blob: 5ff7f7f2689afec2887fe9c387aaaca2d616a119 [file] [log] [blame]
Gleb Natapovaf585b92010-10-14 11:22:46 +02001/*
2 * kvm asynchronous fault support
3 *
4 * Copyright 2010 Red Hat, Inc.
5 *
6 * Author:
7 * Gleb Natapov <gleb@redhat.com>
8 *
9 * This file is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
21 */
22
23#include <linux/kvm_host.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include <linux/mmu_context.h>
27
28#include "async_pf.h"
29#include <trace/events/kvm.h>
30
Dominik Dingele0ead412013-06-06 15:32:37 +020031static inline void kvm_async_page_present_sync(struct kvm_vcpu *vcpu,
32 struct kvm_async_pf *work)
33{
34#ifdef CONFIG_KVM_ASYNC_PF_SYNC
35 kvm_arch_async_page_present(vcpu, work);
36#endif
37}
38static inline void kvm_async_page_present_async(struct kvm_vcpu *vcpu,
39 struct kvm_async_pf *work)
40{
41#ifndef CONFIG_KVM_ASYNC_PF_SYNC
42 kvm_arch_async_page_present(vcpu, work);
43#endif
44}
45
Gleb Natapovaf585b92010-10-14 11:22:46 +020046static struct kmem_cache *async_pf_cache;
47
48int kvm_async_pf_init(void)
49{
50 async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);
51
52 if (!async_pf_cache)
53 return -ENOMEM;
54
55 return 0;
56}
57
58void kvm_async_pf_deinit(void)
59{
60 if (async_pf_cache)
61 kmem_cache_destroy(async_pf_cache);
62 async_pf_cache = NULL;
63}
64
65void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu)
66{
67 INIT_LIST_HEAD(&vcpu->async_pf.done);
68 INIT_LIST_HEAD(&vcpu->async_pf.queue);
69 spin_lock_init(&vcpu->async_pf.lock);
70}
71
72static void async_pf_execute(struct work_struct *work)
73{
Gleb Natapovaf585b92010-10-14 11:22:46 +020074 struct kvm_async_pf *apf =
75 container_of(work, struct kvm_async_pf, work);
76 struct mm_struct *mm = apf->mm;
77 struct kvm_vcpu *vcpu = apf->vcpu;
78 unsigned long addr = apf->addr;
79 gva_t gva = apf->gva;
80
81 might_sleep();
82
Andres Lagar-Cavilla234b2392014-09-17 10:51:48 -070083 kvm_get_user_page_io(NULL, mm, addr, 1, NULL);
Dominik Dingele0ead412013-06-06 15:32:37 +020084 kvm_async_page_present_sync(vcpu, apf);
Gleb Natapovaf585b92010-10-14 11:22:46 +020085
86 spin_lock(&vcpu->async_pf.lock);
87 list_add_tail(&apf->link, &vcpu->async_pf.done);
Gleb Natapovaf585b92010-10-14 11:22:46 +020088 spin_unlock(&vcpu->async_pf.lock);
89
90 /*
91 * apf may be freed by kvm_check_async_pf_completion() after
92 * this point
93 */
94
chai wenf2e10662013-10-14 22:22:33 +080095 trace_kvm_async_pf_completed(addr, gva);
Gleb Natapovaf585b92010-10-14 11:22:46 +020096
97 if (waitqueue_active(&vcpu->wq))
98 wake_up_interruptible(&vcpu->wq);
99
Oleg Nesterov41c22f62014-04-21 15:26:01 +0200100 mmput(mm);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200101 kvm_put_kvm(vcpu->kvm);
102}
103
104void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
105{
106 /* cancel outstanding work queue item */
107 while (!list_empty(&vcpu->async_pf.queue)) {
108 struct kvm_async_pf *work =
109 list_entry(vcpu->async_pf.queue.next,
110 typeof(*work), queue);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200111 list_del(&work->queue);
Dominik Dingel9f2ceda2013-09-03 12:31:16 +0200112
113#ifdef CONFIG_KVM_ASYNC_PF_SYNC
114 flush_work(&work->work);
115#else
Radim Krčmář98fda162013-09-04 22:32:24 +0200116 if (cancel_work_sync(&work->work)) {
Oleg Nesterov41c22f62014-04-21 15:26:01 +0200117 mmput(work->mm);
Radim Krčmář28b441e2013-09-04 22:32:23 +0200118 kvm_put_kvm(vcpu->kvm); /* == work->vcpu->kvm */
Gleb Natapovaf585b92010-10-14 11:22:46 +0200119 kmem_cache_free(async_pf_cache, work);
Radim Krčmář28b441e2013-09-04 22:32:23 +0200120 }
Dominik Dingel9f2ceda2013-09-03 12:31:16 +0200121#endif
Gleb Natapovaf585b92010-10-14 11:22:46 +0200122 }
123
124 spin_lock(&vcpu->async_pf.lock);
125 while (!list_empty(&vcpu->async_pf.done)) {
126 struct kvm_async_pf *work =
127 list_entry(vcpu->async_pf.done.next,
