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x86: Drop redundant stgi from SVM's vcpu_deactivate_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         0x0007040600070406UL
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 /* bit cleared: direct access allowed */
53 // TODO: convert to whitelist
54 static u8 __attribute__((aligned(PAGE_SIZE))) msrpm[][0x2000/4] = {
55         [ SVM_MSRPM_0000 ] = {
56                 [      0/4 ...  0x017/4 ] = 0,
57                 [  0x018/4 ...  0x01b/4 ] = 0x80, /* 0x01b (w) */
58                 [  0x01c/4 ...  0x2fb/4 ] = 0,
59                 [  0x2fc/4 ...  0x2ff/4 ] = 0x80, /* 0x2ff (w) */
60                 [  0x300/4 ...  0x7ff/4 ] = 0,
61                 /* x2APIC MSRs - emulated if not present */
62                 [  0x800/4 ...  0x803/4 ] = 0x90, /* 0x802 (r), 0x803 (r) */
63                 [  0x804/4 ...  0x807/4 ] = 0,
64                 [  0x808/4 ...  0x80b/4 ] = 0x93, /* 0x808 (rw), 0x80a (r), 0x80b (w) */
65                 [  0x80c/4 ...  0x80f/4 ] = 0xc8, /* 0x80d (w), 0x80f (rw) */
66                 [  0x810/4 ...  0x813/4 ] = 0x55, /* 0x810 - 0x813 (r) */
67                 [  0x814/4 ...  0x817/4 ] = 0x55, /* 0x814 - 0x817 (r) */
68                 [  0x818/4 ...  0x81b/4 ] = 0x55, /* 0x818 - 0x81b (r) */
69                 [  0x81c/4 ...  0x81f/4 ] = 0x55, /* 0x81c - 0x81f (r) */
70                 [  0x820/4 ...  0x823/4 ] = 0x55, /* 0x820 - 0x823 (r) */
71                 [  0x824/4 ...  0x827/4 ] = 0x55, /* 0x823 - 0x827 (r) */
72                 [  0x828/4 ...  0x82b/4 ] = 0x03, /* 0x828 (rw) */
73                 [  0x82c/4 ...  0x82f/4 ] = 0xc0, /* 0x82f (rw) */
74                 [  0x830/4 ...  0x833/4 ] = 0xf3, /* 0x830 (rw), 0x832 (rw), 0x833 (rw) */
75                 [  0x834/4 ...  0x837/4 ] = 0xff, /* 0x834 - 0x837 (rw) */
76                 [  0x838/4 ...  0x83b/4 ] = 0x07, /* 0x838 (rw), 0x839 (r) */
77                 [  0x83c/4 ...  0x83f/4 ] = 0x70, /* 0x83e (rw), 0x83f (r) */
78                 [  0x840/4 ... 0x1fff/4 ] = 0,
79         },
80         [ SVM_MSRPM_C000 ] = {
81                 [      0/4 ...  0x07f/4 ] = 0,
82                 [  0x080/4 ...  0x083/4 ] = 0x02, /* 0x080 (w) */
83                 [  0x084/4 ... 0x1fff/4 ] = 0
84         },
85         [ SVM_MSRPM_C001 ] = {
86                 [      0/4 ... 0x1fff/4 ] = 0,
87         },
88         [ SVM_MSRPM_RESV ] = {
89                 [      0/4 ... 0x1fff/4 ] = 0,
90         }
91 };
92
93 /* This page is mapped so the code begins at 0x000ffff0 */
94 static u8 __attribute__((aligned(PAGE_SIZE))) parking_code[PAGE_SIZE] = {
95         [0xff0] = 0xfa, /* 1: cli */
96         [0xff1] = 0xf4, /*    hlt */
97         [0xff2] = 0xeb,
98         [0xff3] = 0xfc  /*    jmp 1b */
99 };
100
101 static void *parked_mode_npt;
102
103 static void *avic_page;
104
105 static int svm_check_features(void)
106 {
107         /* SVM is available */
108         if (!(cpuid_ecx(0x80000001) & X86_FEATURE_SVM))
109                 return -ENODEV;
110
111         /* Nested paging */
112         if (!(cpuid_edx(0x8000000A) & X86_FEATURE_NP))
113                 return -EIO;
114
115         /* Decode assists */
116         if ((cpuid_edx(0x8000000A) & X86_FEATURE_DECODE_ASSISTS))
117                 has_assists = true;
118
119         /* AVIC support */
120         if (cpuid_edx(0x8000000A) & X86_FEATURE_AVIC)
121                 has_avic = true;
122
123         /* TLB Flush by ASID support */
124         if (cpuid_edx(0x8000000A) & X86_FEATURE_FLUSH_BY_ASID)
125                 has_flush_by_asid = true;
126
127         return 0;
128 }
129
130 static void set_svm_segment_from_dtr(struct svm_segment *svm_segment,
131                                      const struct desc_table_reg *dtr)
132 {
133         struct svm_segment tmp = { 0 };
134
135         if (dtr) {
136                 tmp.base = dtr->base;
137                 tmp.limit = dtr->limit & 0xffff;
138         }
139
140         *svm_segment = tmp;
141 }
142
143 /* TODO: struct segment needs to be x86 generic, not VMX-specific one here */
144 static void set_svm_segment_from_segment(struct svm_segment *svm_segment,
145                                          const struct segment *segment)
146 {
147         u32 ar;
148
149         svm_segment->selector = segment->selector;
150
151         if (segment->access_rights == 0x10000) {
152                 svm_segment->access_rights = 0;
153         } else {
154                 ar = segment->access_rights;
155                 svm_segment->access_rights =
156                         ((ar & 0xf000) >> 4) | (ar & 0x00ff);
157         }
158
159         svm_segment->limit = segment->limit;
160         svm_segment->base = segment->base;
161 }
162
163 static bool svm_set_cell_config(struct cell *cell, struct vmcb *vmcb)
164 {
