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x86: Eliminate dead code in vcpu_activate_vmm()
[jailhouse.git] / 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_CLEARED_BITS    ~X86_CR0_NW
41
42 #define MTRR_DEFTYPE            0x2ff
43
44 #define PAT_RESET_VALUE         0x0007040600070406
45
46 static bool has_avic, has_assists, has_flush_by_asid;
47
48 static const struct segment invalid_seg;
49
50 static struct paging npt_paging[NPT_PAGE_DIR_LEVELS];
51
52 static u8 __attribute__((aligned(PAGE_SIZE))) msrpm[][0x2000/4] = {
53         [ SVM_MSRPM_0000 ] = {
54                 [      0/4 ...  0x017/4 ] = 0,
55                 [  0x018/4 ...  0x01b/4 ] = 0x80, /* 0x01b (w) */
56                 [  0x01c/4 ...  0x2fb/4 ] = 0,
57                 [  0x2fc/4 ...  0x2ff/4 ] = 0x80, /* 0x2ff (w) */
58                 [  0x300/4 ...  0x7ff/4 ] = 0,
59                 /* x2APIC MSRs - emulated if not present */
60                 [  0x800/4 ...  0x803/4 ] = 0x90, /* 0x802 (r), 0x803 (r) */
61                 [  0x804/4 ...  0x807/4 ] = 0,
62                 [  0x808/4 ...  0x80b/4 ] = 0x93, /* 0x808 (rw), 0x80a (r), 0x80b (w) */
63                 [  0x80c/4 ...  0x80f/4 ] = 0xc8, /* 0x80d (w), 0x80f (rw) */
64                 [  0x810/4 ...  0x813/4 ] = 0x55, /* 0x810 - 0x813 (r) */
65                 [  0x814/4 ...  0x817/4 ] = 0x55, /* 0x814 - 0x817 (r) */
66                 [  0x818/4 ...  0x81b/4 ] = 0x55, /* 0x818 - 0x81b (r) */
67                 [  0x81c/4 ...  0x81f/4 ] = 0x55, /* 0x81c - 0x81f (r) */
68                 [  0x820/4 ...  0x823/4 ] = 0x55, /* 0x820 - 0x823 (r) */
69                 [  0x824/4 ...  0x827/4 ] = 0x55, /* 0x823 - 0x827 (r) */
70                 [  0x828/4 ...  0x82b/4 ] = 0x03, /* 0x828 (rw) */
71                 [  0x82c/4 ...  0x82f/4 ] = 0xc0, /* 0x82f (rw) */
72                 [  0x830/4 ...  0x833/4 ] = 0xf3, /* 0x830 (rw), 0x832 (rw), 0x833 (rw) */
73                 [  0x834/4 ...  0x837/4 ] = 0xff, /* 0x834 - 0x837 (rw) */
74                 [  0x838/4 ...  0x83b/4 ] = 0x07, /* 0x838 (rw), 0x839 (r) */
75                 [  0x83c/4 ...  0x83f/4 ] = 0x70, /* 0x83e (rw), 0x83f (r) */
76                 [  0x840/4 ... 0x1fff/4 ] = 0,
77         },
78         [ SVM_MSRPM_C000 ] = {
79                 [      0/4 ...  0x07f/4 ] = 0,
80                 [  0x080/4 ...  0x083/4 ] = 0x02, /* 0x080 (w) */
81                 [  0x084/4 ... 0x1fff/4 ] = 0
82         },
83         [ SVM_MSRPM_C001 ] = {
84                 [      0/4 ... 0x1fff/4 ] = 0,
85         },
86         [ SVM_MSRPM_RESV ] = {
87                 [      0/4 ... 0x1fff/4 ] = 0,
88         }
89 };
90
91 /* This page is mapped so the code begins at 0x000ffff0 */
92 static u8 __attribute__((aligned(PAGE_SIZE))) parking_code[PAGE_SIZE] = {
93         [0xff0] = 0xfa, /* 1: cli */
94         [0xff1] = 0xf4, /*    hlt */
95         [0xff2] = 0xeb,
96         [0xff3] = 0xfc  /*    jmp 1b */
97 };
98
99 static void *parked_mode_npt;
100
101 static void *avic_page;
102
103 static int svm_check_features(void)
104 {
105         /* SVM is available */
106         if (!(cpuid_ecx(0x80000001) & X86_FEATURE_SVM))
107                 return -ENODEV;
108
109         /* Nested paging */
110         if (!(cpuid_edx(0x8000000A) & X86_FEATURE_NP))
111                 return -EIO;
112
113         /* Decode assists */
114         if ((cpuid_edx(0x8000000A) & X86_FEATURE_DECODE_ASSISTS))
115                 has_assists = true;
116
117         /* AVIC support */
118         if (cpuid_edx(0x8000000A) & X86_FEATURE_AVIC)
119                 has_avic = true;
120
121         /* TLB Flush by ASID support */
122         if (cpuid_edx(0x8000000A) & X86_FEATURE_FLUSH_BY_ASID)
123                 has_flush_by_asid = true;
124
125         return 0;
126 }
127
128 static void set_svm_segment_from_dtr(struct svm_segment *svm_segment,
129                                      const struct desc_table_reg *dtr)
130 {
131         struct svm_segment tmp = { 0 };
132
133         if (dtr) {
134                 tmp.base = dtr->base;
135                 tmp.limit = dtr->limit & 0xffff;
136         }
137
138         *svm_segment = tmp;
139 }
140
141 /* TODO: struct segment needs to be x86 generic, not VMX-specific one here */
