_enter if there are any pending asynchronous exceptions so hyp will 162 * always return to the host without having consumerd host SErrors. 163 * 164 * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the 165 * host knows about the EL2 vectors already, and there is no point in hiding 166 * them. 167 */ 168 .align 11 169SYM_CODE_START(__kvm_hyp_host_vector) 170 invalid_host_el2_vect // Synchronous EL2t 171 invalid_host_el2_vect // IRQ EL2t 172 invalid_host_el2_vect // FIQ EL2t 173 invalid_host_el2_vect // Error EL2t 174 175 invalid_host_el2_vect // Synchronous EL2h 176 invalid_host_el2_vect // IRQ EL2h 177 invalid_host_el2_vect // FIQ EL2h 178 invalid_host_el2_vect // Error EL2h 179 180 host_el1_sync_vect // Synchronous 64-bit EL1 181 invalid_host_el1_vect // IRQ 64-bit EL1 182 invalid_host_el1_vect // FIQ 64-bit EL1 183 invalid_host_el1_vect // Error 64-bit EL1 184 185 invalid_host_el1_vect // Synchronous 32-bit EL1 186 invalid_host_el1_vect // IRQ 32-bit EL1 187 invalid_host_el1_vect // FIQ 32-bit EL1 188 invalid_host_el1_vect // Error 32-bit EL1 189SYM_CODE_END(__kvm_hyp_host_vector) 190 191/* 192 * Forward SMC with arguments in struct kvm_cpu_context, and 193 * store the result into the same struct. Assumes SMCCC 1.2 or older. 194 * 195 * x0: struct kvm_cpu_context* 196 */ 197SYM_CODE_START(__kvm_hyp_host_forward_smc) 198 /* 199 * Use x18 to keep the pointer to the host context because 200 * x18 is callee-saved in SMCCC but not in AAPCS64. 201 */ 202 mov x18, x0 203 204 ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 205 ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 206 ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 207 ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 208 ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 209 ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 210 ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 211 ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 212 ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 213 214 smc #0 215 216 stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 217 stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 218 stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 219 stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 220 stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 221 stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 222 stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 223 stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 224 stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 225 226 ret 227SYM_CODE_END(__kvm_hyp_host_forward_smc) 228