arch/x86/kvm/svm/nested.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Kernel-based Virtual Machine driver for Linux
   4  *
   5  * AMD SVM support
   6  *
   7  * Copyright (C) 2006 Qumranet, Inc.
   8  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
   9  *
  10  * Authors:
  11  *   Yaniv Kamay  <yaniv@qumranet.com>
  12  *   Avi Kivity   <avi@qumranet.com>
  13  */
  14
  15 #define pr_fmt(fmt) "SVM: " fmt
  16
  17 #include <linux/kvm_types.h>
  18 #include <linux/kvm_host.h>
  19 #include <linux/kernel.h>
  20
  21 #include <asm/msr-index.h>
  22 #include <asm/debugreg.h>
  23
  24 #include "kvm_emulate.h"
  25 #include "trace.h"
  26 #include "mmu.h"
  27 #include "x86.h"
  28 #include "svm.h"
  29
  30 static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu,
  31                                        struct x86_exception *fault)
  32 {
  33         struct vcpu_svm *svm = to_svm(vcpu);
  34
  35         if (svm->vmcb->control.exit_code != SVM_EXIT_NPF) {
  36                 /*
  37                  * TODO: track the cause of the nested page fault, and
  38                  * correctly fill in the high bits of exit_info_1.
  39                  */
  40                 svm->vmcb->control.exit_code = SVM_EXIT_NPF;
  41                 svm->vmcb->control.exit_code_hi = 0;
  42                 svm->vmcb->control.exit_info_1 = (1ULL << 32);
  43                 svm->vmcb->control.exit_info_2 = fault->address;
  44         }
  45
  46         svm->vmcb->control.exit_info_1 &= ~0xffffffffULL;
  47         svm->vmcb->control.exit_info_1 |= fault->error_code;
  48
  49         /*
  50          * The present bit is always zero for page structure faults on real
  51          * hardware.
  52          */
  53         if (svm->vmcb->control.exit_info_1 & (2ULL << 32))
  54                 svm->vmcb->control.exit_info_1 &= ~1;
  55
  56         nested_svm_vmexit(svm);
  57 }
  58
  59 static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
  60 {
  61         struct vcpu_svm *svm = to_svm(vcpu);
  62         u64 cr3 = svm->nested.nested_cr3;
  63         u64 pdpte;
  64         int ret;
  65
  66         ret = kvm_vcpu_read_guest_page(vcpu, gpa_to_gfn(__sme_clr(cr3)), &pdpte,
  67                                        offset_in_page(cr3) + index * 8, 8);
  68         if (ret)
  69                 return 0;
  70         return pdpte;
  71 }
  72
  73 static unsigned long nested_svm_get_tdp_cr3(struct kvm_vcpu *vcpu)
  74 {
  75         struct vcpu_svm *svm = to_svm(vcpu);
  76
  77         return svm->nested.nested_cr3;
  78 }
  79
  80 static void nested_svm_init_mmu_context(struct kvm_vcpu *vcpu)
  81 {
  82         WARN_ON(mmu_is_nested(vcpu));
  83
  84         vcpu->arch.mmu = &vcpu->arch.guest_mmu;
  85         kvm_init_shadow_mmu(vcpu);
  86         vcpu->arch.mmu->get_guest_pgd     = nested_svm_get_tdp_cr3;
  87         vcpu->arch.mmu->get_pdptr         = nested_svm_get_tdp_pdptr;
  88         vcpu->arch.mmu->inject_page_fault = nested_svm_inject_npf_exit;
  89         vcpu->arch.mmu->shadow_root_level = kvm_x86_ops.get_tdp_level(vcpu);
  90         reset_shadow_zero_bits_mask(vcpu, vcpu->arch.mmu);
  91         vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
  92 }
  93
  94 static void nested_svm_uninit_mmu_context(struct kvm_vcpu *vcpu)
  95 {
  96         vcpu->arch.mmu = &vcpu->arch.root_mmu;
  97         vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
  98 }
  99
 100 void recalc_intercepts(struct vcpu_svm *svm)
 101 {
 102         struct vmcb_control_area *c, *h;
 103         struct nested_state *g;
 104
 105         mark_dirty(svm->vmcb, VMCB_INTERCEPTS);
 106
 107         if (!is_guest_mode(&svm->vcpu))
 108                 return;
 109
 110         c = &svm->vmcb->control;
 111         h = &svm->nested.hsave->control;
 112         g = &svm->nested;
 113
 114         c->intercept_cr = h->intercept_cr;
 115         c->intercept_dr = h->intercept_dr;
 116         c->intercept_exceptions = h->intercept_exceptions;
 117         c->intercept = h->intercept;
 118
 119         if (svm->vcpu.arch.hflags & HF_VINTR_MASK) {
 120                 /* We only want the cr8 intercept bits of L1 */
 121                 c->intercept_cr &= ~(1U << INTERCEPT_CR8_READ);
 122                 c->intercept_cr &= ~(1U << INTERCEPT_CR8_WRITE);
 123
 124                 /*
 125                  * Once running L2 with HF_VINTR_MASK, EFLAGS.IF does not
 126                  * affect any interrupt we may want to inject; therefore,
 127                  * interrupt window vmexits are irrelevant to L0.
