hypervisor/arch/x86/svm.c

   1 /*
   2  * Jailhouse, a Linux-based partitioning hypervisor
   3  *
   4  * Copyright (c) Siemens AG, 2013
   5  * Copyright (c) Valentine Sinitsyn, 2014
   6  *
   7  * Authors:
   8  *  Jan Kiszka <jan.kiszka@siemens.com>
   9  *  Valentine Sinitsyn <valentine.sinitsyn@gmail.com>
  10  *
  11  * Based on vmx.c written by Jan Kiszka.
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2.  See
  14  * the COPYING file in the top-level directory.
  15  */
  16
  17 #include <jailhouse/entry.h>
  18 #include <jailhouse/cell-config.h>
  19 #include <jailhouse/control.h>
  20 #include <jailhouse/paging.h>
  21 #include <jailhouse/printk.h>
  22 #include <jailhouse/processor.h>
  23 #include <jailhouse/string.h>
  24 #include <jailhouse/utils.h>
  25 #include <asm/apic.h>
  26 #include <asm/cell.h>
  27 #include <asm/control.h>
  28 #include <asm/iommu.h>
  29 #include <asm/paging.h>
  30 #include <asm/percpu.h>
  31 #include <asm/processor.h>
  32 #include <asm/svm.h>
  33 #include <asm/vcpu.h>
  34
  35 /*
  36  * NW bit is ignored by all modern processors, however some
  37  * combinations of NW and CD bits are prohibited by SVM (see APMv2,
  38  * Sect. 15.5). To handle this, we always keep the NW bit off.
  39  */
  40 #define SVM_CR0_ALLOWED_BITS    (~X86_CR0_NW)
  41
  42 static bool has_avic, has_assists, has_flush_by_asid;
  43
  44 static const struct segment invalid_seg;
  45
  46 static struct paging npt_paging[NPT_PAGE_DIR_LEVELS];
  47
  48 /* bit cleared: direct access allowed */
  49 // TODO: convert to whitelist
  50 static u8 __attribute__((aligned(PAGE_SIZE))) msrpm[][0x2000/4] = {
  51         [ SVM_MSRPM_0000 ] = {
  52                 [      0/4 ...  0x017/4 ] = 0,
  53                 [  0x018/4 ...  0x01b/4 ] = 0x80, /* 0x01b (w) */
  54                 [  0x01c/4 ...  0x1ff/4 ] = 0,
  55                 [  0x200/4 ...  0x273/4 ] = 0xaa, /* 0x200 - 0x273 (w) */
  56                 [  0x274/4 ...  0x277/4 ] = 0xea, /* 0x274 - 0x276 (w), 0x277 (rw) */
  57                 [  0x278/4 ...  0x2fb/4 ] = 0,
  58                 [  0x2fc/4 ...  0x2ff/4 ] = 0x80, /* 0x2ff (w) */
  59                 [  0x300/4 ...  0x7ff/4 ] = 0,
  60                 /* x2APIC MSRs - emulated if not present */
  61                 [  0x800/4 ...  0x803/4 ] = 0x90, /* 0x802 (r), 0x803 (r) */
  62                 [  0x804/4 ...  0x807/4 ] = 0,
  63                 [  0x808/4 ...  0x80b/4 ] = 0x93, /* 0x808 (rw), 0x80a (r), 0x80b (w) */
  64                 [  0x80c/4 ...  0x80f/4 ] = 0xc8, /* 0x80d (w), 0x80f (rw) */
  65                 [  0x810/4 ...  0x813/4 ] = 0x55, /* 0x810 - 0x813 (r) */
  66                 [  0x814/4 ...  0x817/4 ] = 0x55, /* 0x814 - 0x817 (r) */
  67                 [  0x818/4 ...  0x81b/4 ] = 0x55, /* 0x818 - 0x81b (r) */
  68                 [  0x81c/4 ...  0x81f/4 ] = 0x55, /* 0x81c - 0x81f (r) */
  69                 [  0x820/4 ...  0x823/4 ] = 0x55, /* 0x820 - 0x823 (r) */
  70                 [  0x824/4 ...  0x827/4 ] = 0x55, /* 0x823 - 0x827 (r) */
  71                 [  0x828/4 ...  0x82b/4 ] = 0x03, /* 0x828 (rw) */
  72                 [  0x82c/4 ...  0x82f/4 ] = 0xc0, /* 0x82f (rw) */
  73                 [  0x830/4 ...  0x833/4 ] = 0xf3, /* 0x830 (rw), 0x832 (rw), 0x833 (rw) */
  74                 [  0x834/4 ...  0x837/4 ] = 0xff, /* 0x834 - 0x837 (rw) */
  75                 [  0x838/4 ...  0x83b/4 ] = 0x07, /* 0x838 (rw), 0x839 (r) */
  76                 [  0x83c/4 ...  0x83f/4 ] = 0x70, /* 0x83e (rw), 0x83f (r) */
  77                 [  0x840/4 ... 0x1fff/4 ] = 0,
  78         },
  79         [ SVM_MSRPM_C000 ] = {
  80                 [      0/4 ...  0x07f/4 ] = 0,
  81                 [  0x080/4 ...  0x083/4 ] = 0x02, /* 0x080 (w) */
  82                 [  0x084/4 ... 0x1fff/4 ] = 0
  83         },
  84         [ SVM_MSRPM_C001 ] = {
  85                 [      0/4 ... 0x1fff/4 ] = 0,
  86         },
  87         [ SVM_MSRPM_RESV ] = {
  88                 [      0/4 ... 0x1fff/4 ] = 0,
  89         }
  90 };
  91
  92 /* This page is mapped so the code begins at 0x000ffff0 */
  93 static u8 __attribute__((aligned(PAGE_SIZE))) parking_code[PAGE_SIZE] = {
  94         [0xff0] = 0xfa, /* 1: cli */
  95         [0xff1] = 0xf4, /*    hlt */
  96         [0xff2] = 0xeb,
  97         [0xff3] = 0xfc  /*    jmp 1b */
  98 };
  99
 100 static void *parked_mode_npt;
 101
 102 static void *avic_page;
 103
 104 static int svm_check_features(void)
 105 {
 106         /* SVM is available */
 107         if (!(cpuid_ecx(0x80000001) & X86_FEATURE_SVM))
 108                 return trace_error(-ENODEV);
 109
 110         /* Nested paging */
 111         if (!(cpuid_edx(0x8000000A) & X86_FEATURE_NP))
 112                 return trace_error(-EIO);
 113
 114         /* Decode assists */
 115         if ((cpuid_edx(0x8000000A) & X86_FEATURE_DECODE_ASSISTS))
 116                 has_assists = true;
 117
 118         /* AVIC support */
 119         if (cpuid_edx(0x8000000A) & X86_FEATURE_AVIC)
 120                 has_avic = true;
 121
 122         /* TLB Flush by ASID support */
 123         if (cpuid_edx(0x8000000A) & X86_FEATURE_FLUSH_BY_ASID)
 124                 has_flush_by_asid = true;
 125
 126         return 0;
 127 }
 128
 129 static void set_svm_segment_from_dtr(struct svm_segment *svm_segment,
 130                                      const struct desc_table_reg *dtr)
 131 {
