Linux 6.9-rc1
[linux-2.6-microblaze.git] / arch / x86 / kvm / svm / avic.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Kernel-based Virtual Machine driver for Linux
4  *
5  * AMD SVM support
6  *
7  * Copyright (C) 2006 Qumranet, Inc.
8  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
9  *
10  * Authors:
11  *   Yaniv Kamay  <yaniv@qumranet.com>
12  *   Avi Kivity   <avi@qumranet.com>
13  */
14
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16
17 #include <linux/kvm_types.h>
18 #include <linux/hashtable.h>
19 #include <linux/amd-iommu.h>
20 #include <linux/kvm_host.h>
21
22 #include <asm/irq_remapping.h>
23
24 #include "trace.h"
25 #include "lapic.h"
26 #include "x86.h"
27 #include "irq.h"
28 #include "svm.h"
29
30 /*
31  * Encode the arbitrary VM ID and the vCPU's default APIC ID, i.e the vCPU ID,
32  * into the GATag so that KVM can retrieve the correct vCPU from a GALog entry
33  * if an interrupt can't be delivered, e.g. because the vCPU isn't running.
34  *
35  * For the vCPU ID, use however many bits are currently allowed for the max
36  * guest physical APIC ID (limited by the size of the physical ID table), and
37  * use whatever bits remain to assign arbitrary AVIC IDs to VMs.  Note, the
38  * size of the GATag is defined by hardware (32 bits), but is an opaque value
39  * as far as hardware is concerned.
40  */
41 #define AVIC_VCPU_ID_MASK               AVIC_PHYSICAL_MAX_INDEX_MASK
42
43 #define AVIC_VM_ID_SHIFT                HWEIGHT32(AVIC_PHYSICAL_MAX_INDEX_MASK)
44 #define AVIC_VM_ID_MASK                 (GENMASK(31, AVIC_VM_ID_SHIFT) >> AVIC_VM_ID_SHIFT)
45
46 #define AVIC_GATAG_TO_VMID(x)           ((x >> AVIC_VM_ID_SHIFT) & AVIC_VM_ID_MASK)
47 #define AVIC_GATAG_TO_VCPUID(x)         (x & AVIC_VCPU_ID_MASK)
48
49 #define __AVIC_GATAG(vm_id, vcpu_id)    ((((vm_id) & AVIC_VM_ID_MASK) << AVIC_VM_ID_SHIFT) | \
50                                          ((vcpu_id) & AVIC_VCPU_ID_MASK))
51 #define AVIC_GATAG(vm_id, vcpu_id)                                      \
52 ({                                                                      \
53         u32 ga_tag = __AVIC_GATAG(vm_id, vcpu_id);                      \
54                                                                         \
55         WARN_ON_ONCE(AVIC_GATAG_TO_VCPUID(ga_tag) != (vcpu_id));        \
56         WARN_ON_ONCE(AVIC_GATAG_TO_VMID(ga_tag) != (vm_id));            \
57         ga_tag;                                                         \
58 })
59
60 static_assert(__AVIC_GATAG(AVIC_VM_ID_MASK, AVIC_VCPU_ID_MASK) == -1u);
61
62 static bool force_avic;
63 module_param_unsafe(force_avic, bool, 0444);
64
65 /* Note:
66  * This hash table is used to map VM_ID to a struct kvm_svm,
67  * when handling AMD IOMMU GALOG notification to schedule in
68  * a particular vCPU.
69  */
70 #define SVM_VM_DATA_HASH_BITS   8
71 static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS);
72 static u32 next_vm_id = 0;
73 static bool next_vm_id_wrapped = 0;
74 static DEFINE_SPINLOCK(svm_vm_data_hash_lock);
75 bool x2avic_enabled;
76
77 /*
78  * This is a wrapper of struct amd_iommu_ir_data.
79  */
80 struct amd_svm_iommu_ir {
81         struct list_head node;  /* Used by SVM for per-vcpu ir_list */
82         void *data;             /* Storing pointer to struct amd_ir_data */
83 };
84
85 static void avic_activate_vmcb(struct vcpu_svm *svm)
86 {
87         struct vmcb *vmcb = svm->vmcb01.ptr;
88
89         vmcb->control.int_ctl &= ~(AVIC_ENABLE_MASK | X2APIC_MODE_MASK);
90         vmcb->control.avic_physical_id &= ~AVIC_PHYSICAL_MAX_INDEX_MASK;
91
92         vmcb->control.int_ctl |= AVIC_ENABLE_MASK;
93
94         /*
95          * Note: KVM supports hybrid-AVIC mode, where KVM emulates x2APIC MSR
96          * accesses, while interrupt injection to a running vCPU can be
97          * achieved using AVIC doorbell.  KVM disables the APIC access page
98          * (deletes the memslot) if any vCPU has x2APIC enabled, thus enabling
99          * AVIC in hybrid mode activates only the doorbell mechanism.
100          */
101         if (x2avic_enabled && apic_x2apic_mode(svm->vcpu.arch.apic)) {
102                 vmcb->control.int_ctl |= X2APIC_MODE_MASK;
103                 vmcb->control.avic_physical_id |= X2AVIC_MAX_PHYSICAL_ID;
104                 /* Disabling MSR intercept for x2APIC registers */
105                 svm_set_x2apic_msr_interception(svm, false);
106         } else {
107                 /*
108                  * Flush the TLB, the guest may have inserted a non-APIC
109                  * mapping into the TLB while AVIC was disabled.