142 static void set_svm_segment_from_segment(struct svm_segment *svm_segment,
143                                          const struct segment *segment)
144 {
145         u32 ar;
146
147         svm_segment->selector = segment->selector;
148
149         if (segment->access_rights == 0x10000) {
150                 svm_segment->access_rights = 0;
151         } else {
152                 ar = segment->access_rights;
153                 svm_segment->access_rights =
154                         ((ar & 0xf000) >> 4) | (ar & 0x00ff);
155         }
156
157         svm_segment->limit = segment->limit;
158         svm_segment->base = segment->base;
159 }
160
161 static bool svm_set_cell_config(struct cell *cell, struct vmcb *vmcb)
162 {
163         /* No real need for this function; used for consistency with vmx.c */
164         vmcb->iopm_base_pa = paging_hvirt2phys(cell->svm.iopm);
165         vmcb->n_cr3 = paging_hvirt2phys(cell->svm.npt_structs.root_table);
166
167         return true;
168 }
169
170 static int vmcb_setup(struct per_cpu *cpu_data)
171 {
172         struct vmcb *vmcb = &cpu_data->vmcb;
173
174         memset(vmcb, 0, sizeof(struct vmcb));
175
176         vmcb->cr0 = read_cr0() & SVM_CR0_CLEARED_BITS;
177         vmcb->cr3 = cpu_data->linux_cr3;
178         vmcb->cr4 = read_cr4();
179
180         set_svm_segment_from_segment(&vmcb->cs, &cpu_data->linux_cs);
181         set_svm_segment_from_segment(&vmcb->ds, &cpu_data->linux_ds);
182         set_svm_segment_from_segment(&vmcb->es, &cpu_data->linux_es);
183         set_svm_segment_from_segment(&vmcb->fs, &cpu_data->linux_fs);
184         set_svm_segment_from_segment(&vmcb->gs, &cpu_data->linux_gs);
185         set_svm_segment_from_segment(&vmcb->ss, &invalid_seg);
186         set_svm_segment_from_segment(&vmcb->tr, &cpu_data->linux_tss);
187
188         set_svm_segment_from_dtr(&vmcb->ldtr, NULL);
189         set_svm_segment_from_dtr(&vmcb->gdtr, &cpu_data->linux_gdtr);
190         set_svm_segment_from_dtr(&vmcb->idtr, &cpu_data->linux_idtr);
191
192         vmcb->cpl = 0; /* Linux runs in ring 0 before migration */
193
194         vmcb->rflags = 0x02;
195         /* Indicate success to the caller of arch_entry */
196         vmcb->rax = 0;
197         vmcb->rsp = cpu_data->linux_sp +
198                 (NUM_ENTRY_REGS + 1) * sizeof(unsigned long);
199         vmcb->rip = cpu_data->linux_ip;
200
201         vmcb->sysenter_cs = read_msr(MSR_IA32_SYSENTER_CS);
202         vmcb->sysenter_eip = read_msr(MSR_IA32_SYSENTER_EIP);
203         vmcb->sysenter_esp = read_msr(MSR_IA32_SYSENTER_ESP);
204         vmcb->star = read_msr(MSR_STAR);
205         vmcb->lstar = read_msr(MSR_LSTAR);
206         vmcb->cstar = read_msr(MSR_CSTAR);
207         vmcb->sfmask = read_msr(MSR_SFMASK);
208         vmcb->kerngsbase = read_msr(MSR_KERNGS_BASE);
209
210         vmcb->dr6 = 0x00000ff0;
211         vmcb->dr7 = 0x00000400;
212
213         /* Make the hypervisor visible */
214         vmcb->efer = (cpu_data->linux_efer | EFER_SVME);
215
216         /* Linux uses custom PAT setting */
217         vmcb->g_pat = read_msr(MSR_IA32_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 -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                 /* Enable Extended Interrupt LVT */
300                 apic_reserved_bits[0x50] = 0;
301                 if (has_avic) {
302                         avic_page = page_alloc(&remap_pool, 1);
303                         if (!avic_page)
304                                 return -ENOMEM;
305                 }
306         }
307
308         return vcpu_cell_init(&root_cell);
309 }
310
311 int vcpu_vendor_cell_init(struct cell *cell)
312 {
313         u64 flags;
314         int err;
315
316         /* allocate iopm (two 4-K pages + 3 bits) */
317         cell->svm.iopm = page_alloc(&mem_pool, 3);
318         if (!cell->svm.iopm)
319                 return -ENOMEM;
320
321         /* build root NPT of cell */
322         cell->svm.npt_structs.root_paging = npt_paging;
323         cell->svm.npt_structs.root_table = page_alloc(&mem_pool, 1);
324         if (!cell->svm.npt_structs.root_table)
325                 return -ENOMEM;
326
327         if (!has_avic) {
328                 /*
329                  * Map xAPIC as is; reads are passed, writes are trapped.