 132         struct svm_segment tmp = { 0 };
 133
 134         if (dtr) {
 135                 tmp.base = dtr->base;
 136                 tmp.limit = dtr->limit & 0xffff;
 137         }
 138
 139         *svm_segment = tmp;
 140 }
 141
 142 /* TODO: struct segment needs to be x86 generic, not VMX-specific one here */
 143 static void set_svm_segment_from_segment(struct svm_segment *svm_segment,
 144                                          const struct segment *segment)
 145 {
 146         u32 ar;
 147
 148         svm_segment->selector = segment->selector;
 149
 150         if (segment->access_rights == 0x10000) {
 151                 svm_segment->access_rights = 0;
 152         } else {
 153                 ar = segment->access_rights;
 154                 svm_segment->access_rights =
 155                         ((ar & 0xf000) >> 4) | (ar & 0x00ff);
 156         }
 157
 158         svm_segment->limit = segment->limit;
 159         svm_segment->base = segment->base;
 160 }
 161
 162 static bool svm_set_cell_config(struct cell *cell, struct vmcb *vmcb)
 163 {
 164         /* No real need for this function; used for consistency with vmx.c */
 165         vmcb->iopm_base_pa = paging_hvirt2phys(cell->svm.iopm);
 166         vmcb->n_cr3 = paging_hvirt2phys(cell->svm.npt_structs.root_table);
 167
 168         return true;
 169 }
 170
 171 static int vmcb_setup(struct per_cpu *cpu_data)
 172 {
 173         struct vmcb *vmcb = &cpu_data->vmcb;
 174
 175         memset(vmcb, 0, sizeof(struct vmcb));
 176
 177         vmcb->cr0 = cpu_data->linux_cr0 & SVM_CR0_ALLOWED_BITS;
 178         vmcb->cr3 = cpu_data->linux_cr3;
 179         vmcb->cr4 = cpu_data->linux_cr4;
 180
 181         set_svm_segment_from_segment(&vmcb->cs, &cpu_data->linux_cs);
 182         set_svm_segment_from_segment(&vmcb->ds, &cpu_data->linux_ds);
 183         set_svm_segment_from_segment(&vmcb->es, &cpu_data->linux_es);
 184         set_svm_segment_from_segment(&vmcb->fs, &cpu_data->linux_fs);
 185         set_svm_segment_from_segment(&vmcb->gs, &cpu_data->linux_gs);
 186         set_svm_segment_from_segment(&vmcb->ss, &invalid_seg);
 187         set_svm_segment_from_segment(&vmcb->tr, &cpu_data->linux_tss);
 188
 189         set_svm_segment_from_dtr(&vmcb->ldtr, NULL);
 190         set_svm_segment_from_dtr(&vmcb->gdtr, &cpu_data->linux_gdtr);
 191         set_svm_segment_from_dtr(&vmcb->idtr, &cpu_data->linux_idtr);
 192
 193         vmcb->cpl = 0; /* Linux runs in ring 0 before migration */
 194
 195         vmcb->rflags = 0x02;
 196         /* Indicate success to the caller of arch_entry */
 197         vmcb->rax = 0;
 198         vmcb->rsp = cpu_data->linux_sp +
 199                 (NUM_ENTRY_REGS + 1) * sizeof(unsigned long);
 200         vmcb->rip = cpu_data->linux_ip;
 201
 202         vmcb->sysenter_cs = read_msr(MSR_IA32_SYSENTER_CS);
 203         vmcb->sysenter_eip = read_msr(MSR_IA32_SYSENTER_EIP);
 204         vmcb->sysenter_esp = read_msr(MSR_IA32_SYSENTER_ESP);
 205         vmcb->star = read_msr(MSR_STAR);
 206         vmcb->lstar = read_msr(MSR_LSTAR);
 207         vmcb->cstar = read_msr(MSR_CSTAR);
 208         vmcb->sfmask = read_msr(MSR_SFMASK);
 209         vmcb->kerngsbase = read_msr(MSR_KERNGS_BASE);
 210
 211         vmcb->dr6 = 0x00000ff0;
 212         vmcb->dr7 = 0x00000400;
 213
 214         /* Make the hypervisor visible */
 215         vmcb->efer = (cpu_data->linux_efer | EFER_SVME);
 216
 217         vmcb->g_pat = cpu_data->pat;
 218
 219         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_NMI;
 220         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_CR0_SEL_WRITE;
 221         /* TODO: Do we need this for SVM ? */
 222         /* vmcb->general1_intercepts |= GENERAL1_INTERCEPT_CPUID; */
 223         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_IOIO_PROT;
 224         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_MSR_PROT;
 225         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_SHUTDOWN_EVT;
 226
 227         vmcb->general2_intercepts |= GENERAL2_INTERCEPT_VMRUN; /* Required */
 228         vmcb->general2_intercepts |= GENERAL2_INTERCEPT_VMMCALL;
 229
 230         vmcb->msrpm_base_pa = paging_hvirt2phys(msrpm);
 231
 232         vmcb->np_enable = 1;
 233         /* No more than one guest owns the CPU */
 234         vmcb->guest_asid = 1;
 235
 236         /* TODO: Setup AVIC */
 237
 238         /* Explicitly mark all of the state as new */
 239         vmcb->clean_bits = 0;
 240
 241         return svm_set_cell_config(cpu_data->cell, vmcb);
 242 }
 243
 244 unsigned long arch_paging_gphys2phys(struct per_cpu *cpu_data,
 245                                      unsigned long gphys,
 246                                      unsigned long flags)
 247 {
 248         return paging_virt2phys(&cpu_data->cell->svm.npt_structs,
 249                         gphys, flags);
 250 }
 251
 252 static void npt_set_next_pt(pt_entry_t pte, unsigned long next_pt)
 253 {
 254         /* See APMv2, Section 15.25.5 */
 255         *pte = (next_pt & 0x000ffffffffff000UL) |
 256                 (PAGE_DEFAULT_FLAGS | PAGE_FLAG_US);
 257 }
 258
 259 int vcpu_vendor_init(void)
 260 {
 261         struct paging_structures parking_pt;
 262         unsigned long vm_cr;
 263         int err, n;
 264
 265         err = svm_check_features();
 266         if (err)
 267                 return err;
 268
 269         vm_cr = read_msr(MSR_VM_CR);
 270         if (vm_cr & VM_CR_SVMDIS)
