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 void kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) 77 { 78 vcpu->arch.sve_max_vl = kvm_sve_max_vl; 79 80 /* 81 * Userspace can still customize the vector lengths by writing 82 * KVM_REG_ARM64_SVE_VLS. Allocation is deferred until 83 * kvm_arm_vcpu_finalize(), which freezes the configuration. 84 */ 85 vcpu_set_flag(vcpu, GUEST_HAS_SVE); 86 } 87 88 /* 89 * Finalize vcpu's maximum SVE vector length, allocating 90 * vcpu->arch.sve_state as necessary. 91 */ 92 static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu) 93 { 94 void *buf; 95 unsigned int vl; 96 size_t reg_sz; 97 int ret; 98 99 vl = vcpu->arch.sve_max_vl; 100 101 /* 102 * Responsibility for these properties is shared between 103 * kvm_arm_init_sve(), kvm_vcpu_enable_sve() and 104 * set_sve_vls(). Double-check here just to be sure: 105 */ 106 if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl() || 107 vl > VL_ARCH_MAX)) 108 return -EIO; 109 110 reg_sz = vcpu_sve_state_size(vcpu); 111 buf = kzalloc(reg_sz, GFP_KERNEL_ACCOUNT); 112 if (!buf) 113 return -ENOMEM; 114 115 ret = kvm_share_hyp(buf, buf + reg_sz); 116 if (ret) { 117 kfree(buf); 118 return ret; 119 } 120 121 vcpu->arch.sve_state = buf; 122 vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED); 123 return 0; 124 } 125 126 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature) 127 { 128 switch (feature) { 129 case KVM_ARM_VCPU_SVE: 130 if (!vcpu_has_sve(vcpu)) 131 return -EINVAL; 132 133 if (kvm_arm_vcpu_sve_finalized(vcpu)) 134 return -EPERM; 135 136 return kvm_vcpu_finalize_sve(vcpu); 137 } 138 139 return -EINVAL; 140 } 141 142 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu) 143 { 144 if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu)) 145 return false; 146 147 return true; 148 } 149 150 void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu) 151 { 152 void *sve_state = vcpu->arch.sve_state; 153 154 kvm_vcpu_unshare_task_fp(vcpu); 155 kvm_unshare_hyp(vcpu, vcpu + 1); 156 if (sve_state) 157 kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu)); 158 kfree(sve_state); 159 kfree(vcpu->arch.ccsidr); 160 } 161 162 static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu) 163 { 164 if (vcpu_has_sve(vcpu)) 165 memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu)); 166 } 167 168 static void kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu) 169 { 170 vcpu_set_flag(vcpu, GUEST_HAS_PTRAUTH); 171 } 172 173 /** 174 * kvm_reset_vcpu - sets core registers and sys_regs to reset value 175 * @vcpu: The VCPU pointer 176 * 177 * This function sets the registers on the virtual CPU struct to their 178 * architecturally defined reset values, except for registers whose reset is 179 * deferred until kvm_arm_vcpu_finalize(). 180 * 181 * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT 182 * ioctl or as part of handling a request issued by another VCPU in the PSCI 183 * handling code. In the first case, the VCPU will not be loaded, and in the 184 * second case the VCPU will be loaded. Because this function operates purely 185 * on the memory-backed values of system registers, we want to do a full put if 186 * we were loaded (handling a request) and load the values back at the end of 187 * the function. Otherwise we leave the state alone. In both cases, we 188 * disable preemption around the vcpu reset as we would otherwise race with 189 * preempt notifiers which also call put/load. 190 */ 191 void kvm_reset_vcpu(struct kvm_vcpu *vcpu) 192 { 193 struct vcpu_reset_state reset_state; 194 bool loaded; 195 u32 pstate; 196 197 spin_lock(&vcpu->arch.mp_state_lock); 