1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
4 * Copyright © 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 *
6 * KVM Xen emulation
7 */
8
9 #include "x86.h"
10 #include "xen.h"
11 #include "hyperv.h"
12
13 #include <linux/kvm_host.h>
14 #include <linux/sched/stat.h>
15
16 #include <trace/events/kvm.h>
17 #include <xen/interface/xen.h>
18 #include <xen/interface/vcpu.h>
19
20 #include "trace.h"
21
22 DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ);
23
kvm_xen_shared_info_init(struct kvm * kvm,gfn_t gfn)24 static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
25 {
26 gpa_t gpa = gfn_to_gpa(gfn);
27 int wc_ofs, sec_hi_ofs;
28 int ret = 0;
29 int idx = srcu_read_lock(&kvm->srcu);
30
31 if (kvm_is_error_hva(gfn_to_hva(kvm, gfn))) {
32 ret = -EFAULT;
33 goto out;
34 }
35 kvm->arch.xen.shinfo_gfn = gfn;
36
37 /* Paranoia checks on the 32-bit struct layout */
38 BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900);
39 BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924);
40 BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
41
42 /* 32-bit location by default */
43 wc_ofs = offsetof(struct compat_shared_info, wc);
44 sec_hi_ofs = offsetof(struct compat_shared_info, arch.wc_sec_hi);
45
46 #ifdef CONFIG_X86_64
47 /* Paranoia checks on the 64-bit struct layout */
48 BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00);
49 BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c);
50
51 if (kvm->arch.xen.long_mode) {
52 wc_ofs = offsetof(struct shared_info, wc);
53 sec_hi_ofs = offsetof(struct shared_info, wc_sec_hi);
54 }
55 #endif
56
57 kvm_write_wall_clock(kvm, gpa + wc_ofs, sec_hi_ofs - wc_ofs);
58 kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE);
59
60 out:
61 srcu_read_unlock(&kvm->srcu, idx);
62 return ret;
63 }
64
kvm_xen_update_runstate(struct kvm_vcpu * v,int state)65 static void kvm_xen_update_runstate(struct kvm_vcpu *v, int state)
66 {
67 struct kvm_vcpu_xen *vx = &v->arch.xen;
68 u64 now = get_kvmclock_ns(v->kvm);
69 u64 delta_ns = now - vx->runstate_entry_time;
70 u64 run_delay = current->sched_info.run_delay;
71
72 if (unlikely(!vx->runstate_entry_time))
73 vx->current_runstate = RUNSTATE_offline;
74
75 /*
76 * Time waiting for the scheduler isn't "stolen" if the
77 * vCPU wasn't running anyway.
78 */
79 if (vx->current_runstate == RUNSTATE_running) {
80 u64 steal_ns = run_delay - vx->last_steal;
81
82 delta_ns -= steal_ns;
83
84 vx->runstate_times[RUNSTATE_runnable] += steal_ns;
85 }
86 vx->last_steal = run_delay;
87
88 vx->runstate_times[vx->current_runstate] += delta_ns;
89 vx->current_runstate = state;
90 vx->runstate_entry_time = now;
91 }
92
kvm_xen_update_runstate_guest(struct kvm_vcpu * v,int state)93 void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
94 {
95 struct kvm_vcpu_xen *vx = &v->arch.xen;
96 uint64_t state_entry_time;
97 unsigned int offset;
98
99 kvm_xen_update_runstate(v, state);
100
101 if (!vx->runstate_set)
102 return;
103
104 BUILD_BUG_ON(sizeof(struct compat_vcpu_runstate_info) != 0x2c);
105
106 offset = offsetof(struct compat_vcpu_runstate_info, state_entry_time);
107 #ifdef CONFIG_X86_64
108 /*
109 * The only difference is alignment of uint64_t in 32-bit.
110 * So the first field 'state' is accessed directly using
111 * offsetof() (where its offset happens to be zero), while the
112 * remaining fields which are all uint64_t, start at 'offset'
113 * which we tweak here by adding 4.
114 */
115 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
116 offsetof(struct compat_vcpu_runstate_info, state_entry_time) + 4);
117 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, time) !=
118 offsetof(struct compat_vcpu_runstate_info, time) + 4);
119
120 if (v->kvm->arch.xen.long_mode)
121 offset = offsetof(struct vcpu_runstate_info, state_entry_time);
122 #endif
123 /*
124 * First write the updated state_entry_time at the appropriate
125 * location determined by 'offset'.