165         /* No real need for this function; used for consistency with vmx.c */
166         vmcb->iopm_base_pa = paging_hvirt2phys(cell->svm.iopm);
167         vmcb->n_cr3 = paging_hvirt2phys(cell->svm.npt_structs.root_table);
168
169         return true;
170 }
171
172 static int vmcb_setup(struct per_cpu *cpu_data)
173 {
174         struct vmcb *vmcb = &cpu_data->vmcb;
175
176         memset(vmcb, 0, sizeof(struct vmcb));
177
178         vmcb->cr0 = read_cr0() & SVM_CR0_CLEARED_BITS;
179         vmcb->cr3 = cpu_data->linux_cr3;
180         vmcb->cr4 = read_cr4();
181
182         set_svm_segment_from_segment(&vmcb->cs, &cpu_data->linux_cs);
183         set_svm_segment_from_segment(&vmcb->ds, &cpu_data->linux_ds);
184         set_svm_segment_from_segment(&vmcb->es, &cpu_data->linux_es);
185         set_svm_segment_from_segment(&vmcb->fs, &cpu_data->linux_fs);
186         set_svm_segment_from_segment(&vmcb->gs, &cpu_data->linux_gs);
187         set_svm_segment_from_segment(&vmcb->ss, &invalid_seg);
188         set_svm_segment_from_segment(&vmcb->tr, &cpu_data->linux_tss);
189
190         set_svm_segment_from_dtr(&vmcb->ldtr, NULL);
191         set_svm_segment_from_dtr(&vmcb->gdtr, &cpu_data->linux_gdtr);
192         set_svm_segment_from_dtr(&vmcb->idtr, &cpu_data->linux_idtr);
193
194         vmcb->cpl = 0; /* Linux runs in ring 0 before migration */
195
196         vmcb->rflags = 0x02;
197         /* Indicate success to the caller of arch_entry */
198         vmcb->rax = 0;
199         vmcb->rsp = cpu_data->linux_sp +
200                 (NUM_ENTRY_REGS + 1) * sizeof(unsigned long);
201         vmcb->rip = cpu_data->linux_ip;
202
203         vmcb->sysenter_cs = read_msr(MSR_IA32_SYSENTER_CS);
204         vmcb->sysenter_eip = read_msr(MSR_IA32_SYSENTER_EIP);
205         vmcb->sysenter_esp = read_msr(MSR_IA32_SYSENTER_ESP);
206         vmcb->star = read_msr(MSR_STAR);
207         vmcb->lstar = read_msr(MSR_LSTAR);
208         vmcb->cstar = read_msr(MSR_CSTAR);
209         vmcb->sfmask = read_msr(MSR_SFMASK);
210         vmcb->kerngsbase = read_msr(MSR_KERNGS_BASE);
211
212         vmcb->dr6 = 0x00000ff0;
213         vmcb->dr7 = 0x00000400;
214
215         /* Make the hypervisor visible */
216         vmcb->efer = (cpu_data->linux_efer | EFER_SVME);
217
218         /* Linux uses custom PAT setting */
219         vmcb->g_pat = read_msr(MSR_IA32_PAT);
220
221         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_NMI;
222         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_CR0_SEL_WRITE;
223         /* TODO: Do we need this for SVM ? */
224         /* vmcb->general1_intercepts |= GENERAL1_INTERCEPT_CPUID; */
225         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_IOIO_PROT;
226         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_MSR_PROT;
227         vmcb->general1_intercepts |= GENERAL1_INTERCEPT_SHUTDOWN_EVT;
228
229         vmcb->general2_intercepts |= GENERAL2_INTERCEPT_VMRUN; /* Required */
230         vmcb->general2_intercepts |= GENERAL2_INTERCEPT_VMMCALL;
231
232         vmcb->msrpm_base_pa = paging_hvirt2phys(msrpm);
233
234         vmcb->np_enable = 1;
235         /* No more than one guest owns the CPU */
236         vmcb->guest_asid = 1;
237
238         /* TODO: Setup AVIC */
239
240         /* Explicitly mark all of the state as new */
241         vmcb->clean_bits = 0;
242
243         return svm_set_cell_config(cpu_data->cell, vmcb);
244 }
245
246 unsigned long arch_paging_gphys2phys(struct per_cpu *cpu_data,
247                                      unsigned long gphys,
248                                      unsigned long flags)
249 {
250         return paging_virt2phys(&cpu_data->cell->svm.npt_structs,
251                         gphys, flags);
252 }
253
254 static void npt_set_next_pt(pt_entry_t pte, unsigned long next_pt)
255 {
256         /* See APMv2, Section 15.25.5 */
257         *pte = (next_pt & 0x000ffffffffff000UL) |
258                 (PAGE_DEFAULT_FLAGS | PAGE_FLAG_US);
259 }
260
261 int vcpu_vendor_init(void)
262 {
263         struct paging_structures parking_pt;
264         unsigned long vm_cr;
265         int err, n;
266
267         err = svm_check_features();
268         if (err)
269                 return err;
270
271         vm_cr = read_msr(MSR_VM_CR);
272         if (vm_cr & VM_CR_SVMDIS)
273                 /* SVM disabled in BIOS */
274                 return -EPERM;
275
276         /* Nested paging is the same as the native one */
277         memcpy(npt_paging, x86_64_paging, sizeof(npt_paging));
278         for (n = 0; n < NPT_PAGE_DIR_LEVELS; n++)
279                 npt_paging[n].set_next_pt = npt_set_next_pt;
280
281         /* Map guest parking code (shared between cells and CPUs) */
282         parking_pt.root_paging = npt_paging;
283         parking_pt.root_table = parked_mode_npt = page_alloc(&mem_pool, 1);
284         if (!parked_mode_npt)
