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_arm.h> 11#include <asm/kvm_asm.h> 12#include <asm/kvm_mmu.h> 13 14 .text 15 16SYM_FUNC_START(__host_exit) 17 get_host_ctxt x0, x1 18 19 /* Store the host regs x2 and x3 */ 20 stp x2, x3, [x0, #CPU_XREG_OFFSET(2)] 21 22 /* Retrieve the host regs x0-x1 from the stack */ 23 ldp x2, x3, [sp], #16 // x0, x1 24 25 /* Store the host regs x0-x1 and x4-x17 */ 26 stp x2, x3, [x0, #CPU_XREG_OFFSET(0)] 27 stp x4, x5, [x0, #CPU_XREG_OFFSET(4)] 28 stp x6, x7, [x0, #CPU_XREG_OFFSET(6)] 29 stp x8, x9, [x0, #CPU_XREG_OFFSET(8)] 30 stp x10, x11, [x0, #CPU_XREG_OFFSET(10)] 31 stp x12, x13, [x0, #CPU_XREG_OFFSET(12)] 32 stp x14, x15, [x0, #CPU_XREG_OFFSET(14)] 33 stp x16, x17, [x0, #CPU_XREG_OFFSET(16)] 34 35 /* Store the host regs x18-x29, lr */ 36 save_callee_saved_regs x0 37 38 /* Save the host context pointer in x29 across the function call */ 39 mov x29, x0 40 bl handle_trap 41 42 /* Restore host regs x0-x17 */ 43__host_enter_restore_full: 44 ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] 45 ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] 46 ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] 47 ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] 48 49 /* x0-7 are use for panic arguments */ 50__host_enter_for_panic: 51 ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] 52 ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] 53 ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] 54 ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] 55 ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] 56 57 /* Restore host regs x18-x29, lr */ 58 restore_callee_saved_regs x29 59 60 /* Do not touch any register after this! */ 61__host_enter_without_restoring: 62 eret 63 sb 64SYM_FUNC_END(__host_exit) 65 66/* 67 * void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); 68 */ 69SYM_FUNC_START(__host_enter) 70 mov x29, x0 71 b __host_enter_restore_full 72SYM_FUNC_END(__host_enter) 73 74/* 75 * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, 76 * u64 elr, u64 par); 77 */ 78SYM_FUNC_START(__hyp_do_panic) 79 /* Prepare and exit to the host's panic funciton. */ 80 mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ 81 PSR_MODE_EL1h) 82 msr spsr_el2, lr 83 ldr lr, =nvhe_hyp_panic_handler 84 hyp_kimg_va lr, x6 85 msr elr_el2, lr 86 87 mov x29, x0 88 89#ifdef CONFIG_NVHE_EL2_DEBUG 90 /* Ensure host stage-2 is disabled */ 91 mrs x0, hcr_el2 92 bic x0, x0, #HCR_VM 93 msr hcr_el2, x0 94 isb 95 tlbi vmalls12e1 96 dsb nsh 97#endif 98 99 /* Load the panic arguments into x0-7 */ 100 mrs x0, esr_el2 101 mov x4, x3 102 mov x3, x2 103 hyp_pa x3, x6 104 get_vcpu_ptr x5, x6 105 mrs x6, far_el2 106 mrs x7, hpfar_el2 107 108 /* Enter the host, conditionally restoring the host context. */ 109 cbz x29, __host_enter_without_restoring 110 b __host_enter_for_panic 111SYM_FUNC_END(__hyp_do_panic) 112 113SYM_FUNC_START(__host_hvc) 114 ldp x0, x1, [sp] // Don't fixup the stack yet 115 116 /* No stub for you, sonny Jim */ 117alternative_if ARM64_KVM_PROTECTED_MODE 118 b __host_exit 119alternative_else_nop_endif 120 121 /* Check for a stub HVC call */ 122 cmp x0, #HVC_STUB_HCALL_NR 123 b.hs __host_exit 124 125 add sp, sp, #16 126 /* 127 * Compute the idmap address of __kvm_handle_stub_hvc and 128 * jump there. Since we use kimage_voffset, do not use the 129 * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead 130 * (by loading it from the constant pool). 131 * 132 * Preserve x0-x4, which may contain stub parameters. 133 */ 134 ldr x5, =__kvm_handle_stub_hvc 135 hyp_pa x5, x6 136 br x5 137SYM_FUNC_END(__host_hvc) 138 139.macro host_el1_sync_vect 140 .align 7 141.L__vect_start\@: 142 stp x0, x1, [sp, #-16]! 