1 /*
2 * TPR optimization for 32-bit Windows guests (XP and Server 2003)
3 *
4 * Copyright (C) 2007-2008 Qumranet Technologies
5 * Copyright (C) 2012 Jan Kiszka, Siemens AG
6 *
7 * This work is licensed under the terms of the GNU GPL version 2, or
8 * (at your option) any later version. See the COPYING file in the
9 * top-level directory.
10 */
11
12 #include "qemu/osdep.h"
13 #include "qemu/module.h"
14 #include "sysemu/sysemu.h"
15 #include "sysemu/cpus.h"
16 #include "sysemu/hw_accel.h"
17 #include "sysemu/kvm.h"
18 #include "sysemu/runstate.h"
19 #include "exec/address-spaces.h"
20 #include "hw/i386/apic_internal.h"
21 #include "hw/sysbus.h"
22 #include "hw/boards.h"
23 #include "migration/vmstate.h"
24 #include "qom/object.h"
25
26 #define VAPIC_IO_PORT 0x7e
27
28 #define VAPIC_CPU_SHIFT 7
29
30 #define ROM_BLOCK_SIZE 512
31 #define ROM_BLOCK_MASK (~(ROM_BLOCK_SIZE - 1))
32
33 typedef enum VAPICMode {
34 VAPIC_INACTIVE = 0,
35 VAPIC_ACTIVE = 1,
36 VAPIC_STANDBY = 2,
37 } VAPICMode;
38
39 typedef struct VAPICHandlers {
40 uint32_t set_tpr;
41 uint32_t set_tpr_eax;
42 uint32_t get_tpr[8];
43 uint32_t get_tpr_stack;
44 } QEMU_PACKED VAPICHandlers;
45
46 typedef struct GuestROMState {
47 char signature[8];
48 uint32_t vaddr;
49 uint32_t fixup_start;
50 uint32_t fixup_end;
51 uint32_t vapic_vaddr;
52 uint32_t vapic_size;
53 uint32_t vcpu_shift;
54 uint32_t real_tpr_addr;
55 VAPICHandlers up;
56 VAPICHandlers mp;
57 } QEMU_PACKED GuestROMState;
58
59 struct VAPICROMState {
60 SysBusDevice busdev;
61
62 MemoryRegion io;
63 MemoryRegion rom;
64 uint32_t state;
65 uint32_t rom_state_paddr;
66 uint32_t rom_state_vaddr;
67 uint32_t vapic_paddr;
68 uint32_t real_tpr_addr;
69 GuestROMState rom_state;
70 size_t rom_size;
71 bool rom_mapped_writable;
72 VMChangeStateEntry *vmsentry;
73 };
74
75 #define TYPE_VAPIC "kvmvapic"
76 OBJECT_DECLARE_SIMPLE_TYPE(VAPICROMState, VAPIC)
77
78 #define TPR_INSTR_ABS_MODRM 0x1
79 #define TPR_INSTR_MATCH_MODRM_REG 0x2
80
81 typedef struct TPRInstruction {
82 uint8_t opcode;
83 uint8_t modrm_reg;
84 unsigned int flags;
85 TPRAccess access;
86 size_t length;
87 off_t addr_offset;
88 } TPRInstruction;
89
90 /* must be sorted by length, shortest first */
91 static const TPRInstruction tpr_instr[] = {
92 { /* mov abs to eax */
93 .opcode = 0xa1,
94 .access = TPR_ACCESS_READ,
95 .length = 5,
96 .addr_offset = 1,
97 },
98 { /* mov eax to abs */
99 .opcode = 0xa3,
100 .access = TPR_ACCESS_WRITE,
101 .length = 5,
102 .addr_offset = 1,
103 },
104 { /* mov r32 to r/m32 */
105 .opcode = 0x89,
106 .flags = TPR_INSTR_ABS_MODRM,
107 .access = TPR_ACCESS_WRITE,
108 .length = 6,
109 .addr_offset = 2,
110 },
111 { /* mov r/m32 to r32 */
112 .opcode = 0x8b,
113 .flags = TPR_INSTR_ABS_MODRM,
114 .access = TPR_ACCESS_READ,
115 .length = 6,
116 .addr_offset = 2,
117 },
118 { /* push r/m32 */
119 .opcode = 0xff,
120 .modrm_reg = 6,
121 .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
122 .access = TPR_ACCESS_READ,
123 .length = 6,
124 .addr_offset = 2,
125 },
126 { /* mov imm32, r/m32 (c7/0) */