285                 return -ENOMEM;
286         err = paging_create(&parking_pt, paging_hvirt2phys(parking_code),
287                             PAGE_SIZE, 0x000ff000,
288                             PAGE_READONLY_FLAGS | PAGE_FLAG_US,
289                             PAGING_NON_COHERENT);
290         if (err)
291                 return err;
292
293         /* This is always false for AMD now (except in nested SVM);
294            see Sect. 16.3.1 in APMv2 */
295         if (using_x2apic) {
296                 /* allow direct x2APIC access except for ICR writes */
297                 memset(&msrpm[SVM_MSRPM_0000][MSR_X2APIC_BASE/4], 0,
298                                 (MSR_X2APIC_END - MSR_X2APIC_BASE + 1)/4);
299                 msrpm[SVM_MSRPM_0000][MSR_X2APIC_ICR/4] = 0x02;
300         } else {
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 | PAGE_FLAG_US | PAGE_FLAG_DEVICE;
332                 err = paging_create(&cell->svm.npt_structs, XAPIC_BASE,
333                                     PAGE_SIZE, XAPIC_BASE,
334                                     flags,
335                                     PAGING_NON_COHERENT);
336         } else {
337                 flags = PAGE_DEFAULT_FLAGS | PAGE_FLAG_DEVICE;
338                 err = paging_create(&cell->svm.npt_structs,
339                                     paging_hvirt2phys(avic_page),
340                                     PAGE_SIZE, XAPIC_BASE,
341                                     flags,
342                                     PAGING_NON_COHERENT);
343         }
344
345         return err;
346 }
347
348 int vcpu_map_memory_region(struct cell *cell,
349                            const struct jailhouse_memory *mem)
350 {
351         u64 phys_start = mem->phys_start;
352         u64 flags = PAGE_FLAG_US; /* See APMv2, Section 15.25.5 */
353
354         if (mem->flags & JAILHOUSE_MEM_READ)
355                 flags |= PAGE_FLAG_PRESENT;
356         if (mem->flags & JAILHOUSE_MEM_WRITE)
357                 flags |= PAGE_FLAG_RW;
358         if (!(mem->flags & JAILHOUSE_MEM_EXECUTE))
359                 flags |= PAGE_FLAG_NOEXECUTE;
360         if (mem->flags & JAILHOUSE_MEM_COMM_REGION)
361                 phys_start = paging_hvirt2phys(&cell->comm_page);
362
363         return paging_create(&cell->svm.npt_structs, phys_start, mem->size,
364                              mem->virt_start, flags, PAGING_NON_COHERENT);
365 }
366
367 int vcpu_unmap_memory_region(struct cell *cell,
368                              const struct jailhouse_memory *mem)
369 {
370         return paging_destroy(&cell->svm.npt_structs, mem->virt_start,
371                               mem->size, PAGING_NON_COHERENT);
372 }
373
374 void vcpu_vendor_cell_exit(struct cell *cell)
375 {
376         paging_destroy(&cell->svm.npt_structs, XAPIC_BASE, PAGE_SIZE,
377                        PAGING_NON_COHERENT);
378         page_free(&mem_pool, cell->svm.npt_structs.root_table, 1);
379 }
380
381 int vcpu_init(struct per_cpu *cpu_data)
382 {
383         unsigned long efer;
384         int err;
385
386         err = svm_check_features();
387         if (err)
388                 return err;
389
390         efer = read_msr(MSR_EFER);
391         if (efer & EFER_SVME)
392                 return -EBUSY;
393
394         efer |= EFER_SVME;
395         write_msr(MSR_EFER, efer);
396
397         cpu_data->svm_state = SVMON;
398
399         if (!vmcb_setup(cpu_data))
400                 return -EIO;
401
402         write_msr(MSR_VM_HSAVE_PA, paging_hvirt2phys(cpu_data->host_state));
403
404         return 0;
405 }
406
407 void vcpu_exit(struct per_cpu *cpu_data)
408 {
409         unsigned long efer;
410
411         if (cpu_data->svm_state == SVMOFF)
412                 return;
413
414         cpu_data->svm_state = SVMOFF;
415
416         /* We are leaving - set the GIF */
417         asm volatile ("stgi" : : : "memory");
418
419         efer = read_msr(MSR_EFER);
420         efer &= ~EFER_SVME;
421         write_msr(MSR_EFER, efer);
422
423         write_msr(MSR_VM_HSAVE_PA, 0);
424 }
425
426 void __attribute__((noreturn)) vcpu_activate_vmm(struct per_cpu *cpu_data)
427 {
428         unsigned long vmcb_pa, host_stack;
429
430         vmcb_pa = paging_hvirt2phys(&cpu_data->vmcb);
431         host_stack = (unsigned long)cpu_data->stack + sizeof(cpu_data->stack);
432
433         /*
434          * XXX: Jailhouse doesn't use PAT, so it is explicitly set to the
435          * reset value. However, this value is later combined with vmcb->g_pat
436          * (as per APMv2, Sect. 15.25.8) which may lead to subtle bugs as the
437          * actual memory type might slightly differ from what Linux expects.
438          */
439         write_msr(MSR_IA32_PAT, PAT_RESET_VALUE);
440
441         /* We enter Linux at the point arch_entry would return to as well.