110                  */
111                 kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, &svm->vcpu);
112
113                 /* For xAVIC and hybrid-xAVIC modes */
114                 vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID;
115                 /* Enabling MSR intercept for x2APIC registers */
116                 svm_set_x2apic_msr_interception(svm, true);
117         }
118 }
119
120 static void avic_deactivate_vmcb(struct vcpu_svm *svm)
121 {
122         struct vmcb *vmcb = svm->vmcb01.ptr;
123
124         vmcb->control.int_ctl &= ~(AVIC_ENABLE_MASK | X2APIC_MODE_MASK);
125         vmcb->control.avic_physical_id &= ~AVIC_PHYSICAL_MAX_INDEX_MASK;
126
127         /*
128          * If running nested and the guest uses its own MSR bitmap, there
129          * is no need to update L0's msr bitmap
130          */
131         if (is_guest_mode(&svm->vcpu) &&
132             vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT))
133                 return;
134
135         /* Enabling MSR intercept for x2APIC registers */
136         svm_set_x2apic_msr_interception(svm, true);
137 }
138
139 /* Note:
140  * This function is called from IOMMU driver to notify
141  * SVM to schedule in a particular vCPU of a particular VM.
142  */
143 int avic_ga_log_notifier(u32 ga_tag)
144 {
145         unsigned long flags;
146         struct kvm_svm *kvm_svm;
147         struct kvm_vcpu *vcpu = NULL;
148         u32 vm_id = AVIC_GATAG_TO_VMID(ga_tag);
149         u32 vcpu_id = AVIC_GATAG_TO_VCPUID(ga_tag);
150
151         pr_debug("SVM: %s: vm_id=%#x, vcpu_id=%#x\n", __func__, vm_id, vcpu_id);
152         trace_kvm_avic_ga_log(vm_id, vcpu_id);
153
154         spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
155         hash_for_each_possible(svm_vm_data_hash, kvm_svm, hnode, vm_id) {
156                 if (kvm_svm->avic_vm_id != vm_id)
157                         continue;
158                 vcpu = kvm_get_vcpu_by_id(&kvm_svm->kvm, vcpu_id);
159                 break;
160         }
161         spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);
162
163         /* Note:
164          * At this point, the IOMMU should have already set the pending
165          * bit in the vAPIC backing page. So, we just need to schedule
166          * in the vcpu.
167          */
168         if (vcpu)
169                 kvm_vcpu_wake_up(vcpu);
170
171         return 0;
172 }
173
174 void avic_vm_destroy(struct kvm *kvm)
175 {
176         unsigned long flags;
177         struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
178
179         if (!enable_apicv)
180                 return;
181
182         if (kvm_svm->avic_logical_id_table_page)
183                 __free_page(kvm_svm->avic_logical_id_table_page);
184         if (kvm_svm->avic_physical_id_table_page)
185                 __free_page(kvm_svm->avic_physical_id_table_page);
186
187         spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
188         hash_del(&kvm_svm->hnode);
189         spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);
190 }
191
192 int avic_vm_init(struct kvm *kvm)
193 {
194         unsigned long flags;
195         int err = -ENOMEM;
196         struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
197         struct kvm_svm *k2;
198         struct page *p_page;
199         struct page *l_page;
200         u32 vm_id;
201
202         if (!enable_apicv)
203                 return 0;
204
205         /* Allocating physical APIC ID table (4KB) */
206         p_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
207         if (!p_page)
208                 goto free_avic;
209
210         kvm_svm->avic_physical_id_table_page = p_page;
211
212         /* Allocating logical APIC ID table (4KB) */
213         l_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
214         if (!l_page)
215                 goto free_avic;
216
217         kvm_svm->avic_logical_id_table_page = l_page;
218
219         spin_lock_irqsave(&svm_vm_data_hash_lock, flags);
220  again:
221         vm_id = next_vm_id = (next_vm_id + 1) & AVIC_VM_ID_MASK;
222         if (vm_id == 0) { /* id is 1-based, zero is not okay */
223                 next_vm_id_wrapped = 1;
224                 goto again;
225         }
226         /* Is it still in use? Only possible if wrapped at least once */
227         if (next_vm_id_wrapped) {
228                 hash_for_each_possible(svm_vm_data_hash, k2, hnode, vm_id) {
229                         if (k2->avic_vm_id == vm_id)
230                                 goto again;
231                 }
232         }
233         kvm_svm->avic_vm_id = vm_id;
234         hash_add(svm_vm_data_hash, &kvm_svm->hnode, kvm_svm->avic_vm_id);
235         spin_unlock_irqrestore(&svm_vm_data_hash_lock, flags);
236
237         return 0;
238
239 free_avic:
240         avic_vm_destroy(kvm);
241         return err;
242 }
243
244 void avic_init_vmcb(struct vcpu_svm *svm, struct vmcb *vmcb)
245 {
246         struct kvm_svm *kvm_svm = to_kvm_svm(svm->vcpu.kvm);
247         phys_addr_t bpa = __sme_set(page_to_phys(svm->avic_backing_page));
248         phys_addr_t lpa = __sme_set(page_to_phys(kvm_svm->avic_logical_id_table_page));
249         phys_addr_t ppa = __sme_set(page_to_phys(kvm_svm->avic_physical_id_table_page));
250
251         vmcb->control.avic_backing_page = bpa & AVIC_HPA_MASK;
252         vmcb->control.avic_logical_id = lpa & AVIC_HPA_MASK;
253         vmcb->control.avic_physical_id = ppa & AVIC_HPA_MASK;
254         vmcb->control.avic_vapic_bar = APIC_DEFAULT_PHYS_BASE & VMCB_AVIC_APIC_BAR_MASK;
255
256         if (kvm_apicv_activated(svm->vcpu.kvm))
257                 avic_activate_vmcb(svm);
258         else
259                 avic_deactivate_vmcb(svm);
260 }
261
262 static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu,
263                                        unsigned int index)
264 {
265         u64 *avic_physical_id_table;
266         struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm);
267
268         if ((!x2avic_enabled && index > AVIC_MAX_PHYSICAL_ID) ||
269             (index > X2AVIC_MAX_PHYSICAL_ID))
270                 return NULL;
271
272         avic_physical_id_table = page_address(kvm_svm->avic_physical_id_table_page);
273
274         return &avic_physical_id_table[index];
275 }
276
277 static int avic_init_backing_page(struct kvm_vcpu *vcpu)
278 {
279         u64 *entry, new_entry;
280         int id = vcpu->vcpu_id;
281         struct vcpu_svm *svm = to_svm(vcpu);
282
283         if ((!x2avic_enabled && id > AVIC_MAX_PHYSICAL_ID) ||
284             (id > X2AVIC_MAX_PHYSICAL_ID))
285                 return -EINVAL;
286
287         if (!vcpu->arch.apic->regs)
288                 return -EINVAL;
289
290         if (kvm_apicv_activated(vcpu->kvm)) {
291                 int ret;
292
293                 /*
294                  * Note, AVIC hardware walks the nested page table to check
295                  * permissions, but does not use the SPA address specified in
296                  * the leaf SPTE since it uses address in the AVIC_BACKING_PAGE
297                  * pointer field of the VMCB.
