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 * Derived from arch/arm/kvm/reset.c 7 * Copyright (C) 2012 - Virtual Open Systems and Columbia University 8 * Author: Christoffer Dall <c.dall@virtualopensystems.com> 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/kernel.h> 13 #include <linux/kvm_host.h> 14 #include <linux/kvm.h> 15 #include <linux/hw_breakpoint.h> 16 #include <linux/slab.h> 17 #include <linux/string.h> 18 #include <linux/types.h> 19 20 #include <kvm/arm_arch_timer.h> 21 22 #include <asm/cpufeature.h> 23 #include <asm/cputype.h> 24 #include <asm/fpsimd.h> 25 #include <asm/ptrace.h> 26 #include <asm/kvm_arm.h> 27 #include <asm/kvm_asm.h> 28 #include <asm/kvm_emulate.h> 29 #include <asm/kvm_mmu.h> 30 #include <asm/kvm_nested.h> 31 #include <asm/virt.h> 32 33 /* Maximum phys_shift supported for any VM on this host */ 34 static u32 __ro_after_init kvm_ipa_limit; 35 36 /* 37 * ARMv8 Reset Values 38 */ 39 #define VCPU_RESET_PSTATE_EL1 (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT | \ 40 PSR_F_BIT | PSR_D_BIT) 41 42 #define VCPU_RESET_PSTATE_EL2 (PSR_MODE_EL2h | PSR_A_BIT | PSR_I_BIT | \ 43 PSR_F_BIT | PSR_D_BIT) 44 45 #define VCPU_RESET_PSTATE_SVC (PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \ 46 PSR_AA32_I_BIT | PSR_AA32_F_BIT) 47 48 unsigned int __ro_after_init kvm_sve_max_vl; 49 50 int __init kvm_arm_init_sve(void) 51 { 52 if (system_supports_sve()) { 53 kvm_sve_max_vl = sve_max_virtualisable_vl(); 54 55 /* 56 * The get_sve_reg()/set_sve_reg() ioctl interface will need 57 * to be extended with multiple register slice support in 58 * order to support vector lengths greater than 59 * VL_ARCH_MAX: 60 */ 61 if (WARN_ON(kvm_sve_max_vl > VL_ARCH_MAX)) 62 kvm_sve_max_vl = VL_ARCH_MAX; 63 64 /* 65 * Don't even try to make use of vector lengths that 66 * aren't available on all CPUs, for now: 67 */ 68 if (kvm_sve_max_vl < sve_max_vl()) 69 pr_warn("KVM: SVE vector length for guests limited to %u bytes\n", 70 kvm_sve_max_vl); 71 } 72 73 return 0; 74 } 75 76 static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) 77 { 78 if (!system_supports_sve()) 79 return -EINVAL; 80 81 vcpu->arch.sve_max_vl = kvm_sve_max_vl; 82 83 /* 84 * Userspace can still customize the vector lengths by writing 85 * KVM_REG_ARM64_SVE_VLS. Allocation is deferred until 86 * kvm_arm_vcpu_finalize(), which freezes the configuration. 87 */ 88 vcpu_set_flag(vcpu, GUEST_HAS_SVE); 89 90 return 0; 91 } 92 93 /* 94 * Finalize vcpu's maximum SVE vector length, allocating 95 * vcpu->arch.sve_state as necessary. 96 */ 97 static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) 98 { 99 void *buf; 100 unsigned int vl; 101 size_t reg_sz; 102 int ret; 103 104 vl = vcpu->arch.sve_max_vl; 105 106 /* 107 * Responsibility for these properties is shared between 108 * kvm_arm_init_sve(), kvm_vcpu_enable_sve() and 109 * set_sve_vls(). Double-check here just to be sure: 110 */ 111 if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl() || 112 vl > VL_ARCH_MAX)) 113 return -EIO; 114 115 reg_sz = vcpu_sve_state_size(vcpu); 116 buf = kzalloc(reg_sz, GFP_KERNEL_ACCOUNT); 117 if (!buf) 118 return -ENOMEM; 119 120 ret = kvm_share_hyp(buf, buf + reg_sz); 121 if (ret) { 122 kfree(buf); 123 return ret; 124 } 125 126 vcpu->arch.sve_state = buf; 127 vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED); 128 return 0; 129 } 130 131 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature) 132 { 133 switch (feature) { 134 case KVM_ARM_VCPU_SVE: 135 if (!vcpu_has_sve(vcpu)) 136 return -EINVAL; 137 138 if (kvm_arm_vcpu_sve_finalized(vcpu)) 139 return -EPERM; 140 141 return kvm_vcpu_finalize_sve(vcpu); 142 } 143 144 return -EINVAL; 145 } 146 147 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) 148 { 149 if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu)) 150 return false; 151 152 return true; 153 } 154 155 void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) 156 { 157 void *sve_state = vcpu->arch.sve_state; 158 159 kvm_vcpu_unshare_task_fp(vcpu); 160 kvm_unshare_hyp(vcpu, vcpu + 1); 161 if (sve_state) 162 kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu)); 163 kfree(sve_state); 164 kfree(vcpu->arch.ccsidr); 165 } 166 167 static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) 168 { 169 if (vcpu_has_sve(vcpu)) 170 memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu)); 171 } 172 173 static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) 174 { 175 /* 176 * For now make sure that both address/generic pointer authentication 177 * features are requested by the userspace together and the system 178 * supports these capabilities. 179 */ 180 if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || 181 !test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features) || 182 !system_has_full_ptr_auth()) 183 return -EINVAL; 184 185 vcpu_set_flag(vcpu, GUEST_HAS_PTRAUTH); 186 return 0; 187 } 188 189 /** 190 * kvm_set_vm_width() - set the register width for the guest 191 * @vcpu: Pointer to the vcpu being configured 192 * 193 * Set both KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED 194 * in the VM flags based on the vcpu's requested register width, the HW 195 * capabilities and other options (such as MTE). 196 * When REG_WIDTH_CONFIGURED is already set, the vcpu settings must be 197 * consistent with the value of the FLAG_EL1_32BIT bit in the flags. 198 * 199 * Return: 0 on success, negative error code on failure. 200 */ 201 static int kvm_set_vm_width(struct kvm_vcpu *vcpu) 202 { 203 struct kvm *kvm = vcpu->kvm; 204 bool is32bit; 205 206 is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT); 207 208 lockdep_assert_held(&kvm->lock); 209 210 if (test_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, &kvm->arch.flags)) { 211 /* 212 * The guest's register width is already configured. 213 * Make sure that the vcpu is consistent with it. 214 */ 215 if (is32bit == test_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags)) 216 return 0; 217 218 return -EINVAL; 219 } 220 221 if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit) 222 return -EINVAL; 223 224 /* MTE is incompatible with AArch32 */ 225 if (kvm_has_mte(kvm) && is32bit) 226 return -EINVAL; 227 228 /* NV is incompatible with AArch32 */ 229 if (vcpu_has_nv(vcpu) && is32bit) 230 return -EINVAL; 231 232 if (is32bit) 233 set_bit(KVM_ARCH_FLAG_EL1_32BIT, &kvm->arch.flags); 234 235 set_bit(KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED, &kvm->arch.flags); 236 237 return 0; 238 } 239 240 /** 241 * kvm_reset_vcpu - sets core registers and sys_regs to reset value 242 * @vcpu: The VCPU pointer 243 * 244 * This function sets the registers on the virtual CPU struct to their 245 * architecturally defined reset values, except for registers whose reset is 246 * deferred until kvm_arm_vcpu_finalize(). 247 * 248 * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT 249 * ioctl or as part of handling a request issued by another VCPU in the PSCI 250 * handling code. In the first case, the VCPU will not be loaded, and in the 251 * second case the VCPU will be loaded. Because this function operates purely 252 * on the memory-backed values of system registers, we want to do a full put if 253 * we were loaded (handling a request) and load the values back at the end of 254 * the function. Otherwise we leave the state alone. In both cases, we 255 * disable preemption around the vcpu reset as we would otherwise race with 256 * preempt notifiers which also call put/load. 257 */ 258 int kvm_reset_vcpu(struct kvm_vcpu *vcpu) 259 { 260 struct vcpu_reset_state reset_state; 261 int ret; 262 bool loaded; 263 u32 pstate; 264 265 mutex_lock(&vcpu->kvm->lock); 266 ret = kvm_set_vm_width(vcpu); 267 if (!ret) { 268 reset_state = vcpu->arch.reset_state; 269 WRITE_ONCE(vcpu->arch.reset_state.reset, false); 270 } 271 mutex_unlock(&vcpu->kvm->lock); 272 273 if (ret) 274 return ret; 275 