442          * rax is cleared to signal success to the caller. */
443         asm volatile(
444                 "clgi\n\t"
445                 "mov (%%rdi),%%r15\n\t"
446                 "mov 0x8(%%rdi),%%r14\n\t"
447                 "mov 0x10(%%rdi),%%r13\n\t"
448                 "mov 0x18(%%rdi),%%r12\n\t"
449                 "mov 0x20(%%rdi),%%rbx\n\t"
450                 "mov 0x28(%%rdi),%%rbp\n\t"
451                 "mov %0, %%rax\n\t"
452                 "vmload %%rax\n\t"
453                 "vmrun %%rax\n\t"
454                 "vmsave %%rax\n\t"
455                 /* Restore hypervisor stack */
456                 "mov %2, %%rsp\n\t"
457                 "jmp svm_vmexit"
458                 : /* no output */
459                 : "m" (vmcb_pa), "D" (cpu_data->linux_reg), "m" (host_stack)
460                 : "memory", "r15", "r14", "r13", "r12",
461                   "rbx", "rbp", "rax", "cc");
462         __builtin_unreachable();
463 }
464
465 void __attribute__((noreturn))
466 vcpu_deactivate_vmm(struct registers *guest_regs)
467 {
468         struct per_cpu *cpu_data = this_cpu_data();
469         struct vmcb *vmcb = &cpu_data->vmcb;
470         unsigned long *stack = (unsigned long *)vmcb->rsp;
471         unsigned long linux_ip = vmcb->rip;
472
473         /*
474          * Restore the MSRs.
475          *
476          * XXX: One could argue this is better to be done in
477          * arch_cpu_restore(), however, it would require changes
478          * to cpu_data to store STAR and friends.
479          */
480         write_msr(MSR_STAR, vmcb->star);
481         write_msr(MSR_LSTAR, vmcb->lstar);
482         write_msr(MSR_CSTAR, vmcb->cstar);
483         write_msr(MSR_SFMASK, vmcb->sfmask);
484         write_msr(MSR_KERNGS_BASE, vmcb->kerngsbase);
485         write_msr(MSR_IA32_PAT, vmcb->g_pat);
486
487         cpu_data->linux_cr3 = vmcb->cr3;
488
489         cpu_data->linux_gdtr.base = vmcb->gdtr.base;
490         cpu_data->linux_gdtr.limit = vmcb->gdtr.limit;
491         cpu_data->linux_idtr.base = vmcb->idtr.base;
492         cpu_data->linux_idtr.limit = vmcb->idtr.limit;
493
494         cpu_data->linux_cs.selector = vmcb->cs.selector;
495
496         cpu_data->linux_tss.selector = vmcb->tr.selector;
497
498         cpu_data->linux_efer = vmcb->efer & (~EFER_SVME);
499         cpu_data->linux_fs.base = vmcb->fs.base;
500         cpu_data->linux_gs.base = vmcb->gs.base;
501
502         cpu_data->linux_sysenter_cs = vmcb->sysenter_cs;
503         cpu_data->linux_sysenter_eip = vmcb->sysenter_eip;
504         cpu_data->linux_sysenter_esp = vmcb->sysenter_esp;
505
506         cpu_data->linux_ds.selector = vmcb->ds.selector;
507         cpu_data->linux_es.selector = vmcb->es.selector;
508         cpu_data->linux_fs.selector = vmcb->fs.selector;
509         cpu_data->linux_gs.selector = vmcb->gs.selector;
510
511         arch_cpu_restore(cpu_data, 0);
512
513         stack--;
514         *stack = linux_ip;
515
516         asm volatile (
517                 "mov %%rbx,%%rsp\n\t"
518                 "pop %%r15\n\t"
519                 "pop %%r14\n\t"
520                 "pop %%r13\n\t"
521                 "pop %%r12\n\t"
522                 "pop %%r11\n\t"
523                 "pop %%r10\n\t"
524                 "pop %%r9\n\t"
525                 "pop %%r8\n\t"
526                 "pop %%rdi\n\t"
527                 "pop %%rsi\n\t"
528                 "pop %%rbp\n\t"
529                 "add $8,%%rsp\n\t"
530                 "pop %%rbx\n\t"
531                 "pop %%rdx\n\t"
532                 "pop %%rcx\n\t"
533                 "mov %%rax,%%rsp\n\t"
534                 "xor %%rax,%%rax\n\t"
535                 "ret"
536                 : : "a" (stack), "b" (guest_regs));
537         __builtin_unreachable();
538 }
539
540 static void svm_vcpu_reset(struct per_cpu *cpu_data, unsigned int sipi_vector)
541 {
542         struct vmcb *vmcb = &cpu_data->vmcb;
543         unsigned long val;
544         bool ok = true;
545
546         vmcb->cr0 = X86_CR0_NW | X86_CR0_CD | X86_CR0_ET;
547         vmcb->cr3 = 0;
548         vmcb->cr4 = 0;
549
550         vmcb->rflags = 0x02;
551
552         val = 0;
553         if (sipi_vector == APIC_BSP_PSEUDO_SIPI) {
554                 val = 0xfff0;
555                 sipi_vector = 0xf0;
556         }
557         vmcb->rip = val;
558         vmcb->rsp = 0;
559
560         vmcb->cs.selector = sipi_vector << 8;
561         vmcb->cs.base = sipi_vector << 12;
562         vmcb->cs.limit = 0xffff;
563         vmcb->cs.access_rights = 0x009b;
564
565         vmcb->ds.selector = 0;
566         vmcb->ds.base = 0;
567         vmcb->ds.limit = 0xffff;
568         vmcb->ds.access_rights = 0x0093;
569
570         vmcb->es.selector = 0;
571         vmcb->es.base = 0;
572         vmcb->es.limit = 0xffff;
573         vmcb->es.access_rights = 0x0093;
574
575         vmcb->fs.selector = 0;
576         vmcb->fs.base = 0;
577         vmcb->fs.limit = 0xffff;
578         vmcb->fs.access_rights = 0x0093;
579
580         vmcb->gs.selector = 0;
581         vmcb->gs.base = 0;
582         vmcb->gs.limit = 0xffff;
583         vmcb->gs.access_rights = 0x0093;
584
585         vmcb->ss.selector = 0;
586         vmcb->ss.base = 0;
587         vmcb->ss.limit = 0xffff;
588         vmcb->ss.access_rights = 0x0093;
589
590         vmcb->tr.selector = 0;
591         vmcb->tr.base = 0;
592         vmcb->tr.limit = 0xffff;
593         vmcb->tr.access_rights = 0x008b;
594
595         vmcb->ldtr.selector = 0;
596         vmcb->ldtr.base = 0;
597         vmcb->ldtr.limit = 0xffff;
598         vmcb->ldtr.access_rights = 0x0082;
599
600         vmcb->gdtr.selector = 0;
601         vmcb->gdtr.base = 0;
602         vmcb->gdtr.limit = 0xffff;