127 .opcode = 0xc7,
128 .modrm_reg = 0,
129 .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
130 .access = TPR_ACCESS_WRITE,
131 .length = 10,
132 .addr_offset = 2,
133 },
134 };
135
read_guest_rom_state(VAPICROMState * s)136 static void read_guest_rom_state(VAPICROMState *s)
137 {
138 cpu_physical_memory_read(s->rom_state_paddr, &s->rom_state,
139 sizeof(GuestROMState));
140 }
141
write_guest_rom_state(VAPICROMState * s)142 static void write_guest_rom_state(VAPICROMState *s)
143 {
144 cpu_physical_memory_write(s->rom_state_paddr, &s->rom_state,
145 sizeof(GuestROMState));
146 }
147
update_guest_rom_state(VAPICROMState * s)148 static void update_guest_rom_state(VAPICROMState *s)
149 {
150 read_guest_rom_state(s);
151
152 s->rom_state.real_tpr_addr = cpu_to_le32(s->real_tpr_addr);
153 s->rom_state.vcpu_shift = cpu_to_le32(VAPIC_CPU_SHIFT);
154
155 write_guest_rom_state(s);
156 }
157
find_real_tpr_addr(VAPICROMState * s,CPUX86State * env)158 static int find_real_tpr_addr(VAPICROMState *s, CPUX86State *env)
159 {
160 CPUState *cs = env_cpu(env);
161 hwaddr paddr;
162 target_ulong addr;
163
164 if (s->state == VAPIC_ACTIVE) {
165 return 0;
166 }
167 /*
168 * If there is no prior TPR access instruction we could analyze (which is
169 * the case after resume from hibernation), we need to scan the possible
170 * virtual address space for the APIC mapping.
171 */
172 for (addr = 0xfffff000; addr >= 0x80000000; addr -= TARGET_PAGE_SIZE) {
173 paddr = cpu_get_phys_page_debug(cs, addr);
174 if (paddr != APIC_DEFAULT_ADDRESS) {
175 continue;
176 }
177 s->real_tpr_addr = addr + 0x80;
178 update_guest_rom_state(s);
179 return 0;
180 }
181 return -1;
182 }
183
modrm_reg(uint8_t modrm)184 static uint8_t modrm_reg(uint8_t modrm)
185 {
186 return (modrm >> 3) & 7;
187 }
188
is_abs_modrm(uint8_t modrm)189 static bool is_abs_modrm(uint8_t modrm)
190 {
191 return (modrm & 0xc7) == 0x05;
192 }
193
opcode_matches(uint8_t * opcode,const TPRInstruction * instr)194 static bool opcode_matches(uint8_t *opcode, const TPRInstruction *instr)
195 {
196 return opcode[0] == instr->opcode &&
197 (!(instr->flags & TPR_INSTR_ABS_MODRM) || is_abs_modrm(opcode[1])) &&
198 (!(instr->flags & TPR_INSTR_MATCH_MODRM_REG) ||
199 modrm_reg(opcode[1]) == instr->modrm_reg);
200 }
201
evaluate_tpr_instruction(VAPICROMState * s,X86CPU * cpu,target_ulong * pip,TPRAccess access)202 static int evaluate_tpr_instruction(VAPICROMState *s, X86CPU *cpu,
203 target_ulong *pip, TPRAccess access)
204 {
205 CPUState *cs = CPU(cpu);
206 const TPRInstruction *instr;
207 target_ulong ip = *pip;
208 uint8_t opcode[2];
209 uint32_t real_tpr_addr;
210 int i;
211
212 if ((ip & 0xf0000000ULL) != 0x80000000ULL &&
213 (ip & 0xf0000000ULL) != 0xe0000000ULL) {
214 return -1;
215 }
216
217 /*
218 * Early Windows 2003 SMP initialization contains a
219 *
220 * mov imm32, r/m32
221 *
222 * instruction that is patched by TPR optimization. The problem is that
223 * RSP, used by the patched instruction, is zero, so the guest gets a
224 * double fault and dies.