 128                  */
 129                 c->intercept &= ~(1ULL << INTERCEPT_VINTR);
 130         }
 131
 132         /* We don't want to see VMMCALLs from a nested guest */
 133         c->intercept &= ~(1ULL << INTERCEPT_VMMCALL);
 134
 135         c->intercept_cr |= g->intercept_cr;
 136         c->intercept_dr |= g->intercept_dr;
 137         c->intercept_exceptions |= g->intercept_exceptions;
 138         c->intercept |= g->intercept;
 139 }
 140
 141 static void copy_vmcb_control_area(struct vmcb *dst_vmcb, struct vmcb *from_vmcb)
 142 {
 143         struct vmcb_control_area *dst  = &dst_vmcb->control;
 144         struct vmcb_control_area *from = &from_vmcb->control;
 145
 146         dst->intercept_cr         = from->intercept_cr;
 147         dst->intercept_dr         = from->intercept_dr;
 148         dst->intercept_exceptions = from->intercept_exceptions;
 149         dst->intercept            = from->intercept;
 150         dst->iopm_base_pa         = from->iopm_base_pa;
 151         dst->msrpm_base_pa        = from->msrpm_base_pa;
 152         dst->tsc_offset           = from->tsc_offset;
 153         dst->asid                 = from->asid;
 154         dst->tlb_ctl              = from->tlb_ctl;
 155         dst->int_ctl              = from->int_ctl;
 156         dst->int_vector           = from->int_vector;
 157         dst->int_state            = from->int_state;
 158         dst->exit_code            = from->exit_code;
 159         dst->exit_code_hi         = from->exit_code_hi;
 160         dst->exit_info_1          = from->exit_info_1;
 161         dst->exit_info_2          = from->exit_info_2;
 162         dst->exit_int_info        = from->exit_int_info;
 163         dst->exit_int_info_err    = from->exit_int_info_err;
 164         dst->nested_ctl           = from->nested_ctl;
 165         dst->event_inj            = from->event_inj;
 166         dst->event_inj_err        = from->event_inj_err;
 167         dst->nested_cr3           = from->nested_cr3;
 168         dst->virt_ext              = from->virt_ext;
 169         dst->pause_filter_count   = from->pause_filter_count;
 170         dst->pause_filter_thresh  = from->pause_filter_thresh;
 171 }
 172
 173 static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 174 {
 175         /*
 176          * This function merges the msr permission bitmaps of kvm and the
 177          * nested vmcb. It is optimized in that it only merges the parts where
 178          * the kvm msr permission bitmap may contain zero bits
 179          */
 180         int i;
 181
 182         if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
 183                 return true;
 184
 185         for (i = 0; i < MSRPM_OFFSETS; i++) {
 186                 u32 value, p;
 187                 u64 offset;
 188
 189                 if (msrpm_offsets[i] == 0xffffffff)
 190                         break;
 191
 192                 p      = msrpm_offsets[i];
 193                 offset = svm->nested.vmcb_msrpm + (p * 4);
 194
 195                 if (kvm_vcpu_read_guest(&svm->vcpu, offset, &value, 4))
 196                         return false;
 197
 198                 svm->nested.msrpm[p] = svm->msrpm[p] | value;
 199         }
 200
 201         svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));
 202
 203         return true;
 204 }
 205
 206 static bool nested_vmcb_checks(struct vmcb *vmcb)
 207 {
 208         if ((vmcb->save.efer & EFER_SVME) == 0)
 209                 return false;
 210
 211         if ((vmcb->control.intercept & (1ULL << INTERCEPT_VMRUN)) == 0)
 212                 return false;
 213
 214         if (vmcb->control.asid == 0)
 215                 return false;
 216
 217         if ((vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE) &&
 218             !npt_enabled)
 219                 return false;
 220
 221         return true;
 222 }
 223
 224 void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 225                           struct vmcb *nested_vmcb, struct kvm_host_map *map)
 226 {
 227         bool evaluate_pending_interrupts =
 228                 is_intercept(svm, INTERCEPT_VINTR) ||
 229                 is_intercept(svm, INTERCEPT_IRET);
 230
 231         if (kvm_get_rflags(&svm->vcpu) & X86_EFLAGS_IF)
 232                 svm->vcpu.arch.hflags |= HF_HIF_MASK;
 233         else
 234                 svm->vcpu.arch.hflags &= ~HF_HIF_MASK;
 235
 236         if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE) {
 237                 svm->nested.nested_cr3 = nested_vmcb->control.nested_cr3;
