arch/arm64/kvm/hyp/nvhe/hyp-main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2020 - Google Inc
   4  * Author: Andrew Scull <ascull@google.com>
   5  */
   6
   7 #include <hyp/adjust_pc.h>
   8
   9 #include <asm/pgtable-types.h>
  10 #include <asm/kvm_asm.h>
  11 #include <asm/kvm_emulate.h>
  12 #include <asm/kvm_host.h>
  13 #include <asm/kvm_hyp.h>
  14 #include <asm/kvm_mmu.h>
  15
  16 #include <nvhe/mem_protect.h>
  17 #include <nvhe/mm.h>
  18 #include <nvhe/pkvm.h>
  19 #include <nvhe/trap_handler.h>
  20
  21 DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
  22
  23 void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);
  24
  25 static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
  26 {
  27         struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
  28
  29         hyp_vcpu->vcpu.arch.ctxt        = host_vcpu->arch.ctxt;
  30
  31         hyp_vcpu->vcpu.arch.sve_state   = kern_hyp_va(host_vcpu->arch.sve_state);
  32         hyp_vcpu->vcpu.arch.sve_max_vl  = host_vcpu->arch.sve_max_vl;
  33
  34         hyp_vcpu->vcpu.arch.hw_mmu      = host_vcpu->arch.hw_mmu;
  35
  36         hyp_vcpu->vcpu.arch.hcr_el2     = host_vcpu->arch.hcr_el2;
  37         hyp_vcpu->vcpu.arch.mdcr_el2    = host_vcpu->arch.mdcr_el2;
  38         hyp_vcpu->vcpu.arch.cptr_el2    = host_vcpu->arch.cptr_el2;
  39
  40         hyp_vcpu->vcpu.arch.iflags      = host_vcpu->arch.iflags;
  41         hyp_vcpu->vcpu.arch.fp_state    = host_vcpu->arch.fp_state;
  42
  43         hyp_vcpu->vcpu.arch.debug_ptr   = kern_hyp_va(host_vcpu->arch.debug_ptr);
  44         hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state;
  45
  46         hyp_vcpu->vcpu.arch.vsesr_el2   = host_vcpu->arch.vsesr_el2;
  47
  48         hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
  49 }
  50
  51 static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
  52 {
  53         struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
  54         struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3;
  55         struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3;
  56         unsigned int i;
  57
  58         host_vcpu->arch.ctxt            = hyp_vcpu->vcpu.arch.ctxt;
  59
  60         host_vcpu->arch.hcr_el2         = hyp_vcpu->vcpu.arch.hcr_el2;
  61         host_vcpu->arch.cptr_el2        = hyp_vcpu->vcpu.arch.cptr_el2;
  62
  63         host_vcpu->arch.fault           = hyp_vcpu->vcpu.arch.fault;
  64
  65         host_vcpu->arch.iflags          = hyp_vcpu->vcpu.arch.iflags;
  66         host_vcpu->arch.fp_state        = hyp_vcpu->vcpu.arch.fp_state;
  67
  68         host_cpu_if->vgic_hcr           = hyp_cpu_if->vgic_hcr;
  69         for (i = 0; i < hyp_cpu_if->used_lrs; ++i)
  70                 host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i];
  71 }
  72
  73 static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
  74 {
  75         DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1);
  76         int ret;
  77
  78         host_vcpu = kern_hyp_va(host_vcpu);
  79
  80         if (unlikely(is_protected_kvm_enabled())) {
  81                 struct pkvm_hyp_vcpu *hyp_vcpu;
  82                 struct kvm *host_kvm;
  83
  84                 host_kvm = kern_hyp_va(host_vcpu->kvm);
  85                 hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle,
  86                                               host_vcpu->vcpu_idx);
  87                 if (!hyp_vcpu) {
  88                         ret = -EINVAL;
  89                         goto out;
  90                 }
  91
  92                 flush_hyp_vcpu(hyp_vcpu);
  93
  94                 ret = __kvm_vcpu_run(&hyp_vcpu->vcpu);
  95
  96                 sync_hyp_vcpu(hyp_vcpu);
  97                 pkvm_put_hyp_vcpu(hyp_vcpu);
  98         } else {
  99                 /* The host is fully trusted, run its vCPU directly. */
 100                 ret = __kvm_vcpu_run(host_vcpu);
 101         }
 102
 103 out:
 104         cpu_reg(host_ctxt, 1) =  ret;
 105 }
 106
 107 static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt)
 108 {
 109         DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
 110
 111         __kvm_adjust_pc(kern_hyp_va(vcpu));
 112 }
 113
 114 static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
 115 {
 116         __kvm_flush_vm_context();
 117 }
 118
 119 static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
 120 {