 271                 /* SVM disabled in BIOS */
 272                 return trace_error(-EPERM);
 273
 274         /* Nested paging is the same as the native one */
 275         memcpy(npt_paging, x86_64_paging, sizeof(npt_paging));
 276         for (n = 0; n < NPT_PAGE_DIR_LEVELS; n++)
 277                 npt_paging[n].set_next_pt = npt_set_next_pt;
 278
 279         /* Map guest parking code (shared between cells and CPUs) */
 280         parking_pt.root_paging = npt_paging;
 281         parking_pt.root_table = parked_mode_npt = page_alloc(&mem_pool, 1);
 282         if (!parked_mode_npt)
 283                 return -ENOMEM;
 284         err = paging_create(&parking_pt, paging_hvirt2phys(parking_code),
 285                             PAGE_SIZE, 0x000ff000,
 286                             PAGE_READONLY_FLAGS | PAGE_FLAG_US,
 287                             PAGING_NON_COHERENT);
 288         if (err)
 289                 return err;
 290
 291         /* This is always false for AMD now (except in nested SVM);
 292            see Sect. 16.3.1 in APMv2 */
 293         if (using_x2apic) {
 294                 /* allow direct x2APIC access except for ICR writes */
 295                 memset(&msrpm[SVM_MSRPM_0000][MSR_X2APIC_BASE/4], 0,
 296                                 (MSR_X2APIC_END - MSR_X2APIC_BASE + 1)/4);
 297                 msrpm[SVM_MSRPM_0000][MSR_X2APIC_ICR/4] = 0x02;
 298         } else {
 299                 if (has_avic) {
 300                         avic_page = page_alloc(&remap_pool, 1);
 301                         if (!avic_page)
 302                                 return trace_error(-ENOMEM);
 303                 }
 304         }
 305
 306         return vcpu_cell_init(&root_cell);
 307 }
 308
 309 int vcpu_vendor_cell_init(struct cell *cell)
 310 {
 311         u64 flags;
 312         int err;
 313
 314         /* allocate iopm (two 4-K pages + 3 bits) */
 315         cell->svm.iopm = page_alloc(&mem_pool, 3);
 316         if (!cell->svm.iopm)
 317                 return -ENOMEM;
 318
 319         /* build root NPT of cell */
 320         cell->svm.npt_structs.root_paging = npt_paging;
 321         cell->svm.npt_structs.root_table = page_alloc(&mem_pool, 1);
 322         if (!cell->svm.npt_structs.root_table)
 323                 return -ENOMEM;
 324
 325         if (!has_avic) {
 326                 /*
 327                  * Map xAPIC as is; reads are passed, writes are trapped.
 328                  */
 329                 flags = PAGE_READONLY_FLAGS | PAGE_FLAG_US | PAGE_FLAG_DEVICE;
 330                 err = paging_create(&cell->svm.npt_structs, XAPIC_BASE,
 331                                     PAGE_SIZE, XAPIC_BASE,
 332                                     flags,
 333                                     PAGING_NON_COHERENT);
 334         } else {
 335                 flags = PAGE_DEFAULT_FLAGS | PAGE_FLAG_DEVICE;
 336                 err = paging_create(&cell->svm.npt_structs,
 337                                     paging_hvirt2phys(avic_page),
 338                                     PAGE_SIZE, XAPIC_BASE,
 339                                     flags,
 340                                     PAGING_NON_COHERENT);
 341         }
 342
 343         return err;
 344 }
 345
 346 int vcpu_map_memory_region(struct cell *cell,
 347                            const struct jailhouse_memory *mem)
 348 {
 349         u64 phys_start = mem->phys_start;
 350         u64 flags = PAGE_FLAG_US; /* See APMv2, Section 15.25.5 */
 351
 352         if (mem->flags & JAILHOUSE_MEM_READ)
 353                 flags |= PAGE_FLAG_PRESENT;
 354         if (mem->flags & JAILHOUSE_MEM_WRITE)
 355                 flags |= PAGE_FLAG_RW;
 356         if (!(mem->flags & JAILHOUSE_MEM_EXECUTE))
 357                 flags |= PAGE_FLAG_NOEXECUTE;
 358         if (mem->flags & JAILHOUSE_MEM_COMM_REGION)
 359                 phys_start = paging_hvirt2phys(&cell->comm_page);
 360
 361         return paging_create(&cell->svm.npt_structs, phys_start, mem->size,
 362                              mem->virt_start, flags, PAGING_NON_COHERENT);
 363 }
 364
 365 int vcpu_unmap_memory_region(struct cell *cell,
 366                              const struct jailhouse_memory *mem)
 367 {
 368         return paging_destroy(&cell->svm.npt_structs, mem->virt_start,
 369                               mem->size, PAGING_NON_COHERENT);
 370 }
 371
 372 void vcpu_vendor_cell_exit(struct cell *cell)
 373 {
 374         paging_destroy(&cell->svm.npt_structs, XAPIC_BASE, PAGE_SIZE,
 375                        PAGING_NON_COHERENT);
 376         page_free(&mem_pool, cell->svm.npt_structs.root_table, 1);
 377 }
 378
 379 int vcpu_init(struct per_cpu *cpu_data)
 380 {
 381         unsigned long efer;
 382         int err;
 383
 384         err = svm_check_features();
 385         if (err)
 386                 return err;
 387
 388         efer = read_msr(MSR_EFER);
 389         if (efer & EFER_SVME)
 390                 return trace_error(-EBUSY);
 391
 392         efer |= EFER_SVME;
 393         write_msr(MSR_EFER, efer);
 394
 395         cpu_data->svm_state = SVMON;
 396
 397         if (!vmcb_setup(cpu_data))
 398                 return trace_error(-EIO);
 399
 400         /*
 401          * APM Volume 2, 3.1.1: "When writing the CR0 register, software should
 402          * set the values of reserved bits to the values found during the
 403          * previous CR0 read."