126 */
127 state_entry_time = vx->runstate_entry_time;
128 state_entry_time |= XEN_RUNSTATE_UPDATE;
129
130 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state_entry_time) !=
131 sizeof(state_entry_time));
132 BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state_entry_time) !=
133 sizeof(state_entry_time));
134
135 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
136 &state_entry_time, offset,
137 sizeof(state_entry_time)))
138 return;
139 smp_wmb();
140
141 /*
142 * Next, write the new runstate. This is in the *same* place
143 * for 32-bit and 64-bit guests, asserted here for paranoia.
144 */
145 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state) !=
146 offsetof(struct compat_vcpu_runstate_info, state));
147 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->state) !=
148 sizeof(vx->current_runstate));
149 BUILD_BUG_ON(sizeof(((struct compat_vcpu_runstate_info *)0)->state) !=
150 sizeof(vx->current_runstate));
151
152 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
153 &vx->current_runstate,
154 offsetof(struct vcpu_runstate_info, state),
155 sizeof(vx->current_runstate)))
156 return;
157
158 /*
159 * Write the actual runstate times immediately after the
160 * runstate_entry_time.
161 */
162 BUILD_BUG_ON(offsetof(struct vcpu_runstate_info, state_entry_time) !=
163 offsetof(struct vcpu_runstate_info, time) - sizeof(u64));
164 BUILD_BUG_ON(offsetof(struct compat_vcpu_runstate_info, state_entry_time) !=
165 offsetof(struct compat_vcpu_runstate_info, time) - sizeof(u64));
166 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) !=
167 sizeof(((struct compat_vcpu_runstate_info *)0)->time));
168 BUILD_BUG_ON(sizeof(((struct vcpu_runstate_info *)0)->time) !=
169 sizeof(vx->runstate_times));
170
171 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
172 &vx->runstate_times[0],
173 offset + sizeof(u64),
174 sizeof(vx->runstate_times)))
175 return;
176
177 smp_wmb();
178
179 /*
180 * Finally, clear the XEN_RUNSTATE_UPDATE bit in the guest's
181 * runstate_entry_time field.
182 */
183
184 state_entry_time &= ~XEN_RUNSTATE_UPDATE;
185 if (kvm_write_guest_offset_cached(v->kvm, &v->arch.xen.runstate_cache,
186 &state_entry_time, offset,
187 sizeof(state_entry_time)))
188 return;
189 }
190
__kvm_xen_has_interrupt(struct kvm_vcpu * v)191 int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
192 {
193 int err;
194 u8 rc = 0;
195
196 /*
197 * If the global upcall vector (HVMIRQ_callback_vector) is set and
198 * the vCPU's evtchn_upcall_pending flag is set, the IRQ is pending.
199 */
200 struct gfn_to_hva_cache *ghc = &v->arch.xen.vcpu_info_cache;
201 struct kvm_memslots *slots = kvm_memslots(v->kvm);
202 unsigned int offset = offsetof(struct vcpu_info, evtchn_upcall_pending);
203
204 /* No need for compat handling here */
205 BUILD_BUG_ON(offsetof(struct vcpu_info, evtchn_upcall_pending) !=
206 offsetof(struct compat_vcpu_info, evtchn_upcall_pending));
207 BUILD_BUG_ON(sizeof(rc) !=
208 sizeof(((struct vcpu_info *)0)->evtchn_upcall_pending));
209 BUILD_BUG_ON(sizeof(rc) !=
210 sizeof(((struct compat_vcpu_info *)0)->evtchn_upcall_pending));
211
212 /*
213 * For efficiency, this mirrors the checks for using the valid
214 * cache in kvm_read_guest_offset_cached(), but just uses
215 * __get_user() instead. And falls back to the slow path.
216 */
217 if (likely(slots->generation == ghc->generation &&
218 !kvm_is_error_hva(ghc->hva) && ghc->memslot)) {
219 /* Fast path */
220 pagefault_disable();
221 err = __get_user(rc, (u8 __user *)ghc->hva + offset);
222 pagefault_enable();
223 if (!err)
224 return rc;
225 }
226
227 /* Slow path */
228
229 /*
230 * This function gets called from kvm_vcpu_block() after setting the
231 * task to TASK_INTERRUPTIBLE, to see if it needs to wake immediately
232 * from a HLT. So we really mustn't sleep. If the page ended up absent
233 * at that point, just return 1 in order to trigger an immediate wake,
234 * and we'll end up getting called again from a context where we *can*
235 * fault in the page and wait for it.