 121         DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
 122         DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
 123         DECLARE_REG(int, level, host_ctxt, 3);
 124
 125         __kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
 126 }
 127
 128 static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
 129 {
 130         DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
 131
 132         __kvm_tlb_flush_vmid(kern_hyp_va(mmu));
 133 }
 134
 135 static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt)
 136 {
 137         DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
 138
 139         __kvm_flush_cpu_context(kern_hyp_va(mmu));
 140 }
 141
 142 static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt)
 143 {
 144         __kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1));
 145 }
 146
 147 static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt)
 148 {
 149         u64 tmp;
 150
 151         tmp = read_sysreg_el2(SYS_SCTLR);
 152         tmp |= SCTLR_ELx_DSSBS;
 153         write_sysreg_el2(tmp, SYS_SCTLR);
 154 }
 155
 156 static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt)
 157 {
 158         cpu_reg(host_ctxt, 1) = __vgic_v3_get_gic_config();
 159 }
 160
 161 static void handle___vgic_v3_read_vmcr(struct kvm_cpu_context *host_ctxt)
 162 {
 163         cpu_reg(host_ctxt, 1) = __vgic_v3_read_vmcr();
 164 }
 165
 166 static void handle___vgic_v3_write_vmcr(struct kvm_cpu_context *host_ctxt)
 167 {
 168         __vgic_v3_write_vmcr(cpu_reg(host_ctxt, 1));
 169 }
 170
 171 static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
 172 {
 173         __vgic_v3_init_lrs();
 174 }
 175
 176 static void handle___kvm_get_mdcr_el2(struct kvm_cpu_context *host_ctxt)
 177 {
 178         cpu_reg(host_ctxt, 1) = __kvm_get_mdcr_el2();
 179 }
 180
 181 static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
 182 {
 183         DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
 184
 185         __vgic_v3_save_aprs(kern_hyp_va(cpu_if));
 186 }
 187
 188 static void handle___vgic_v3_restore_aprs(struct kvm_cpu_context *host_ctxt)
 189 {
 190         DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);
 191
 192         __vgic_v3_restore_aprs(kern_hyp_va(cpu_if));
 193 }
 194
 195 static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt)
 196 {
 197         DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
 198         DECLARE_REG(unsigned long, size, host_ctxt, 2);
 199         DECLARE_REG(unsigned long, nr_cpus, host_ctxt, 3);
 200         DECLARE_REG(unsigned long *, per_cpu_base, host_ctxt, 4);
 201         DECLARE_REG(u32, hyp_va_bits, host_ctxt, 5);
 202
 203         /*
 204          * __pkvm_init() will return only if an error occurred, otherwise it
 205          * will tail-call in __pkvm_init_finalise() which will have to deal
 206          * with the host context directly.
 207          */
 208         cpu_reg(host_ctxt, 1) = __pkvm_init(phys, size, nr_cpus, per_cpu_base,
 209                                             hyp_va_bits);
 210 }
 211
 212 static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt)
 213 {
 214         DECLARE_REG(enum arm64_hyp_spectre_vector, slot, host_ctxt, 1);
 215
 216         cpu_reg(host_ctxt, 1) = pkvm_cpu_set_vector(slot);
 217 }
 218
 219 static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
 220 {
 221         DECLARE_REG(u64, pfn, host_ctxt, 1);
 222
 223         cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
 224 }
 225
 226 static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
 227 {
 228         DECLARE_REG(u64, pfn, host_ctxt, 1);
 229
 230         cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
 231 }
 232
 233 static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
 234 {
 235         DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
 236         DECLARE_REG(size_t, size, host_ctxt, 2);
 237         DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);
 238
 239         /*
 240          * __pkvm_create_private_mapping() populates a pointer with the
 241          * hypervisor start address of the allocation.
 242          *
 243          * However, handle___pkvm_create_private_mapping() hypercall crosses the
 244          * EL1/EL2 boundary so the pointer would not be valid in this context.
 245          *
 246          * Instead pass the allocation address as the return value (or return
 247          * ERR_PTR() on failure).