 404          * But we want to avoid surprises with new features unknown to us but
 405          * set by Linux. So check if any assumed revered bit was set and bail
 406          * out if so.
 407          * Note that the APM defines all reserved CR4 bits as must-be-zero.
 408          */
 409         if (cpu_data->linux_cr0 & X86_CR0_RESERVED)
 410                 return -EIO;
 411
 412         /* bring CR0 and CR4 into well-defined states */
 413         write_cr0(X86_CR0_HOST_STATE);
 414         write_cr4(X86_CR4_HOST_STATE);
 415
 416         write_msr(MSR_VM_HSAVE_PA, paging_hvirt2phys(cpu_data->host_state));
 417
 418         return 0;
 419 }
 420
 421 void vcpu_exit(struct per_cpu *cpu_data)
 422 {
 423         unsigned long efer;
 424
 425         if (cpu_data->svm_state == SVMOFF)
 426                 return;
 427
 428         cpu_data->svm_state = SVMOFF;
 429
 430         /* We are leaving - set the GIF */
 431         asm volatile ("stgi" : : : "memory");
 432
 433         efer = read_msr(MSR_EFER);
 434         efer &= ~EFER_SVME;
 435         write_msr(MSR_EFER, efer);
 436
 437         write_msr(MSR_VM_HSAVE_PA, 0);
 438 }
 439
 440 void __attribute__((noreturn)) vcpu_activate_vmm(struct per_cpu *cpu_data)
 441 {
 442         unsigned long vmcb_pa, host_stack;
 443
 444         vmcb_pa = paging_hvirt2phys(&cpu_data->vmcb);
 445         host_stack = (unsigned long)cpu_data->stack + sizeof(cpu_data->stack);
 446
 447         /* We enter Linux at the point arch_entry would return to as well.
 448          * rax is cleared to signal success to the caller. */
 449         asm volatile(
 450                 "clgi\n\t"
 451                 "mov (%%rdi),%%r15\n\t"
 452                 "mov 0x8(%%rdi),%%r14\n\t"
 453                 "mov 0x10(%%rdi),%%r13\n\t"
 454                 "mov 0x18(%%rdi),%%r12\n\t"
 455                 "mov 0x20(%%rdi),%%rbx\n\t"
 456                 "mov 0x28(%%rdi),%%rbp\n\t"
 457                 "mov %0, %%rax\n\t"
 458                 "vmload %%rax\n\t"
 459                 "vmrun %%rax\n\t"
 460                 "vmsave %%rax\n\t"
 461                 /* Restore hypervisor stack */
 462                 "mov %2, %%rsp\n\t"
 463                 "jmp svm_vmexit"
 464                 : /* no output */
 465                 : "m" (vmcb_pa), "D" (cpu_data->linux_reg), "m" (host_stack)
 466                 : "memory", "r15", "r14", "r13", "r12",
 467                   "rbx", "rbp", "rax", "cc");
 468         __builtin_unreachable();
 469 }
 470
 471 void __attribute__((noreturn))
 472 vcpu_deactivate_vmm(struct registers *guest_regs)
 473 {
 474         struct per_cpu *cpu_data = this_cpu_data();
 475         struct vmcb *vmcb = &cpu_data->vmcb;
 476         unsigned long *stack = (unsigned long *)vmcb->rsp;
 477         unsigned long linux_ip = vmcb->rip;
 478
 479         /*
 480          * Restore the MSRs.
 481          *
 482          * XXX: One could argue this is better to be done in
 483          * arch_cpu_restore(), however, it would require changes
 484          * to cpu_data to store STAR and friends.
