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/linkage.h> 9 10 #include <asm/alternative.h> 11 #include <asm/assembler.h> 12 #include <asm/el2_setup.h> 13 #include <asm/kvm_arm.h> 14 #include <asm/kvm_asm.h> 15 #include <asm/kvm_mmu.h> 16 #include <asm/pgtable-hwdef.h> 17 #include <asm/sysreg.h> 18 #include <asm/virt.h> 19 20 .text 21 .pushsection .idmap.text, "ax" 22 23 .align 11 24 25 SYM_CODE_START(__kvm_hyp_init) 26 ventry __invalid // Synchronous EL2t 27 ventry __invalid // IRQ EL2t 28 ventry __invalid // FIQ EL2t 29 ventry __invalid // Error EL2t 30 31 ventry __invalid // Synchronous EL2h 32 ventry __invalid // IRQ EL2h 33 ventry __invalid // FIQ EL2h 34 ventry __invalid // Error EL2h 35 36 ventry __do_hyp_init // Synchronous 64-bit EL1 37 ventry __invalid // IRQ 64-bit EL1 38 ventry __invalid // FIQ 64-bit EL1 39 ventry __invalid // Error 64-bit EL1 40 41 ventry __invalid // Synchronous 32-bit EL1 42 ventry __invalid // IRQ 32-bit EL1 43 ventry __invalid // FIQ 32-bit EL1 44 ventry __invalid // Error 32-bit EL1 45 46 __invalid: 47 b . 48 49 /* 50 * Only uses x0..x3 so as to not clobber callee-saved SMCCC registers. 51 * 52 * x0: SMCCC function ID 53 * x1: struct kvm_nvhe_init_params PA 54 */ 55 __do_hyp_init: 56 /* Check for a stub HVC call */ 57 cmp x0, #HVC_STUB_HCALL_NR 58 b.lo __kvm_handle_stub_hvc 59 60 bic x0, x0, #ARM_SMCCC_CALL_HINTS 61 mov x3, #KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) 62 cmp x0, x3 63 b.eq 1f 64 65 mov x0, #SMCCC_RET_NOT_SUPPORTED 66 eret 67 68 1: mov x0, x1 69 mov x3, lr 70 bl ___kvm_hyp_init // Clobbers x0..x2 71 mov lr, x3 72 73 /* Hello, World! */ 74 mov x0, #SMCCC_RET_SUCCESS 75 eret 76 SYM_CODE_END(__kvm_hyp_init) 77 78 /* 79 * Initialize the hypervisor in EL2. 80 * 81 * Only uses x0..x2 so as to not clobber callee-saved SMCCC registers 82 * and leave x3 for the caller. 83 * 84 * x0: struct kvm_nvhe_init_params PA 85 */ 86 SYM_CODE_START_LOCAL(___kvm_hyp_init) 87 ldr x1, [x0, #NVHE_INIT_STACK_HYP_VA] 88 mov sp, x1 89 90 ldr x1, [x0, #NVHE_INIT_MAIR_EL2] 91 msr mair_el2, x1 92 93 ldr x1, [x0, #NVHE_INIT_HCR_EL2] 94 msr hcr_el2, x1 95 96 mov x2, #HCR_E2H 97 and x2, x1, x2 98 cbz x2, 1f 99 100 // hVHE: Replay the EL2 setup to account for the E2H bit 101 // TPIDR_EL2 is used to preserve x0 across the macro maze... 102 isb 103 msr tpidr_el2, x0 104 init_el2_state 105 finalise_el2_state 106 mrs x0, tpidr_el2 107 108 1: 109 ldr x1, [x0, #NVHE_INIT_TPIDR_EL2] 110 msr tpidr_el2, x1 111 112 ldr x1, [x0, #NVHE_INIT_VTTBR] 113 msr vttbr_el2, x1 114 115 ldr x1, [x0, #NVHE_INIT_VTCR] 116 msr vtcr_el2, x1 117 118 ldr x1, [x0, #NVHE_INIT_PGD_PA] 119 phys_to_ttbr x2, x1 120 alternative_if ARM64_HAS_CNP 121 orr x2, x2, #TTBR_CNP_BIT 122 alternative_else_nop_endif 123 msr ttbr0_el2, x2 124 125 /* 126 * Set the PS bits in TCR_EL2. 127 */ 128 ldr x0, [x0, #NVHE_INIT_TCR_EL2] 129 tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2 130 msr tcr_el2, x0 131 132 isb 133 134 /* Invalidate the stale TLBs from Bootloader */ 135 tlbi alle2 136 tlbi vmalls12e1 137 dsb sy 138 139 mov_q x0, INIT_SCTLR_EL2_MMU_ON 140 alternative_if ARM64_HAS_ADDRESS_AUTH 141 mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ 142 SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) 143 orr x0, x0, x1 144 alternative_else_nop_endif 145 146 #ifdef CONFIG_ARM64_BTI_KERNEL 147 alternative_if ARM64_BTI 148 orr x0, x0, #SCTLR_EL2_BT 149 alternative_else_nop_endif 150 #endif /* CONFIG_ARM64_BTI_KERNEL */ 151 152 msr sctlr_el2, x0 153 isb 154 