 238                 nested_svm_init_mmu_context(&svm->vcpu);
 239         }
 240
 241         /* Load the nested guest state */
 242         svm->vmcb->save.es = nested_vmcb->save.es;
 243         svm->vmcb->save.cs = nested_vmcb->save.cs;
 244         svm->vmcb->save.ss = nested_vmcb->save.ss;
 245         svm->vmcb->save.ds = nested_vmcb->save.ds;
 246         svm->vmcb->save.gdtr = nested_vmcb->save.gdtr;
 247         svm->vmcb->save.idtr = nested_vmcb->save.idtr;
 248         kvm_set_rflags(&svm->vcpu, nested_vmcb->save.rflags);
 249         svm_set_efer(&svm->vcpu, nested_vmcb->save.efer);
 250         svm_set_cr0(&svm->vcpu, nested_vmcb->save.cr0);
 251         svm_set_cr4(&svm->vcpu, nested_vmcb->save.cr4);
 252         if (npt_enabled) {
 253                 svm->vmcb->save.cr3 = nested_vmcb->save.cr3;
 254                 svm->vcpu.arch.cr3 = nested_vmcb->save.cr3;
 255         } else
 256                 (void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);
 257
 258         /* Guest paging mode is active - reset mmu */
 259         kvm_mmu_reset_context(&svm->vcpu);
 260
 261         svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = nested_vmcb->save.cr2;
 262         kvm_rax_write(&svm->vcpu, nested_vmcb->save.rax);
 263         kvm_rsp_write(&svm->vcpu, nested_vmcb->save.rsp);
 264         kvm_rip_write(&svm->vcpu, nested_vmcb->save.rip);
 265
 266         /* In case we don't even reach vcpu_run, the fields are not updated */
 267         svm->vmcb->save.rax = nested_vmcb->save.rax;
 268         svm->vmcb->save.rsp = nested_vmcb->save.rsp;
 269         svm->vmcb->save.rip = nested_vmcb->save.rip;
 270         svm->vmcb->save.dr7 = nested_vmcb->save.dr7;
 271         svm->vcpu.arch.dr6  = nested_vmcb->save.dr6;
 272         svm->vmcb->save.cpl = nested_vmcb->save.cpl;
 273
 274         svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa & ~0x0fffULL;
 275         svm->nested.vmcb_iopm  = nested_vmcb->control.iopm_base_pa  & ~0x0fffULL;
 276
 277         /* cache intercepts */
 278         svm->nested.intercept_cr         = nested_vmcb->control.intercept_cr;
 279         svm->nested.intercept_dr         = nested_vmcb->control.intercept_dr;
 280         svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
 281         svm->nested.intercept            = nested_vmcb->control.intercept;
 282
 283         svm_flush_tlb(&svm->vcpu, true);
 284         svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
 285         if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
 286                 svm->vcpu.arch.hflags |= HF_VINTR_MASK;
 287         else
 288                 svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;
 289
 290         svm->vcpu.arch.tsc_offset += nested_vmcb->control.tsc_offset;
 291         svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;
 292
 293         svm->vmcb->control.virt_ext = nested_vmcb->control.virt_ext;
 294         svm->vmcb->control.int_vector = nested_vmcb->control.int_vector;
 295         svm->vmcb->control.int_state = nested_vmcb->control.int_state;
 296         svm->vmcb->control.event_inj = nested_vmcb->control.event_inj;
 297         svm->vmcb->control.event_inj_err = nested_vmcb->control.event_inj_err;
 298
 299         svm->vmcb->control.pause_filter_count =
 300                 nested_vmcb->control.pause_filter_count;
 301         svm->vmcb->control.pause_filter_thresh =
 302                 nested_vmcb->control.pause_filter_thresh;
 303
 304         kvm_vcpu_unmap(&svm->vcpu, map, true);
 305
 306         /* Enter Guest-Mode */
 307         enter_guest_mode(&svm->vcpu);
 308
 309         /*
 310          * Merge guest and host intercepts - must be called  with vcpu in
 311          * guest-mode to take affect here
 312          */
 313         recalc_intercepts(svm);
 314
 315         svm->nested.vmcb = vmcb_gpa;
 316
 317         /*
 318          * If L1 had a pending IRQ/NMI before executing VMRUN,
 319          * which wasn't delivered because it was disallowed (e.g.
 320          * interrupts disabled), L0 needs to evaluate if this pending
 321          * event should cause an exit from L2 to L1 or be delivered
 322          * directly to L2.
 323          *
 324          * Usually this would be handled by the processor noticing an
 325          * IRQ/NMI window request.  However, VMRUN can unblock interrupts
 326          * by implicitly setting GIF, so force L0 to perform pending event
 327          * evaluation by requesting a KVM_REQ_EVENT.