330                  */
331                 flags = PAGE_READONLY_FLAGS |
332                         PAGE_FLAG_US |
333                         PAGE_FLAG_UNCACHED;
334                 err = paging_create(&cell->svm.npt_structs, XAPIC_BASE,
335                                     PAGE_SIZE, XAPIC_BASE,
336                                     flags,
337                                     PAGING_NON_COHERENT);
338         } else {
339                 flags = PAGE_DEFAULT_FLAGS | PAGE_FLAG_UNCACHED;
340                 err = paging_create(&cell->svm.npt_structs,
341                                     paging_hvirt2phys(avic_page),
342                                     PAGE_SIZE, XAPIC_BASE,
343                                     flags,
344                                     PAGING_NON_COHERENT);
345         }
346
347         return err;
348 }
349
350 int vcpu_map_memory_region(struct cell *cell,
351                            const struct jailhouse_memory *mem)
352 {
353         u64 phys_start = mem->phys_start;
354         u32 flags = PAGE_FLAG_US; /* See APMv2, Section 15.25.5 */
355
356         if (mem->flags & JAILHOUSE_MEM_READ)
357                 flags |= PAGE_FLAG_PRESENT;
358         if (mem->flags & JAILHOUSE_MEM_WRITE)
359                 flags |= PAGE_FLAG_RW;
360         if (mem->flags & JAILHOUSE_MEM_EXECUTE)
361                 flags |= PAGE_FLAG_EXECUTE;
362         if (mem->flags & JAILHOUSE_MEM_COMM_REGION)
363                 phys_start = paging_hvirt2phys(&cell->comm_page);
364
365         return paging_create(&cell->svm.npt_structs, phys_start, mem->size,
366                              mem->virt_start, flags, PAGING_NON_COHERENT);
367 }
368
369 int vcpu_unmap_memory_region(struct cell *cell,
370                              const struct jailhouse_memory *mem)
371 {
372         return paging_destroy(&cell->svm.npt_structs, mem->virt_start,
373                               mem->size, PAGING_NON_COHERENT);
374 }
375
376 void vcpu_vendor_cell_exit(struct cell *cell)
377 {
378         paging_destroy(&cell->svm.npt_structs, XAPIC_BASE, PAGE_SIZE,
379                        PAGING_NON_COHERENT);
380         page_free(&mem_pool, cell->svm.npt_structs.root_table, 1);
381 }
382
383 int vcpu_init(struct per_cpu *cpu_data)
384 {
385         unsigned long efer;
386         int err;
387
388         err = svm_check_features();
389         if (err)
390                 return err;
391
392         efer = read_msr(MSR_EFER);
393         if (efer & EFER_SVME)
394                 return -EBUSY;
395
396         efer |= EFER_SVME;
397         write_msr(MSR_EFER, efer);
398
399         cpu_data->svm_state = SVMON;
400
401         if (!vmcb_setup(cpu_data))
402                 return -EIO;
403
404         write_msr(MSR_VM_HSAVE_PA, paging_hvirt2phys(cpu_data->host_state));
405
406         /* Enable Extended Interrupt LVT (xAPIC, as it is AMD-only) */
407         if (!using_x2apic)
408                 apic_reserved_bits[0x50] = 0;
409
410         return 0;
411 }
412
413 void vcpu_exit(struct per_cpu *cpu_data)
414 {
415         unsigned long efer;
416
417         if (cpu_data->svm_state == SVMOFF)
418                 return;
419
420         cpu_data->svm_state = SVMOFF;
421
422         /* We are leaving - set the GIF */
423         asm volatile ("stgi" : : : "memory");
424
425         efer = read_msr(MSR_EFER);
426         efer &= ~EFER_SVME;
427         write_msr(MSR_EFER, efer);
428
429         write_msr(MSR_VM_HSAVE_PA, 0);
430 }
431
432 void vcpu_activate_vmm(struct per_cpu *cpu_data)
433 {
434         unsigned long vmcb_pa, host_stack;
435
436         vmcb_pa = paging_hvirt2phys(&cpu_data->vmcb);
437         host_stack = (unsigned long)cpu_data->stack + sizeof(cpu_data->stack);
438
439         /*
440          * XXX: Jailhouse doesn't use PAT, so it is explicitly set to the
441          * reset value. However, this value is later combined with vmcb->g_pat
442          * (as per APMv2, Sect. 15.25.8) which may lead to subtle bugs as the
443          * actual memory type might slightly differ from what Linux expects.
444          */
445         write_msr(MSR_IA32_PAT, PAT_RESET_VALUE);
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\n\t"
459                 "vmrun\n\t"
460                 "vmsave\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         /* We are leaving - set the GIF */
480         asm volatile ("stgi" : : : "memory");
481
482         /*
483          * Restore the MSRs.
484          *
485          * XXX: One could argue this is better to be done in
486          * arch_cpu_restore(), however, it would require changes
487          * to cpu_data to store STAR and friends.
