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11#include <linux/kvm_host.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/mmu_context.h>
15#include <linux/sched/mm.h>
16
17#include "async_pf.h"
18#include <trace/events/kvm.h>
19
20static inline void kvm_async_page_present_sync(struct kvm_vcpu *vcpu,
21 struct kvm_async_pf *work)
22{
23#ifdef CONFIG_KVM_ASYNC_PF_SYNC
24 kvm_arch_async_page_present(vcpu, work);
25#endif
26}
27static inline void kvm_async_page_present_async(struct kvm_vcpu *vcpu,
28 struct kvm_async_pf *work)
29{
30#ifndef CONFIG_KVM_ASYNC_PF_SYNC
31 kvm_arch_async_page_present(vcpu, work);
32#endif
33}
34
35static struct kmem_cache *async_pf_cache;
36
37int kvm_async_pf_init(void)
38{
39 async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);
40
41 if (!async_pf_cache)
42 return -ENOMEM;
43
44 return 0;
45}
46
47void kvm_async_pf_deinit(void)
48{
49 kmem_cache_destroy(async_pf_cache);
50 async_pf_cache = NULL;
51}
52
53void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu)
54{
55 INIT_LIST_HEAD(&vcpu->async_pf.done);
56 INIT_LIST_HEAD(&vcpu->async_pf.queue);
57 spin_lock_init(&vcpu->async_pf.lock);
58}
59
60static void async_pf_execute(struct work_struct *work)
61{
62 struct kvm_async_pf *apf =
63 container_of(work, struct kvm_async_pf, work);
64 struct mm_struct *mm = apf->mm;
65 struct kvm_vcpu *vcpu = apf->vcpu;
66 unsigned long addr = apf->addr;
67 gva_t gva = apf->gva;
68 int locked = 1;
69
70 might_sleep();
71
72
73
74
75
76
77 down_read(&mm->mmap_sem);
78 get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL,
79 &locked);
80 if (locked)
81 up_read(&mm->mmap_sem);
82
83 kvm_async_page_present_sync(vcpu, apf);
84
85 spin_lock(&vcpu->async_pf.lock);
86 list_add_tail(&apf->link, &vcpu->async_pf.done);
87 apf->vcpu = NULL;
88 spin_unlock(&vcpu->async_pf.lock);
89
90
91
92
93
94
95 trace_kvm_async_pf_completed(addr, gva);
96
97 if (swq_has_sleeper(&vcpu->wq))
98 swake_up_one(&vcpu->wq);
99
100 mmput(mm);
101 kvm_put_kvm(vcpu->kvm);
102}
103
104void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
105{
106 spin_lock(&vcpu->async_pf.lock);
107
108
109 while (!list_empty(&vcpu->async_pf.queue)) {
110 struct kvm_async_pf *work =
111 list_first_entry(&vcpu->async_pf.queue,
112 typeof(*work), queue);
113 list_del(&work->queue);
114
115
116
117
118
119 if (!work->vcpu)
120 continue;
121
122 spin_unlock(&vcpu->async_pf.lock);
123#ifdef CONFIG_KVM_ASYNC_PF_SYNC
124 flush_work(&work->work);
125#else
126 if (cancel_work_sync(&work->work)) {
127 mmput(work->mm);
128 kvm_put_kvm(vcpu->kvm);
129 kmem_cache_free(async_pf_cache, work);
130 }
131#endif
132 spin_lock(&vcpu->async_pf.lock);
133 }
134
135 while (!list_empty(&vcpu->async_pf.done)) {
136 struct kvm_async_pf *work =
137 list_first_entry(&vcpu->async_pf.done,
138 typeof(*work), link);
139 list_del(&work->link);
140 kmem_cache_free(async_pf_cache, work);
141 }
142 spin_unlock(&vcpu->async_pf.lock);
143
144 vcpu->async_pf.queued = 0;
145}
146
147void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
148{
149 struct kvm_async_pf *work;
150
151 while (!list_empty_careful(&vcpu->async_pf.done) &&
152 kvm_arch_can_inject_async_page_present(vcpu)) {
153 spin_lock(&vcpu->async_pf.lock);
154 work = list_first_entry(&vcpu->async_pf.done, typeof(*work),
155 link);
156 list_del(&work->link);
157 spin_unlock(&vcpu->async_pf.lock);
158
159 kvm_arch_async_page_ready(vcpu, work);
160 kvm_async_page_present_async(vcpu, work);
161
162 list_del(&work->queue);
163 vcpu->async_pf.queued--;
164 kmem_cache_free(async_pf_cache, work);
165 }
166}
167
168int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, unsigned long hva,
169 struct kvm_arch_async_pf *arch)
170{
171 struct kvm_async_pf *work;
172
173 if (vcpu->async_pf.queued >= ASYNC_PF_PER_VCPU)
174 return 0;
175
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179
180
181
182 work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT | __GFP_NOWARN);
183 if (!work)
184 return 0;
185
186 work->wakeup_all = false;
187 work->vcpu = vcpu;
188 work->gva = gva;
189 work->addr = hva;
190 work->arch = *arch;
191 work->mm = current->mm;
192 mmget(work->mm);
193 kvm_get_kvm(work->vcpu->kvm);
194
195
196
197 if (unlikely(kvm_is_error_hva(work->addr)))
198 goto retry_sync;
199
200 INIT_WORK(&work->work, async_pf_execute);
201 if (!schedule_work(&work->work))
202 goto retry_sync;
203
204 list_add_tail(&work->queue, &vcpu->async_pf.queue);
205 vcpu->async_pf.queued++;
206 kvm_arch_async_page_not_present(vcpu, work);
207 return 1;
208retry_sync:
209 kvm_put_kvm(work->vcpu->kvm);
210 mmput(work->mm);
211 kmem_cache_free(async_pf_cache, work);
212 return 0;
213}
214
215int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
216{
217 struct kvm_async_pf *work;
218
219 if (!list_empty_careful(&vcpu->async_pf.done))
220 return 0;
221
222 work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
223 if (!work)
224 return -ENOMEM;
225
226 work->wakeup_all = true;
227 INIT_LIST_HEAD(&work->queue);
228
229 spin_lock(&vcpu->async_pf.lock);
230 list_add_tail(&work->link, &vcpu->async_pf.done);
231 spin_unlock(&vcpu->async_pf.lock);
232
233 vcpu->async_pf.queued++;
234 return 0;
235}
236