 328          */
 329         enable_gif(svm);
 330         if (unlikely(evaluate_pending_interrupts))
 331                 kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
 332
 333         mark_all_dirty(svm->vmcb);
 334 }
 335
 336 int nested_svm_vmrun(struct vcpu_svm *svm)
 337 {
 338         int ret;
 339         struct vmcb *nested_vmcb;
 340         struct vmcb *hsave = svm->nested.hsave;
 341         struct vmcb *vmcb = svm->vmcb;
 342         struct kvm_host_map map;
 343         u64 vmcb_gpa;
 344
 345         vmcb_gpa = svm->vmcb->save.rax;
 346
 347         ret = kvm_vcpu_map(&svm->vcpu, gpa_to_gfn(vmcb_gpa), &map);
 348         if (ret == -EINVAL) {
 349                 kvm_inject_gp(&svm->vcpu, 0);
 350                 return 1;
 351         } else if (ret) {
 352                 return kvm_skip_emulated_instruction(&svm->vcpu);
 353         }
 354
 355         ret = kvm_skip_emulated_instruction(&svm->vcpu);
 356
 357         nested_vmcb = map.hva;
 358
 359         if (!nested_vmcb_checks(nested_vmcb)) {
 360                 nested_vmcb->control.exit_code    = SVM_EXIT_ERR;
 361                 nested_vmcb->control.exit_code_hi = 0;
 362                 nested_vmcb->control.exit_info_1  = 0;
 363                 nested_vmcb->control.exit_info_2  = 0;
 364
 365                 kvm_vcpu_unmap(&svm->vcpu, &map, true);
 366
 367                 return ret;
 368         }
 369
 370         trace_kvm_nested_vmrun(svm->vmcb->save.rip, vmcb_gpa,
 371                                nested_vmcb->save.rip,
 372                                nested_vmcb->control.int_ctl,
 373                                nested_vmcb->control.event_inj,
 374                                nested_vmcb->control.nested_ctl);
 375
 376         trace_kvm_nested_intercepts(nested_vmcb->control.intercept_cr & 0xffff,
 377                                     nested_vmcb->control.intercept_cr >> 16,
 378                                     nested_vmcb->control.intercept_exceptions,
 379                                     nested_vmcb->control.intercept);
 380
 381         /* Clear internal status */
 382         kvm_clear_exception_queue(&svm->vcpu);
 383         kvm_clear_interrupt_queue(&svm->vcpu);
 384
 385         /*
 386          * Save the old vmcb, so we don't need to pick what we save, but can
 387          * restore everything when a VMEXIT occurs
 388          */
 389         hsave->save.es     = vmcb->save.es;
 390         hsave->save.cs     = vmcb->save.cs;
 391         hsave->save.ss     = vmcb->save.ss;
 392         hsave->save.ds     = vmcb->save.ds;
 393         hsave->save.gdtr   = vmcb->save.gdtr;
 394         hsave->save.idtr   = vmcb->save.idtr;
 395         hsave->save.efer   = svm->vcpu.arch.efer;
 396         hsave->save.cr0    = kvm_read_cr0(&svm->vcpu);
 397         hsave->save.cr4    = svm->vcpu.arch.cr4;
 398         hsave->save.rflags = kvm_get_rflags(&svm->vcpu);
 399         hsave->save.rip    = kvm_rip_read(&svm->vcpu);
 400         hsave->save.rsp    = vmcb->save.rsp;
 401         hsave->save.rax    = vmcb->save.rax;
 402         if (npt_enabled)
 403                 hsave->save.cr3    = vmcb->save.cr3;
 404         else
 405                 hsave->save.cr3    = kvm_read_cr3(&svm->vcpu);
 406
 407         copy_vmcb_control_area(hsave, vmcb);
 408
 409         enter_svm_guest_mode(svm, vmcb_gpa, nested_vmcb, &map);
 410
 411         if (!nested_svm_vmrun_msrpm(svm)) {
 412                 svm->vmcb->control.exit_code    = SVM_EXIT_ERR;
 413                 svm->vmcb->control.exit_code_hi = 0;
 414                 svm->vmcb->control.exit_info_1  = 0;
 415                 svm->vmcb->control.exit_info_2  = 0;
 416
 417                 nested_svm_vmexit(svm);
 418         }
 419
 420         return ret;
 421 }
 422
 423 void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb)
 424 {
 425         to_vmcb->save.fs = from_vmcb->save.fs;
 426         to_vmcb->save.gs = from_vmcb->save.gs;
 427         to_vmcb->save.tr = from_vmcb->save.tr;
 428         to_vmcb->save.ldtr = from_vmcb->save.ldtr;