 485          */
 486         write_msr(MSR_STAR, vmcb->star);
 487         write_msr(MSR_LSTAR, vmcb->lstar);
 488         write_msr(MSR_CSTAR, vmcb->cstar);
 489         write_msr(MSR_SFMASK, vmcb->sfmask);
 490         write_msr(MSR_KERNGS_BASE, vmcb->kerngsbase);
 491
 492         cpu_data->linux_cr0 = vmcb->cr0;
 493         cpu_data->linux_cr3 = vmcb->cr3;
 494
 495         cpu_data->linux_gdtr.base = vmcb->gdtr.base;
 496         cpu_data->linux_gdtr.limit = vmcb->gdtr.limit;
 497         cpu_data->linux_idtr.base = vmcb->idtr.base;
 498         cpu_data->linux_idtr.limit = vmcb->idtr.limit;
 499
 500         cpu_data->linux_cs.selector = vmcb->cs.selector;
 501
 502         cpu_data->linux_tss.selector = vmcb->tr.selector;
 503
 504         cpu_data->linux_efer = vmcb->efer & (~EFER_SVME);
 505         cpu_data->linux_fs.base = vmcb->fs.base;
 506         cpu_data->linux_gs.base = vmcb->gs.base;
 507
 508         cpu_data->linux_sysenter_cs = vmcb->sysenter_cs;
 509         cpu_data->linux_sysenter_eip = vmcb->sysenter_eip;
 510         cpu_data->linux_sysenter_esp = vmcb->sysenter_esp;
 511
 512         cpu_data->linux_ds.selector = vmcb->ds.selector;
 513         cpu_data->linux_es.selector = vmcb->es.selector;
 514         cpu_data->linux_fs.selector = vmcb->fs.selector;
 515         cpu_data->linux_gs.selector = vmcb->gs.selector;
 516
 517         arch_cpu_restore(cpu_data, 0);
 518
 519         stack--;
 520         *stack = linux_ip;
 521
 522         asm volatile (
 523                 "mov %%rbx,%%rsp\n\t"
 524                 "pop %%r15\n\t"
 525                 "pop %%r14\n\t"
 526                 "pop %%r13\n\t"
 527                 "pop %%r12\n\t"
 528                 "pop %%r11\n\t"
 529                 "pop %%r10\n\t"
 530                 "pop %%r9\n\t"
 531                 "pop %%r8\n\t"
 532                 "pop %%rdi\n\t"
 533                 "pop %%rsi\n\t"
 534                 "pop %%rbp\n\t"
 535                 "add $8,%%rsp\n\t"
 536                 "pop %%rbx\n\t"
 537                 "pop %%rdx\n\t"
 538                 "pop %%rcx\n\t"
 539                 "mov %%rax,%%rsp\n\t"
 540                 "xor %%rax,%%rax\n\t"
 541                 "ret"
 542                 : : "a" (stack), "b" (guest_regs));
 543         __builtin_unreachable();
 544 }
 545
 546 static void svm_vcpu_reset(struct per_cpu *cpu_data, unsigned int sipi_vector)
 547 {
 548         struct vmcb *vmcb = &cpu_data->vmcb;
 549         unsigned long val;
 550         bool ok = true;
 551
 552         vmcb->cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
 553         vmcb->cr3 = 0;
 554         vmcb->cr4 = 0;
 555
 556         vmcb->rflags = 0x02;
 557
 558         val = 0;
 559         if (sipi_vector == APIC_BSP_PSEUDO_SIPI) {
 560                 val = 0xfff0;
 561                 sipi_vector = 0xf0;
 562         }
 563         vmcb->rip = val;
 564         vmcb->rsp = 0;
 565
 566         vmcb->cs.selector = sipi_vector << 8;
 567         vmcb->cs.base = sipi_vector << 12;
 568         vmcb->cs.limit = 0xffff;
 569         vmcb->cs.access_rights = 0x009b;
 570
 571         vmcb->ds.selector = 0;
 572         vmcb->ds.base = 0;
 573         vmcb->ds.limit = 0xffff;
 574         vmcb->ds.access_rights = 0x0093;
 575
 576         vmcb->es.selector = 0;
 577         vmcb->es.base = 0;
 578         vmcb->es.limit = 0xffff;
 579         vmcb->es.access_rights = 0x0093;
 580
 581         vmcb->fs.selector = 0;
 582         vmcb->fs.base = 0;
 583         vmcb->fs.limit = 0xffff;
 584         vmcb->fs.access_rights = 0x0093;
 585
 586         vmcb->gs.selector = 0;
 587         vmcb->gs.base = 0;
 588         vmcb->gs.limit = 0xffff;
 589         vmcb->gs.access_rights = 0x0093;
 590
 591         vmcb->ss.selector = 0;
 592         vmcb->ss.base = 0;
 593         vmcb->ss.limit = 0xffff;
 594         vmcb->ss.access_rights = 0x0093;
 595
 596         vmcb->tr.selector = 0;
 597         vmcb->tr.base = 0;
 598         vmcb->tr.limit = 0xffff;
 599         vmcb->tr.access_rights = 0x008b;
 600
 601         vmcb->ldtr.selector = 0;
 602         vmcb->ldtr.base = 0;
 603         vmcb->ldtr.limit = 0xffff;
 604         vmcb->ldtr.access_rights = 0x0082;
 605
 606         vmcb->gdtr.selector = 0;
 607         vmcb->gdtr.base = 0;
 608         vmcb->gdtr.limit = 0xffff;
 609         vmcb->gdtr.access_rights = 0;
 610
 611         vmcb->idtr.selector = 0;
 612         vmcb->idtr.base = 0;
 613         vmcb->idtr.limit = 0xffff;
 614         vmcb->idtr.access_rights = 0;
 615
 616         vmcb->efer = EFER_SVME;
 617
 618         /* These MSRs are undefined on reset */
 619         vmcb->star = 0;
 620         vmcb->lstar = 0;
 621         vmcb->cstar = 0;
 622         vmcb->sfmask = 0;
 623         vmcb->sysenter_cs = 0;
 624         vmcb->sysenter_eip = 0;
 625         vmcb->sysenter_esp = 0;
 626         vmcb->kerngsbase = 0;
 627
 628         vmcb->dr7 = 0x00000400;
 629
 630         /* Almost all of the guest state changed */
 631         vmcb->clean_bits = 0;
 632
 633         ok &= svm_set_cell_config(cpu_data->cell, vmcb);
 634
 635         /* This is always false, but to be consistent with vmx.c... */
 636         if (!ok) {
 637                 panic_printk("FATAL: CPU reset failed\n");
 638                 panic_stop();
 639         }
 640 }
 641
 642 void vcpu_skip_emulated_instruction(unsigned int inst_len)
 643 {
 644         struct per_cpu *cpu_data = this_cpu_data();
 645         struct vmcb *vmcb = &cpu_data->vmcb;
 646         vmcb->rip += inst_len;
 647 }
 648
 649 static void update_efer(struct per_cpu *cpu_data)
 650 {
 651         struct vmcb *vmcb = &cpu_data->vmcb;
 652         unsigned long efer = vmcb->efer;
 653
 654         if ((efer & (EFER_LME | EFER_LMA)) != EFER_LME)
 655                 return;
 656
 657         efer |= EFER_LMA;
 658
 659         /* Flush TLB on LMA/LME change: See APMv2, Sect. 15.16 */
 660         if ((vmcb->efer ^ efer) & EFER_LMA)
 661                 vcpu_tlb_flush();
 662
 663         vmcb->efer = efer;
 664         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
 665 }
 666
 667 bool vcpu_get_guest_paging_structs(struct guest_paging_structures *pg_structs)
 668 {
 669         struct per_cpu *cpu_data = this_cpu_data();
 670         struct vmcb *vmcb = &cpu_data->vmcb;
 671
 672         if (vmcb->efer & EFER_LMA) {
 673                 pg_structs->root_paging = x86_64_paging;
 674                 pg_structs->root_table_gphys =
 675                         vmcb->cr3 & 0x000ffffffffff000UL;
 676         } else if ((vmcb->cr0 & X86_CR0_PG) &&
 677                    !(vmcb->cr4 & X86_CR4_PAE)) {
 678                 pg_structs->root_paging = i386_paging;
 679                 pg_structs->root_table_gphys =
 680                         vmcb->cr3 & 0xfffff000UL;
 681         } else if (!(vmcb->cr0 & X86_CR0_PG)) {
 682                 /*
 683                  * Can be in non-paged protected mode as well, but
 684                  * the translation mechanism will stay the same ayway.