225 */
226 if (cpu->env.regs[R_ESP] == 0) {
227 return -1;
228 }
229
230 if (kvm_enabled() && !kvm_irqchip_in_kernel()) {
231 /*
232 * KVM without kernel-based TPR access reporting will pass an IP that
233 * points after the accessing instruction. So we need to look backward
234 * to find the reason.
235 */
236 for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
237 instr = &tpr_instr[i];
238 if (instr->access != access) {
239 continue;
240 }
241 if (cpu_memory_rw_debug(cs, ip - instr->length, opcode,
242 sizeof(opcode), 0) < 0) {
243 return -1;
244 }
245 if (opcode_matches(opcode, instr)) {
246 ip -= instr->length;
247 goto instruction_ok;
248 }
249 }
250 return -1;
251 } else {
252 if (cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0) < 0) {
253 return -1;
254 }
255 for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
256 instr = &tpr_instr[i];
257 if (opcode_matches(opcode, instr)) {
258 goto instruction_ok;
259 }
260 }
261 return -1;
262 }
263
264 instruction_ok:
265 /*
266 * Grab the virtual TPR address from the instruction
267 * and update the cached values.
268 */
269 if (cpu_memory_rw_debug(cs, ip + instr->addr_offset,
270 (void *)&real_tpr_addr,
271 sizeof(real_tpr_addr), 0) < 0) {
272 return -1;
273 }
274 real_tpr_addr = le32_to_cpu(real_tpr_addr);
275 if ((real_tpr_addr & 0xfff) != 0x80) {
276 return -1;
277 }
278 s->real_tpr_addr = real_tpr_addr;
279 update_guest_rom_state(s);
280
281 *pip = ip;
282 return 0;
283 }
284
update_rom_mapping(VAPICROMState * s,CPUX86State * env,target_ulong ip)285 static int update_rom_mapping(VAPICROMState *s, CPUX86State *env, target_ulong ip)
286 {
287 CPUState *cs = env_cpu(env);
288 hwaddr paddr;
289 uint32_t rom_state_vaddr;
290 uint32_t pos, patch, offset;
291
292 /* nothing to do if already activated */
293 if (s->state == VAPIC_ACTIVE) {
294 return 0;
295 }
296
297 /* bail out if ROM init code was not executed (missing ROM?) */
298 if (s->state == VAPIC_INACTIVE) {
299 return -1;
300 }
301
302 /* find out virtual address of the ROM */
303 rom_state_vaddr = s->rom_state_paddr + (ip & 0xf0000000);
304 paddr = cpu_get_phys_page_debug(cs, rom_state_vaddr);
305 if (paddr == -1) {
306 return -1;
307 }
308 paddr += rom_state_vaddr & ~TARGET_PAGE_MASK;
309 if (paddr != s->rom_state_paddr) {
310 return -1;
311 }
312 read_guest_rom_state(s);
313 if (memcmp(s->rom_state.signature, "kvm aPiC", 8) != 0) {
314 return -1;
315 }
316 s->rom_state_vaddr = rom_state_vaddr;
317
318 /* fixup addresses in ROM if needed */
319 if (rom_state_vaddr == le32_to_cpu(s->rom_state.vaddr)) {
320 return 0;
321 }
322 for (pos = le32_to_cpu(s->rom_state.fixup_start);
323 pos < le32_to_cpu(s->rom_state.fixup_end);
324 pos += 4) {
325 cpu_physical_memory_read(paddr + pos - s->rom_state.vaddr,
326 &offset, sizeof(offset));
327 offset = le32_to_cpu(offset);
328 cpu_physical_memory_read(paddr + offset, &patch, sizeof(patch));
329 patch = le32_to_cpu(patch);
330 patch += rom_state_vaddr - le32_to_cpu(s->rom_state.vaddr);
331 patch = cpu_to_le32(patch);
332 cpu_physical_memory_write(paddr + offset, &patch, sizeof(patch));
333 }
334 read_guest_rom_state(s);
335 s->vapic_paddr = paddr + le32_to_cpu(s->rom_state.vapic_vaddr) -
336 le32_to_cpu(s->rom_state.vaddr);
337
338 return 0;
339 }
340
341 /*
342 * Tries to read the unique processor number from the Kernel Processor Control
343 * Region (KPCR) of 32-bit Windows XP and Server 2003. Returns -1 if the KPCR
344 * cannot be accessed or is considered invalid. This also ensures that we are
345 * not patching the wrong guest.