 429         to_vmcb->save.kernel_gs_base = from_vmcb->save.kernel_gs_base;
 430         to_vmcb->save.star = from_vmcb->save.star;
 431         to_vmcb->save.lstar = from_vmcb->save.lstar;
 432         to_vmcb->save.cstar = from_vmcb->save.cstar;
 433         to_vmcb->save.sfmask = from_vmcb->save.sfmask;
 434         to_vmcb->save.sysenter_cs = from_vmcb->save.sysenter_cs;
 435         to_vmcb->save.sysenter_esp = from_vmcb->save.sysenter_esp;
 436         to_vmcb->save.sysenter_eip = from_vmcb->save.sysenter_eip;
 437 }
 438
 439 int nested_svm_vmexit(struct vcpu_svm *svm)
 440 {
 441         int rc;
 442         struct vmcb *nested_vmcb;
 443         struct vmcb *hsave = svm->nested.hsave;
 444         struct vmcb *vmcb = svm->vmcb;
 445         struct kvm_host_map map;
 446
 447         trace_kvm_nested_vmexit_inject(vmcb->control.exit_code,
 448                                        vmcb->control.exit_info_1,
 449                                        vmcb->control.exit_info_2,
 450                                        vmcb->control.exit_int_info,
 451                                        vmcb->control.exit_int_info_err,
 452                                        KVM_ISA_SVM);
 453
 454         rc = kvm_vcpu_map(&svm->vcpu, gpa_to_gfn(svm->nested.vmcb), &map);
 455         if (rc) {
 456                 if (rc == -EINVAL)
 457                         kvm_inject_gp(&svm->vcpu, 0);
 458                 return 1;
 459         }
 460
 461         nested_vmcb = map.hva;
 462
 463         /* Exit Guest-Mode */
 464         leave_guest_mode(&svm->vcpu);
 465         svm->nested.vmcb = 0;
 466
 467         /* Give the current vmcb to the guest */
 468         disable_gif(svm);
 469
 470         nested_vmcb->save.es     = vmcb->save.es;
 471         nested_vmcb->save.cs     = vmcb->save.cs;
 472         nested_vmcb->save.ss     = vmcb->save.ss;
 473         nested_vmcb->save.ds     = vmcb->save.ds;
 474         nested_vmcb->save.gdtr   = vmcb->save.gdtr;
 475         nested_vmcb->save.idtr   = vmcb->save.idtr;
 476         nested_vmcb->save.efer   = svm->vcpu.arch.efer;
 477         nested_vmcb->save.cr0    = kvm_read_cr0(&svm->vcpu);
 478         nested_vmcb->save.cr3    = kvm_read_cr3(&svm->vcpu);
 479         nested_vmcb->save.cr2    = vmcb->save.cr2;
 480         nested_vmcb->save.cr4    = svm->vcpu.arch.cr4;
 481         nested_vmcb->save.rflags = kvm_get_rflags(&svm->vcpu);
 482         nested_vmcb->save.rip    = vmcb->save.rip;
 483         nested_vmcb->save.rsp    = vmcb->save.rsp;
 484         nested_vmcb->save.rax    = vmcb->save.rax;
 485         nested_vmcb->save.dr7    = vmcb->save.dr7;
 486         nested_vmcb->save.dr6    = svm->vcpu.arch.dr6;
 487         nested_vmcb->save.cpl    = vmcb->save.cpl;
 488
 489         nested_vmcb->control.int_ctl           = vmcb->control.int_ctl;
 490         nested_vmcb->control.int_vector        = vmcb->control.int_vector;
 491         nested_vmcb->control.int_state         = vmcb->control.int_state;
 492         nested_vmcb->control.exit_code         = vmcb->control.exit_code;
 493         nested_vmcb->control.exit_code_hi      = vmcb->control.exit_code_hi;
 494         nested_vmcb->control.exit_info_1       = vmcb->control.exit_info_1;
 495         nested_vmcb->control.exit_info_2       = vmcb->control.exit_info_2;
 496         nested_vmcb->control.exit_int_info     = vmcb->control.exit_int_info;
 497         nested_vmcb->control.exit_int_info_err = vmcb->control.exit_int_info_err;
 498
 499         if (svm->nrips_enabled)
 500                 nested_vmcb->control.next_rip  = vmcb->control.next_rip;
 501
 502         /*
 503          * If we emulate a VMRUN/#VMEXIT in the same host #vmexit cycle we have
 504          * to make sure that we do not lose injected events. So check event_inj
 505          * here and copy it to exit_int_info if it is valid.
 506          * Exit_int_info and event_inj can't be both valid because the case
 507          * below only happens on a VMRUN instruction intercept which has
 508          * no valid exit_int_info set.