155 /* Set the host vector */ 156 ldr x0, =__kvm_hyp_host_vector 157 msr vbar_el2, x0 158 159 ret 160 SYM_CODE_END(___kvm_hyp_init) 161 162 /* 163 * PSCI CPU_ON entry point 164 * 165 * x0: struct kvm_nvhe_init_params PA 166 */ 167 SYM_CODE_START(kvm_hyp_cpu_entry) 168 mov x1, #1 // is_cpu_on = true 169 b __kvm_hyp_init_cpu 170 SYM_CODE_END(kvm_hyp_cpu_entry) 171 172 /* 173 * PSCI CPU_SUSPEND / SYSTEM_SUSPEND entry point 174 * 175 * x0: struct kvm_nvhe_init_params PA 176 */ 177 SYM_CODE_START(kvm_hyp_cpu_resume) 178 mov x1, #0 // is_cpu_on = false 179 b __kvm_hyp_init_cpu 180 SYM_CODE_END(kvm_hyp_cpu_resume) 181 182 /* 183 * Common code for CPU entry points. Initializes EL2 state and 184 * installs the hypervisor before handing over to a C handler. 185 * 186 * x0: struct kvm_nvhe_init_params PA 187 * x1: bool is_cpu_on 188 */ 189 SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) 190 mov x28, x0 // Stash arguments 191 mov x29, x1 192 193 /* Check that the core was booted in EL2. */ 194 mrs x0, CurrentEL 195 cmp x0, #CurrentEL_EL2 196 b.eq 2f 197 198 /* The core booted in EL1. KVM cannot be initialized on it. */ 199 1: wfe 200 wfi 201 b 1b 202 203 2: msr SPsel, #1 // We want to use SP_EL{1,2} 204 205 /* Initialize EL2 CPU state to sane values. */ 206 init_el2_state // Clobbers x0..x2 207 finalise_el2_state 208 __init_el2_nvhe_prepare_eret 209 210 /* Enable MMU, set vectors and stack. */ 211 mov x0, x28 212 bl ___kvm_hyp_init // Clobbers x0..x2 213 214 /* Leave idmap. */ 215 mov x0, x29 216 ldr x1, =kvm_host_psci_cpu_entry 217 br x1 218 SYM_CODE_END(__kvm_hyp_init_cpu) 219 220 SYM_CODE_START(__kvm_handle_stub_hvc) 221 /* 222 * __kvm_handle_stub_hvc called from __host_hvc through branch instruction(br) so 223 * we need bti j at beginning. 224 */ 225 bti j 226 cmp x0, #HVC_SOFT_RESTART 227 b.ne 1f 228 229 /* This is where we're about to jump, staying at EL2 */ 230 msr elr_el2, x1 231 mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT | PSR_MODE_EL2h) 232 msr spsr_el2, x0 233 234 /* Shuffle the arguments, and don't come back */ 235 mov x0, x2 236 mov x1, x3 237 mov x2, x4 238 b reset 239 240 1: cmp x0, #HVC_RESET_VECTORS 241 b.ne 1f 242 243 /* 244 * Set the HVC_RESET_VECTORS return code before entering the common 245 * path so that we do not clobber x0-x2 in case we are coming via 246 * HVC_SOFT_RESTART. 247 */ 248 mov x0, xzr 249 reset: 250 /* Reset kvm back to the hyp stub. */ 251 mov_q x5, INIT_SCTLR_EL2_MMU_OFF 252 pre_disable_mmu_workaround 253 msr sctlr_el2, x5 254 isb 255 256 alternative_if ARM64_KVM_PROTECTED_MODE 257 mov_q x5, HCR_HOST_NVHE_FLAGS 258 msr hcr_el2, x5 259 alternative_else_nop_endif 260 261 /* Install stub vectors */ 262 adr_l x5, __hyp_stub_vectors 263 msr vbar_el2, x5 264 eret 265 266 1: /* Bad stub call */ 267 mov_q x0, HVC_STUB_ERR 268 eret 269 270 SYM_CODE_END(__kvm_handle_stub_hvc) 271 272 SYM_FUNC_START(__pkvm_init_switch_pgd) 273 /* Turn the MMU off */ 274 pre_disable_mmu_workaround 275 mrs x2, sctlr_el2 276 bic x3, x2, #SCTLR_ELx_M 277 msr sctlr_el2, x3 278 isb 279 280 tlbi alle2 281 282 /* Install the new pgtables */ 283 ldr x3, [x0, #NVHE_INIT_PGD_PA] 284 phys_to_ttbr x4, x3 285 alternative_if ARM64_HAS_CNP 286 orr x4, x4, #TTBR_CNP_BIT 287 alternative_else_nop_endif 288 msr ttbr0_el2, x4 289 290 /* Set the new stack pointer */ 291 ldr x0, [x0, #NVHE_INIT_STACK_HYP_VA] 292 mov sp, x0 293 294 /* And turn the MMU back on! */ 295 set_sctlr_el2 x2 296 ret x1 297 SYM_FUNC_END(__pkvm_init_switch_pgd) 298 299 .popsection 300