346 */
get_kpcr_number(X86CPU * cpu)347 static int get_kpcr_number(X86CPU *cpu)
348 {
349 CPUX86State *env = &cpu->env;
350 struct kpcr {
351 uint8_t fill1[0x1c];
352 uint32_t self;
353 uint8_t fill2[0x31];
354 uint8_t number;
355 } QEMU_PACKED kpcr;
356
357 if (cpu_memory_rw_debug(CPU(cpu), env->segs[R_FS].base,
358 (void *)&kpcr, sizeof(kpcr), 0) < 0 ||
359 kpcr.self != env->segs[R_FS].base) {
360 return -1;
361 }
362 return kpcr.number;
363 }
364
vapic_enable(VAPICROMState * s,X86CPU * cpu)365 static int vapic_enable(VAPICROMState *s, X86CPU *cpu)
366 {
367 int cpu_number = get_kpcr_number(cpu);
368 hwaddr vapic_paddr;
369 static const uint8_t enabled = 1;
370
371 if (cpu_number < 0) {
372 return -1;
373 }
374 vapic_paddr = s->vapic_paddr +
375 (((hwaddr)cpu_number) << VAPIC_CPU_SHIFT);
376 cpu_physical_memory_write(vapic_paddr + offsetof(VAPICState, enabled),
377 &enabled, sizeof(enabled));
378 apic_enable_vapic(cpu->apic_state, vapic_paddr);
379
380 s->state = VAPIC_ACTIVE;
381
382 return 0;
383 }
384
patch_byte(X86CPU * cpu,target_ulong addr,uint8_t byte)385 static void patch_byte(X86CPU *cpu, target_ulong addr, uint8_t byte)
386 {
387 cpu_memory_rw_debug(CPU(cpu), addr, &byte, 1, 1);
388 }
389
patch_call(X86CPU * cpu,target_ulong ip,uint32_t target)390 static void patch_call(X86CPU *cpu, target_ulong ip, uint32_t target)
391 {
392 uint32_t offset;
393
394 offset = cpu_to_le32(target - ip - 5);
395 patch_byte(cpu, ip, 0xe8); /* call near */
396 cpu_memory_rw_debug(CPU(cpu), ip + 1, (void *)&offset, sizeof(offset), 1);
397 }
398
399 typedef struct PatchInfo {
400 VAPICHandlers *handler;
401 target_ulong ip;
402 } PatchInfo;
403
do_patch_instruction(CPUState * cs,run_on_cpu_data data)404 static void do_patch_instruction(CPUState *cs, run_on_cpu_data data)
405 {
406 X86CPU *x86_cpu = X86_CPU(cs);
407 PatchInfo *info = (PatchInfo *) data.host_ptr;
408 VAPICHandlers *handlers = info->handler;
409 target_ulong ip = info->ip;
410 uint8_t opcode[2];
411 uint32_t imm32 = 0;
412
413 cpu_memory_rw_debug(cs, ip, opcode, sizeof(opcode), 0);
414
415 switch (opcode[0]) {
416 case 0x89: /* mov r32 to r/m32 */
417 patch_byte(x86_cpu, ip, 0x50 + modrm_reg(opcode[1])); /* push reg */
418 patch_call(x86_cpu, ip + 1, handlers->set_tpr);
419 break;
420 case 0x8b: /* mov r/m32 to r32 */
421 patch_byte(x86_cpu, ip, 0x90);
422 patch_call(x86_cpu, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]);
423 break;
424 case 0xa1: /* mov abs to eax */
425 patch_call(x86_cpu, ip, handlers->get_tpr[0]);
426 break;
427 case 0xa3: /* mov eax to abs */
428 patch_call(x86_cpu, ip, handlers->set_tpr_eax);
429 break;
430 case 0xc7: /* mov imm32, r/m32 (c7/0) */
431 patch_byte(x86_cpu, ip, 0x68); /* push imm32 */
432 cpu_memory_rw_debug(cs, ip + 6, (void *)&imm32, sizeof(imm32), 0);
433 cpu_memory_rw_debug(cs, ip + 1, (void *)&imm32, sizeof(imm32), 1);
434 patch_call(x86_cpu, ip + 5, handlers->set_tpr);
435 break;
436 case 0xff: /* push r/m32 */
437 patch_byte(x86_cpu, ip, 0x50); /* push eax */
438 patch_call(x86_cpu, ip + 1, handlers->get_tpr_stack);
439 break;
440 default:
441 abort();
442 }
443