298                  */
299                 ret = kvm_alloc_apic_access_page(vcpu->kvm);
300                 if (ret)
301                         return ret;
302         }
303
304         svm->avic_backing_page = virt_to_page(vcpu->arch.apic->regs);
305
306         /* Setting AVIC backing page address in the phy APIC ID table */
307         entry = avic_get_physical_id_entry(vcpu, id);
308         if (!entry)
309                 return -EINVAL;
310
311         new_entry = __sme_set((page_to_phys(svm->avic_backing_page) &
312                               AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK) |
313                               AVIC_PHYSICAL_ID_ENTRY_VALID_MASK);
314         WRITE_ONCE(*entry, new_entry);
315
316         svm->avic_physical_id_cache = entry;
317
318         return 0;
319 }
320
321 void avic_ring_doorbell(struct kvm_vcpu *vcpu)
322 {
323         /*
324          * Note, the vCPU could get migrated to a different pCPU at any point,
325          * which could result in signalling the wrong/previous pCPU.  But if
326          * that happens the vCPU is guaranteed to do a VMRUN (after being
327          * migrated) and thus will process pending interrupts, i.e. a doorbell
328          * is not needed (and the spurious one is harmless).
329          */
330         int cpu = READ_ONCE(vcpu->cpu);
331
332         if (cpu != get_cpu()) {
333                 wrmsrl(MSR_AMD64_SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu));
334                 trace_kvm_avic_doorbell(vcpu->vcpu_id, kvm_cpu_get_apicid(cpu));
335         }
336         put_cpu();
337 }
338
339
340 static void avic_kick_vcpu(struct kvm_vcpu *vcpu, u32 icrl)
341 {
342         vcpu->arch.apic->irr_pending = true;
343         svm_complete_interrupt_delivery(vcpu,
344                                         icrl & APIC_MODE_MASK,
345                                         icrl & APIC_INT_LEVELTRIG,
346                                         icrl & APIC_VECTOR_MASK);
347 }
348
349 static void avic_kick_vcpu_by_physical_id(struct kvm *kvm, u32 physical_id,
350                                           u32 icrl)
351 {
352         /*
353          * KVM inhibits AVIC if any vCPU ID diverges from the vCPUs APIC ID,
354          * i.e. APIC ID == vCPU ID.
355          */
356         struct kvm_vcpu *target_vcpu = kvm_get_vcpu_by_id(kvm, physical_id);
357
358         /* Once again, nothing to do if the target vCPU doesn't exist. */
359         if (unlikely(!target_vcpu))
360                 return;
361
362         avic_kick_vcpu(target_vcpu, icrl);
363 }
364
365 static void avic_kick_vcpu_by_logical_id(struct kvm *kvm, u32 *avic_logical_id_table,
366                                          u32 logid_index, u32 icrl)
367 {
368         u32 physical_id;
369
370         if (avic_logical_id_table) {
371                 u32 logid_entry = avic_logical_id_table[logid_index];
372
373                 /* Nothing to do if the logical destination is invalid. */
374                 if (unlikely(!(logid_entry & AVIC_LOGICAL_ID_ENTRY_VALID_MASK)))
375                         return;
376
377                 physical_id = logid_entry &
378                               AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK;
379         } else {
380                 /*
381                  * For x2APIC, the logical APIC ID is a read-only value that is
382                  * derived from the x2APIC ID, thus the x2APIC ID can be found
383                  * by reversing the calculation (stored in logid_index).  Note,
384                  * bits 31:20 of the x2APIC ID aren't propagated to the logical
385                  * ID, but KVM limits the x2APIC ID limited to KVM_MAX_VCPU_IDS.
386                  */
387                 physical_id = logid_index;
388         }
389
390         avic_kick_vcpu_by_physical_id(kvm, physical_id, icrl);
391 }
392
393 /*
394  * A fast-path version of avic_kick_target_vcpus(), which attempts to match
395  * destination APIC ID to vCPU without looping through all vCPUs.
396  */
397 static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source,
398                                        u32 icrl, u32 icrh, u32 index)
399 {
400         int dest_mode = icrl & APIC_DEST_MASK;
401         int shorthand = icrl & APIC_SHORT_MASK;
402         struct kvm_svm *kvm_svm = to_kvm_svm(kvm);
403         u32 dest;
404
405         if (shorthand != APIC_DEST_NOSHORT)
406                 return -EINVAL;
407
408         if (apic_x2apic_mode(source))
409                 dest = icrh;
410         else
411                 dest = GET_XAPIC_DEST_FIELD(icrh);
412
413         if (dest_mode == APIC_DEST_PHYSICAL) {
414                 /* broadcast destination, use slow path */
415                 if (apic_x2apic_mode(source) && dest == X2APIC_BROADCAST)
416                         return -EINVAL;
417                 if (!apic_x2apic_mode(source) && dest == APIC_BROADCAST)
418                         return -EINVAL;
419
420                 if (WARN_ON_ONCE(dest != index))
421                         return -EINVAL;
422
423                 avic_kick_vcpu_by_physical_id(kvm, dest, icrl);
424         } else {
425                 u32 *avic_logical_id_table;
426                 unsigned long bitmap, i;
427                 u32 cluster;
428
429                 if (apic_x2apic_mode(source)) {
430                         /* 16 bit dest mask, 16 bit cluster id */
431                         bitmap = dest & 0xFFFF;
432                         cluster = (dest >> 16) << 4;
433                 } else if (kvm_lapic_get_reg(source, APIC_DFR) == APIC_DFR_FLAT) {
434                         /* 8 bit dest mask*/
435                         bitmap = dest;
436                         cluster = 0;
437                 } else {
438                         /* 4 bit desk mask, 4 bit cluster id */
439                         bitmap = dest & 0xF;
440                         cluster = (dest >> 4) << 2;
441                 }
442
443                 /* Nothing to do if there are no destinations in the cluster. */
444                 if (unlikely(!bitmap))
445                         return 0;
446
447                 if (apic_x2apic_mode(source))
448                         avic_logical_id_table = NULL;
449                 else
450                         avic_logical_id_table = page_address(kvm_svm->avic_logical_id_table_page);
451
452                 /*
453                  * AVIC is inhibited if vCPUs aren't mapped 1:1 with logical
454                  * IDs, thus each bit in the destination is guaranteed to map
455                  * to at most one vCPU.