236 */
237 if (in_atomic() || !task_is_running(current))
238 return 1;
239
240 kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset,
241 sizeof(rc));
242
243 return rc;
244 }
245
kvm_xen_hvm_set_attr(struct kvm * kvm,struct kvm_xen_hvm_attr * data)246 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
247 {
248 int r = -ENOENT;
249
250 mutex_lock(&kvm->lock);
251
252 switch (data->type) {
253 case KVM_XEN_ATTR_TYPE_LONG_MODE:
254 if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) {
255 r = -EINVAL;
256 } else {
257 kvm->arch.xen.long_mode = !!data->u.long_mode;
258 r = 0;
259 }
260 break;
261
262 case KVM_XEN_ATTR_TYPE_SHARED_INFO:
263 if (data->u.shared_info.gfn == GPA_INVALID) {
264 kvm->arch.xen.shinfo_gfn = GPA_INVALID;
265 r = 0;
266 break;
267 }
268 r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
269 break;
270
271
272 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
273 if (data->u.vector && data->u.vector < 0x10)
274 r = -EINVAL;
275 else {
276 kvm->arch.xen.upcall_vector = data->u.vector;
277 r = 0;
278 }
279 break;
280
281 default:
282 break;
283 }
284
285 mutex_unlock(&kvm->lock);
286 return r;
287 }
288
kvm_xen_hvm_get_attr(struct kvm * kvm,struct kvm_xen_hvm_attr * data)289 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
290 {
291 int r = -ENOENT;
292
293 mutex_lock(&kvm->lock);
294
295 switch (data->type) {
296 case KVM_XEN_ATTR_TYPE_LONG_MODE:
297 data->u.long_mode = kvm->arch.xen.long_mode;
298 r = 0;
299 break;
300
301 case KVM_XEN_ATTR_TYPE_SHARED_INFO:
302 data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_gfn);
303 r = 0;
304 break;
305
306 case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
307 data->u.vector = kvm->arch.xen.upcall_vector;
308 r = 0;
309 break;
310
311 default:
312 break;
313 }
314
315 mutex_unlock(&kvm->lock);
316 return r;
317 }
318
kvm_xen_vcpu_set_attr(struct kvm_vcpu * vcpu,struct kvm_xen_vcpu_attr * data)319 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
320 {
321 int idx, r = -ENOENT;
322
323 mutex_lock(&vcpu->kvm->lock);
324 idx = srcu_read_lock(&vcpu->kvm->srcu);
325
326 switch (data->type) {
327 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
328 /* No compat necessary here. */
329 BUILD_BUG_ON(sizeof(struct vcpu_info) !=
330 sizeof(struct compat_vcpu_info));
331 BUILD_BUG_ON(offsetof(struct vcpu_info, time) !=
332 offsetof(struct compat_vcpu_info, time));
333
334 if (data->u.gpa == GPA_INVALID) {
335 vcpu->arch.xen.vcpu_info_set = false;
336 r = 0;
337 break;
338 }
339
340 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
341 &vcpu->arch.xen.vcpu_info_cache,
342 data->u.gpa,
343 sizeof(struct vcpu_info));
344 if (!r) {
345 vcpu->arch.xen.vcpu_info_set = true;
346 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
347 }
348 break;
349
350 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
351 if (data->u.gpa == GPA_INVALID) {
352 vcpu->arch.xen.vcpu_time_info_set = false;
353 r = 0;
354 break;
355 }
356
357 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
358 &vcpu->arch.xen.vcpu_time_info_cache,
359 data->u.gpa,
360 sizeof(struct pvclock_vcpu_time_info));
361 if (!r) {
362 vcpu->arch.xen.vcpu_time_info_set = true;
363 kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
364 }
365 break;
366
367 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
368 if (!sched_info_on()) {
369 r = -EOPNOTSUPP;
370 break;
371 }
372 if (data->u.gpa == GPA_INVALID) {
373 vcpu->arch.xen.runstate_set = false;
374 r = 0;
375 break;
376 }
377
378 r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
379 &vcpu->arch.xen.runstate_cache,
380 data->u.gpa,
381 sizeof(struct vcpu_runstate_info));