 685                  */
 686                 pg_structs->root_paging = realmode_paging;
 687                 /*
 688                  * This will make paging_get_guest_pages map the page
 689                  * that also contains the bootstrap code and, thus, is
 690                  * always present in a cell.
 691                  */
 692                 pg_structs->root_table_gphys = 0xff000;
 693         } else {
 694                 printk("FATAL: Unsupported paging mode\n");
 695                 return false;
 696         }
 697         return true;
 698 }
 699
 700 void vcpu_vendor_set_guest_pat(unsigned long val)
 701 {
 702         struct vmcb *vmcb = &this_cpu_data()->vmcb;
 703
 704         vmcb->g_pat = val;
 705         vmcb->clean_bits &= ~CLEAN_BITS_NP;
 706 }
 707
 708 struct parse_context {
 709         unsigned int remaining;
 710         unsigned int size;
 711         unsigned long cs_base;
 712         const u8 *inst;
 713 };
 714
 715 static bool ctx_advance(struct parse_context *ctx,
 716                         unsigned long *pc,
 717                         struct guest_paging_structures *pg_structs)
 718 {
 719         if (!ctx->size) {
 720                 ctx->size = ctx->remaining;
 721                 ctx->inst = vcpu_map_inst(pg_structs, ctx->cs_base + *pc,
 722                                           &ctx->size);
 723                 if (!ctx->inst)
 724                         return false;
 725                 ctx->remaining -= ctx->size;
 726                 *pc += ctx->size;
 727         }
 728         return true;
 729 }
 730
 731 static bool x86_parse_mov_to_cr(struct per_cpu *cpu_data,
 732                                 unsigned long pc,
 733                                 unsigned char reg,
 734                                 unsigned long *gpr)
 735 {
 736         struct guest_paging_structures pg_structs;
 737         struct vmcb *vmcb = &cpu_data->vmcb;
 738         struct parse_context ctx = {};
 739         /* No prefixes are supported yet */
 740         u8 opcodes[] = {0x0f, 0x22}, modrm;
 741         bool ok = false;
 742         int n;
 743
 744         ctx.remaining = ARRAY_SIZE(opcodes);
 745         if (!vcpu_get_guest_paging_structs(&pg_structs))
 746                 goto out;
 747         ctx.cs_base = (vmcb->efer & EFER_LMA) ? 0 : vmcb->cs.base;
 748
 749         if (!ctx_advance(&ctx, &pc, &pg_structs))
 750                 goto out;
 751
 752         for (n = 0; n < ARRAY_SIZE(opcodes); n++, ctx.inst++) {
 753                 if (*(ctx.inst) != opcodes[n])
 754                         goto out;
 755                 if (!ctx_advance(&ctx, &pc, &pg_structs))
 756                         goto out;
 757         }
 758
 759         if (!ctx_advance(&ctx, &pc, &pg_structs))
 760                 goto out;
 761
 762         modrm = *(ctx.inst);
 763
 764         if (((modrm & 0x38) >> 3) != reg)
 765                 goto out;
 766
 767         if (gpr)
 768                 *gpr = (modrm & 0x7);
 769
 770         ok = true;
 771 out:
 772         return ok;
 773 }
 774
 775 /*
 776  * XXX: The only visible reason to have this function (vmx.c consistency
 777  * aside) is to prevent cells from setting invalid CD+NW combinations that
 778  * result in no more than VMEXIT_INVALID. Maybe we can get along without it
 779  * altogether?
 780  */
 781 static bool svm_handle_cr(struct registers *guest_regs,
 782                           struct per_cpu *cpu_data)
 783 {
 784         struct vmcb *vmcb = &cpu_data->vmcb;
 785         /* Workaround GCC 4.8 warning on uninitialized variable 'reg' */
 786         unsigned long reg = -1, val, bits;
 787         bool ok = true;
 788
 789         if (has_assists) {
 790                 if (!(vmcb->exitinfo1 & (1UL << 63))) {
 791                         panic_printk("FATAL: Unsupported CR access (LMSW or CLTS)\n");
 792                         ok = false;
 793                         goto out;
 794                 }
 795                 reg = vmcb->exitinfo1 & 0x07;
 796         } else {
 797                 if (!x86_parse_mov_to_cr(cpu_data, vmcb->rip, 0, &reg)) {
 798                         panic_printk("FATAL: Unable to parse MOV-to-CR instruction\n");
 799                         ok = false;
 800                         goto out;
 801                 }
 802         };
 803
 804         if (reg == 4)
 805                 val = vmcb->rsp;
 806         else
 807                 val = ((unsigned long *)guest_regs)[15 - reg];
 808
 809         vcpu_skip_emulated_instruction(X86_INST_LEN_MOV_TO_CR);
 810         /* Flush TLB on PG/WP/CD/NW change: See APMv2, Sect. 15.16 */
 811         bits = (X86_CR0_PG | X86_CR0_WP | X86_CR0_CD | X86_CR0_NW);
 812         if ((val ^ vmcb->cr0) & bits)
 813                 vcpu_tlb_flush();
 814         /* TODO: better check for #GP reasons */
 815         vmcb->cr0 = val & SVM_CR0_ALLOWED_BITS;
 816         if (val & X86_CR0_PG)
 817                 update_efer(cpu_data);
 818         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
 819
 820 out:
 821         return ok;
 822 }
 823
 824 static bool svm_handle_msr_write(struct registers *guest_regs,
 825                 struct per_cpu *cpu_data)
 826 {
 827         struct vmcb *vmcb = &cpu_data->vmcb;
 828         unsigned long efer;
 829
 830         if (guest_regs->rcx == MSR_EFER) {
 831                 /* Never let a guest to disable SVME; see APMv2, Sect. 3.1.7 */
 832                 efer = get_wrmsr_value(guest_regs) | EFER_SVME;
 833                 /* Flush TLB on LME/NXE change: See APMv2, Sect. 15.16 */
 834                 if ((efer ^ vmcb->efer) & (EFER_LME | EFER_NXE))
 835                         vcpu_tlb_flush();
 836                 vmcb->efer = efer;
 837                 vmcb->clean_bits &= ~CLEAN_BITS_CRX;
 838                 vcpu_skip_emulated_instruction(X86_INST_LEN_WRMSR);
 839                 return true;
 840         }
 841
 842         return vcpu_handle_msr_write(guest_regs);
 843 }
 844
 845 /*
 846  * TODO: This handles unaccelerated (non-AVIC) access. AVIC should
 847  * be treated separately in svm_handle_avic_access().
