]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - virt/kvm/async_pf.c
2 * kvm asynchronous fault support
4 * Copyright 2010 Red Hat, Inc.
7 * Gleb Natapov <gleb@redhat.com>
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.
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.
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.
23 #include <linux/kvm_host.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/mmu_context.h>
29 #include <trace/events/kvm.h>
31 static struct kmem_cache
*async_pf_cache
;
33 int kvm_async_pf_init(void)
35 async_pf_cache
= KMEM_CACHE(kvm_async_pf
, 0);
43 void kvm_async_pf_deinit(void)
46 kmem_cache_destroy(async_pf_cache
);
47 async_pf_cache
= NULL
;
50 void kvm_async_pf_vcpu_init(struct kvm_vcpu
*vcpu
)
52 INIT_LIST_HEAD(&vcpu
->async_pf
.done
);
53 INIT_LIST_HEAD(&vcpu
->async_pf
.queue
);
54 spin_lock_init(&vcpu
->async_pf
.lock
);
57 static void async_pf_execute(struct work_struct
*work
)
59 struct page
*page
= NULL
;
60 struct kvm_async_pf
*apf
=
61 container_of(work
, struct kvm_async_pf
, work
);
62 struct mm_struct
*mm
= apf
->mm
;
63 struct kvm_vcpu
*vcpu
= apf
->vcpu
;
64 unsigned long addr
= apf
->addr
;
70 down_read(&mm
->mmap_sem
);
71 get_user_pages(current
, mm
, addr
, 1, 1, 0, &page
, NULL
);
72 up_read(&mm
->mmap_sem
);
75 spin_lock(&vcpu
->async_pf
.lock
);
76 list_add_tail(&apf
->link
, &vcpu
->async_pf
.done
);
79 spin_unlock(&vcpu
->async_pf
.lock
);
82 * apf may be freed by kvm_check_async_pf_completion() after
86 trace_kvm_async_pf_completed(addr
, page
, gva
);
88 if (waitqueue_active(&vcpu
->wq
))
89 wake_up_interruptible(&vcpu
->wq
);
92 kvm_put_kvm(vcpu
->kvm
);
95 void kvm_clear_async_pf_completion_queue(struct kvm_vcpu
*vcpu
)
97 /* cancel outstanding work queue item */
98 while (!list_empty(&vcpu
->async_pf
.queue
)) {
99 struct kvm_async_pf
*work
=
100 list_entry(vcpu
->async_pf
.queue
.next
,
101 typeof(*work
), queue
);
102 cancel_work_sync(&work
->work
);
103 list_del(&work
->queue
);
104 if (!work
->done
) /* work was canceled */
105 kmem_cache_free(async_pf_cache
, work
);
108 spin_lock(&vcpu
->async_pf
.lock
);
109 while (!list_empty(&vcpu
->async_pf
.done
)) {
110 struct kvm_async_pf
*work
=
111 list_entry(vcpu
->async_pf
.done
.next
,
112 typeof(*work
), link
);
113 list_del(&work
->link
);
114 if (!is_error_page(work
->page
))
115 kvm_release_page_clean(work
->page
);
116 kmem_cache_free(async_pf_cache
, work
);
118 spin_unlock(&vcpu
->async_pf
.lock
);
120 vcpu
->async_pf
.queued
= 0;
123 void kvm_check_async_pf_completion(struct kvm_vcpu
*vcpu
)
125 struct kvm_async_pf
*work
;
127 while (!list_empty_careful(&vcpu
->async_pf
.done
) &&
128 kvm_arch_can_inject_async_page_present(vcpu
)) {
129 spin_lock(&vcpu
->async_pf
.lock
);
130 work
= list_first_entry(&vcpu
->async_pf
.done
, typeof(*work
),
132 list_del(&work
->link
);
133 spin_unlock(&vcpu
->async_pf
.lock
);
136 kvm_arch_async_page_ready(vcpu
, work
);
137 kvm_arch_async_page_present(vcpu
, work
);
139 list_del(&work
->queue
);
140 vcpu
->async_pf
.queued
--;
141 if (!is_error_page(work
->page
))
142 kvm_release_page_clean(work
->page
);
143 kmem_cache_free(async_pf_cache
, work
);
147 int kvm_setup_async_pf(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
,
148 struct kvm_arch_async_pf
*arch
)
150 struct kvm_async_pf
*work
;
152 if (vcpu
->async_pf
.queued
>= ASYNC_PF_PER_VCPU
)
155 /* setup delayed work */
158 * do alloc nowait since if we are going to sleep anyway we
159 * may as well sleep faulting in page
161 work
= kmem_cache_zalloc(async_pf_cache
, GFP_NOWAIT
);
169 work
->addr
= gfn_to_hva(vcpu
->kvm
, gfn
);
171 work
->mm
= current
->mm
;
172 atomic_inc(&work
->mm
->mm_count
);
173 kvm_get_kvm(work
->vcpu
->kvm
);
175 /* this can't really happen otherwise gfn_to_pfn_async
177 if (unlikely(kvm_is_error_hva(work
->addr
)))
180 INIT_WORK(&work
->work
, async_pf_execute
);
181 if (!schedule_work(&work
->work
))
184 list_add_tail(&work
->queue
, &vcpu
->async_pf
.queue
);
185 vcpu
->async_pf
.queued
++;
186 kvm_arch_async_page_not_present(vcpu
, work
);
189 kvm_put_kvm(work
->vcpu
->kvm
);
191 kmem_cache_free(async_pf_cache
, work
);
195 int kvm_async_pf_wakeup_all(struct kvm_vcpu
*vcpu
)
197 struct kvm_async_pf
*work
;
199 if (!list_empty_careful(&vcpu
->async_pf
.done
))
202 work
= kmem_cache_zalloc(async_pf_cache
, GFP_ATOMIC
);
206 work
->page
= KVM_ERR_PTR_BAD_PAGE
;
207 INIT_LIST_HEAD(&work
->queue
); /* for list_del to work */
209 spin_lock(&vcpu
->async_pf
.lock
);
210 list_add_tail(&work
->link
, &vcpu
->async_pf
.done
);
211 spin_unlock(&vcpu
->async_pf
.lock
);
213 vcpu
->async_pf
.queued
++;