128 typeof(*work), link);
129 list_del(&work->link);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200130 kmem_cache_free(async_pf_cache, work);
131 }
132 spin_unlock(&vcpu->async_pf.lock);
133
134 vcpu->async_pf.queued = 0;
135}
136
137void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu)
138{
139 struct kvm_async_pf *work;
140
Xiao Guangrong15096ff2010-11-02 17:35:35 +0800141 while (!list_empty_careful(&vcpu->async_pf.done) &&
142 kvm_arch_can_inject_async_page_present(vcpu)) {
143 spin_lock(&vcpu->async_pf.lock);
144 work = list_first_entry(&vcpu->async_pf.done, typeof(*work),
145 link);
146 list_del(&work->link);
147 spin_unlock(&vcpu->async_pf.lock);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200148
chai wenf2e10662013-10-14 22:22:33 +0800149 kvm_arch_async_page_ready(vcpu, work);
Dominik Dingel1179ba52014-01-31 14:32:46 +0100150 kvm_async_page_present_async(vcpu, work);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200151
Xiao Guangrong15096ff2010-11-02 17:35:35 +0800152 list_del(&work->queue);
153 vcpu->async_pf.queued--;
Xiao Guangrong15096ff2010-11-02 17:35:35 +0800154 kmem_cache_free(async_pf_cache, work);
155 }
Gleb Natapovaf585b92010-10-14 11:22:46 +0200156}
157
Dominik Dingele0ead412013-06-06 15:32:37 +0200158int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, unsigned long hva,
Gleb Natapovaf585b92010-10-14 11:22:46 +0200159 struct kvm_arch_async_pf *arch)
160{
161 struct kvm_async_pf *work;
162
163 if (vcpu->async_pf.queued >= ASYNC_PF_PER_VCPU)
164 return 0;
165
166 /* setup delayed work */
167
168 /*
169 * do alloc nowait since if we are going to sleep anyway we
170 * may as well sleep faulting in page
171 */
172 work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT);
173 if (!work)
174 return 0;
175
chai wenf2e10662013-10-14 22:22:33 +0800176 work->wakeup_all = false;
Gleb Natapovaf585b92010-10-14 11:22:46 +0200177 work->vcpu = vcpu;
178 work->gva = gva;
Dominik Dingele0ead412013-06-06 15:32:37 +0200179 work->addr = hva;
Gleb Natapovaf585b92010-10-14 11:22:46 +0200180 work->arch = *arch;
181 work->mm = current->mm;
Oleg Nesterov41c22f62014-04-21 15:26:01 +0200182 atomic_inc(&work->mm->mm_users);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200183 kvm_get_kvm(work->vcpu->kvm);
184
185 /* this can't really happen otherwise gfn_to_pfn_async
186 would succeed */
187 if (unlikely(kvm_is_error_hva(work->addr)))
188 goto retry_sync;
189
190 INIT_WORK(&work->work, async_pf_execute);
191 if (!schedule_work(&work->work))
192 goto retry_sync;
193
194 list_add_tail(&work->queue, &vcpu->async_pf.queue);
195 vcpu->async_pf.queued++;
196 kvm_arch_async_page_not_present(vcpu, work);
197 return 1;
198retry_sync:
199 kvm_put_kvm(work->vcpu->kvm);
Oleg Nesterov41c22f62014-04-21 15:26:01 +0200200 mmput(work->mm);
Gleb Natapovaf585b92010-10-14 11:22:46 +0200201 kmem_cache_free(async_pf_cache, work);
202 return 0;
203}
Gleb Natapov344d9582010-10-14 11:22:50 +0200204
205int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
206{
207 struct kvm_async_pf *work;
208
Xiao Guangrong64f638c2010-11-01 17:03:44 +0800209 if (!list_empty_careful(&vcpu->async_pf.done))
Gleb Natapov344d9582010-10-14 11:22:50 +0200210 return 0;
211
212 work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
213 if (!work)
214 return -ENOMEM;
215
chai wenf2e10662013-10-14 22:22:33 +0800216 work->wakeup_all = true;
Gleb Natapov344d9582010-10-14 11:22:50 +0200217 INIT_LIST_HEAD(&work->queue); /* for list_del to work */
218
Xiao Guangrong64f638c2010-11-01 17:03:44 +0800219 spin_lock(&vcpu->async_pf.lock);
Gleb Natapov344d9582010-10-14 11:22:50 +0200220 list_add_tail(&work->link, &vcpu->async_pf.done);
Xiao Guangrong64f638c2010-11-01 17:03:44 +0800221 spin_unlock(&vcpu->async_pf.lock);
222
Gleb Natapov344d9582010-10-14 11:22:50 +0200223 vcpu->async_pf.queued++;
224 return 0;
225}