488          */
489         write_msr(MSR_STAR, vmcb->star);
490         write_msr(MSR_LSTAR, vmcb->lstar);
491         write_msr(MSR_CSTAR, vmcb->cstar);
492         write_msr(MSR_SFMASK, vmcb->sfmask);
493         write_msr(MSR_KERNGS_BASE, vmcb->kerngsbase);
494         write_msr(MSR_IA32_PAT, vmcb->g_pat);
495
496         cpu_data->linux_cr3 = vmcb->cr3;
497
498         cpu_data->linux_gdtr.base = vmcb->gdtr.base;
499         cpu_data->linux_gdtr.limit = vmcb->gdtr.limit;
500         cpu_data->linux_idtr.base = vmcb->idtr.base;
501         cpu_data->linux_idtr.limit = vmcb->idtr.limit;
502
503         cpu_data->linux_cs.selector = vmcb->cs.selector;
504
505         cpu_data->linux_tss.selector = vmcb->tr.selector;
506
507         cpu_data->linux_efer = vmcb->efer & (~EFER_SVME);
508         cpu_data->linux_fs.base = vmcb->fs.base;
509         cpu_data->linux_gs.base = vmcb->gs.base;
510
511         cpu_data->linux_sysenter_cs = vmcb->sysenter_cs;
512         cpu_data->linux_sysenter_eip = vmcb->sysenter_eip;
513         cpu_data->linux_sysenter_esp = vmcb->sysenter_esp;
514
515         cpu_data->linux_ds.selector = vmcb->ds.selector;
516         cpu_data->linux_es.selector = vmcb->es.selector;
517         cpu_data->linux_fs.selector = vmcb->fs.selector;
518         cpu_data->linux_gs.selector = vmcb->gs.selector;
519
520         arch_cpu_restore(cpu_data);
521
522         stack--;
523         *stack = linux_ip;
524
525         asm volatile (
526                 "mov %%rbx,%%rsp\n\t"
527                 "pop %%r15\n\t"
528                 "pop %%r14\n\t"
529                 "pop %%r13\n\t"
530                 "pop %%r12\n\t"
531                 "pop %%r11\n\t"
532                 "pop %%r10\n\t"
533                 "pop %%r9\n\t"
534                 "pop %%r8\n\t"
535                 "pop %%rdi\n\t"
536                 "pop %%rsi\n\t"
537                 "pop %%rbp\n\t"
538                 "add $8,%%rsp\n\t"
539                 "pop %%rbx\n\t"
540                 "pop %%rdx\n\t"
541                 "pop %%rcx\n\t"
542                 "mov %%rax,%%rsp\n\t"
543                 "xor %%rax,%%rax\n\t"
544                 "ret"
545                 : : "a" (stack), "b" (guest_regs));
546         __builtin_unreachable();
547 }
548
549 static void svm_vcpu_reset(struct per_cpu *cpu_data, unsigned int sipi_vector)
550 {
551         struct vmcb *vmcb = &cpu_data->vmcb;
552         unsigned long val;
553         bool ok = true;
554
555         vmcb->cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
556         vmcb->cr3 = 0;
557         vmcb->cr4 = 0;
558
559         vmcb->rflags = 0x02;
560
561         val = 0;
562         if (sipi_vector == APIC_BSP_PSEUDO_SIPI) {
563                 val = 0xfff0;
564                 sipi_vector = 0xf0;
565         }
566         vmcb->rip = val;
567         vmcb->rsp = 0;
568
569         vmcb->cs.selector = sipi_vector << 8;
570         vmcb->cs.base = sipi_vector << 12;
571         vmcb->cs.limit = 0xffff;
572         vmcb->cs.access_rights = 0x009b;
573
574         vmcb->ds.selector = 0;
575         vmcb->ds.base = 0;
576         vmcb->ds.limit = 0xffff;
577         vmcb->ds.access_rights = 0x0093;
578
579         vmcb->es.selector = 0;
580         vmcb->es.base = 0;
581         vmcb->es.limit = 0xffff;
582         vmcb->es.access_rights = 0x0093;
583
584         vmcb->fs.selector = 0;
585         vmcb->fs.base = 0;
586         vmcb->fs.limit = 0xffff;
587         vmcb->fs.access_rights = 0x0093;
588
589         vmcb->gs.selector = 0;
590         vmcb->gs.base = 0;
591         vmcb->gs.limit = 0xffff;
592         vmcb->gs.access_rights = 0x0093;
593
594         vmcb->ss.selector = 0;
595         vmcb->ss.base = 0;
596         vmcb->ss.limit = 0xffff;
597         vmcb->ss.access_rights = 0x0093;
598
599         vmcb->tr.selector = 0;
600         vmcb->tr.base = 0;
601         vmcb->tr.limit = 0xffff;
602         vmcb->tr.access_rights = 0x008b;
603
604         vmcb->ldtr.selector = 0;
605         vmcb->ldtr.base = 0;
606         vmcb->ldtr.limit = 0xffff;
607         vmcb->ldtr.access_rights = 0x0082;
608
609         vmcb->gdtr.selector = 0;
610         vmcb->gdtr.base = 0;
611         vmcb->gdtr.limit = 0xffff;
612         vmcb->gdtr.access_rights = 0;
613
614         vmcb->idtr.selector = 0;
615         vmcb->idtr.base = 0;
616         vmcb->idtr.limit = 0xffff;
617         vmcb->idtr.access_rights = 0;
618
619         vmcb->efer = EFER_SVME;
620
621         /* These MSRs are undefined on reset */
622         vmcb->star = 0;
623         vmcb->lstar = 0;
624         vmcb->cstar = 0;
625         vmcb->sfmask = 0;
626         vmcb->sysenter_cs = 0;
627         vmcb->sysenter_eip = 0;
628         vmcb->sysenter_esp = 0;
629         vmcb->kerngsbase = 0;
630
631         vmcb->g_pat = PAT_RESET_VALUE;
632
633         vmcb->dr7 = 0x00000400;
634
635         /* Almost all of the guest state changed */
636         vmcb->clean_bits = 0;
637