444 g_free(info);
445 }
446
patch_instruction(VAPICROMState * s,X86CPU * cpu,target_ulong ip)447 static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip)
448 {
449 MachineState *ms = MACHINE(qdev_get_machine());
450 CPUState *cs = CPU(cpu);
451 VAPICHandlers *handlers;
452 PatchInfo *info;
453
454 if (ms->smp.cpus == 1) {
455 handlers = &s->rom_state.up;
456 } else {
457 handlers = &s->rom_state.mp;
458 }
459
460 info = g_new(PatchInfo, 1);
461 info->handler = handlers;
462 info->ip = ip;
463
464 async_safe_run_on_cpu(cs, do_patch_instruction, RUN_ON_CPU_HOST_PTR(info));
465 }
466
vapic_report_tpr_access(DeviceState * dev,CPUState * cs,target_ulong ip,TPRAccess access)467 void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip,
468 TPRAccess access)
469 {
470 VAPICROMState *s = VAPIC(dev);
471 X86CPU *cpu = X86_CPU(cs);
472 CPUX86State *env = &cpu->env;
473
474 cpu_synchronize_state(cs);
475
476 if (evaluate_tpr_instruction(s, cpu, &ip, access) < 0) {
477 if (s->state == VAPIC_ACTIVE) {
478 vapic_enable(s, cpu);
479 }
480 return;
481 }
482 if (update_rom_mapping(s, env, ip) < 0) {
483 return;
484 }
485 if (vapic_enable(s, cpu) < 0) {
486 return;
487 }
488 patch_instruction(s, cpu, ip);
489 }
490
491 typedef struct VAPICEnableTPRReporting {
492 DeviceState *apic;
493 bool enable;
494 } VAPICEnableTPRReporting;
495
vapic_do_enable_tpr_reporting(CPUState * cpu,run_on_cpu_data data)496 static void vapic_do_enable_tpr_reporting(CPUState *cpu, run_on_cpu_data data)
497 {
498 VAPICEnableTPRReporting *info = data.host_ptr;
499 apic_enable_tpr_access_reporting(info->apic, info->enable);
500 }
501
vapic_enable_tpr_reporting(bool enable)502 static void vapic_enable_tpr_reporting(bool enable)
503 {
504 VAPICEnableTPRReporting info = {
505 .enable = enable,
506 };
507 CPUState *cs;
508 X86CPU *cpu;
509
510 CPU_FOREACH(cs) {
511 cpu = X86_CPU(cs);
512 info.apic = cpu->apic_state;
513 run_on_cpu(cs, vapic_do_enable_tpr_reporting, RUN_ON_CPU_HOST_PTR(&info));
514 }
515 }
516
vapic_reset(DeviceState * dev)517 static void vapic_reset(DeviceState *dev)
518 {
519 VAPICROMState *s = VAPIC(dev);
520
521 s->state = VAPIC_INACTIVE;
522 s->rom_state_paddr = 0;
523 vapic_enable_tpr_reporting(false);
524 }
525
526 /*
527 * Set the IRQ polling hypercalls to the supported variant:
528 * - vmcall if using KVM in-kernel irqchip
529 * - 32-bit VAPIC port write otherwise
530 */
patch_hypercalls(VAPICROMState * s)531 static int patch_hypercalls(VAPICROMState *s)
532 {
533 hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
534 static const uint8_t vmcall_pattern[] = { /* vmcall */
535 0xb8, 0x1, 0, 0, 0, 0xf, 0x1, 0xc1
536 };
537 static const uint8_t outl_pattern[] = { /* nop; outl %eax,0x7e */
538 0xb8, 0x1, 0, 0, 0, 0x90, 0xe7, 0x7e
539 };
540 uint8_t alternates[2];
541 const uint8_t *pattern;
542 const uint8_t *patch;
543 off_t pos;
544 uint8_t *rom;
545
546 rom = g_malloc(s->rom_size);
547 cpu_physical_memory_read(rom_paddr, rom, s->rom_size);
548
549 for (pos = 0; pos < s->rom_size - sizeof(vmcall_pattern); pos++) {
550 if (kvm_irqchip_in_kernel()) {
551 pattern = outl_pattern;