603         vmcb->gdtr.access_rights = 0;
604
605         vmcb->idtr.selector = 0;
606         vmcb->idtr.base = 0;
607         vmcb->idtr.limit = 0xffff;
608         vmcb->idtr.access_rights = 0;
609
610         vmcb->efer = EFER_SVME;
611
612         /* These MSRs are undefined on reset */
613         vmcb->star = 0;
614         vmcb->lstar = 0;
615         vmcb->cstar = 0;
616         vmcb->sfmask = 0;
617         vmcb->sysenter_cs = 0;
618         vmcb->sysenter_eip = 0;
619         vmcb->sysenter_esp = 0;
620         vmcb->kerngsbase = 0;
621
622         vmcb->g_pat = PAT_RESET_VALUE;
623
624         vmcb->dr7 = 0x00000400;
625
626         /* Almost all of the guest state changed */
627         vmcb->clean_bits = 0;
628
629         ok &= svm_set_cell_config(cpu_data->cell, vmcb);
630
631         /* This is always false, but to be consistent with vmx.c... */
632         if (!ok) {
633                 panic_printk("FATAL: CPU reset failed\n");
634                 panic_stop();
635         }
636 }
637
638 void vcpu_skip_emulated_instruction(unsigned int inst_len)
639 {
640         struct per_cpu *cpu_data = this_cpu_data();
641         struct vmcb *vmcb = &cpu_data->vmcb;
642         vmcb->rip += inst_len;
643 }
644
645 static void update_efer(struct per_cpu *cpu_data)
646 {
647         struct vmcb *vmcb = &cpu_data->vmcb;
648         unsigned long efer = vmcb->efer;
649
650         if ((efer & (EFER_LME | EFER_LMA)) != EFER_LME)
651                 return;
652
653         efer |= EFER_LMA;
654
655         /* Flush TLB on LMA/LME change: See APMv2, Sect. 15.16 */
656         if ((vmcb->efer ^ efer) & EFER_LMA)
657                 vcpu_tlb_flush();
658
659         vmcb->efer = efer;
660         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
661 }
662
663 bool vcpu_get_guest_paging_structs(struct guest_paging_structures *pg_structs)
664 {
665         struct per_cpu *cpu_data = this_cpu_data();
666         struct vmcb *vmcb = &cpu_data->vmcb;
667
668         if (vmcb->efer & EFER_LMA) {
669                 pg_structs->root_paging = x86_64_paging;
670                 pg_structs->root_table_gphys =
671                         vmcb->cr3 & 0x000ffffffffff000UL;
672         } else if ((vmcb->cr0 & X86_CR0_PG) &&
673                    !(vmcb->cr4 & X86_CR4_PAE)) {
674                 pg_structs->root_paging = i386_paging;
675                 pg_structs->root_table_gphys =
676                         vmcb->cr3 & 0xfffff000UL;
677         } else if (!(vmcb->cr0 & X86_CR0_PG)) {
678                 /*
679                  * Can be in non-paged protected mode as well, but
680                  * the translation mechanism will stay the same ayway.
681                  */
682                 pg_structs->root_paging = realmode_paging;
683                 /*
684                  * This will make paging_get_guest_pages map the page
685                  * that also contains the bootstrap code and, thus, is
686                  * always present in a cell.
687                  */
688                 pg_structs->root_table_gphys = 0xff000;
689         } else {
690                 printk("FATAL: Unsupported paging mode\n");
691                 return false;
692         }
693         return true;
694 }
695
696 struct parse_context {
697         unsigned int remaining;
698         unsigned int size;
699         unsigned long cs_base;
700         const u8 *inst;
701 };
702
703 static bool ctx_advance(struct parse_context *ctx,
704                         unsigned long *pc,
705                         struct guest_paging_structures *pg_structs)
706 {
707         if (!ctx->size) {
708                 ctx->size = ctx->remaining;
709                 ctx->inst = vcpu_map_inst(pg_structs, ctx->cs_base + *pc,
710                                           &ctx->size);
711                 if (!ctx->inst)
712                         return false;
713                 ctx->remaining -= ctx->size;
714                 *pc += ctx->size;
715         }
716         return true;
717 }
718
719 static bool x86_parse_mov_to_cr(struct per_cpu *cpu_data,
720                                 unsigned long pc,
721                                 unsigned char reg,
722                                 unsigned long *gpr)
723 {
724         struct guest_paging_structures pg_structs;
725         struct vmcb *vmcb = &cpu_data->vmcb;
726         struct parse_context ctx = {};
727         /* No prefixes are supported yet */
728         u8 opcodes[] = {0x0f, 0x22}, modrm;
729         bool ok = false;
730         int n;
731
732         ctx.remaining = ARRAY_SIZE(opcodes);
733         if (!vcpu_get_guest_paging_structs(&pg_structs))
734                 goto out;
735         ctx.cs_base = (vmcb->efer & EFER_LMA) ? 0 : vmcb->cs.base;
736
737         if (!ctx_advance(&ctx, &pc, &pg_structs))
738                 goto out;
739
740         for (n = 0; n < ARRAY_SIZE(opcodes); n++, ctx.inst++) {
741                 if (*(ctx.inst) != opcodes[n])
742                         goto out;
743                 if (!ctx_advance(&ctx, &pc, &pg_structs))
744                         goto out;
745         }
746
747         if (!ctx_advance(&ctx, &pc, &pg_structs))
748                 goto out;
749
750         modrm = *(ctx.inst);
751
752         if (((modrm & 0x38) >> 3) != reg)
753                 goto out;
754
755         if (gpr)
756                 *gpr = (modrm & 0x7);
757
758         ok = true;
759 out:
760         return ok;
761 }
762
763 /*
764  * XXX: The only visible reason to have this function (vmx.c consistency
765  * aside) is to prevent cells from setting invalid CD+NW combinations that
766  * result in no more than VMEXIT_INVALID. Maybe we can get along without it
767  * altogether?