638         ok &= svm_set_cell_config(cpu_data->cell, vmcb);
639
640         /* This is always false, but to be consistent with vmx.c... */
641         if (!ok) {
642                 panic_printk("FATAL: CPU reset failed\n");
643                 panic_stop();
644         }
645 }
646
647 void vcpu_skip_emulated_instruction(unsigned int inst_len)
648 {
649         struct per_cpu *cpu_data = this_cpu_data();
650         struct vmcb *vmcb = &cpu_data->vmcb;
651         vmcb->rip += inst_len;
652 }
653
654 static void update_efer(struct per_cpu *cpu_data)
655 {
656         struct vmcb *vmcb = &cpu_data->vmcb;
657         unsigned long efer = vmcb->efer;
658
659         if ((efer & (EFER_LME | EFER_LMA)) != EFER_LME)
660                 return;
661
662         efer |= EFER_LMA;
663
664         /* Flush TLB on LMA/LME change: See APMv2, Sect. 15.16 */
665         if ((vmcb->efer ^ efer) & EFER_LMA)
666                 vcpu_tlb_flush();
667
668         vmcb->efer = efer;
669         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
670 }
671
672 bool vcpu_get_guest_paging_structs(struct guest_paging_structures *pg_structs)
673 {
674         struct per_cpu *cpu_data = this_cpu_data();
675         struct vmcb *vmcb = &cpu_data->vmcb;
676
677         if (vmcb->efer & EFER_LMA) {
678                 pg_structs->root_paging = x86_64_paging;
679                 pg_structs->root_table_gphys =
680                         vmcb->cr3 & 0x000ffffffffff000UL;
681         } else if ((vmcb->cr0 & X86_CR0_PG) &&
682                    !(vmcb->cr4 & X86_CR4_PAE)) {
683                 pg_structs->root_paging = i386_paging;
684                 pg_structs->root_table_gphys =
685                         vmcb->cr3 & 0xfffff000UL;
686         } else if (!(vmcb->cr0 & X86_CR0_PG)) {
687                 /*
688                  * Can be in non-paged protected mode as well, but
689                  * the translation mechanism will stay the same ayway.
690                  */
691                 pg_structs->root_paging = realmode_paging;
692                 /*
693                  * This will make paging_get_guest_pages map the page
694                  * that also contains the bootstrap code and, thus, is
695                  * always present in a cell.
696                  */
697                 pg_structs->root_table_gphys = 0xff000;
698         } else {
699                 printk("FATAL: Unsupported paging mode\n");
700                 return false;
701         }
702         return true;
703 }
704
705 struct parse_context {
706         unsigned int remaining;
707         unsigned int size;
708         unsigned long cs_base;
709         const u8 *inst;
710 };
711
712 static bool ctx_advance(struct parse_context *ctx,
713                         unsigned long *pc,
714                         struct guest_paging_structures *pg_structs)
715 {
716         if (!ctx->size) {
717                 ctx->size = ctx->remaining;
718                 ctx->inst = vcpu_map_inst(pg_structs, ctx->cs_base + *pc,
719                                           &ctx->size);
720                 if (!ctx->inst)
721                         return false;
722                 ctx->remaining -= ctx->size;
723                 *pc += ctx->size;
724         }
725         return true;
726 }
727
728 static bool x86_parse_mov_to_cr(struct per_cpu *cpu_data,
729                                 unsigned long pc,
730                                 unsigned char reg,
731                                 unsigned long *gpr)
732 {
733         struct guest_paging_structures pg_structs;
734         struct vmcb *vmcb = &cpu_data->vmcb;
735         struct parse_context ctx = {};
736         /* No prefixes are supported yet */
737         u8 opcodes[] = {0x0f, 0x22}, modrm;
738         bool ok = false;
739         int n;
740
741         ctx.remaining = ARRAY_SIZE(opcodes);
742         if (!vcpu_get_guest_paging_structs(&pg_structs))
743                 goto out;
744         ctx.cs_base = (vmcb->efer & EFER_LMA) ? 0 : vmcb->cs.base;
745
746         if (!ctx_advance(&ctx, &pc, &pg_structs))
747                 goto out;
748
749         for (n = 0; n < ARRAY_SIZE(opcodes); n++, ctx.inst++) {
750                 if (*(ctx.inst) != opcodes[n])
751                         goto out;
752                 if (!ctx_advance(&ctx, &pc, &pg_structs))
753                         goto out;
754         }
755
756         if (!ctx_advance(&ctx, &pc, &pg_structs))
757                 goto out;
758
759         modrm = *(ctx.inst);
760
761         if (((modrm & 0x38) >> 3) != reg)
762                 goto out;
763
764         if (gpr)
765                 *gpr = (modrm & 0x7);
766
767         ok = true;
768 out:
769         return ok;
770 }
771
772 /*
773  * XXX: The only visible reason to have this function (vmx.c consistency
774  * aside) is to prevent cells from setting invalid CD+NW combinations that
775  * result in no more than VMEXIT_INVALID. Maybe we can get along without it
776  * altogether?