 848  */
 849 static bool svm_handle_apic_access(struct registers *guest_regs,
 850                                    struct per_cpu *cpu_data)
 851 {
 852         struct vmcb *vmcb = &cpu_data->vmcb;
 853         struct guest_paging_structures pg_structs;
 854         unsigned int inst_len, offset;
 855         bool is_write;
 856
 857         /* The caller is responsible for sanity checks */
 858         is_write = !!(vmcb->exitinfo1 & 0x2);
 859         offset = vmcb->exitinfo2 - XAPIC_BASE;
 860
 861         if (offset & 0x00f)
 862                 goto out_err;
 863
 864         if (!vcpu_get_guest_paging_structs(&pg_structs))
 865                 goto out_err;
 866
 867         inst_len = apic_mmio_access(guest_regs, cpu_data, vmcb->rip,
 868                                     &pg_structs, offset >> 4, is_write);
 869         if (!inst_len)
 870                 goto out_err;
 871
 872         vcpu_skip_emulated_instruction(inst_len);
 873         return true;
 874
 875 out_err:
 876         panic_printk("FATAL: Unhandled APIC access, offset %d, is_write: %d\n",
 877                      offset, is_write);
 878         return false;
 879 }
 880
 881 static void dump_guest_regs(struct registers *guest_regs, struct vmcb *vmcb)
 882 {
 883         panic_printk("RIP: %p RSP: %p FLAGS: %x\n", vmcb->rip,
 884                      vmcb->rsp, vmcb->rflags);
 885         panic_printk("RAX: %p RBX: %p RCX: %p\n", guest_regs->rax,
 886                      guest_regs->rbx, guest_regs->rcx);
 887         panic_printk("RDX: %p RSI: %p RDI: %p\n", guest_regs->rdx,
 888                      guest_regs->rsi, guest_regs->rdi);
 889         panic_printk("CS: %x BASE: %p AR-BYTES: %x EFER.LMA %d\n",
 890                      vmcb->cs.selector, vmcb->cs.base, vmcb->cs.access_rights,
 891                      !!(vmcb->efer & EFER_LMA));
 892         panic_printk("CR0: %p CR3: %p CR4: %p\n", vmcb->cr0,
 893                      vmcb->cr3, vmcb->cr4);
 894         panic_printk("EFER: %p\n", vmcb->efer);
 895 }
 896
 897 static void svm_get_vcpu_pf_intercept(struct per_cpu *cpu_data,
 898                                       struct vcpu_pf_intercept *out)
 899 {
 900         struct vmcb *vmcb = &cpu_data->vmcb;
 901
 902         out->phys_addr = vmcb->exitinfo2;
 903         out->is_write = !!(vmcb->exitinfo1 & 0x2);
 904 }
 905
 906 static void svm_get_vcpu_io_intercept(struct per_cpu *cpu_data,
 907                                       struct vcpu_io_intercept *out)
 908 {
 909         struct vmcb *vmcb = &cpu_data->vmcb;
 910         u64 exitinfo = vmcb->exitinfo1;
 911
 912         /* parse exit info for I/O instructions (see APM, 15.10.2 ) */
 913         out->port = (exitinfo >> 16) & 0xFFFF;
 914         out->size = (exitinfo >> 4) & 0x7;
 915         out->in = !!(exitinfo & 0x1);
 916         out->inst_len = vmcb->exitinfo2 - vmcb->rip;
 917         out->rep_or_str = !!(exitinfo & 0x0c);
 918 }
 919
 920 void vcpu_handle_exit(struct registers *guest_regs, struct per_cpu *cpu_data)
 921 {
 922         struct vmcb *vmcb = &cpu_data->vmcb;
 923         struct vcpu_execution_state x_state;
 924         struct vcpu_pf_intercept pf;
 925         struct vcpu_io_intercept io;
 926         bool res = false;
 927         int sipi_vector;
 928
 929         /* Restore GS value expected by per_cpu data accessors */
 930         write_msr(MSR_GS_BASE, (unsigned long)cpu_data);
 931
 932         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_TOTAL]++;
 933         /*
 934          * All guest state is marked unmodified; individual handlers must clear
 935          * the bits as needed.