456                  */
457                 for_each_set_bit(i, &bitmap, 16)
458                         avic_kick_vcpu_by_logical_id(kvm, avic_logical_id_table,
459                                                      cluster + i, icrl);
460         }
461
462         return 0;
463 }
464
465 static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source,
466                                    u32 icrl, u32 icrh, u32 index)
467 {
468         u32 dest = apic_x2apic_mode(source) ? icrh : GET_XAPIC_DEST_FIELD(icrh);
469         unsigned long i;
470         struct kvm_vcpu *vcpu;
471
472         if (!avic_kick_target_vcpus_fast(kvm, source, icrl, icrh, index))
473                 return;
474
475         trace_kvm_avic_kick_vcpu_slowpath(icrh, icrl, index);
476
477         /*
478          * Wake any target vCPUs that are blocking, i.e. waiting for a wake
479          * event.  There's no need to signal doorbells, as hardware has handled
480          * vCPUs that were in guest at the time of the IPI, and vCPUs that have
481          * since entered the guest will have processed pending IRQs at VMRUN.
482          */
483         kvm_for_each_vcpu(i, vcpu, kvm) {
484                 if (kvm_apic_match_dest(vcpu, source, icrl & APIC_SHORT_MASK,
485                                         dest, icrl & APIC_DEST_MASK))
486                         avic_kick_vcpu(vcpu, icrl);
487         }
488 }
489
490 int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu)
491 {
492         struct vcpu_svm *svm = to_svm(vcpu);
493         u32 icrh = svm->vmcb->control.exit_info_1 >> 32;
494         u32 icrl = svm->vmcb->control.exit_info_1;
495         u32 id = svm->vmcb->control.exit_info_2 >> 32;
496         u32 index = svm->vmcb->control.exit_info_2 & 0x1FF;
497         struct kvm_lapic *apic = vcpu->arch.apic;
498
499         trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index);
500
501         switch (id) {
502         case AVIC_IPI_FAILURE_INVALID_TARGET:
503         case AVIC_IPI_FAILURE_INVALID_INT_TYPE:
504                 /*
505                  * Emulate IPIs that are not handled by AVIC hardware, which
506                  * only virtualizes Fixed, Edge-Triggered INTRs, and falls over
507                  * if _any_ targets are invalid, e.g. if the logical mode mask
508                  * is a superset of running vCPUs.
509                  *
510                  * The exit is a trap, e.g. ICR holds the correct value and RIP
511                  * has been advanced, KVM is responsible only for emulating the
512                  * IPI.  Sadly, hardware may sometimes leave the BUSY flag set,
513                  * in which case KVM needs to emulate the ICR write as well in
514                  * order to clear the BUSY flag.
515                  */
516                 if (icrl & APIC_ICR_BUSY)
517                         kvm_apic_write_nodecode(vcpu, APIC_ICR);
518                 else
519                         kvm_apic_send_ipi(apic, icrl, icrh);
520                 break;
521         case AVIC_IPI_FAILURE_TARGET_NOT_RUNNING:
522                 /*
523                  * At this point, we expect that the AVIC HW has already
524                  * set the appropriate IRR bits on the valid target
525                  * vcpus. So, we just need to kick the appropriate vcpu.
526                  */
527                 avic_kick_target_vcpus(vcpu->kvm, apic, icrl, icrh, index);
528                 break;
529         case AVIC_IPI_FAILURE_INVALID_BACKING_PAGE:
530                 WARN_ONCE(1, "Invalid backing page\n");
531                 break;
532         case AVIC_IPI_FAILURE_INVALID_IPI_VECTOR:
533                 /* Invalid IPI with vector < 16 */
534                 break;
535         default:
536                 vcpu_unimpl(vcpu, "Unknown avic incomplete IPI interception\n");
537         }
538
539         return 1;
540 }
541
542 unsigned long avic_vcpu_get_apicv_inhibit_reasons(struct kvm_vcpu *vcpu)
543 {
544         if (is_guest_mode(vcpu))
545                 return APICV_INHIBIT_REASON_NESTED;
546         return 0;
547 }
548
549 static u32 *avic_get_logical_id_entry(struct kvm_vcpu *vcpu, u32 ldr, bool flat)
550 {
551         struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm);
552         u32 *logical_apic_id_table;
553         u32 cluster, index;
554
555         ldr = GET_APIC_LOGICAL_ID(ldr);
556
557         if (flat) {
558                 cluster = 0;
559         } else {
560                 cluster = (ldr >> 4);
561                 if (cluster >= 0xf)
562                         return NULL;
563                 ldr &= 0xf;
564         }
565         if (!ldr || !is_power_of_2(ldr))
566                 return NULL;
567
568         index = __ffs(ldr);
569         if (WARN_ON_ONCE(index > 7))
570                 return NULL;
571         index += (cluster << 2);
572
573         logical_apic_id_table = (u32 *) page_address(kvm_svm->avic_logical_id_table_page);
574
575         return &logical_apic_id_table[index];
576 }
577
578 static void avic_ldr_write(struct kvm_vcpu *vcpu, u8 g_physical_id, u32 ldr)
579 {
580         bool flat;
581         u32 *entry, new_entry;
582
583         flat = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR) == APIC_DFR_FLAT;
584         entry = avic_get_logical_id_entry(vcpu, ldr, flat);
585         if (!entry)
586                 return;
587
588         new_entry = READ_ONCE(*entry);