777  */
778 static bool svm_handle_cr(struct registers *guest_regs,
779                           struct per_cpu *cpu_data)
780 {
781         struct vmcb *vmcb = &cpu_data->vmcb;
782         /* Workaround GCC 4.8 warning on uninitialized variable 'reg' */
783         unsigned long reg = -1, val, bits;
784         bool ok = true;
785
786         if (has_assists) {
787                 if (!(vmcb->exitinfo1 & (1UL << 63))) {
788                         panic_printk("FATAL: Unsupported CR access (LMSW or CLTS)\n");
789                         ok = false;
790                         goto out;
791                 }
792                 reg = vmcb->exitinfo1 & 0x07;
793         } else {
794                 if (!x86_parse_mov_to_cr(cpu_data, vmcb->rip, 0, &reg)) {
795                         panic_printk("FATAL: Unable to parse MOV-to-CR instruction\n");
796                         ok = false;
797                         goto out;
798                 }
799         };
800
801         if (reg == 4)
802                 val = vmcb->rsp;
803         else
804                 val = ((unsigned long *)guest_regs)[15 - reg];
805
806         vcpu_skip_emulated_instruction(X86_INST_LEN_MOV_TO_CR);
807         /* Flush TLB on PG/WP/CD/NW change: See APMv2, Sect. 15.16 */
808         bits = (X86_CR0_PG | X86_CR0_WP | X86_CR0_CD | X86_CR0_NW);
809         if ((val ^ vmcb->cr0) & bits)
810                 vcpu_tlb_flush();
811         /* TODO: better check for #GP reasons */
812         vmcb->cr0 = val & SVM_CR0_CLEARED_BITS;
813         if (val & X86_CR0_PG)
814                 update_efer(cpu_data);
815         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
816
817 out:
818         return ok;
819 }
820
821 static bool svm_handle_msr_read(struct registers *guest_regs,
822                 struct per_cpu *cpu_data)
823 {
824         if (guest_regs->rcx >= MSR_X2APIC_BASE &&
825             guest_regs->rcx <= MSR_X2APIC_END) {
826                 vcpu_skip_emulated_instruction(X86_INST_LEN_RDMSR);
827                 x2apic_handle_read(guest_regs);
828                 return true;
829         } else {
830                 panic_printk("FATAL: Unhandled MSR read: %x\n",
831                              guest_regs->rcx);
832                 return false;
833         }
834 }
835
836 static bool svm_handle_msr_write(struct registers *guest_regs,
837                 struct per_cpu *cpu_data)
838 {
839         struct vmcb *vmcb = &cpu_data->vmcb;
840         unsigned long efer, val;
841         bool result = true;
842
843         if (guest_regs->rcx >= MSR_X2APIC_BASE &&
844             guest_regs->rcx <= MSR_X2APIC_END) {
845                 result = x2apic_handle_write(guest_regs, cpu_data);
846                 goto out;
847         }
848         if (guest_regs->rcx == MSR_EFER) {
849                 /* Never let a guest to disable SVME; see APMv2, Sect. 3.1.7 */
850                 efer = (guest_regs->rax & 0xffffffff) |
851                         (guest_regs->rdx << 32) | EFER_SVME;
852                 /* Flush TLB on LME/NXE change: See APMv2, Sect. 15.16 */
853                 if ((efer ^ vmcb->efer) & (EFER_LME | EFER_NXE))
854                         vcpu_tlb_flush();
855                 vmcb->efer = efer;
856                 vmcb->clean_bits &= ~CLEAN_BITS_CRX;
857                 goto out;
858         }
859         if (guest_regs->rcx == MTRR_DEFTYPE) {
860                 val = (guest_regs->rax & 0xffffffff) | (guest_regs->rdx << 32);
861                 /*
862                  * Quick (and very incomplete) guest MTRRs emulation.
863                  *
864                  * For Linux, emulating MTRR Enable bit seems to be enough.
865                  * If it is cleared, we set hPAT to all zeroes, effectively
866                  * making all NPT-mapped memory UC (see APMv2, Sect. 15.25.8).
867                  *
868                  * Otherwise, default PAT value is restored. This can also
869                  * make NPT-mapped memory's type different from what Linux
870                  * expects, however.
871                  */
872                 if (val & 0x800)
873                         write_msr(MSR_IA32_PAT, PAT_RESET_VALUE);
874                 else
875                         write_msr(MSR_IA32_PAT, 0);
876                 goto out;
877         }
878
879         result = false;
880         panic_printk("FATAL: Unhandled MSR write: %x\n",
881                      guest_regs->rcx);
882 out:
883         if (result)
884                 vcpu_skip_emulated_instruction(X86_INST_LEN_WRMSR);
885         return result;
886 }
887
888 /*
889  * TODO: This handles unaccelerated (non-AVIC) access. AVIC should
890  * be treated separately in svm_handle_avic_access().