768  */
769 static bool svm_handle_cr(struct registers *guest_regs,
770                           struct per_cpu *cpu_data)
771 {
772         struct vmcb *vmcb = &cpu_data->vmcb;
773         /* Workaround GCC 4.8 warning on uninitialized variable 'reg' */
774         unsigned long reg = -1, val, bits;
775         bool ok = true;
776
777         if (has_assists) {
778                 if (!(vmcb->exitinfo1 & (1UL << 63))) {
779                         panic_printk("FATAL: Unsupported CR access (LMSW or CLTS)\n");
780                         ok = false;
781                         goto out;
782                 }
783                 reg = vmcb->exitinfo1 & 0x07;
784         } else {
785                 if (!x86_parse_mov_to_cr(cpu_data, vmcb->rip, 0, &reg)) {
786                         panic_printk("FATAL: Unable to parse MOV-to-CR instruction\n");
787                         ok = false;
788                         goto out;
789                 }
790         };
791
792         if (reg == 4)
793                 val = vmcb->rsp;
794         else
795                 val = ((unsigned long *)guest_regs)[15 - reg];
796
797         vcpu_skip_emulated_instruction(X86_INST_LEN_MOV_TO_CR);
798         /* Flush TLB on PG/WP/CD/NW change: See APMv2, Sect. 15.16 */
799         bits = (X86_CR0_PG | X86_CR0_WP | X86_CR0_CD | X86_CR0_NW);
800         if ((val ^ vmcb->cr0) & bits)
801                 vcpu_tlb_flush();
802         /* TODO: better check for #GP reasons */
803         vmcb->cr0 = val & SVM_CR0_CLEARED_BITS;
804         if (val & X86_CR0_PG)
805                 update_efer(cpu_data);
806         vmcb->clean_bits &= ~CLEAN_BITS_CRX;
807
808 out:
809         return ok;
810 }
811
812 static bool svm_handle_msr_read(struct registers *guest_regs,
813                 struct per_cpu *cpu_data)
814 {
815         if (guest_regs->rcx >= MSR_X2APIC_BASE &&
816             guest_regs->rcx <= MSR_X2APIC_END) {
817                 vcpu_skip_emulated_instruction(X86_INST_LEN_RDMSR);
818                 x2apic_handle_read(guest_regs);
819                 return true;
820         } else {
821                 panic_printk("FATAL: Unhandled MSR read: %x\n",
822                              guest_regs->rcx);
823                 return false;
824         }
825 }
826
827 static bool svm_handle_msr_write(struct registers *guest_regs,
828                 struct per_cpu *cpu_data)
829 {
830         struct vmcb *vmcb = &cpu_data->vmcb;
831         unsigned long efer, val;
832         bool result = true;
833
834         if (guest_regs->rcx >= MSR_X2APIC_BASE &&
835             guest_regs->rcx <= MSR_X2APIC_END) {
836                 result = x2apic_handle_write(guest_regs, cpu_data);
837                 goto out;
838         }
839         if (guest_regs->rcx == MSR_EFER) {
840                 /* Never let a guest to disable SVME; see APMv2, Sect. 3.1.7 */
841                 efer = (guest_regs->rax & 0xffffffff) |
842                         (guest_regs->rdx << 32) | EFER_SVME;
843                 /* Flush TLB on LME/NXE change: See APMv2, Sect. 15.16 */
844                 if ((efer ^ vmcb->efer) & (EFER_LME | EFER_NXE))
845                         vcpu_tlb_flush();
846                 vmcb->efer = efer;
847                 vmcb->clean_bits &= ~CLEAN_BITS_CRX;
848                 goto out;
849         }
850         if (guest_regs->rcx == MTRR_DEFTYPE) {
851                 val = (guest_regs->rax & 0xffffffff) | (guest_regs->rdx << 32);
852                 /*
853                  * Quick (and very incomplete) guest MTRRs emulation.
854                  *
855                  * For Linux, emulating MTRR Enable bit seems to be enough.
856                  * If it is cleared, we set hPAT to all zeroes, effectively
857                  * making all NPT-mapped memory UC (see APMv2, Sect. 15.25.8).
858                  *
859                  * Otherwise, default PAT value is restored. This can also
860                  * make NPT-mapped memory's type different from what Linux
861                  * expects, however.
862                  */
863                 if (val & 0x800)
864                         write_msr(MSR_IA32_PAT, PAT_RESET_VALUE);
865                 else
866                         write_msr(MSR_IA32_PAT, 0);
867                 goto out;
868         }
869
870         result = false;
871         panic_printk("FATAL: Unhandled MSR write: %x\n",
872                      guest_regs->rcx);
873 out:
874         if (result)
875                 vcpu_skip_emulated_instruction(X86_INST_LEN_WRMSR);
876         return result;
877 }
878
879 /*
880  * TODO: This handles unaccelerated (non-AVIC) access. AVIC should
881  * be treated separately in svm_handle_avic_access().