 509          */
 510         if (vmcb->control.event_inj & SVM_EVTINJ_VALID) {
 511                 struct vmcb_control_area *nc = &nested_vmcb->control;
 512
 513                 nc->exit_int_info     = vmcb->control.event_inj;
 514                 nc->exit_int_info_err = vmcb->control.event_inj_err;
 515         }
 516
 517         nested_vmcb->control.tlb_ctl           = 0;
 518         nested_vmcb->control.event_inj         = 0;
 519         nested_vmcb->control.event_inj_err     = 0;
 520
 521         nested_vmcb->control.pause_filter_count =
 522                 svm->vmcb->control.pause_filter_count;
 523         nested_vmcb->control.pause_filter_thresh =
 524                 svm->vmcb->control.pause_filter_thresh;
 525
 526         /* We always set V_INTR_MASKING and remember the old value in hflags */
 527         if (!(svm->vcpu.arch.hflags & HF_VINTR_MASK))
 528                 nested_vmcb->control.int_ctl &= ~V_INTR_MASKING_MASK;
 529
 530         /* Restore the original control entries */
 531         copy_vmcb_control_area(vmcb, hsave);
 532
 533         svm->vcpu.arch.tsc_offset = svm->vmcb->control.tsc_offset;
 534         kvm_clear_exception_queue(&svm->vcpu);
 535         kvm_clear_interrupt_queue(&svm->vcpu);
 536
 537         svm->nested.nested_cr3 = 0;
 538
 539         /* Restore selected save entries */
 540         svm->vmcb->save.es = hsave->save.es;
 541         svm->vmcb->save.cs = hsave->save.cs;
 542         svm->vmcb->save.ss = hsave->save.ss;
 543         svm->vmcb->save.ds = hsave->save.ds;
 544         svm->vmcb->save.gdtr = hsave->save.gdtr;
 545         svm->vmcb->save.idtr = hsave->save.idtr;
 546         kvm_set_rflags(&svm->vcpu, hsave->save.rflags);
 547         svm_set_efer(&svm->vcpu, hsave->save.efer);
 548         svm_set_cr0(&svm->vcpu, hsave->save.cr0 | X86_CR0_PE);
 549         svm_set_cr4(&svm->vcpu, hsave->save.cr4);
 550         if (npt_enabled) {
 551                 svm->vmcb->save.cr3 = hsave->save.cr3;
 552                 svm->vcpu.arch.cr3 = hsave->save.cr3;
 553         } else {
 554                 (void)kvm_set_cr3(&svm->vcpu, hsave->save.cr3);
 555         }
 556         kvm_rax_write(&svm->vcpu, hsave->save.rax);
 557         kvm_rsp_write(&svm->vcpu, hsave->save.rsp);
 558         kvm_rip_write(&svm->vcpu, hsave->save.rip);
 559         svm->vmcb->save.dr7 = 0;
 560         svm->vmcb->save.cpl = 0;
 561         svm->vmcb->control.exit_int_info = 0;
 562
 563         mark_all_dirty(svm->vmcb);
 564
 565         kvm_vcpu_unmap(&svm->vcpu, &map, true);
 566
 567         nested_svm_uninit_mmu_context(&svm->vcpu);
 568         kvm_mmu_reset_context(&svm->vcpu);
 569         kvm_mmu_load(&svm->vcpu);
 570
 571         /*
 572          * Drop what we picked up for L2 via svm_complete_interrupts() so it
 573          * doesn't end up in L1.
 574          */
 575         svm->vcpu.arch.nmi_injected = false;
 576         kvm_clear_exception_queue(&svm->vcpu);
 577         kvm_clear_interrupt_queue(&svm->vcpu);
 578
 579         return 0;
 580 }
 581
 582 static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
 583 {
 584         u32 offset, msr, value;
 585         int write, mask;
 586
 587         if (!(svm->nested.intercept & (1ULL << INTERCEPT_MSR_PROT)))
 588                 return NESTED_EXIT_HOST;
 589
 590         msr    = svm->vcpu.arch.regs[VCPU_REGS_RCX];
 591         offset = svm_msrpm_offset(msr);
 592         write  = svm->vmcb->control.exit_info_1 & 1;
 593         mask   = 1 << ((2 * (msr & 0xf)) + write);
 594
 595         if (offset == MSR_INVALID)
 596                 return NESTED_EXIT_DONE;
 597
 598         /* Offset is in 32 bit units but need in 8 bit units */
 599         offset *= 4;
 600
 601         if (kvm_vcpu_read_guest(&svm->vcpu, svm->nested.vmcb_msrpm + offset, &value, 4))
 602                 return NESTED_EXIT_DONE;
 603
 604         return (value & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
 605 }
 606
 607 /* DB exceptions for our internal use must not cause vmexit */
 608 static int nested_svm_intercept_db(struct vcpu_svm *svm)
 609 {
 610         unsigned long dr6 = svm->vmcb->save.dr6;
 611
 612         /* Always catch it and pass it to userspace if debugging.  */
 613         if (svm->vcpu.guest_debug &
 614             (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
 615                 return NESTED_EXIT_HOST;
 616
 617         /* if we're not singlestepping, it's not ours */
 618         if (!svm->nmi_singlestep)
 619                 goto reflected_db;
 620
 621         /* if it's not a singlestep exception, it's not ours */
 622         if (!(dr6 & DR6_BS))
 623                 goto reflected_db;
 624
 625         /* if the guest is singlestepping, it should get the vmexit */
 626         if (svm->nmi_singlestep_guest_rflags & X86_EFLAGS_TF) {
 627                 disable_nmi_singlestep(svm);
 628                 goto reflected_db;
 629         }
 630
 631         /* it's ours, the nested hypervisor must not see this one */
 632         return NESTED_EXIT_HOST;
 633
 634 reflected_db:
 635         /*
 636          * Synchronize guest DR6 here just like in kvm_deliver_exception_payload;
 637          * it will be moved into the nested VMCB by nested_svm_vmexit.  Once
 638          * exceptions will be moved to svm_check_nested_events, all this stuff
 639          * will just go away and we could just return NESTED_EXIT_HOST
 640          * unconditionally.  db_interception will queue the exception, which
 641          * will be processed by svm_check_nested_events if a nested vmexit is
 642          * required, and we will just use kvm_deliver_exception_payload to copy
 643          * the payload to DR6 before vmexit.