 248          */
 249         unsigned long haddr;
 250         int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);
 251
 252         if (err)
 253                 haddr = (unsigned long)ERR_PTR(err);
 254
 255         cpu_reg(host_ctxt, 1) = haddr;
 256 }
 257
 258 static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
 259 {
 260         cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize();
 261 }
 262
 263 static void handle___pkvm_vcpu_init_traps(struct kvm_cpu_context *host_ctxt)
 264 {
 265         DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);
 266
 267         __pkvm_vcpu_init_traps(kern_hyp_va(vcpu));
 268 }
 269
 270 static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt)
 271 {
 272         DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1);
 273         DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2);
 274         DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3);
 275
 276         host_kvm = kern_hyp_va(host_kvm);
 277         cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva);
 278 }
 279
 280 static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)
 281 {
 282         DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
 283         DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2);
 284         DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3);
 285
 286         host_vcpu = kern_hyp_va(host_vcpu);
 287         cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva);
 288 }
 289
 290 static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt)
 291 {
 292         DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
 293
 294         cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle);
 295 }
 296
 297 typedef void (*hcall_t)(struct kvm_cpu_context *);
 298
 299 #define HANDLE_FUNC(x)  [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
 300
 301 static const hcall_t host_hcall[] = {
 302         /* ___kvm_hyp_init */
 303         HANDLE_FUNC(__kvm_get_mdcr_el2),
 304         HANDLE_FUNC(__pkvm_init),
 305         HANDLE_FUNC(__pkvm_create_private_mapping),
 306         HANDLE_FUNC(__pkvm_cpu_set_vector),
 307         HANDLE_FUNC(__kvm_enable_ssbs),
 308         HANDLE_FUNC(__vgic_v3_init_lrs),
 309         HANDLE_FUNC(__vgic_v3_get_gic_config),
 310         HANDLE_FUNC(__pkvm_prot_finalize),
 311
 312         HANDLE_FUNC(__pkvm_host_share_hyp),
 313         HANDLE_FUNC(__pkvm_host_unshare_hyp),
 314         HANDLE_FUNC(__kvm_adjust_pc),
 315         HANDLE_FUNC(__kvm_vcpu_run),
 316         HANDLE_FUNC(__kvm_flush_vm_context),
 317         HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
 318         HANDLE_FUNC(__kvm_tlb_flush_vmid),
 319         HANDLE_FUNC(__kvm_flush_cpu_context),
 320         HANDLE_FUNC(__kvm_timer_set_cntvoff),
 321         HANDLE_FUNC(__vgic_v3_read_vmcr),
 322         HANDLE_FUNC(__vgic_v3_write_vmcr),
 323         HANDLE_FUNC(__vgic_v3_save_aprs),
 324         HANDLE_FUNC(__vgic_v3_restore_aprs),
 325         HANDLE_FUNC(__pkvm_vcpu_init_traps),
 326         HANDLE_FUNC(__pkvm_init_vm),
 327         HANDLE_FUNC(__pkvm_init_vcpu),
 328         HANDLE_FUNC(__pkvm_teardown_vm),
 329 };
 330
 331 static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
 332 {
 333         DECLARE_REG(unsigned long, id, host_ctxt, 0);
 334         unsigned long hcall_min = 0;
 335         hcall_t hfn;
 336
 337         /*
 338          * If pKVM has been initialised then reject any calls to the
 339          * early "privileged" hypercalls. Note that we cannot reject
 340          * calls to __pkvm_prot_finalize for two reasons: (1) The static
 341          * key used to determine initialisation must be toggled prior to
 342          * finalisation and (2) finalisation is performed on a per-CPU
 343          * basis. This is all fine, however, since __pkvm_prot_finalize
 344          * returns -EPERM after the first call for a given CPU.
 345          */
 346         if (static_branch_unlikely(&kvm_protected_mode_initialized))
 347                 hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize;
 348
 349         id -= KVM_HOST_SMCCC_ID(0);
 350
 351         if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall)))
 352                 goto inval;
 353
 354         hfn = host_hcall[id];
 355         if (unlikely(!hfn))
 356                 goto inval;
 357
 358         cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
 359         hfn(host_ctxt);
 360
 361         return;
 362 inval:
 363         cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED;
 364 }
 365
 366 static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
 367 {
 368         __kvm_hyp_host_forward_smc(host_ctxt);
 369 }
 370
 371 static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
 372 {
 373         bool handled;
 374
 375         handled = kvm_host_psci_handler(host_ctxt);
 376         if (!handled)
 377                 default_host_smc_handler(host_ctxt);
 378
 379         /* SMC was trapped, move ELR past the current PC. */
 380         kvm_skip_host_instr();
 381 }
 382
 383 void handle_trap(struct kvm_cpu_context *host_ctxt)
 384 {
 385         u64 esr = read_sysreg_el2(SYS_ESR);
 386
 387         switch (ESR_ELx_EC(esr)) {
 388         case ESR_ELx_EC_HVC64:
 389                 handle_host_hcall(host_ctxt);
 390                 break;
 391         case ESR_ELx_EC_SMC64:
 392                 handle_host_smc(host_ctxt);
 393                 break;
 394         case ESR_ELx_EC_SVE:
 395                 sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
 396                 isb();
 397                 sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
 398                 break;
 399         case ESR_ELx_EC_IABT_LOW:
 400         case ESR_ELx_EC_DABT_LOW:
 401                 handle_host_mem_abort(host_ctxt);
 402                 break;
 403         default:
 404                 BUG();
 405         }
 406 }