1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
// SPDX-License-Identifier: GPL-2.0
/*
* ACRN HSM irqfd: use eventfd objects to inject virtual interrupts
*
* Copyright (C) 2020 Intel Corporation. All rights reserved.
*
* Authors:
* Shuo Liu <shuo.a.liu@intel.com>
* Yakui Zhao <yakui.zhao@intel.com>
*/
#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include "acrn_drv.h"
static LIST_HEAD(acrn_irqfd_clients);
/**
* struct hsm_irqfd - Properties of HSM irqfd
* @vm: Associated VM pointer
* @wait: Entry of wait-queue
* @shutdown: Async shutdown work
* @eventfd: Associated eventfd
* @list: Entry within &acrn_vm.irqfds of irqfds of a VM
* @pt: Structure for select/poll on the associated eventfd
* @msi: MSI data
*/
struct hsm_irqfd {
struct acrn_vm *vm;
wait_queue_entry_t wait;
struct work_struct shutdown;
struct eventfd_ctx *eventfd;
struct list_head list;
poll_table pt;
struct acrn_msi_entry msi;
};
static void acrn_irqfd_inject(struct hsm_irqfd *irqfd)
{
struct acrn_vm *vm = irqfd->vm;
acrn_msi_inject(vm, irqfd->msi.msi_addr,
irqfd->msi.msi_data);
}
static void hsm_irqfd_shutdown(struct hsm_irqfd *irqfd)
{
u64 cnt;
lockdep_assert_held(&irqfd->vm->irqfds_lock);
/* remove from wait queue */
list_del_init(&irqfd->list);
eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
eventfd_ctx_put(irqfd->eventfd);
kfree(irqfd);
}
static void hsm_irqfd_shutdown_work(struct work_struct *work)
{
struct hsm_irqfd *irqfd;
struct acrn_vm *vm;
irqfd = container_of(work, struct hsm_irqfd, shutdown);
vm = irqfd->vm;
mutex_lock(&vm->irqfds_lock);
if (!list_empty(&irqfd->list))
hsm_irqfd_shutdown(irqfd);
mutex_unlock(&vm->irqfds_lock);
}
/* Called with wqh->lock held and interrupts disabled */
static int hsm_irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode,
int sync, void *key)
{
unsigned long poll_bits = (unsigned long)key;
struct hsm_irqfd *irqfd;
struct acrn_vm *vm;
irqfd = container_of(wait, struct hsm_irqfd, wait);
vm = irqfd->vm;
if (poll_bits & POLLIN)
/* An event has been signaled, inject an interrupt */
acrn_irqfd_inject(irqfd);
if (poll_bits & POLLHUP)
/* Do shutdown work in thread to hold wqh->lock */
queue_work(vm->irqfd_wq, &irqfd->shutdown);
return 0;
}
static void hsm_irqfd_poll_func(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
{
struct hsm_irqfd *irqfd;
irqfd = container_of(pt, struct hsm_irqfd, pt);
add_wait_queue(wqh, &irqfd->wait);
}
/*
* Assign an eventfd to a VM and create a HSM irqfd associated with the
* eventfd. The properties of the HSM irqfd are built from a &struct
* acrn_irqfd.
*/
static int acrn_irqfd_assign(struct acrn_vm *vm, struct acrn_irqfd *args)
{
struct eventfd_ctx *eventfd = NULL;
struct hsm_irqfd *irqfd, *tmp;
__poll_t events;
struct fd f;
int ret = 0;
irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
if (!irqfd)
return -ENOMEM;
irqfd->vm = vm;
memcpy(&irqfd->msi, &args->msi, sizeof(args->msi));
INIT_LIST_HEAD(&irqfd->list);
INIT_WORK(&irqfd->shutdown, hsm_irqfd_shutdown_work);
f = fdget(args->fd);
if (!fd_file(f)) {
ret = -EBADF;
goto out;
}
eventfd = eventfd_ctx_fileget(fd_file(f));
if (IS_ERR(eventfd)) {
ret = PTR_ERR(eventfd);
goto fail;
}
irqfd->eventfd = eventfd;
/*
* Install custom wake-up handling to be notified whenever underlying
* eventfd is signaled.
*/
init_waitqueue_func_entry(&irqfd->wait, hsm_irqfd_wakeup);
init_poll_funcptr(&irqfd->pt, hsm_irqfd_poll_func);
mutex_lock(&vm->irqfds_lock);
list_for_each_entry(tmp, &vm->irqfds, list) {
if (irqfd->eventfd != tmp->eventfd)
continue;
ret = -EBUSY;
mutex_unlock(&vm->irqfds_lock);
goto fail;
}
list_add_tail(&irqfd->list, &vm->irqfds);
mutex_unlock(&vm->irqfds_lock);
/* Check the pending event in this stage */
events = vfs_poll(fd_file(f), &irqfd->pt);
if (events & EPOLLIN)
acrn_irqfd_inject(irqfd);
fdput(f);
return 0;
fail:
if (eventfd && !IS_ERR(eventfd))
eventfd_ctx_put(eventfd);
fdput(f);
out:
kfree(irqfd);
return ret;
}
static int acrn_irqfd_deassign(struct acrn_vm *vm,
struct acrn_irqfd *args)
{
struct hsm_irqfd *irqfd, *tmp;
struct eventfd_ctx *eventfd;
eventfd = eventfd_ctx_fdget(args->fd);
if (IS_ERR(eventfd))
return PTR_ERR(eventfd);
mutex_lock(&vm->irqfds_lock);
list_for_each_entry_safe(irqfd, tmp, &vm->irqfds, list) {
if (irqfd->eventfd == eventfd) {
hsm_irqfd_shutdown(irqfd);
break;
}
}
mutex_unlock(&vm->irqfds_lock);
eventfd_ctx_put(eventfd);
return 0;
}
int acrn_irqfd_config(struct acrn_vm *vm, struct acrn_irqfd *args)
{
int ret;
if (args->flags & ACRN_IRQFD_FLAG_DEASSIGN)
ret = acrn_irqfd_deassign(vm, args);
else
ret = acrn_irqfd_assign(vm, args);
return ret;
}
int acrn_irqfd_init(struct acrn_vm *vm)
{
INIT_LIST_HEAD(&vm->irqfds);
mutex_init(&vm->irqfds_lock);
vm->irqfd_wq = alloc_workqueue("acrn_irqfd-%u", 0, 0, vm->vmid);
if (!vm->irqfd_wq)
return -ENOMEM;
dev_dbg(acrn_dev.this_device, "VM %u irqfd init.\n", vm->vmid);
return 0;
}
void acrn_irqfd_deinit(struct acrn_vm *vm)
{
struct hsm_irqfd *irqfd, *next;
dev_dbg(acrn_dev.this_device, "VM %u irqfd deinit.\n", vm->vmid);
destroy_workqueue(vm->irqfd_wq);
mutex_lock(&vm->irqfds_lock);
list_for_each_entry_safe(irqfd, next, &vm->irqfds, list)
hsm_irqfd_shutdown(irqfd);
mutex_unlock(&vm->irqfds_lock);
}
|
