1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Copyright (C) 2012,2013 - ARM Ltd 4 * Author: Marc Zyngier <marc.zyngier@arm.com> 5 */ 6 7#include <linux/arm-smccc.h> 8#include <linux/cfi_types.h> 9#include <linux/linkage.h> 10 11#include <asm/alternative.h> 12#include <asm/assembler.h> 13#include <asm/el2_setup.h> 14#include <asm/kvm_arm.h> 15#include <asm/kvm_asm.h> 16#include <asm/kvm_mmu.h> 17#include <asm/pgtable-hwdef.h> 18#include <asm/sysreg.h> 19#include <asm/virt.h> 20 21 .text 22 .pushsection .idmap.text, "ax" 23 24 .align 11 25 26SYM_CODE_START(__kvm_hyp_init) 27 ventry . // Synchronous EL2t 28 ventry . // IRQ EL2t 29 ventry . // FIQ EL2t 30 ventry . // Error EL2t 31 32 ventry . // Synchronous EL2h 33 ventry . // IRQ EL2h 34 ventry . // FIQ EL2h 35 ventry . // Error EL2h 36 37 ventry __do_hyp_init // Synchronous 64-bit EL1 38 ventry . // IRQ 64-bit EL1 39 ventry . // FIQ 64-bit EL1 40 ventry . // Error 64-bit EL1 41 42 ventry . // Synchronous 32-bit EL1 43 ventry . // IRQ 32-bit EL1 44 ventry . // FIQ 32-bit EL1 45 ventry . // Error 32-bit EL1 46 47 /* 48 * Only uses x0..x3 so as to not clobber callee-saved SMCCC registers. 49 * 50 * x0: SMCCC function ID 51 * x1: struct kvm_nvhe_init_params PA 52 */ 53__do_hyp_init: 54 /* Check for a stub HVC call */ 55 cmp x0, #HVC_STUB_HCALL_NR 56 b.lo __kvm_handle_stub_hvc 57 58 bic x0, x0, #ARM_SMCCC_CALL_HINTS 59 mov x3, #KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) 60 cmp x0, x3 61 b.eq 1f 62 63 mov x0, #SMCCC_RET_NOT_SUPPORTED 64 eret 65 661: mov x0, x1 67 mov x3, lr 68 bl ___kvm_hyp_init // Clobbers x0..x2 69 mov lr, x3 70 71 /* Hello, World! */ 72 mov x0, #SMCCC_RET_SUCCESS 73 eret 74SYM_CODE_END(__kvm_hyp_init) 75 76SYM_CODE_START_LOCAL(__kvm_init_el2_state) 77 /* Initialize EL2 CPU state to sane values. */ 78 init_el2_state // Clobbers x0..x2 79 finalise_el2_state 80 ret 81SYM_CODE_END(__kvm_init_el2_state) 82 83/* 84 * Initialize the hypervisor in EL2. 85 * 86 * Only uses x0..x2 so as to not clobber callee-saved SMCCC registers 87 * and leave x3 for the caller. 88 * 89 * x0: struct kvm_nvhe_init_params PA 90 */ 91SYM_CODE_START_LOCAL(___kvm_hyp_init) 92 ldr x1, [x0, #NVHE_INIT_STACK_HYP_VA] 93 mov sp, x1 94 95 ldr x1, [x0, #NVHE_INIT_MAIR_EL2] 96 msr mair_el2, x1 97 98 ldr x1, [x0, #NVHE_INIT_HCR_EL2] 99 msr hcr_el2, x1 100 101 mov x2, #HCR_E2H 102 and x2, x1, x2 103 cbz x2, 1f 104 105 // hVHE: Replay the EL2 setup to account for the E2H bit 106 // TPIDR_EL2 is used to preserve x0 across the macro maze... 107 isb 108 msr tpidr_el2, x0 109 str lr, [x0, #NVHE_INIT_TMP] 110 111 bl __kvm_init_el2_state 112 113 mrs x0, tpidr_el2 114 ldr lr, [x0, #NVHE_INIT_TMP] 115 1161: 117 ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] 118 msr tpidr_el2, x1 119 120 ldr x1, [x0, #NVHE_INIT_VTTBR] 121 msr vttbr_el2, x1 122 123 ldr x1, [x0, #NVHE_INIT_VTCR] 124 msr vtcr_el2, x1 125 126 ldr x1, [x0, #NVHE_INIT_PGD_PA] 127 phys_to_ttbr x2, x1 128alternative_if ARM64_HAS_CNP 129 orr x2, x2, #TTBR_CNP_BIT 130alternative_else_nop_endif 131 msr ttbr0_el2, x2 132 133 ldr x0, [x0, #NVHE_INIT_TCR_EL2] 134 msr tcr_el2, x0 135 136 isb 137 138 /* Invalidate the stale TLBs from Bootloader */ 139 tlbi alle2 140 tlbi alle1 141 dsb sy 142 143 mov_q x0, INIT_SCTLR_EL2_MMU_ON 144alternative_if ARM64_HAS_ADDRESS_AUTH 145 mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ 146 SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) 147 orr x0, x0, x1 148alternative_else_nop_endif 149 150#ifdef CONFIG_ARM64_BTI_KERNEL 151alternative_if ARM64_BTI 152 orr x0, x0, #SCTLR_EL2_BT 153alternative_else_nop_endif 154#endif /* CONFIG_ARM64_BTI_KERNEL */ 155 156 msr sctlr_el2, x0 157 isb 158 159 /* Set the host vector */ 160 ldr x0, =__kvm_hyp_host_vector 161 msr vbar_el2, x0 162 163 ret 164SYM_CODE_END(___kvm_hyp_init) 165 166/* 167 * PSCI CPU_ON entry point 168 * 169 * x0: struct kvm_nvhe_init_params PA 170 */ 171SYM_CODE_START(kvm_hyp_cpu_entry) 172 mov x1, #1 // is_cpu_on = true 173 b __kvm_hyp_init_cpu 174SYM_CODE_END(kvm_hyp_cpu_entry) 175 176/* 177 * PSCI CPU_SUSPEND / SYSTEM_SUSPEND entry point 178 * 179 * x0: struct kvm_nvhe_init_params PA 180 */ 181SYM_CODE_START(kvm_hyp_cpu_resume) 182 mov x1, #0 // is_cpu_on = false 183 b __kvm_hyp_init_cpu 184SYM_CODE_END(kvm_hyp_cpu_resume) 185 186/* 187 * Common code for CPU entry points. Initializes EL2 state and 188 * installs the hypervisor before handing over to a C handler. 189 * 190 * x0: struct kvm_nvhe_init_params PA 191 * x1: bool is_cpu_on 192 */ 193SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) 194 mov x28, x0 // Stash arguments 195 mov x29, x1 196 197 /* Check that the core was booted in EL2. */ 198 mrs x0, CurrentEL 199 cmp x0, #CurrentEL_EL2 200 b.eq 2f 201 202 /* The core booted in EL1. KVM cannot be initialized on it. */ 2031: wfe 204 wfi 205 b 1b 206 2072: msr SPsel, #1 // We want to use SP_EL{1,2} 208 209 bl __kvm_init_el2_state 210 211 __init_el2_nvhe_prepare_eret 212 213 /* Enable MMU, set vectors and stack. */ 214 mov x0, x28 215 bl ___kvm_hyp_init // Clobbers x0..x2 216 217 /* Leave idmap. */ 218 mov x0, x29 219 ldr x1, =kvm_host_psci_cpu_entry 220 br x1 221SYM_CODE_END(__kvm_hyp_init_cpu) 222 223SYM_CODE_START(__kvm_handle_stub_hvc) 224 /* 225 * __kvm_handle_stub_hvc called from __host_hvc through branch instruction(br) so 226 * we need bti j at beginning. 227 */ 228 bti j 229 cmp x0, #HVC_SOFT_RESTART 230 b.ne 1f 231 232 /* This is where we're about to jump, staying at EL2 */ 233 msr elr_el2, x1 234 mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) 235 msr spsr_el2, x0 236 237 /* Shuffle the arguments, and don't come back */ 238 mov x0, x2 239 mov x1, x3 240 mov x2, x4 241 b reset 242 2431: cmp x0, #HVC_RESET_VECTORS 244 b.ne 1f 245 246 /* 247 * Set the HVC_RESET_VECTORS return code before entering the common 248 * path so that we do not clobber x0-x2 in case we are coming via 249 * HVC_SOFT_RESTART. 250 */ 251 mov x0, xzr 252reset: 253 /* Reset kvm back to the hyp stub. */ 254 mov_q x5, INIT_SCTLR_EL2_MMU_OFF 255 pre_disable_mmu_workaround 256 msr sctlr_el2, x5 257 isb 258 259alternative_if ARM64_KVM_PROTECTED_MODE 260 mov_q x5, HCR_HOST_NVHE_FLAGS 261 msr hcr_el2, x5 262alternative_else_nop_endif 263 264 /* Install stub vectors */ 265 adr_l x5, __hyp_stub_vectors 266 msr vbar_el2, x5 267 eret 268 2691: /* Bad stub call */ 270 mov_q x0, HVC_STUB_ERR 271 eret 272 273SYM_CODE_END(__kvm_handle_stub_hvc) 274 275/* 276 * void __pkvm_init_switch_pgd(phys_addr_t pgd, unsigned long sp, 277 * void (*fn)(void)); 278 * 279 * SYM_TYPED_FUNC_START() allows C to call this ID-mapped function indirectly 280 * using a physical pointer without triggering a kCFI failure. 281 */ 282SYM_TYPED_FUNC_START(__pkvm_init_switch_pgd) 283 /* Turn the MMU off */ 284 pre_disable_mmu_workaround 285 mrs x3, sctlr_el2 286 bic x4, x3, #SCTLR_ELx_M 287 msr sctlr_el2, x4 288 isb 289 290 tlbi alle2 291 292 /* Install the new pgtables */ 293 phys_to_ttbr x5, x0 294alternative_if ARM64_HAS_CNP 295 orr x5, x5, #TTBR_CNP_BIT 296alternative_else_nop_endif 297 msr ttbr0_el2, x5 298 299 /* Set the new stack pointer */ 300 mov sp, x1 301 302 /* And turn the MMU back on! */ 303 dsb nsh 304 isb 305 set_sctlr_el2 x3 306 ret x2 307SYM_FUNC_END(__pkvm_init_switch_pgd) 308 309 .popsection 310