382 if (!r) {
383 vcpu->arch.xen.runstate_set = true;
384 }
385 break;
386
387 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
388 if (!sched_info_on()) {
389 r = -EOPNOTSUPP;
390 break;
391 }
392 if (data->u.runstate.state > RUNSTATE_offline) {
393 r = -EINVAL;
394 break;
395 }
396
397 kvm_xen_update_runstate(vcpu, data->u.runstate.state);
398 r = 0;
399 break;
400
401 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
402 if (!sched_info_on()) {
403 r = -EOPNOTSUPP;
404 break;
405 }
406 if (data->u.runstate.state > RUNSTATE_offline) {
407 r = -EINVAL;
408 break;
409 }
410 if (data->u.runstate.state_entry_time !=
411 (data->u.runstate.time_running +
412 data->u.runstate.time_runnable +
413 data->u.runstate.time_blocked +
414 data->u.runstate.time_offline)) {
415 r = -EINVAL;
416 break;
417 }
418 if (get_kvmclock_ns(vcpu->kvm) <
419 data->u.runstate.state_entry_time) {
420 r = -EINVAL;
421 break;
422 }
423
424 vcpu->arch.xen.current_runstate = data->u.runstate.state;
425 vcpu->arch.xen.runstate_entry_time =
426 data->u.runstate.state_entry_time;
427 vcpu->arch.xen.runstate_times[RUNSTATE_running] =
428 data->u.runstate.time_running;
429 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] =
430 data->u.runstate.time_runnable;
431 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] =
432 data->u.runstate.time_blocked;
433 vcpu->arch.xen.runstate_times[RUNSTATE_offline] =
434 data->u.runstate.time_offline;
435 vcpu->arch.xen.last_steal = current->sched_info.run_delay;
436 r = 0;
437 break;
438
439 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
440 if (!sched_info_on()) {
441 r = -EOPNOTSUPP;
442 break;
443 }
444 if (data->u.runstate.state > RUNSTATE_offline &&
445 data->u.runstate.state != (u64)-1) {
446 r = -EINVAL;
447 break;
448 }
449 /* The adjustment must add up */
450 if (data->u.runstate.state_entry_time !=
451 (data->u.runstate.time_running +
452 data->u.runstate.time_runnable +
453 data->u.runstate.time_blocked +
454 data->u.runstate.time_offline)) {
455 r = -EINVAL;
456 break;
457 }
458
459 if (get_kvmclock_ns(vcpu->kvm) <
460 (vcpu->arch.xen.runstate_entry_time +
461 data->u.runstate.state_entry_time)) {
462 r = -EINVAL;
463 break;
464 }
465
466 vcpu->arch.xen.runstate_entry_time +=
467 data->u.runstate.state_entry_time;
468 vcpu->arch.xen.runstate_times[RUNSTATE_running] +=
469 data->u.runstate.time_running;
470 vcpu->arch.xen.runstate_times[RUNSTATE_runnable] +=
471 data->u.runstate.time_runnable;
472 vcpu->arch.xen.runstate_times[RUNSTATE_blocked] +=
473 data->u.runstate.time_blocked;
474 vcpu->arch.xen.runstate_times[RUNSTATE_offline] +=
475 data->u.runstate.time_offline;
476
477 if (data->u.runstate.state <= RUNSTATE_offline)
478 kvm_xen_update_runstate(vcpu, data->u.runstate.state);
479 r = 0;
480 break;
481
482 default:
483 break;
484 }
485
486 srcu_read_unlock(&vcpu->kvm->srcu, idx);
487 mutex_unlock(&vcpu->kvm->lock);
488 return r;
489 }
490
kvm_xen_vcpu_get_attr(struct kvm_vcpu * vcpu,struct kvm_xen_vcpu_attr * data)491 int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
492 {
493 int r = -ENOENT;
494
495 mutex_lock(&vcpu->kvm->lock);
496
497 switch (data->type) {
498 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
499 if (vcpu->arch.xen.vcpu_info_set)
500 data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa;
501 else
502 data->u.gpa = GPA_INVALID;
503 r = 0;
504 break;
505
506 case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
507 if (vcpu->arch.xen.vcpu_time_info_set)
508 data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa;
509 else
510 data->u.gpa = GPA_INVALID;
511 r = 0;
512 break;
513