 644          */
 645         WARN_ON(svm->vcpu.arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT);
 646         svm->vcpu.arch.dr6 &= ~(DR_TRAP_BITS | DR6_RTM);
 647         svm->vcpu.arch.dr6 |= dr6 & ~DR6_FIXED_1;
 648         return NESTED_EXIT_DONE;
 649 }
 650
 651 static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
 652 {
 653         unsigned port, size, iopm_len;
 654         u16 val, mask;
 655         u8 start_bit;
 656         u64 gpa;
 657
 658         if (!(svm->nested.intercept & (1ULL << INTERCEPT_IOIO_PROT)))
 659                 return NESTED_EXIT_HOST;
 660
 661         port = svm->vmcb->control.exit_info_1 >> 16;
 662         size = (svm->vmcb->control.exit_info_1 & SVM_IOIO_SIZE_MASK) >>
 663                 SVM_IOIO_SIZE_SHIFT;
 664         gpa  = svm->nested.vmcb_iopm + (port / 8);
 665         start_bit = port % 8;
 666         iopm_len = (start_bit + size > 8) ? 2 : 1;
 667         mask = (0xf >> (4 - size)) << start_bit;
 668         val = 0;
 669
 670         if (kvm_vcpu_read_guest(&svm->vcpu, gpa, &val, iopm_len))
 671                 return NESTED_EXIT_DONE;
 672
 673         return (val & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
 674 }
 675
 676 static int nested_svm_intercept(struct vcpu_svm *svm)
 677 {
 678         u32 exit_code = svm->vmcb->control.exit_code;
 679         int vmexit = NESTED_EXIT_HOST;
 680
 681         switch (exit_code) {
 682         case SVM_EXIT_MSR:
 683                 vmexit = nested_svm_exit_handled_msr(svm);
 684                 break;
 685         case SVM_EXIT_IOIO:
 686                 vmexit = nested_svm_intercept_ioio(svm);
 687                 break;
 688         case SVM_EXIT_READ_CR0 ... SVM_EXIT_WRITE_CR8: {
 689                 u32 bit = 1U << (exit_code - SVM_EXIT_READ_CR0);
 690                 if (svm->nested.intercept_cr & bit)
 691                         vmexit = NESTED_EXIT_DONE;
 692                 break;
 693         }
 694         case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
 695                 u32 bit = 1U << (exit_code - SVM_EXIT_READ_DR0);
 696                 if (svm->nested.intercept_dr & bit)
 697                         vmexit = NESTED_EXIT_DONE;
 698                 break;
 699         }
 700         case SVM_EXIT_EXCP_BASE ... SVM_EXIT_EXCP_BASE + 0x1f: {
 701                 u32 excp_bits = 1 << (exit_code - SVM_EXIT_EXCP_BASE);
 702                 if (svm->nested.intercept_exceptions & excp_bits) {
 703                         if (exit_code == SVM_EXIT_EXCP_BASE + DB_VECTOR)
 704                                 vmexit = nested_svm_intercept_db(svm);
 705                         else if (exit_code == SVM_EXIT_EXCP_BASE + BP_VECTOR &&
 706                                  svm->vcpu.guest_debug & KVM_GUESTDBG_USE_SW_BP)
 707                                 vmexit = NESTED_EXIT_HOST;
 708                         else
 709                                 vmexit = NESTED_EXIT_DONE;
 710                 }
 711                 /* async page fault always cause vmexit */
 712                 else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) &&
 713                          svm->vcpu.arch.exception.nested_apf != 0)
 714                         vmexit = NESTED_EXIT_DONE;
 715                 break;
 716         }
 717         case SVM_EXIT_ERR: {
 718                 vmexit = NESTED_EXIT_DONE;
 719                 break;
 720         }
 721         default: {
 722                 u64 exit_bits = 1ULL << (exit_code - SVM_EXIT_INTR);
 723                 if (svm->nested.intercept & exit_bits)
 724                         vmexit = NESTED_EXIT_DONE;
 725         }
 726         }
 727
 728         return vmexit;
 729 }
 730
 731 int nested_svm_exit_handled(struct vcpu_svm *svm)
 732 {
 733         int vmexit;
 734
 735         vmexit = nested_svm_intercept(svm);