276 /* Reset PMU outside of the non-preemptible section */ 277 kvm_pmu_vcpu_reset(vcpu); 278 279 preempt_disable(); 280 loaded = (vcpu->cpu != -1); 281 if (loaded) 282 kvm_arch_vcpu_put(vcpu); 283 284 /* Disallow NV+SVE for the time being */ 285 if (vcpu_has_nv(vcpu) && vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) { 286 ret = -EINVAL; 287 goto out; 288 } 289 290 if (!kvm_arm_vcpu_sve_finalized(vcpu)) { 291 if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) { 292 ret = kvm_vcpu_enable_sve(vcpu); 293 if (ret) 294 goto out; 295 } 296 } else { 297 kvm_vcpu_reset_sve(vcpu); 298 } 299 300 if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || 301 test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { 302 if (kvm_vcpu_enable_ptrauth(vcpu)) { 303 ret = -EINVAL; 304 goto out; 305 } 306 } 307 308 switch (vcpu->arch.target) { 309 default: 310 if (vcpu_el1_is_32bit(vcpu)) { 311 pstate = VCPU_RESET_PSTATE_SVC; 312 } else if (vcpu_has_nv(vcpu)) { 313 pstate = VCPU_RESET_PSTATE_EL2; 314 } else { 315 pstate = VCPU_RESET_PSTATE_EL1; 316 } 317 318 if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) { 319 ret = -EINVAL; 320 goto out; 321 } 322 break; 323 } 324 325 /* Reset core registers */ 326 memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu))); 327 memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs)); 328 vcpu->arch.ctxt.spsr_abt = 0; 329 vcpu->arch.ctxt.spsr_und = 0; 330 vcpu->arch.ctxt.spsr_irq = 0; 331 vcpu->arch.ctxt.spsr_fiq = 0; 332 vcpu_gp_regs(vcpu)->pstate = pstate; 333 334 /* Reset system registers */ 335 kvm_reset_sys_regs(vcpu); 336 337 /* 338 * Additional reset state handling that PSCI may have imposed on us. 339 * Must be done after all the sys_reg reset. 340 */ 341 if (reset_state.reset) { 342 unsigned long target_pc = reset_state.pc; 343 344 /* Gracefully handle Thumb2 entry point */ 345 if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { 346 target_pc &= ~1UL; 347 vcpu_set_thumb(vcpu); 348 } 349 350 /* Propagate caller endianness */ 351 if (reset_state.be) 352 kvm_vcpu_set_be(vcpu); 353 354 *vcpu_pc(vcpu) = target_pc; 355 vcpu_set_reg(vcpu, 0, reset_state.r0); 356 } 357 358 /* Reset timer */ 359 ret = kvm_timer_vcpu_reset(vcpu); 360 out: 361 if (loaded) 362 kvm_arch_vcpu_load(vcpu, smp_processor_id()); 363 preempt_enable(); 364 return ret; 365 } 366 367 u32 get_kvm_ipa_limit(void) 368 { 369 return kvm_ipa_limit; 370 } 371 372 int __init kvm_set_ipa_limit(void) 373 { 374 unsigned int parange; 375 u64 mmfr0; 376 377 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); 378 parange = cpuid_feature_extract_unsigned_field(mmfr0, 379 ID_AA64MMFR0_EL1_PARANGE_SHIFT); 380 /* 381 * IPA size beyond 48 bits could not be supported 382 * on either 4K or 16K page size. Hence let's cap 383 * it to 48 bits, in case it's reported as larger 384 * on the system. 385 */ 386 if (PAGE_SIZE != SZ_64K) 387 parange = min(parange, (unsigned int)ID_AA64MMFR0_EL1_PARANGE_48); 388 389 /* 390 * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at 391 * Stage-2. If not, things will stop very quickly. 392 */ 393 switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_EL1_TGRAN_2_SHIFT)) { 394 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_NONE: 395 kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n"); 396 return -EINVAL; 397 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_DEFAULT: 398 kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n"); 399 break; 400 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MAX: 401 kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n"); 402 break; 403 default: 404 kvm_err("Unsupported value for TGRAN_2, giving up\n"); 405 return -EINVAL; 406 } 407 408 kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); 409 kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit, 410 ((kvm_ipa_limit < KVM_PHYS_SHIFT) ? 411 " (Reduced IPA size, limited VM/VMM compatibility)" : "")); 412 413 return 0; 414 } 415