552 alternates[0] = outl_pattern[7];
553 alternates[1] = outl_pattern[7];
554 patch = &vmcall_pattern[5];
555 } else {
556 pattern = vmcall_pattern;
557 alternates[0] = vmcall_pattern[7];
558 alternates[1] = 0xd9; /* AMD's VMMCALL */
559 patch = &outl_pattern[5];
560 }
561 if (memcmp(rom + pos, pattern, 7) == 0 &&
562 (rom[pos + 7] == alternates[0] || rom[pos + 7] == alternates[1])) {
563 cpu_physical_memory_write(rom_paddr + pos + 5, patch, 3);
564 /*
565 * Don't flush the tb here. Under ordinary conditions, the patched
566 * calls are miles away from the current IP. Under malicious
567 * conditions, the guest could trick us to crash.
568 */
569 }
570 }
571
572 g_free(rom);
573 return 0;
574 }
575
576 /*
577 * For TCG mode or the time KVM honors read-only memory regions, we need to
578 * enable write access to the option ROM so that variables can be updated by
579 * the guest.
580 */
vapic_map_rom_writable(VAPICROMState * s)581 static int vapic_map_rom_writable(VAPICROMState *s)
582 {
583 hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
584 MemoryRegionSection section;
585 MemoryRegion *mr = get_system_memory();
586 size_t rom_size;
587 uint8_t *ram;
588
589 if (s->rom_mapped_writable) {
590 memory_region_del_subregion(mr, &s->rom);
591 object_unparent(OBJECT(&s->rom));
592 }
593
594 /* grab RAM memory region (region @rom_paddr may still be pc.rom) */
595 section = memory_region_find(mr, 0, 1);
596
597 /* read ROM size from RAM region */
598 if (rom_paddr + 2 >= memory_region_size(section.mr)) {
599 return -1;
600 }
601 ram = memory_region_get_ram_ptr(section.mr);
602 rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
603 if (rom_size == 0) {
604 return -1;
605 }
606 s->rom_size = rom_size;
607
608 /* We need to round to avoid creating subpages
609 * from which we cannot run code. */
610 rom_size += rom_paddr & ~TARGET_PAGE_MASK;
611 rom_paddr &= TARGET_PAGE_MASK;
612 rom_size = TARGET_PAGE_ALIGN(rom_size);
613
614 memory_region_init_alias(&s->rom, OBJECT(s), "kvmvapic-rom", section.mr,
615 rom_paddr, rom_size);
616 memory_region_add_subregion_overlap(mr, rom_paddr, &s->rom, 1000);
617 s->rom_mapped_writable = true;
618 memory_region_unref(section.mr);
619
620 return 0;
621 }
622
vapic_prepare(VAPICROMState * s)623 static int vapic_prepare(VAPICROMState *s)
624 {
625 if (vapic_map_rom_writable(s) < 0) {
626 return -1;
627 }
628
629 if (patch_hypercalls(s) < 0) {
630 return -1;
631 }
632
633 vapic_enable_tpr_reporting(true);
634
635 return 0;
636 }
637
vapic_write(void * opaque,hwaddr addr,uint64_t data,unsigned int size)638 static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
639 unsigned int size)
640 {
641 VAPICROMState *s = opaque;
642 X86CPU *cpu;
643 CPUX86State *env;
644 hwaddr rom_paddr;
645
646 if (!current_cpu) {
647 return;
648 }
649
650 cpu_synchronize_state(current_cpu);
651 cpu = X86_CPU(current_cpu);
652 env = &cpu->env;
653
654 /*
655 * The VAPIC supports two PIO-based hypercalls, both via port 0x7E.
656 * o 16-bit write access:
657 * Reports the option ROM initialization to the hypervisor. Written
658 * value is the offset of the state structure in the ROM.