882  */
883 static bool svm_handle_apic_access(struct registers *guest_regs,
884                                    struct per_cpu *cpu_data)
885 {
886         struct vmcb *vmcb = &cpu_data->vmcb;
887         struct guest_paging_structures pg_structs;
888         unsigned int inst_len, offset;
889         bool is_write;
890
891         /* The caller is responsible for sanity checks */
892         is_write = !!(vmcb->exitinfo1 & 0x2);
893         offset = vmcb->exitinfo2 - XAPIC_BASE;
894
895         if (offset & 0x00f)
896                 goto out_err;
897
898         if (!vcpu_get_guest_paging_structs(&pg_structs))
899                 goto out_err;
900
901         inst_len = apic_mmio_access(guest_regs, cpu_data, vmcb->rip,
902                                     &pg_structs, offset >> 4, is_write);
903         if (!inst_len)
904                 goto out_err;
905
906         vcpu_skip_emulated_instruction(inst_len);
907         return true;
908
909 out_err:
910         panic_printk("FATAL: Unhandled APIC access, offset %d, is_write: %d\n",
911                      offset, is_write);
912         return false;
913 }
914
915 static void dump_guest_regs(struct registers *guest_regs, struct vmcb *vmcb)
916 {
917         panic_printk("RIP: %p RSP: %p FLAGS: %x\n", vmcb->rip,
918                      vmcb->rsp, vmcb->rflags);
919         panic_printk("RAX: %p RBX: %p RCX: %p\n", guest_regs->rax,
920                      guest_regs->rbx, guest_regs->rcx);
921         panic_printk("RDX: %p RSI: %p RDI: %p\n", guest_regs->rdx,
922                      guest_regs->rsi, guest_regs->rdi);
923         panic_printk("CS: %x BASE: %p AR-BYTES: %x EFER.LMA %d\n",
924                      vmcb->cs.selector,
925                      vmcb->cs.base,
926                      vmcb->cs.access_rights,
927                      (vmcb->efer & EFER_LMA));
928         panic_printk("CR0: %p CR3: %p CR4: %p\n", vmcb->cr0,
929                      vmcb->cr3, vmcb->cr4);
930         panic_printk("EFER: %p\n", vmcb->efer);
931 }
932
933 static void svm_get_vcpu_pf_intercept(struct per_cpu *cpu_data,
934                                       struct vcpu_pf_intercept *out)
935 {
936         struct vmcb *vmcb = &cpu_data->vmcb;
937
938         out->phys_addr = vmcb->exitinfo2;
939         out->is_write = !!(vmcb->exitinfo1 & 0x2);
940 }
941
942 static void svm_get_vcpu_io_intercept(struct per_cpu *cpu_data,
943                                       struct vcpu_io_intercept *out)
944 {
945         struct vmcb *vmcb = &cpu_data->vmcb;
946         u64 exitinfo = vmcb->exitinfo1;
947
948         /* parse exit info for I/O instructions (see APM, 15.10.2 ) */
949         out->port = (exitinfo >> 16) & 0xFFFF;
950         out->size = (exitinfo >> 4) & 0x7;
951         out->in = !!(exitinfo & 0x1);
952         out->inst_len = vmcb->exitinfo2 - vmcb->rip;
953         out->rep_or_str = !!(exitinfo & 0x0c);
954 }
955
956 void vcpu_handle_exit(struct registers *guest_regs, struct per_cpu *cpu_data)
957 {
958         struct vmcb *vmcb = &cpu_data->vmcb;
959         struct vcpu_execution_state x_state;
960         struct vcpu_pf_intercept pf;
961         struct vcpu_io_intercept io;
962         bool res = false;
963         int sipi_vector;
964
965         /* Restore GS value expected by per_cpu data accessors */
966         write_msr(MSR_GS_BASE, (unsigned long)cpu_data);
967
968         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_TOTAL]++;
969         /*
970          * All guest state is marked unmodified; individual handlers must clear
971          * the bits as needed.
972          */
973         vmcb->clean_bits = 0xffffffff;
974
975         switch (vmcb->exitcode) {
976         case VMEXIT_INVALID:
977                 panic_printk("FATAL: VM-Entry failure, error %d\n",
978                              vmcb->exitcode);
979                 break;
980         case VMEXIT_NMI:
981                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MANAGEMENT]++;
982                 /* Temporarily enable GIF to consume pending NMI */
983                 asm volatile("stgi; clgi" : : : "memory");
984                 sipi_vector = x86_handle_events(cpu_data);
985                 if (sipi_vector >= 0) {
986                         printk("CPU %d received SIPI, vector %x\n",
987                                cpu_data->cpu_id, sipi_vector);
988                         svm_vcpu_reset(cpu_data, sipi_vector);
989                         memset(guest_regs, 0, sizeof(*guest_regs));
990                 }
991                 iommu_check_pending_faults(cpu_data);
992                 return;
993         case VMEXIT_CPUID:
994                 /* FIXME: We are not intercepting CPUID now */
995                 return;
996         case VMEXIT_VMMCALL:
997                 vcpu_vendor_get_execution_state(&x_state);
998                 vcpu_handle_hypercall(guest_regs, &x_state);
999                 return;
1000         case VMEXIT_CR0_SEL_WRITE:
1001                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_CR]++;
1002                 if (svm_handle_cr(guest_regs, cpu_data))
1003                         return;
1004                 break;
1005         case VMEXIT_MSR:
1006                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MSR]++;
1007                 if (!vmcb->exitinfo1)
1008                         res = svm_handle_msr_read(guest_regs, cpu_data);
1009                 else
1010                         res = svm_handle_msr_write(guest_regs, cpu_data);