589         new_entry &= ~AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK;
590         new_entry |= (g_physical_id & AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK);
591         new_entry |= AVIC_LOGICAL_ID_ENTRY_VALID_MASK;
592         WRITE_ONCE(*entry, new_entry);
593 }
594
595 static void avic_invalidate_logical_id_entry(struct kvm_vcpu *vcpu)
596 {
597         struct vcpu_svm *svm = to_svm(vcpu);
598         bool flat = svm->dfr_reg == APIC_DFR_FLAT;
599         u32 *entry;
600
601         /* Note: x2AVIC does not use logical APIC ID table */
602         if (apic_x2apic_mode(vcpu->arch.apic))
603                 return;
604
605         entry = avic_get_logical_id_entry(vcpu, svm->ldr_reg, flat);
606         if (entry)
607                 clear_bit(AVIC_LOGICAL_ID_ENTRY_VALID_BIT, (unsigned long *)entry);
608 }
609
610 static void avic_handle_ldr_update(struct kvm_vcpu *vcpu)
611 {
612         struct vcpu_svm *svm = to_svm(vcpu);
613         u32 ldr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LDR);
614         u32 id = kvm_xapic_id(vcpu->arch.apic);
615
616         /* AVIC does not support LDR update for x2APIC */
617         if (apic_x2apic_mode(vcpu->arch.apic))
618                 return;
619
620         if (ldr == svm->ldr_reg)
621                 return;
622
623         avic_invalidate_logical_id_entry(vcpu);
624
625         svm->ldr_reg = ldr;
626         avic_ldr_write(vcpu, id, ldr);
627 }
628
629 static void avic_handle_dfr_update(struct kvm_vcpu *vcpu)
630 {
631         struct vcpu_svm *svm = to_svm(vcpu);
632         u32 dfr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_DFR);
633
634         if (svm->dfr_reg == dfr)
635                 return;
636
637         avic_invalidate_logical_id_entry(vcpu);
638         svm->dfr_reg = dfr;
639 }
640
641 static int avic_unaccel_trap_write(struct kvm_vcpu *vcpu)
642 {
643         u32 offset = to_svm(vcpu)->vmcb->control.exit_info_1 &
644                                 AVIC_UNACCEL_ACCESS_OFFSET_MASK;
645
646         switch (offset) {
647         case APIC_LDR:
648                 avic_handle_ldr_update(vcpu);
649                 break;
650         case APIC_DFR:
651                 avic_handle_dfr_update(vcpu);
652                 break;
653         case APIC_RRR:
654                 /* Ignore writes to Read Remote Data, it's read-only. */
655                 return 1;
656         default:
657                 break;
658         }
659
660         kvm_apic_write_nodecode(vcpu, offset);
661         return 1;
662 }
663
664 static bool is_avic_unaccelerated_access_trap(u32 offset)
665 {
666         bool ret = false;
667
668         switch (offset) {
669         case APIC_ID:
670         case APIC_EOI:
671         case APIC_RRR:
672         case APIC_LDR:
673         case APIC_DFR:
674         case APIC_SPIV:
675         case APIC_ESR:
676         case APIC_ICR:
677         case APIC_LVTT:
678         case APIC_LVTTHMR:
679         case APIC_LVTPC:
680         case APIC_LVT0:
681         case APIC_LVT1:
682         case APIC_LVTERR:
683         case APIC_TMICT:
684         case APIC_TDCR:
685                 ret = true;
686                 break;
687         default:
688                 break;
689         }
690         return ret;
691 }
692
693 int avic_unaccelerated_access_interception(struct kvm_vcpu *vcpu)
694 {
695         struct vcpu_svm *svm = to_svm(vcpu);
696         int ret = 0;
697         u32 offset = svm->vmcb->control.exit_info_1 &
698                      AVIC_UNACCEL_ACCESS_OFFSET_MASK;
699         u32 vector = svm->vmcb->control.exit_info_2 &
700                      AVIC_UNACCEL_ACCESS_VECTOR_MASK;
701         bool write = (svm->vmcb->control.exit_info_1 >> 32) &
702                      AVIC_UNACCEL_ACCESS_WRITE_MASK;
703         bool trap = is_avic_unaccelerated_access_trap(offset);
704
705         trace_kvm_avic_unaccelerated_access(vcpu->vcpu_id, offset,
706                                             trap, write, vector);
707         if (trap) {
708                 /* Handling Trap */
709                 WARN_ONCE(!write, "svm: Handling trap read.\n");
710                 ret = avic_unaccel_trap_write(vcpu);
711         } else {
712                 /* Handling Fault */
713                 ret = kvm_emulate_instruction(vcpu, 0);
714         }
715
716         return ret;
717 }
718
719 int avic_init_vcpu(struct vcpu_svm *svm)
720 {
721         int ret;
722         struct kvm_vcpu *vcpu = &svm->vcpu;
723
724         if (!enable_apicv || !irqchip_in_kernel(vcpu->kvm))
725                 return 0;
726
727         ret = avic_init_backing_page(vcpu);
728         if (ret)
729                 return ret;
730
731         INIT_LIST_HEAD(&svm->ir_list);
732         spin_lock_init(&svm->ir_list_lock);
733         svm->dfr_reg = APIC_DFR_FLAT;
734
735         return ret;
736 }
737
738 void avic_apicv_post_state_restore(struct kvm_vcpu *vcpu)
739 {
740         avic_handle_dfr_update(vcpu);
741         avic_handle_ldr_update(vcpu);
742 }
743
744 static int avic_set_pi_irte_mode(struct kvm_vcpu *vcpu, bool activate)
745 {
746         int ret = 0;
747         unsigned long flags;
748         struct amd_svm_iommu_ir *ir;
749         struct vcpu_svm *svm = to_svm(vcpu);
750
751         if (!kvm_arch_has_assigned_device(vcpu->kvm))
752                 return 0;
753
754         /*
755          * Here, we go through the per-vcpu ir_list to update all existing
756          * interrupt remapping table entry targeting this vcpu.