659 * o 8-bit write access:
660 * Reactivates the VAPIC after a guest hibernation, i.e. after the
661 * option ROM content has been re-initialized by a guest power cycle.
662 * o 32-bit write access:
663 * Poll for pending IRQs, considering the current VAPIC state.
664 */
665 switch (size) {
666 case 2:
667 if (s->state == VAPIC_INACTIVE) {
668 rom_paddr = (env->segs[R_CS].base + env->eip) & ROM_BLOCK_MASK;
669 s->rom_state_paddr = rom_paddr + data;
670
671 s->state = VAPIC_STANDBY;
672 }
673 if (vapic_prepare(s) < 0) {
674 s->state = VAPIC_INACTIVE;
675 s->rom_state_paddr = 0;
676 break;
677 }
678 break;
679 case 1:
680 if (kvm_enabled()) {
681 /*
682 * Disable triggering instruction in ROM by writing a NOP.
683 *
684 * We cannot do this in TCG mode as the reported IP is not
685 * accurate.
686 */
687 pause_all_vcpus();
688 patch_byte(cpu, env->eip - 2, 0x66);
689 patch_byte(cpu, env->eip - 1, 0x90);
690 resume_all_vcpus();
691 }
692
693 if (s->state == VAPIC_ACTIVE) {
694 break;
695 }
696 if (update_rom_mapping(s, env, env->eip) < 0) {
697 break;
698 }
699 if (find_real_tpr_addr(s, env) < 0) {
700 break;
701 }
702 vapic_enable(s, cpu);
703 break;
704 default:
705 case 4:
706 if (!kvm_irqchip_in_kernel()) {
707 apic_poll_irq(cpu->apic_state);
708 }
709 break;
710 }
711 }
712
vapic_read(void * opaque,hwaddr addr,unsigned size)713 static uint64_t vapic_read(void *opaque, hwaddr addr, unsigned size)
714 {
715 return 0xffffffff;
716 }
717
718 static const MemoryRegionOps vapic_ops = {
719 .write = vapic_write,
720 .read = vapic_read,
721 .endianness = DEVICE_NATIVE_ENDIAN,
722 };
723
vapic_realize(DeviceState * dev,Error ** errp)724 static void vapic_realize(DeviceState *dev, Error **errp)
725 {
726 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
727 VAPICROMState *s = VAPIC(dev);
728
729 memory_region_init_io(&s->io, OBJECT(s), &vapic_ops, s, "kvmvapic", 2);
730 memory_region_add_subregion(get_system_io(), VAPIC_IO_PORT, &s->io);
731 sysbus_init_ioports(sbd, VAPIC_IO_PORT, 2);
732
733 option_rom[nb_option_roms].name = "kvmvapic.bin";
734 option_rom[nb_option_roms].bootindex = -1;
735 nb_option_roms++;
736 }
737
do_vapic_enable(CPUState * cs,run_on_cpu_data data)738 static void do_vapic_enable(CPUState *cs, run_on_cpu_data data)
739 {
740 VAPICROMState *s = data.host_ptr;
741 X86CPU *cpu = X86_CPU(cs);
742
743 static const uint8_t enabled = 1;
744 cpu_physical_memory_write(s->vapic_paddr + offsetof(VAPICState, enabled),
745 &enabled, sizeof(enabled));
746 apic_enable_vapic(cpu->apic_state, s->vapic_paddr);
747 s->state = VAPIC_ACTIVE;
748 }
749
vapic_vm_state_change(void * opaque,bool running,RunState state)750 static void vapic_vm_state_change(void *opaque, bool running, RunState state)
751 {
752 MachineState *ms = MACHINE(qdev_get_machine());
753 VAPICROMState *s = opaque;
754 uint8_t *zero;
755
756 if (!running) {
757 return;
758 }
759
760 if (s->state == VAPIC_ACTIVE) {
761 if (ms->smp.cpus == 1) {
762 run_on_cpu(first_cpu, do_vapic_enable, RUN_ON_CPU_HOST_PTR(s));
763 } else {
764 zero = g_malloc0(s->rom_state.vapic_size);
765 cpu_physical_memory_write(s->vapic_paddr, zero,
766 s->rom_state.vapic_size);
767 g_free(zero);
768 }
769 }
770
771 qemu_del_vm_change_state_handler(s->vmsentry);
772 s->vmsentry = NULL;
773 }
774
vapic_post_load(void * opaque,int version_id)775 static int vapic_post_load(void *opaque, int version_id)
776 {
777 VAPICROMState *s = opaque;
778
779 /*
780 * The old implementation of qemu-kvm did not provide the state
781 * VAPIC_STANDBY. Reconstruct it.