198 reset_state = vcpu->arch.reset_state; 199 vcpu->arch.reset_state.reset = false; 200 spin_unlock(&vcpu->arch.mp_state_lock); 201 202 /* Reset PMU outside of the non-preemptible section */ 203 kvm_pmu_vcpu_reset(vcpu); 204 205 preempt_disable(); 206 loaded = (vcpu->cpu != -1); 207 if (loaded) 208 kvm_arch_vcpu_put(vcpu); 209 210 if (!kvm_arm_vcpu_sve_finalized(vcpu)) { 211 if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) 212 kvm_vcpu_enable_sve(vcpu); 213 } else { 214 kvm_vcpu_reset_sve(vcpu); 215 } 216 217 if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_ADDRESS) || 218 vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_GENERIC)) 219 kvm_vcpu_enable_ptrauth(vcpu); 220 221 if (vcpu_el1_is_32bit(vcpu)) 222 pstate = VCPU_RESET_PSTATE_SVC; 223 else if (vcpu_has_nv(vcpu)) 224 pstate = VCPU_RESET_PSTATE_EL2; 225 else 226 pstate = VCPU_RESET_PSTATE_EL1; 227 228 /* Reset core registers */ 229 memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu))); 230 memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs)); 231 vcpu->arch.ctxt.spsr_abt = 0; 232 vcpu->arch.ctxt.spsr_und = 0; 233 vcpu->arch.ctxt.spsr_irq = 0; 234 vcpu->arch.ctxt.spsr_fiq = 0; 235 vcpu_gp_regs(vcpu)->pstate = pstate; 236 237 /* Reset system registers */ 238 kvm_reset_sys_regs(vcpu); 239 240 /* 241 * Additional reset state handling that PSCI may have imposed on us. 242 * Must be done after all the sys_reg reset. 243 */ 244 if (reset_state.reset) { 245 unsigned long target_pc = reset_state.pc; 246 247 /* Gracefully handle Thumb2 entry point */ 248 if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { 249 target_pc &= ~1UL; 250 vcpu_set_thumb(vcpu); 251 } 252 253 /* Propagate caller endianness */ 254 if (reset_state.be) 255 kvm_vcpu_set_be(vcpu); 256 257 *vcpu_pc(vcpu) = target_pc; 258 vcpu_set_reg(vcpu, 0, reset_state.r0); 259 } 260 261 /* Reset timer */ 262 kvm_timer_vcpu_reset(vcpu); 263 264 if (loaded) 265 kvm_arch_vcpu_load(vcpu, smp_processor_id()); 266 preempt_enable(); 267 } 268 269 u32 get_kvm_ipa_limit(void) 270 { 271 return kvm_ipa_limit; 272 } 273 274 int __init kvm_set_ipa_limit(void) 275 { 276 unsigned int parange; 277 u64 mmfr0; 278 279 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); 280 parange = cpuid_feature_extract_unsigned_field(mmfr0, 281 ID_AA64MMFR0_EL1_PARANGE_SHIFT); 282 /* 283 * IPA size beyond 48 bits could not be supported 284 * on either 4K or 16K page size. Hence let's cap 285 * it to 48 bits, in case it's reported as larger 286 * on the system. 287 */ 288 if (PAGE_SIZE != SZ_64K) 289 parange = min(parange, (unsigned int)ID_AA64MMFR0_EL1_PARANGE_48); 290 291 /* 292 * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at 293 * Stage-2. If not, things will stop very quickly. 294 */ 295 switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_EL1_TGRAN_2_SHIFT)) { 296 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_NONE: 297 kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n"); 298 return -EINVAL; 299 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_DEFAULT: 300 kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n"); 301 break; 302 case ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_MAX: 303 kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n"); 304 break; 305 default: 306 kvm_err("Unsupported value for TGRAN_2, giving up\n"); 307 return -EINVAL; 308 } 309 310 kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); 311 kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit, 312 ((kvm_ipa_limit < KVM_PHYS_SHIFT) ? 313 " (Reduced IPA size, limited VM/VMM compatibility)" : "")); 314 315 return 0; 316 } 317