143 mrs x0, esr_el2 144 ubfx x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH 145 cmp x0, #ESR_ELx_EC_HVC64 146 b.eq __host_hvc 147 b __host_exit 148.L__vect_end\@: 149.if ((.L__vect_end\@ - .L__vect_start\@) > 0x80) 150 .error "host_el1_sync_vect larger than vector entry" 151.endif 152.endm 153 154.macro invalid_host_el2_vect 155 .align 7 156 /* If a guest is loaded, panic out of it. */ 157 stp x0, x1, [sp, #-16]! 158 get_loaded_vcpu x0, x1 159 cbnz x0, __guest_exit_panic 160 add sp, sp, #16 161 162 /* 163 * The panic may not be clean if the exception is taken before the host 164 * context has been saved by __host_exit or after the hyp context has 165 * been partially clobbered by __host_enter. 166 */ 167 b hyp_panic 168.endm 169 170.macro invalid_host_el1_vect 171 .align 7 172 mov x0, xzr /* restore_host = false */ 173 mrs x1, spsr_el2 174 mrs x2, elr_el2 175 mrs x3, par_el1 176 b __hyp_do_panic 177.endm 178 179/* 180 * The host vector does not use an ESB instruction in order to avoid consuming 181 * SErrors that should only be consumed by the host. Guest entry is deferred by 182 * __guest_enter if there are any pending asynchronous exceptions so hyp will 183 * always return to the host without having consumerd host SErrors. 184 * 185 * CONFIG_KVM_INDIRECT_VECTORS is not applied to the host vectors because the 186 * host knows about the EL2 vectors already, and there is no point in hiding 187 * them. 188 */ 189 .align 11 190SYM_CODE_START(__kvm_hyp_host_vector) 191 invalid_host_el2_vect // Synchronous EL2t 192 invalid_host_el2_vect // IRQ EL2t 193 invalid_host_el2_vect // FIQ EL2t 194 invalid_host_el2_vect // Error EL2t 195 196 invalid_host_el2_vect // Synchronous EL2h 197 invalid_host_el2_vect // IRQ EL2h 198 invalid_host_el2_vect // FIQ EL2h 199 invalid_host_el2_vect // Error EL2h 200 201 host_el1_sync_vect // Synchronous 64-bit EL1 202 invalid_host_el1_vect // IRQ 64-bit EL1 203 invalid_host_el1_vect // FIQ 64-bit EL1 204 invalid_host_el1_vect // Error 64-bit EL1 205 206 invalid_host_el1_vect // Synchronous 32-bit EL1 207 invalid_host_el1_vect // IRQ 32-bit EL1 208 invalid_host_el1_vect // FIQ 32-bit EL1 209 invalid_host_el1_vect // Error 32-bit EL1 210SYM_CODE_END(__kvm_hyp_host_vector) 211 212/* 213 * Forward SMC with arguments in struct kvm_cpu_context, and 214 * store the result into the same struct. Assumes SMCCC 1.2 or older. 215 * 216 * x0: struct kvm_cpu_context* 217 */ 218SYM_CODE_START(__kvm_hyp_host_forward_smc) 219 /* 220 * Use x18 to keep the pointer to the host context because 221 * x18 is callee-saved in SMCCC but not in AAPCS64. 222 */ 223 mov x18, x0 224 225 ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 226 ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 227 ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 228 ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 229 ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 230 ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 231 ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 232 ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 233 ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 234 235 smc #0 236 237 stp x0, x1, [x18, #CPU_XREG_OFFSET(0)] 238 stp x2, x3, [x18, #CPU_XREG_OFFSET(2)] 239 stp x4, x5, [x18, #CPU_XREG_OFFSET(4)] 240 stp x6, x7, [x18, #CPU_XREG_OFFSET(6)] 241 stp x8, x9, [x18, #CPU_XREG_OFFSET(8)] 242 stp x10, x11, [x18, #CPU_XREG_OFFSET(10)] 243 stp x12, x13, [x18, #CPU_XREG_OFFSET(12)] 244 stp x14, x15, [x18, #CPU_XREG_OFFSET(14)] 245 stp x16, x17, [x18, #CPU_XREG_OFFSET(16)] 246 247 ret 248SYM_CODE_END(__kvm_hyp_host_forward_smc) 249