782 */
783 if (s->state == VAPIC_INACTIVE && s->rom_state_paddr != 0) {
784 s->state = VAPIC_STANDBY;
785 }
786
787 if (s->state != VAPIC_INACTIVE) {
788 if (vapic_prepare(s) < 0) {
789 return -1;
790 }
791 }
792
793 if (!s->vmsentry) {
794 s->vmsentry =
795 qemu_add_vm_change_state_handler(vapic_vm_state_change, s);
796 }
797 return 0;
798 }
799
800 static const VMStateDescription vmstate_handlers = {
801 .name = "kvmvapic-handlers",
802 .version_id = 1,
803 .minimum_version_id = 1,
804 .fields = (const VMStateField[]) {
805 VMSTATE_UINT32(set_tpr, VAPICHandlers),
806 VMSTATE_UINT32(set_tpr_eax, VAPICHandlers),
807 VMSTATE_UINT32_ARRAY(get_tpr, VAPICHandlers, 8),
808 VMSTATE_UINT32(get_tpr_stack, VAPICHandlers),
809 VMSTATE_END_OF_LIST()
810 }
811 };
812
813 static const VMStateDescription vmstate_guest_rom = {
814 .name = "kvmvapic-guest-rom",
815 .version_id = 1,
816 .minimum_version_id = 1,
817 .fields = (const VMStateField[]) {
818 VMSTATE_UNUSED(8), /* signature */
819 VMSTATE_UINT32(vaddr, GuestROMState),
820 VMSTATE_UINT32(fixup_start, GuestROMState),
821 VMSTATE_UINT32(fixup_end, GuestROMState),
822 VMSTATE_UINT32(vapic_vaddr, GuestROMState),
823 VMSTATE_UINT32(vapic_size, GuestROMState),
824 VMSTATE_UINT32(vcpu_shift, GuestROMState),
825 VMSTATE_UINT32(real_tpr_addr, GuestROMState),
826 VMSTATE_STRUCT(up, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
827 VMSTATE_STRUCT(mp, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
828 VMSTATE_END_OF_LIST()
829 }
830 };
831
832 static const VMStateDescription vmstate_vapic = {
833 .name = "kvm-tpr-opt", /* compatible with qemu-kvm VAPIC */
834 .version_id = 1,
835 .minimum_version_id = 1,
836 .post_load = vapic_post_load,
837 .fields = (const VMStateField[]) {
838 VMSTATE_STRUCT(rom_state, VAPICROMState, 0, vmstate_guest_rom,
839 GuestROMState),
840 VMSTATE_UINT32(state, VAPICROMState),
841 VMSTATE_UINT32(real_tpr_addr, VAPICROMState),
842 VMSTATE_UINT32(rom_state_vaddr, VAPICROMState),
843 VMSTATE_UINT32(vapic_paddr, VAPICROMState),
844 VMSTATE_UINT32(rom_state_paddr, VAPICROMState),
845 VMSTATE_END_OF_LIST()
846 }
847 };
848
vapic_class_init(ObjectClass * klass,void * data)849 static void vapic_class_init(ObjectClass *klass, void *data)
850 {
851 DeviceClass *dc = DEVICE_CLASS(klass);
852
853 device_class_set_legacy_reset(dc, vapic_reset);
854 dc->vmsd = &vmstate_vapic;
855 dc->realize = vapic_realize;
856 }
857
858 static const TypeInfo vapic_type = {
859 .name = TYPE_VAPIC,
860 .parent = TYPE_SYS_BUS_DEVICE,
861 .instance_size = sizeof(VAPICROMState),
862 .class_init = vapic_class_init,
863 };
864
vapic_register(void)865 static void vapic_register(void)
866 {
867 type_register_static(&vapic_type);
868 }
869
870 type_init(vapic_register);
871