757          */
758         spin_lock_irqsave(&svm->ir_list_lock, flags);
759
760         if (list_empty(&svm->ir_list))
761                 goto out;
762
763         list_for_each_entry(ir, &svm->ir_list, node) {
764                 if (activate)
765                         ret = amd_iommu_activate_guest_mode(ir->data);
766                 else
767                         ret = amd_iommu_deactivate_guest_mode(ir->data);
768                 if (ret)
769                         break;
770         }
771 out:
772         spin_unlock_irqrestore(&svm->ir_list_lock, flags);
773         return ret;
774 }
775
776 static void svm_ir_list_del(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi)
777 {
778         unsigned long flags;
779         struct amd_svm_iommu_ir *cur;
780
781         spin_lock_irqsave(&svm->ir_list_lock, flags);
782         list_for_each_entry(cur, &svm->ir_list, node) {
783                 if (cur->data != pi->ir_data)
784                         continue;
785                 list_del(&cur->node);
786                 kfree(cur);
787                 break;
788         }
789         spin_unlock_irqrestore(&svm->ir_list_lock, flags);
790 }
791
792 static int svm_ir_list_add(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi)
793 {
794         int ret = 0;
795         unsigned long flags;
796         struct amd_svm_iommu_ir *ir;
797         u64 entry;
798
799         /**
800          * In some cases, the existing irte is updated and re-set,
801          * so we need to check here if it's already been * added
802          * to the ir_list.
803          */
804         if (pi->ir_data && (pi->prev_ga_tag != 0)) {
805                 struct kvm *kvm = svm->vcpu.kvm;
806                 u32 vcpu_id = AVIC_GATAG_TO_VCPUID(pi->prev_ga_tag);
807                 struct kvm_vcpu *prev_vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
808                 struct vcpu_svm *prev_svm;
809
810                 if (!prev_vcpu) {
811                         ret = -EINVAL;
812                         goto out;
813                 }
814
815                 prev_svm = to_svm(prev_vcpu);
816                 svm_ir_list_del(prev_svm, pi);
817         }
818
819         /**
820          * Allocating new amd_iommu_pi_data, which will get
821          * add to the per-vcpu ir_list.
822          */
823         ir = kzalloc(sizeof(struct amd_svm_iommu_ir), GFP_KERNEL_ACCOUNT);
824         if (!ir) {
825                 ret = -ENOMEM;
826                 goto out;
827         }
828         ir->data = pi->ir_data;
829
830         spin_lock_irqsave(&svm->ir_list_lock, flags);
831
832         /*
833          * Update the target pCPU for IOMMU doorbells if the vCPU is running.
834          * If the vCPU is NOT running, i.e. is blocking or scheduled out, KVM
835          * will update the pCPU info when the vCPU awkened and/or scheduled in.
836          * See also avic_vcpu_load().
837          */
838         entry = READ_ONCE(*(svm->avic_physical_id_cache));
839         if (entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK)
840                 amd_iommu_update_ga(entry & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK,
841                                     true, pi->ir_data);
842
843         list_add(&ir->node, &svm->ir_list);
844         spin_unlock_irqrestore(&svm->ir_list_lock, flags);
845 out:
846         return ret;
847 }
848
849 /*
850  * Note:
851  * The HW cannot support posting multicast/broadcast
852  * interrupts to a vCPU. So, we still use legacy interrupt
853  * remapping for these kind of interrupts.
854  *
855  * For lowest-priority interrupts, we only support
856  * those with single CPU as the destination, e.g. user
857  * configures the interrupts via /proc/irq or uses
858  * irqbalance to make the interrupts single-CPU.
859  */
860 static int
861 get_pi_vcpu_info(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
862                  struct vcpu_data *vcpu_info, struct vcpu_svm **svm)
863 {
864         struct kvm_lapic_irq irq;
865         struct kvm_vcpu *vcpu = NULL;
866
867         kvm_set_msi_irq(kvm, e, &irq);
868
869         if (!kvm_intr_is_single_vcpu(kvm, &irq, &vcpu) ||
870             !kvm_irq_is_postable(&irq)) {
871                 pr_debug("SVM: %s: use legacy intr remap mode for irq %u\n",
872                          __func__, irq.vector);
873                 return -1;
874         }
875
876         pr_debug("SVM: %s: use GA mode for irq %u\n", __func__,
877                  irq.vector);
878         *svm = to_svm(vcpu);
879         vcpu_info->pi_desc_addr = __sme_set(page_to_phys((*svm)->avic_backing_page));
880         vcpu_info->vector = irq.vector;
881
882         return 0;
883 }
884
885 /*
886  * avic_pi_update_irte - set IRTE for Posted-Interrupts
887  *
888  * @kvm: kvm
889  * @host_irq: host irq of the interrupt
890  * @guest_irq: gsi of the interrupt
891  * @set: set or unset PI
892  * returns 0 on success, < 0 on failure
893  */
894 int avic_pi_update_irte(struct kvm *kvm, unsigned int host_irq,
895                         uint32_t guest_irq, bool set)
896 {
897         struct kvm_kernel_irq_routing_entry *e;
898         struct kvm_irq_routing_table *irq_rt;
899         int idx, ret = 0;
900
901         if (!kvm_arch_has_assigned_device(kvm) ||
902             !irq_remapping_cap(IRQ_POSTING_CAP))
903                 return 0;
904
905         pr_debug("SVM: %s: host_irq=%#x, guest_irq=%#x, set=%#x\n",
906                  __func__, host_irq, guest_irq, set);
907
908         idx = srcu_read_lock(&kvm->irq_srcu);
909         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
910
911         if (guest_irq >= irq_rt->nr_rt_entries ||
912                 hlist_empty(&irq_rt->map[guest_irq])) {
913                 pr_warn_once("no route for guest_irq %u/%u (broken user space?)\n",
914                              guest_irq, irq_rt->nr_rt_entries);
915                 goto out;
916         }
917
918         hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) {
919                 struct vcpu_data vcpu_info;
920                 struct vcpu_svm *svm = NULL;
921
922                 if (e->type != KVM_IRQ_ROUTING_MSI)
923                         continue;
924
925                 /**
926                  * Here, we setup with legacy mode in the following cases:
927                  * 1. When cannot target interrupt to a specific vcpu.