514 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR:
515 if (!sched_info_on()) {
516 r = -EOPNOTSUPP;
517 break;
518 }
519 if (vcpu->arch.xen.runstate_set) {
520 data->u.gpa = vcpu->arch.xen.runstate_cache.gpa;
521 r = 0;
522 }
523 break;
524
525 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT:
526 if (!sched_info_on()) {
527 r = -EOPNOTSUPP;
528 break;
529 }
530 data->u.runstate.state = vcpu->arch.xen.current_runstate;
531 r = 0;
532 break;
533
534 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA:
535 if (!sched_info_on()) {
536 r = -EOPNOTSUPP;
537 break;
538 }
539 data->u.runstate.state = vcpu->arch.xen.current_runstate;
540 data->u.runstate.state_entry_time =
541 vcpu->arch.xen.runstate_entry_time;
542 data->u.runstate.time_running =
543 vcpu->arch.xen.runstate_times[RUNSTATE_running];
544 data->u.runstate.time_runnable =
545 vcpu->arch.xen.runstate_times[RUNSTATE_runnable];
546 data->u.runstate.time_blocked =
547 vcpu->arch.xen.runstate_times[RUNSTATE_blocked];
548 data->u.runstate.time_offline =
549 vcpu->arch.xen.runstate_times[RUNSTATE_offline];
550 r = 0;
551 break;
552
553 case KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST:
554 r = -EINVAL;
555 break;
556
557 default:
558 break;
559 }
560
561 mutex_unlock(&vcpu->kvm->lock);
562 return r;
563 }
564
kvm_xen_write_hypercall_page(struct kvm_vcpu * vcpu,u64 data)565 int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
566 {
567 struct kvm *kvm = vcpu->kvm;
568 u32 page_num = data & ~PAGE_MASK;
569 u64 page_addr = data & PAGE_MASK;
570 bool lm = is_long_mode(vcpu);
571
572 /* Latch long_mode for shared_info pages etc. */
573 vcpu->kvm->arch.xen.long_mode = lm;
574
575 /*
576 * If Xen hypercall intercept is enabled, fill the hypercall
577 * page with VMCALL/VMMCALL instructions since that's what
578 * we catch. Else the VMM has provided the hypercall pages
579 * with instructions of its own choosing, so use those.
580 */
581 if (kvm_xen_hypercall_enabled(kvm)) {
582 u8 instructions[32];
583 int i;
584
585 if (page_num)
586 return 1;
587
588 /* mov imm32, %eax */
589 instructions[0] = 0xb8;
590
591 /* vmcall / vmmcall */
592 kvm_x86_ops.patch_hypercall(vcpu, instructions + 5);
593
594 /* ret */
595 instructions[8] = 0xc3;
596
597 /* int3 to pad */
598 memset(instructions + 9, 0xcc, sizeof(instructions) - 9);
599
600 for (i = 0; i < PAGE_SIZE / sizeof(instructions); i++) {
601 *(u32 *)&instructions[1] = i;
602 if (kvm_vcpu_write_guest(vcpu,
603 page_addr + (i * sizeof(instructions)),
604 instructions, sizeof(instructions)))
605 return 1;
606 }
607 } else {
608 /*
609 * Note, truncation is a non-issue as 'lm' is guaranteed to be
610 * false for a 32-bit kernel, i.e. when hva_t is only 4 bytes.
611 */
612 hva_t blob_addr = lm ? kvm->arch.xen_hvm_config.blob_addr_64
613 : kvm->arch.xen_hvm_config.blob_addr_32;
614 u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
615 : kvm->arch.xen_hvm_config.blob_size_32;
616 u8 *page;
617
618 if (page_num >= blob_size)
619 return 1;
620
621 blob_addr += page_num * PAGE_SIZE;
622
623 page = memdup_user((u8 __user *)blob_addr, PAGE_SIZE);
624 if (IS_ERR(page))
625 return PTR_ERR(page);
626
627 if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE)) {
628 kfree(page);
629 return 1;
630 }
631 }
632 return 0;
633 }
634
kvm_xen_hvm_config(struct kvm * kvm,struct kvm_xen_hvm_config * xhc)635 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc)
636 {
637 if (xhc->flags & ~KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL)
638 return -EINVAL;
639
640 /*
641 * With hypercall interception the kernel generates its own
642 * hypercall page so it must not be provided.