1011                 if (res)
1012                         return;
1013                 break;
1014         case VMEXIT_NPF:
1015                 if ((vmcb->exitinfo1 & 0x7) == 0x7 &&
1016                      vmcb->exitinfo2 >= XAPIC_BASE &&
1017                      vmcb->exitinfo2 < XAPIC_BASE + PAGE_SIZE) {
1018                         /* APIC access in non-AVIC mode */
1019                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XAPIC]++;
1020                         if (svm_handle_apic_access(guest_regs, cpu_data))
1021                                 return;
1022                 } else {
1023                         /* General MMIO (IOAPIC, PCI etc) */
1024                         cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_MMIO]++;
1025                         svm_get_vcpu_pf_intercept(cpu_data, &pf);
1026                         if (vcpu_handle_pt_violation(guest_regs, &pf))
1027                                 return;
1028                 }
1029
1030                 panic_printk("FATAL: Unhandled Nested Page Fault for (%p), "
1031                              "error code is %x\n", vmcb->exitinfo2,
1032                              vmcb->exitinfo1 & 0xf);
1033                 break;
1034         case VMEXIT_XSETBV:
1035                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_XSETBV]++;
1036                 if ((guest_regs->rax & X86_XCR0_FP) &&
1037                     (guest_regs->rax & ~cpuid_eax(0x0d)) == 0 &&
1038                     guest_regs->rcx == 0 && guest_regs->rdx == 0) {
1039                         vcpu_skip_emulated_instruction(X86_INST_LEN_XSETBV);
1040                         asm volatile(
1041                                 "xsetbv"
1042                                 : /* no output */
1043                                 : "a" (guest_regs->rax), "c" (0), "d" (0));
1044                         return;
1045                 }
1046                 panic_printk("FATAL: Invalid xsetbv parameters: "
1047                              "xcr[%d] = %x:%x\n", guest_regs->rcx,
1048                              guest_regs->rdx, guest_regs->rax);
1049                 break;
1050         case VMEXIT_IOIO:
1051                 cpu_data->stats[JAILHOUSE_CPU_STAT_VMEXITS_PIO]++;
1052                 svm_get_vcpu_io_intercept(cpu_data, &io);
1053                 if (vcpu_handle_io_access(guest_regs, &io))
1054                         return;
1055                 break;
1056         /* TODO: Handle VMEXIT_AVIC_NOACCEL and VMEXIT_AVIC_INCOMPLETE_IPI */
1057         default:
1058                 panic_printk("FATAL: Unexpected #VMEXIT, exitcode %x, "
1059                              "exitinfo1 %p exitinfo2 %p\n",
1060                              vmcb->exitcode, vmcb->exitinfo1, vmcb->exitinfo2);
1061         }
1062         dump_guest_regs(guest_regs, vmcb);
1063         panic_park();
1064 }
1065
1066 void vcpu_park(struct per_cpu *cpu_data)
1067 {
1068         struct vmcb *vmcb = &cpu_data->vmcb;
1069
1070         svm_vcpu_reset(cpu_data, APIC_BSP_PSEUDO_SIPI);
1071         /* No need to clear VMCB Clean bit: vcpu_reset() already does this */
1072         vmcb->n_cr3 = paging_hvirt2phys(parked_mode_npt);
1073
1074         vcpu_tlb_flush();
1075 }
1076
1077 void vcpu_nmi_handler(void)
1078 {
1079 }
1080
1081 void vcpu_tlb_flush(void)
1082 {
1083         struct per_cpu *cpu_data = this_cpu_data();
1084         struct vmcb *vmcb = &cpu_data->vmcb;
1085
1086         if (has_flush_by_asid)
1087                 vmcb->tlb_control = SVM_TLB_FLUSH_GUEST;
1088         else
1089                 vmcb->tlb_control = SVM_TLB_FLUSH_ALL;
1090 }
1091
1092 const u8 *vcpu_get_inst_bytes(const struct guest_paging_structures *pg_structs,
1093                               unsigned long pc, unsigned int *size)
1094 {
1095         struct per_cpu *cpu_data = this_cpu_data();
1096         struct vmcb *vmcb = &cpu_data->vmcb;
1097         unsigned long start;
1098
1099         if (has_assists) {
1100                 if (!*size)
1101                         return NULL;
1102                 start = vmcb->rip - pc;
1103                 if (start < vmcb->bytes_fetched) {
1104                         *size = vmcb->bytes_fetched - start;
1105                         return &vmcb->guest_bytes[start];
1106                 } else {
1107                         return NULL;
1108                 }
1109         } else {
1110                 return vcpu_map_inst(pg_structs, pc, size);
1111         }
1112 }
1113
1114 void vcpu_vendor_get_cell_io_bitmap(struct cell *cell,
1115                                     struct vcpu_io_bitmap *iobm)
1116 {
1117         iobm->data = cell->svm.iopm;
1118         iobm->size = sizeof(cell->svm.iopm);
1119 }
1120
1121 void vcpu_vendor_get_execution_state(struct vcpu_execution_state *x_state)
1122 {
1123         struct per_cpu *cpu_data = this_cpu_data();
1124
1125         x_state->efer = cpu_data->vmcb.efer;
1126         x_state->rflags = cpu_data->vmcb.rflags;
1127         x_state->cs = cpu_data->vmcb.cs.selector;
1128         x_state->rip = cpu_data->vmcb.rip;
1129 }
1130
1131 /* GIF must be set for interrupts to be delivered (APMv2, Sect. 15.17) */
1132 void enable_irq(void)
1133 {
1134         asm volatile("stgi; sti" : : : "memory");
1135 }
1136
1137 /* Jailhouse runs with GIF cleared, so we need to restore this state */
1138 void disable_irq(void)
1139 {
1140         asm volatile("cli; clgi" : : : "memory");
1141 }