 936          */
 937         vmcb->clean_bits = 0xffffffff;
 938
 939         switch (vmcb->exitcode) {
 940         case VMEXIT_INVALID:
 941                 panic_printk("FATAL: VM-Entry failure, error %d\n",
 942                              vmcb->exitcode);
 943                 break;
 944         case VMEXIT_NMI:
 945                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MANAGEMENT]++;
 946                 /* Temporarily enable GIF to consume pending NMI */
 947                 asm volatile("stgi; clgi" : : : "memory");
 948                 sipi_vector = x86_handle_events(cpu_data);
 949                 if (sipi_vector >= 0) {
 950                         printk("CPU %d received SIPI, vector %x\n",
 951                                cpu_data->cpu_id, sipi_vector);
 952                         svm_vcpu_reset(cpu_data, sipi_vector);
 953                         vcpu_reset(guest_regs);
 954                 }
 955                 iommu_check_pending_faults(cpu_data);
 956                 return;
 957         case VMEXIT_CPUID:
 958                 /* FIXME: We are not intercepting CPUID now */
 959                 return;
 960         case VMEXIT_VMMCALL:
 961                 vcpu_vendor_get_execution_state(&x_state);
 962                 vcpu_handle_hypercall(guest_regs, &x_state);
 963                 return;
 964         case VMEXIT_CR0_SEL_WRITE:
 965                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_CR]++;
 966                 if (svm_handle_cr(guest_regs, cpu_data))
 967                         return;
 968                 break;
 969         case VMEXIT_MSR:
 970                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MSR]++;
 971                 if (!vmcb->exitinfo1)
 972                         res = vcpu_handle_msr_read(guest_regs);
 973                 else
 974                         res = svm_handle_msr_write(guest_regs, cpu_data);
 975                 if (res)
 976                         return;
 977                 break;
 978         case VMEXIT_NPF:
 979                 if ((vmcb->exitinfo1 & 0x7) == 0x7 &&
 980                      vmcb->exitinfo2 >= XAPIC_BASE &&
 981                      vmcb->exitinfo2 < XAPIC_BASE + PAGE_SIZE) {
 982                         /* APIC access in non-AVIC mode */
 983                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XAPIC]++;
 984                         if (svm_handle_apic_access(guest_regs, cpu_data))
 985                                 return;
 986                 } else {
 987                         /* General MMIO (IOAPIC, PCI etc) */
 988                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MMIO]++;
 989                         svm_get_vcpu_pf_intercept(cpu_data, &pf);
 990                         if (vcpu_handle_pt_violation(guest_regs, &pf))
 991                                 return;
 992                 }
 993
 994                 panic_printk("FATAL: Unhandled Nested Page Fault for (%p), "
 995                              "error code is %x\n", vmcb->exitinfo2,
 996                              vmcb->exitinfo1 & 0xf);
 997                 break;
 998         case VMEXIT_XSETBV:
 999                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XSETBV]++;
1000                 if ((guest_regs->rax & X86_XCR0_FP) &&
1001                     (guest_regs->rax & ~cpuid_eax(0x0d)) == 0 &&
1002                     guest_regs->rcx == 0 && guest_regs->rdx == 0) {
1003                         vcpu_skip_emulated_instruction(X86_INST_LEN_XSETBV);
1004                         asm volatile(
1005                                 "xsetbv"
1006                                 : /* no output */
1007                                 : "a" (guest_regs->rax), "c" (0), "d" (0));
1008                         return;
1009                 }
1010                 panic_printk("FATAL: Invalid xsetbv parameters: "
1011                              "xcr[%d] = %x:%x\n", guest_regs->rcx,
1012                              guest_regs->rdx, guest_regs->rax);
1013                 break;
1014         case VMEXIT_IOIO:
1015                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_PIO]++;
1016                 svm_get_vcpu_io_intercept(cpu_data, &io);
1017                 if (vcpu_handle_io_access(guest_regs, &io))
1018                         return;
1019                 break;
1020         /* TODO: Handle VMEXIT_AVIC_NOACCEL and VMEXIT_AVIC_INCOMPLETE_IPI */
1021         default:
1022                 panic_printk("FATAL: Unexpected #VMEXIT, exitcode %x, "
1023                              "exitinfo1 %p exitinfo2 %p\n",
1024                              vmcb->exitcode, vmcb->exitinfo1, vmcb->exitinfo2);
1025         }
1026         dump_guest_regs(guest_regs, vmcb);
1027         panic_park();
1028 }
1029
1030 void vcpu_park(void)
1031 {
1032         svm_vcpu_reset(this_cpu_data(), APIC_BSP_PSEUDO_SIPI);
1033         /* No need to clear VMCB Clean bit: vcpu_reset() already does this */
1034         this_cpu_data()->vmcb.n_cr3 = paging_hvirt2phys(parked_mode_npt);
1035
1036         vcpu_tlb_flush();
1037 }
1038
1039 void vcpu_nmi_handler(void)
1040 {
1041 }
1042
1043 void vcpu_tlb_flush(void)
1044 {
1045         struct per_cpu *cpu_data = this_cpu_data();
1046         struct vmcb *vmcb = &cpu_data->vmcb;
1047
1048         if (has_flush_by_asid)
1049                 vmcb->tlb_control = SVM_TLB_FLUSH_GUEST;
1050         else
1051                 vmcb->tlb_control = SVM_TLB_FLUSH_ALL;
1052 }
1053
1054 const u8 *vcpu_get_inst_bytes(const struct guest_paging_structures *pg_structs,
1055                               unsigned long pc, unsigned int *size)
1056 {
1057         struct per_cpu *cpu_data = this_cpu_data();
1058         struct vmcb *vmcb = &cpu_data->vmcb;
1059         unsigned long start;
1060
1061         if (has_assists) {
1062                 if (!*size)
1063                         return NULL;
1064                 start = vmcb->rip - pc;
1065                 if (start < vmcb->bytes_fetched) {
1066                         *size = vmcb->bytes_fetched - start;
1067                         return &vmcb->guest_bytes[start];
1068                 } else {
1069                         return NULL;
1070                 }
1071         } else {
1072                 return vcpu_map_inst(pg_structs, pc, size);
1073         }
1074 }
1075
1076 void vcpu_vendor_get_cell_io_bitmap(struct cell *cell,
1077                                     struct vcpu_io_bitmap *iobm)
1078 {
1079         iobm->data = cell->svm.iopm;
1080         iobm->size = sizeof(cell->svm.iopm);
1081 }
1082
1083 void vcpu_vendor_get_execution_state(struct vcpu_execution_state *x_state)
1084 {
1085         struct per_cpu *cpu_data = this_cpu_data();
1086
1087         x_state->efer = cpu_data->vmcb.efer;
1088         x_state->rflags = cpu_data->vmcb.rflags;
1089         x_state->cs = cpu_data->vmcb.cs.selector;
1090         x_state->rip = cpu_data->vmcb.rip;
1091 }
1092
1093 /* GIF must be set for interrupts to be delivered (APMv2, Sect. 15.17) */
1094 void enable_irq(void)
1095 {
1096         asm volatile("stgi; sti" : : : "memory");
1097 }
1098
1099 /* Jailhouse runs with GIF cleared, so we need to restore this state */
1100 void disable_irq(void)
1101 {
1102         asm volatile("cli; clgi" : : : "memory");
1103 }