928                  * 2. Unsetting posted interrupt.
929                  * 3. APIC virtualization is disabled for the vcpu.
930                  * 4. IRQ has incompatible delivery mode (SMI, INIT, etc)
931                  */
932                 if (!get_pi_vcpu_info(kvm, e, &vcpu_info, &svm) && set &&
933                     kvm_vcpu_apicv_active(&svm->vcpu)) {
934                         struct amd_iommu_pi_data pi;
935
936                         /* Try to enable guest_mode in IRTE */
937                         pi.base = __sme_set(page_to_phys(svm->avic_backing_page) &
938                                             AVIC_HPA_MASK);
939                         pi.ga_tag = AVIC_GATAG(to_kvm_svm(kvm)->avic_vm_id,
940                                                      svm->vcpu.vcpu_id);
941                         pi.is_guest_mode = true;
942                         pi.vcpu_data = &vcpu_info;
943                         ret = irq_set_vcpu_affinity(host_irq, &pi);
944
945                         /**
946                          * Here, we successfully setting up vcpu affinity in
947                          * IOMMU guest mode. Now, we need to store the posted
948                          * interrupt information in a per-vcpu ir_list so that
949                          * we can reference to them directly when we update vcpu
950                          * scheduling information in IOMMU irte.
951                          */
952                         if (!ret && pi.is_guest_mode)
953                                 svm_ir_list_add(svm, &pi);
954                 } else {
955                         /* Use legacy mode in IRTE */
956                         struct amd_iommu_pi_data pi;
957
958                         /**
959                          * Here, pi is used to:
960                          * - Tell IOMMU to use legacy mode for this interrupt.
961                          * - Retrieve ga_tag of prior interrupt remapping data.
962                          */
963                         pi.prev_ga_tag = 0;
964                         pi.is_guest_mode = false;
965                         ret = irq_set_vcpu_affinity(host_irq, &pi);
966
967                         /**
968                          * Check if the posted interrupt was previously
969                          * setup with the guest_mode by checking if the ga_tag
970                          * was cached. If so, we need to clean up the per-vcpu
971                          * ir_list.
972                          */
973                         if (!ret && pi.prev_ga_tag) {
974                                 int id = AVIC_GATAG_TO_VCPUID(pi.prev_ga_tag);
975                                 struct kvm_vcpu *vcpu;
976
977                                 vcpu = kvm_get_vcpu_by_id(kvm, id);
978                                 if (vcpu)
979                                         svm_ir_list_del(to_svm(vcpu), &pi);
980                         }
981                 }
982
983                 if (!ret && svm) {
984                         trace_kvm_pi_irte_update(host_irq, svm->vcpu.vcpu_id,
985                                                  e->gsi, vcpu_info.vector,
986                                                  vcpu_info.pi_desc_addr, set);
987                 }
988
989                 if (ret < 0) {
990                         pr_err("%s: failed to update PI IRTE\n", __func__);
991                         goto out;
992                 }
993         }
994
995         ret = 0;
996 out:
997         srcu_read_unlock(&kvm->irq_srcu, idx);
998         return ret;
999 }
1000
1001 static inline int
1002 avic_update_iommu_vcpu_affinity(struct kvm_vcpu *vcpu, int cpu, bool r)
1003 {
1004         int ret = 0;
1005         struct amd_svm_iommu_ir *ir;
1006         struct vcpu_svm *svm = to_svm(vcpu);
1007
1008         lockdep_assert_held(&svm->ir_list_lock);
1009
1010         if (!kvm_arch_has_assigned_device(vcpu->kvm))
1011                 return 0;
1012
1013         /*
1014          * Here, we go through the per-vcpu ir_list to update all existing
1015          * interrupt remapping table entry targeting this vcpu.
1016          */
1017         if (list_empty(&svm->ir_list))
1018                 return 0;
1019
1020         list_for_each_entry(ir, &svm->ir_list, node) {
1021                 ret = amd_iommu_update_ga(cpu, r, ir->data);
1022                 if (ret)
1023                         return ret;
1024         }
1025         return 0;
1026 }
1027
1028 void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
1029 {
1030         u64 entry;
1031         int h_physical_id = kvm_cpu_get_apicid(cpu);
1032         struct vcpu_svm *svm = to_svm(vcpu);
1033         unsigned long flags;
1034
1035         lockdep_assert_preemption_disabled();
1036
1037         if (WARN_ON(h_physical_id & ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK))
1038                 return;
1039
1040         /*
1041          * No need to update anything if the vCPU is blocking, i.e. if the vCPU
1042          * is being scheduled in after being preempted.  The CPU entries in the
1043          * Physical APIC table and IRTE are consumed iff IsRun{ning} is '1'.
1044          * If the vCPU was migrated, its new CPU value will be stuffed when the
1045          * vCPU unblocks.
1046          */
1047         if (kvm_vcpu_is_blocking(vcpu))
1048                 return;
1049
1050         /*
1051          * Grab the per-vCPU interrupt remapping lock even if the VM doesn't
1052          * _currently_ have assigned devices, as that can change.  Holding
1053          * ir_list_lock ensures that either svm_ir_list_add() will consume
1054          * up-to-date entry information, or that this task will wait until
1055          * svm_ir_list_add() completes to set the new target pCPU.