643 */
644 if ((xhc->flags & KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL) &&
645 (xhc->blob_addr_32 || xhc->blob_addr_64 ||
646 xhc->blob_size_32 || xhc->blob_size_64))
647 return -EINVAL;
648
649 mutex_lock(&kvm->lock);
650
651 if (xhc->msr && !kvm->arch.xen_hvm_config.msr)
652 static_branch_inc(&kvm_xen_enabled.key);
653 else if (!xhc->msr && kvm->arch.xen_hvm_config.msr)
654 static_branch_slow_dec_deferred(&kvm_xen_enabled);
655
656 memcpy(&kvm->arch.xen_hvm_config, xhc, sizeof(*xhc));
657
658 mutex_unlock(&kvm->lock);
659 return 0;
660 }
661
kvm_xen_init_vm(struct kvm * kvm)662 void kvm_xen_init_vm(struct kvm *kvm)
663 {
664 kvm->arch.xen.shinfo_gfn = GPA_INVALID;
665 }
666
kvm_xen_destroy_vm(struct kvm * kvm)667 void kvm_xen_destroy_vm(struct kvm *kvm)
668 {
669 if (kvm->arch.xen_hvm_config.msr)
670 static_branch_slow_dec_deferred(&kvm_xen_enabled);
671 }
672
kvm_xen_hypercall_set_result(struct kvm_vcpu * vcpu,u64 result)673 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
674 {
675 kvm_rax_write(vcpu, result);
676 return kvm_skip_emulated_instruction(vcpu);
677 }
678
kvm_xen_hypercall_complete_userspace(struct kvm_vcpu * vcpu)679 static int kvm_xen_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
680 {
681 struct kvm_run *run = vcpu->run;
682
683 if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.xen.hypercall_rip)))
684 return 1;
685
686 return kvm_xen_hypercall_set_result(vcpu, run->xen.u.hcall.result);
687 }
688
kvm_xen_hypercall(struct kvm_vcpu * vcpu)689 int kvm_xen_hypercall(struct kvm_vcpu *vcpu)
690 {
691 bool longmode;
692 u64 input, params[6];
693
694 input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX);
695
696 /* Hyper-V hypercalls get bit 31 set in EAX */
697 if ((input & 0x80000000) &&
698 kvm_hv_hypercall_enabled(vcpu))
699 return kvm_hv_hypercall(vcpu);
700
701 longmode = is_64_bit_mode(vcpu);
702 if (!longmode) {
703 params[0] = (u32)kvm_rbx_read(vcpu);
704 params[1] = (u32)kvm_rcx_read(vcpu);
705 params[2] = (u32)kvm_rdx_read(vcpu);
706 params[3] = (u32)kvm_rsi_read(vcpu);
707 params[4] = (u32)kvm_rdi_read(vcpu);
708 params[5] = (u32)kvm_rbp_read(vcpu);
709 }
710 #ifdef CONFIG_X86_64
711 else {
712 params[0] = (u64)kvm_rdi_read(vcpu);
713 params[1] = (u64)kvm_rsi_read(vcpu);
714 params[2] = (u64)kvm_rdx_read(vcpu);
715 params[3] = (u64)kvm_r10_read(vcpu);
716 params[4] = (u64)kvm_r8_read(vcpu);
717 params[5] = (u64)kvm_r9_read(vcpu);
718 }
719 #endif
720 trace_kvm_xen_hypercall(input, params[0], params[1], params[2],
721 params[3], params[4], params[5]);
722
723 vcpu->run->exit_reason = KVM_EXIT_XEN;
724 vcpu->run->xen.type = KVM_EXIT_XEN_HCALL;
725 vcpu->run->xen.u.hcall.longmode = longmode;
726 vcpu->run->xen.u.hcall.cpl = kvm_x86_ops.get_cpl(vcpu);
727 vcpu->run->xen.u.hcall.input = input;
728 vcpu->run->xen.u.hcall.params[0] = params[0];
729 vcpu->run->xen.u.hcall.params[1] = params[1];
730 vcpu->run->xen.u.hcall.params[2] = params[2];
731 vcpu->run->xen.u.hcall.params[3] = params[3];
732 vcpu->run->xen.u.hcall.params[4] = params[4];
733 vcpu->run->xen.u.hcall.params[5] = params[5];
734 vcpu->arch.xen.hypercall_rip = kvm_get_linear_rip(vcpu);
735 vcpu->arch.complete_userspace_io =
736 kvm_xen_hypercall_complete_userspace;
737
738 return 0;
739 }
740