 736
 737         if (vmexit == NESTED_EXIT_DONE)
 738                 nested_svm_vmexit(svm);
 739
 740         return vmexit;
 741 }
 742
 743 int nested_svm_check_permissions(struct vcpu_svm *svm)
 744 {
 745         if (!(svm->vcpu.arch.efer & EFER_SVME) ||
 746             !is_paging(&svm->vcpu)) {
 747                 kvm_queue_exception(&svm->vcpu, UD_VECTOR);
 748                 return 1;
 749         }
 750
 751         if (svm->vmcb->save.cpl) {
 752                 kvm_inject_gp(&svm->vcpu, 0);
 753                 return 1;
 754         }
 755
 756         return 0;
 757 }
 758
 759 int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
 760                                bool has_error_code, u32 error_code)
 761 {
 762         int vmexit;
 763
 764         if (!is_guest_mode(&svm->vcpu))
 765                 return 0;
 766
 767         vmexit = nested_svm_intercept(svm);
 768         if (vmexit != NESTED_EXIT_DONE)
 769                 return 0;
 770
 771         svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr;
 772         svm->vmcb->control.exit_code_hi = 0;
 773         svm->vmcb->control.exit_info_1 = error_code;
 774
 775         /*
 776          * EXITINFO2 is undefined for all exception intercepts other
 777          * than #PF.
 778          */
 779         if (svm->vcpu.arch.exception.nested_apf)
 780                 svm->vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token;
 781         else if (svm->vcpu.arch.exception.has_payload)
 782                 svm->vmcb->control.exit_info_2 = svm->vcpu.arch.exception.payload;
 783         else
 784                 svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
 785
 786         svm->nested.exit_required = true;
 787         return vmexit;
 788 }
 789
 790 static void nested_svm_intr(struct vcpu_svm *svm)
 791 {
 792         svm->vmcb->control.exit_code   = SVM_EXIT_INTR;
 793         svm->vmcb->control.exit_info_1 = 0;
 794         svm->vmcb->control.exit_info_2 = 0;
 795
 796         /* nested_svm_vmexit this gets called afterwards from handle_exit */
 797         svm->nested.exit_required = true;
 798         trace_kvm_nested_intr_vmexit(svm->vmcb->save.rip);
 799 }
 800
 801 static bool nested_exit_on_intr(struct vcpu_svm *svm)
 802 {
 803         return (svm->nested.intercept & 1ULL);
 804 }
 805
 806 int svm_check_nested_events(struct kvm_vcpu *vcpu)
 807 {
 808         struct vcpu_svm *svm = to_svm(vcpu);
 809         bool block_nested_events =
 810                 kvm_event_needs_reinjection(vcpu) || svm->nested.exit_required;
 811
 812         if (kvm_cpu_has_interrupt(vcpu) && nested_exit_on_intr(svm)) {
 813                 if (block_nested_events)
 814                         return -EBUSY;
 815                 nested_svm_intr(svm);
 816                 return 0;
 817         }
 818
 819         return 0;
 820 }
 821
 822 int nested_svm_exit_special(struct vcpu_svm *svm)
 823 {
 824         u32 exit_code = svm->vmcb->control.exit_code;
 825
 826         switch (exit_code) {
 827         case SVM_EXIT_INTR:
 828         case SVM_EXIT_NMI:
 829         case SVM_EXIT_EXCP_BASE + MC_VECTOR:
 830                 return NESTED_EXIT_HOST;
 831         case SVM_EXIT_NPF:
 832                 /* For now we are always handling NPFs when using them */
 833                 if (npt_enabled)
 834                         return NESTED_EXIT_HOST;
 835                 break;
 836         case SVM_EXIT_EXCP_BASE + PF_VECTOR:
 837                 /* When we're shadowing, trap PFs, but not async PF */
 838                 if (!npt_enabled && svm->vcpu.arch.apf.host_apf_reason == 0)
 839                         return NESTED_EXIT_HOST;
 840                 break;
 841         default:
 842                 break;
 843         }
 844
 845         return NESTED_EXIT_CONTINUE;
 846 }