891  */
892 static bool svm_handle_apic_access(struct registers *guest_regs,
893                                    struct per_cpu *cpu_data)
894 {
895         struct vmcb *vmcb = &cpu_data->vmcb;
896         struct guest_paging_structures pg_structs;
897         unsigned int inst_len, offset;
898         bool is_write;
899
900         /* The caller is responsible for sanity checks */
901         is_write = !!(vmcb->exitinfo1 & 0x2);
902         offset = vmcb->exitinfo2 - XAPIC_BASE;
903
904         if (offset & 0x00f)
905                 goto out_err;
906
907         if (!vcpu_get_guest_paging_structs(&pg_structs))
908                 goto out_err;
909
910         inst_len = apic_mmio_access(guest_regs, cpu_data, vmcb->rip,
911                                     &pg_structs, offset >> 4, is_write);
912         if (!inst_len)
913                 goto out_err;
914
915         vcpu_skip_emulated_instruction(inst_len);
916         return true;
917
918 out_err:
919         panic_printk("FATAL: Unhandled APIC access, offset %d, is_write: %d\n",
920                      offset, is_write);
921         return false;
922 }
923
924 static void dump_guest_regs(struct registers *guest_regs, struct vmcb *vmcb)
925 {
926         panic_printk("RIP: %p RSP: %p FLAGS: %x\n", vmcb->rip,
927                      vmcb->rsp, vmcb->rflags);
928         panic_printk("RAX: %p RBX: %p RCX: %p\n", guest_regs->rax,
929                      guest_regs->rbx, guest_regs->rcx);
930         panic_printk("RDX: %p RSI: %p RDI: %p\n", guest_regs->rdx,
931                      guest_regs->rsi, guest_regs->rdi);
932         panic_printk("CS: %x BASE: %p AR-BYTES: %x EFER.LMA %d\n",
933                      vmcb->cs.selector,
934                      vmcb->cs.base,
935                      vmcb->cs.access_rights,
936                      (vmcb->efer & EFER_LMA));
937         panic_printk("CR0: %p CR3: %p CR4: %p\n", vmcb->cr0,
938                      vmcb->cr3, vmcb->cr4);
939         panic_printk("EFER: %p\n", vmcb->efer);
940 }
941
942 static void svm_get_vcpu_pf_intercept(struct per_cpu *cpu_data,
943                                       struct vcpu_pf_intercept *out)
944 {
945         struct vmcb *vmcb = &cpu_data->vmcb;
946
947         out->phys_addr = vmcb->exitinfo2;
948         out->is_write = !!(vmcb->exitinfo1 & 0x2);
949 }
950
951 static void svm_get_vcpu_io_intercept(struct per_cpu *cpu_data,
952                                       struct vcpu_io_intercept *out)
953 {
954         struct vmcb *vmcb = &cpu_data->vmcb;
955         u64 exitinfo = vmcb->exitinfo1;
956
957         /* parse exit info for I/O instructions (see APM, 15.10.2 ) */
958         out->port = (exitinfo >> 16) & 0xFFFF;
959         out->size = (exitinfo >> 4) & 0x7;
960         out->in = !!(exitinfo & 0x1);
961         out->inst_len = vmcb->exitinfo2 - vmcb->rip;
962         out->rep_or_str = !!(exitinfo & 0x0c);
963 }
964
965 void vcpu_handle_exit(struct registers *guest_regs, struct per_cpu *cpu_data)
966 {
967         struct vmcb *vmcb = &cpu_data->vmcb;
968         struct vcpu_execution_state x_state;
969         struct vcpu_pf_intercept pf;
970         struct vcpu_io_intercept io;
971         bool res = false;
972         int sipi_vector;
973
974         /* Restore GS value expected by per_cpu data accessors */
975         write_msr(MSR_GS_BASE, (unsigned long)cpu_data);
976
977         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_TOTAL]++;
978         /*
979          * All guest state is marked unmodified; individual handlers must clear
980          * the bits as needed.
981          */
982         vmcb->clean_bits = 0xffffffff;
983
984         switch (vmcb->exitcode) {
985         case VMEXIT_INVALID:
986                 panic_printk("FATAL: VM-Entry failure, error %d\n",
987                              vmcb->exitcode);
988                 break;
989         case VMEXIT_NMI:
990                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MANAGEMENT]++;
991                 /* Temporarily enable GIF to consume pending NMI */
992                 asm volatile("stgi; clgi" : : : "memory");
993                 sipi_vector = x86_handle_events(cpu_data);
994                 if (sipi_vector >= 0) {
995                         printk("CPU %d received SIPI, vector %x\n",
996                                cpu_data->cpu_id, sipi_vector);
997                         svm_vcpu_reset(cpu_data, sipi_vector);
998                         memset(guest_regs, 0, sizeof(*guest_regs));
999                 }
1000                 iommu_check_pending_faults(cpu_data);
1001                 return;
1002         case VMEXIT_CPUID:
1003                 /* FIXME: We are not intercepting CPUID now */
1004                 return;
1005         case VMEXIT_VMMCALL:
1006                 vcpu_vendor_get_execution_state(&x_state);
1007                 vcpu_handle_hypercall(guest_regs, &x_state);
1008                 return;
1009         case VMEXIT_CR0_SEL_WRITE:
1010                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_CR]++;
1011                 if (svm_handle_cr(guest_regs, cpu_data))
1012                         return;
1013                 break;
1014         case VMEXIT_MSR:
1015                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MSR]++;