1056          */
1057         spin_lock_irqsave(&svm->ir_list_lock, flags);
1058
1059         entry = READ_ONCE(*(svm->avic_physical_id_cache));
1060         WARN_ON_ONCE(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK);
1061
1062         entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK;
1063         entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK);
1064         entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
1065
1066         WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
1067         avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, true);
1068
1069         spin_unlock_irqrestore(&svm->ir_list_lock, flags);
1070 }
1071
1072 void avic_vcpu_put(struct kvm_vcpu *vcpu)
1073 {
1074         u64 entry;
1075         struct vcpu_svm *svm = to_svm(vcpu);
1076         unsigned long flags;
1077
1078         lockdep_assert_preemption_disabled();
1079
1080         /*
1081          * Note, reading the Physical ID entry outside of ir_list_lock is safe
1082          * as only the pCPU that has loaded (or is loading) the vCPU is allowed
1083          * to modify the entry, and preemption is disabled.  I.e. the vCPU
1084          * can't be scheduled out and thus avic_vcpu_{put,load}() can't run
1085          * recursively.
1086          */
1087         entry = READ_ONCE(*(svm->avic_physical_id_cache));
1088
1089         /* Nothing to do if IsRunning == '0' due to vCPU blocking. */
1090         if (!(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK))
1091                 return;
1092
1093         /*
1094          * Take and hold the per-vCPU interrupt remapping lock while updating
1095          * the Physical ID entry even though the lock doesn't protect against
1096          * multiple writers (see above).  Holding ir_list_lock ensures that
1097          * either svm_ir_list_add() will consume up-to-date entry information,
1098          * or that this task will wait until svm_ir_list_add() completes to
1099          * mark the vCPU as not running.
1100          */
1101         spin_lock_irqsave(&svm->ir_list_lock, flags);
1102
1103         avic_update_iommu_vcpu_affinity(vcpu, -1, 0);
1104
1105         entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK;
1106         WRITE_ONCE(*(svm->avic_physical_id_cache), entry);
1107
1108         spin_unlock_irqrestore(&svm->ir_list_lock, flags);
1109
1110 }
1111
1112 void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu)
1113 {
1114         struct vcpu_svm *svm = to_svm(vcpu);
1115         struct vmcb *vmcb = svm->vmcb01.ptr;
1116
1117         if (!lapic_in_kernel(vcpu) || !enable_apicv)
1118                 return;
1119
1120         if (kvm_vcpu_apicv_active(vcpu)) {
1121                 /**
1122                  * During AVIC temporary deactivation, guest could update
1123                  * APIC ID, DFR and LDR registers, which would not be trapped
1124                  * by avic_unaccelerated_access_interception(). In this case,
1125                  * we need to check and update the AVIC logical APIC ID table
1126                  * accordingly before re-activating.
1127                  */
1128                 avic_apicv_post_state_restore(vcpu);
1129                 avic_activate_vmcb(svm);
1130         } else {
1131                 avic_deactivate_vmcb(svm);
1132         }
1133         vmcb_mark_dirty(vmcb, VMCB_AVIC);
1134 }
1135
1136 void avic_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu)
1137 {
1138         bool activated = kvm_vcpu_apicv_active(vcpu);
1139
1140         if (!enable_apicv)
1141                 return;
1142
1143         avic_refresh_virtual_apic_mode(vcpu);
1144
1145         if (activated)
1146                 avic_vcpu_load(vcpu, vcpu->cpu);
1147         else
1148                 avic_vcpu_put(vcpu);
1149
1150         avic_set_pi_irte_mode(vcpu, activated);
1151 }
1152
1153 void avic_vcpu_blocking(struct kvm_vcpu *vcpu)
1154 {
1155         if (!kvm_vcpu_apicv_active(vcpu))
1156                 return;
1157
1158        /*
1159         * Unload the AVIC when the vCPU is about to block, _before_
1160         * the vCPU actually blocks.
1161         *
1162         * Any IRQs that arrive before IsRunning=0 will not cause an
1163         * incomplete IPI vmexit on the source, therefore vIRR will also
1164         * be checked by kvm_vcpu_check_block() before blocking.  The
1165         * memory barrier implicit in set_current_state orders writing
1166         * IsRunning=0 before reading the vIRR.  The processor needs a
1167         * matching memory barrier on interrupt delivery between writing
1168         * IRR and reading IsRunning; the lack of this barrier might be
1169         * the cause of errata #1235).
1170         */
1171         avic_vcpu_put(vcpu);
1172 }
1173
1174 void avic_vcpu_unblocking(struct kvm_vcpu *vcpu)
1175 {
1176         if (!kvm_vcpu_apicv_active(vcpu))
1177                 return;
1178
1179         avic_vcpu_load(vcpu, vcpu->cpu);
1180 }
1181
1182 /*
1183  * Note:
1184  * - The module param avic enable both xAPIC and x2APIC mode.
1185  * - Hypervisor can support both xAVIC and x2AVIC in the same guest.
1186  * - The mode can be switched at run-time.
1187  */
1188 bool avic_hardware_setup(void)
1189 {
1190         if (!npt_enabled)
1191                 return false;
1192
1193         /* AVIC is a prerequisite for x2AVIC. */
1194         if (!boot_cpu_has(X86_FEATURE_AVIC) && !force_avic) {
1195                 if (boot_cpu_has(X86_FEATURE_X2AVIC)) {
1196                         pr_warn(FW_BUG "Cannot support x2AVIC due to AVIC is disabled");
1197                         pr_warn(FW_BUG "Try enable AVIC using force_avic option");
1198                 }
1199                 return false;
1200         }
1201
1202         if (boot_cpu_has(X86_FEATURE_AVIC)) {
1203                 pr_info("AVIC enabled\n");
1204         } else if (force_avic) {
1205                 /*
1206                  * Some older systems does not advertise AVIC support.
1207                  * See Revision Guide for specific AMD processor for more detail.
1208                  */
1209                 pr_warn("AVIC is not supported in CPUID but force enabled");
1210                 pr_warn("Your system might crash and burn");
1211         }
1212
1213         /* AVIC is a prerequisite for x2AVIC. */
1214         x2avic_enabled = boot_cpu_has(X86_FEATURE_X2AVIC);
1215         if (x2avic_enabled)
1216                 pr_info("x2AVIC enabled\n");
1217
1218         amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
1219
1220         return true;
1221 }