Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 | /* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2015-2018 - ARM Ltd * Author: Marc Zyngier <marc.zyngier@arm.com> */ #include <linux/arm-smccc.h> #include <linux/linkage.h> #include <asm/alternative.h> #include <asm/assembler.h> #include <asm/cpufeature.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> #include <asm/mmu.h> .text .pushsection .hyp.text, "ax" .macro do_el2_call /* * Shuffle the parameters before calling the function * pointed to in x0. Assumes parameters in x[1,2,3]. */ str lr, [sp, #-16]! mov lr, x0 mov x0, x1 mov x1, x2 mov x2, x3 blr lr ldr lr, [sp], #16 .endm el1_sync: // Guest trapped into EL2 mrs x0, esr_el2 lsr x0, x0, #ESR_ELx_EC_SHIFT cmp x0, #ESR_ELx_EC_HVC64 ccmp x0, #ESR_ELx_EC_HVC32, #4, ne b.ne el1_trap mrs x1, vttbr_el2 // If vttbr is valid, the guest cbnz x1, el1_hvc_guest // called HVC /* Here, we're pretty sure the host called HVC. */ ldp x0, x1, [sp], #16 /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR b.hs 1f /* * Compute the idmap address of __kvm_handle_stub_hvc and * jump there. Since we use kimage_voffset, do not use the * HYP VA for __kvm_handle_stub_hvc, but the kernel VA instead * (by loading it from the constant pool). * * Preserve x0-x4, which may contain stub parameters. */ ldr x5, =__kvm_handle_stub_hvc ldr_l x6, kimage_voffset /* x5 = __pa(x5) */ sub x5, x5, x6 br x5 1: /* * Perform the EL2 call */ kern_hyp_va x0 do_el2_call eret sb el1_hvc_guest: /* * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1. * The workaround has already been applied on the host, * so let's quickly get back to the guest. We don't bother * restoring x1, as it can be clobbered anyway. */ ldr x1, [sp] // Guest's x0 eor w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1 cbz w1, wa_epilogue /* ARM_SMCCC_ARCH_WORKAROUND_2 handling */ eor w1, w1, #(ARM_SMCCC_ARCH_WORKAROUND_1 ^ \ ARM_SMCCC_ARCH_WORKAROUND_2) cbnz w1, el1_trap #ifdef CONFIG_ARM64_SSBD alternative_cb arm64_enable_wa2_handling b wa2_end alternative_cb_end get_vcpu_ptr x2, x0 ldr x0, [x2, #VCPU_WORKAROUND_FLAGS] // Sanitize the argument and update the guest flags ldr x1, [sp, #8] // Guest's x1 clz w1, w1 // Murphy's device: lsr w1, w1, #5 // w1 = !!w1 without using eor w1, w1, #1 // the flags... bfi x0, x1, #VCPU_WORKAROUND_2_FLAG_SHIFT, #1 str x0, [x2, #VCPU_WORKAROUND_FLAGS] /* Check that we actually need to perform the call */ hyp_ldr_this_cpu x0, arm64_ssbd_callback_required, x2 cbz x0, wa2_end mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 smc #0 /* Don't leak data from the SMC call */ mov x3, xzr wa2_end: mov x2, xzr mov x1, xzr #endif wa_epilogue: mov x0, xzr add sp, sp, #16 eret sb el1_trap: get_vcpu_ptr x1, x0 mov x0, #ARM_EXCEPTION_TRAP b __guest_exit el1_irq: get_vcpu_ptr x1, x0 mov x0, #ARM_EXCEPTION_IRQ b __guest_exit el1_error: get_vcpu_ptr x1, x0 mov x0, #ARM_EXCEPTION_EL1_SERROR b __guest_exit el2_sync: /* Check for illegal exception return, otherwise panic */ mrs x0, spsr_el2 /* if this was something else, then panic! */ tst x0, #PSR_IL_BIT b.eq __hyp_panic /* Let's attempt a recovery from the illegal exception return */ get_vcpu_ptr x1, x0 mov x0, #ARM_EXCEPTION_IL b __guest_exit el2_error: ldp x0, x1, [sp], #16 /* * Only two possibilities: * 1) Either we come from the exit path, having just unmasked * PSTATE.A: change the return code to an EL2 fault, and * carry on, as we're already in a sane state to handle it. * 2) Or we come from anywhere else, and that's a bug: we panic. * * For (1), x0 contains the original return code and x1 doesn't * contain anything meaningful at that stage. We can reuse them * as temp registers. * For (2), who cares? */ mrs x0, elr_el2 adr x1, abort_guest_exit_start cmp x0, x1 adr x1, abort_guest_exit_end ccmp x0, x1, #4, ne b.ne __hyp_panic mov x0, #(1 << ARM_EXIT_WITH_SERROR_BIT) eret sb ENTRY(__hyp_do_panic) mov lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ PSR_MODE_EL1h) msr spsr_el2, lr ldr lr, =panic msr elr_el2, lr eret sb ENDPROC(__hyp_do_panic) ENTRY(__hyp_panic) get_host_ctxt x0, x1 b hyp_panic ENDPROC(__hyp_panic) .macro invalid_vector label, target = __hyp_panic .align 2 \label: b \target ENDPROC(\label) .endm /* None of these should ever happen */ invalid_vector el2t_sync_invalid invalid_vector el2t_irq_invalid invalid_vector el2t_fiq_invalid invalid_vector el2t_error_invalid invalid_vector el2h_sync_invalid invalid_vector el2h_irq_invalid invalid_vector el2h_fiq_invalid invalid_vector el1_fiq_invalid .ltorg .align 11 .macro check_preamble_length start, end /* kvm_patch_vector_branch() generates code that jumps over the preamble. */ .if ((\end-\start) != KVM_VECTOR_PREAMBLE) .error "KVM vector preamble length mismatch" .endif .endm .macro valid_vect target .align 7 661: esb stp x0, x1, [sp, #-16]! 662: b \target check_preamble_length 661b, 662b .endm .macro invalid_vect target .align 7 661: b \target nop 662: ldp x0, x1, [sp], #16 b \target check_preamble_length 661b, 662b .endm ENTRY(__kvm_hyp_vector) invalid_vect el2t_sync_invalid // Synchronous EL2t invalid_vect el2t_irq_invalid // IRQ EL2t invalid_vect el2t_fiq_invalid // FIQ EL2t invalid_vect el2t_error_invalid // Error EL2t valid_vect el2_sync // Synchronous EL2h invalid_vect el2h_irq_invalid // IRQ EL2h invalid_vect el2h_fiq_invalid // FIQ EL2h valid_vect el2_error // Error EL2h valid_vect el1_sync // Synchronous 64-bit EL1 valid_vect el1_irq // IRQ 64-bit EL1 invalid_vect el1_fiq_invalid // FIQ 64-bit EL1 valid_vect el1_error // Error 64-bit EL1 valid_vect el1_sync // Synchronous 32-bit EL1 valid_vect el1_irq // IRQ 32-bit EL1 invalid_vect el1_fiq_invalid // FIQ 32-bit EL1 valid_vect el1_error // Error 32-bit EL1 ENDPROC(__kvm_hyp_vector) #ifdef CONFIG_KVM_INDIRECT_VECTORS .macro hyp_ventry .align 7 1: esb .rept 26 nop .endr /* * The default sequence is to directly branch to the KVM vectors, * using the computed offset. This applies for VHE as well as * !ARM64_HARDEN_EL2_VECTORS. The first vector must always run the preamble. * * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced * with: * * stp x0, x1, [sp, #-16]! * movz x0, #(addr & 0xffff) * movk x0, #((addr >> 16) & 0xffff), lsl #16 * movk x0, #((addr >> 32) & 0xffff), lsl #32 * br x0 * * Where: * addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + KVM_VECTOR_PREAMBLE. * See kvm_patch_vector_branch for details. */ alternative_cb kvm_patch_vector_branch stp x0, x1, [sp, #-16]! b __kvm_hyp_vector + (1b - 0b + KVM_VECTOR_PREAMBLE) nop nop nop alternative_cb_end .endm .macro generate_vectors 0: .rept 16 hyp_ventry .endr .org 0b + SZ_2K // Safety measure .endm .align 11 ENTRY(__bp_harden_hyp_vecs_start) .rept BP_HARDEN_EL2_SLOTS generate_vectors .endr ENTRY(__bp_harden_hyp_vecs_end) .popsection ENTRY(__smccc_workaround_1_smc_start) esb sub sp, sp, #(8 * 4) stp x2, x3, [sp, #(8 * 0)] stp x0, x1, [sp, #(8 * 2)] mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 smc #0 ldp x2, x3, [sp, #(8 * 0)] ldp x0, x1, [sp, #(8 * 2)] add sp, sp, #(8 * 4) ENTRY(__smccc_workaround_1_smc_end) #endif |