1016                 if (!vmcb->exitinfo1)
1017                         res = svm_handle_msr_read(guest_regs, cpu_data);
1018                 else
1019                         res = svm_handle_msr_write(guest_regs, cpu_data);
1020                 if (res)
1021                         return;
1022                 break;
1023         case VMEXIT_NPF:
1024                 if ((vmcb->exitinfo1 & 0x7) == 0x7 &&
1025                      vmcb->exitinfo2 >= XAPIC_BASE &&
1026                      vmcb->exitinfo2 < XAPIC_BASE + PAGE_SIZE) {
1027                         /* APIC access in non-AVIC mode */
1028                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XAPIC]++;
1029                         if (svm_handle_apic_access(guest_regs, cpu_data))
1030                                 return;
1031                 } else {
1032                         /* General MMIO (IOAPIC, PCI etc) */
1033                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MMIO]++;
1034                         svm_get_vcpu_pf_intercept(cpu_data, &pf);
1035                         if (vcpu_handle_pt_violation(guest_regs, &pf))
1036                                 return;
1037                 }
1038
1039                 panic_printk("FATAL: Unhandled Nested Page Fault for (%p), "
1040                              "error code is %x\n", vmcb->exitinfo2,
1041                              vmcb->exitinfo1 & 0xf);
1042                 break;
1043         case VMEXIT_XSETBV:
1044                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XSETBV]++;
1045                 if ((guest_regs->rax & X86_XCR0_FP) &&
1046                     (guest_regs->rax & ~cpuid_eax(0x0d)) == 0 &&
1047                     guest_regs->rcx == 0 && guest_regs->rdx == 0) {
1048                         vcpu_skip_emulated_instruction(X86_INST_LEN_XSETBV);
1049                         asm volatile(
1050                                 "xsetbv"
1051                                 : /* no output */
1052                                 : "a" (guest_regs->rax), "c" (0), "d" (0));
1053                         return;
1054                 }
1055                 panic_printk("FATAL: Invalid xsetbv parameters: "
1056                              "xcr[%d] = %x:%x\n", guest_regs->rcx,
1057                              guest_regs->rdx, guest_regs->rax);
1058                 break;
1059         case VMEXIT_IOIO:
1060                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_PIO]++;
1061                 svm_get_vcpu_io_intercept(cpu_data, &io);
1062                 if (vcpu_handle_io_access(guest_regs, &io))
1063                         return;
1064                 break;
1065         /* TODO: Handle VMEXIT_AVIC_NOACCEL and VMEXIT_AVIC_INCOMPLETE_IPI */
1066         default:
1067                 panic_printk("FATAL: Unexpected #VMEXIT, exitcode %x, "
1068                              "exitinfo1 %p exitinfo2 %p\n",
1069                              vmcb->exitcode, vmcb->exitinfo1, vmcb->exitinfo2);
1070         }
1071         dump_guest_regs(guest_regs, vmcb);
1072         panic_park();
1073 }
1074
1075 void vcpu_park(struct per_cpu *cpu_data)
1076 {
1077         struct vmcb *vmcb = &cpu_data->vmcb;
1078
1079         svm_vcpu_reset(cpu_data, APIC_BSP_PSEUDO_SIPI);
1080         /* No need to clear VMCB Clean bit: vcpu_reset() already does this */
1081         vmcb->n_cr3 = paging_hvirt2phys(parked_mode_npt);
1082
1083         vcpu_tlb_flush();
1084 }
1085
1086 void vcpu_nmi_handler(void)
1087 {
1088 }
1089
1090 void vcpu_tlb_flush(void)
1091 {
1092         struct per_cpu *cpu_data = this_cpu_data();
1093         struct vmcb *vmcb = &cpu_data->vmcb;
1094
1095         if (has_flush_by_asid)
1096                 vmcb->tlb_control = SVM_TLB_FLUSH_GUEST;
1097         else
1098                 vmcb->tlb_control = SVM_TLB_FLUSH_ALL;
1099 }
1100
1101 const u8 *vcpu_get_inst_bytes(const struct guest_paging_structures *pg_structs,
1102                               unsigned long pc, unsigned int *size)
1103 {
1104         struct per_cpu *cpu_data = this_cpu_data();
1105         struct vmcb *vmcb = &cpu_data->vmcb;
1106         unsigned long start;
1107
1108         if (has_assists) {
1109                 if (!*size)
1110                         return NULL;
1111                 start = vmcb->rip - pc;
1112                 if (start < vmcb->bytes_fetched) {
1113                         *size = vmcb->bytes_fetched - start;
1114                         return &vmcb->guest_bytes[start];
1115                 } else {
1116                         return NULL;
1117                 }
1118         } else {
1119                 return vcpu_map_inst(pg_structs, pc, size);
1120         }
1121 }
1122
1123 void vcpu_vendor_get_cell_io_bitmap(struct cell *cell,
1124                                     struct vcpu_io_bitmap *iobm)
1125 {
1126         iobm->data = cell->svm.iopm;
1127         iobm->size = sizeof(cell->svm.iopm);
1128 }
1129
1130 void vcpu_vendor_get_execution_state(struct vcpu_execution_state *x_state)
1131 {
1132         struct per_cpu *cpu_data = this_cpu_data();
1133
1134         x_state->efer = cpu_data->vmcb.efer;
1135         x_state->rflags = cpu_data->vmcb.rflags;
1136         x_state->cs = cpu_data->vmcb.cs.selector;
1137         x_state->rip = cpu_data->vmcb.rip;
1138 }