Add G_GNUC_PRINTF to function qemu_set_info_str and fix related issues
[qemu.git] / linux-headers / linux / userfaultfd.h
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3 * include/linux/userfaultfd.h
4 *
5 * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
6 * Copyright (C) 2015 Red Hat, Inc.
7 *
8 */
9
10 #ifndef _LINUX_USERFAULTFD_H
11 #define _LINUX_USERFAULTFD_H
12
13 #include <linux/types.h>
14
15 /*
16 * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and
17 * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR. In
18 * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ
19 * means the userland is reading).
20 */
21 #define UFFD_API ((__u64)0xAA)
22 #define UFFD_API_REGISTER_MODES (UFFDIO_REGISTER_MODE_MISSING | \
23 UFFDIO_REGISTER_MODE_WP | \
24 UFFDIO_REGISTER_MODE_MINOR)
25 #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
26 UFFD_FEATURE_EVENT_FORK | \
27 UFFD_FEATURE_EVENT_REMAP | \
28 UFFD_FEATURE_EVENT_REMOVE | \
29 UFFD_FEATURE_EVENT_UNMAP | \
30 UFFD_FEATURE_MISSING_HUGETLBFS | \
31 UFFD_FEATURE_MISSING_SHMEM | \
32 UFFD_FEATURE_SIGBUS | \
33 UFFD_FEATURE_THREAD_ID | \
34 UFFD_FEATURE_MINOR_HUGETLBFS | \
35 UFFD_FEATURE_MINOR_SHMEM | \
36 UFFD_FEATURE_EXACT_ADDRESS)
37 #define UFFD_API_IOCTLS \
38 ((__u64)1 << _UFFDIO_REGISTER | \
39 (__u64)1 << _UFFDIO_UNREGISTER | \
40 (__u64)1 << _UFFDIO_API)
41 #define UFFD_API_RANGE_IOCTLS \
42 ((__u64)1 << _UFFDIO_WAKE | \
43 (__u64)1 << _UFFDIO_COPY | \
44 (__u64)1 << _UFFDIO_ZEROPAGE | \
45 (__u64)1 << _UFFDIO_WRITEPROTECT | \
46 (__u64)1 << _UFFDIO_CONTINUE)
47 #define UFFD_API_RANGE_IOCTLS_BASIC \
48 ((__u64)1 << _UFFDIO_WAKE | \
49 (__u64)1 << _UFFDIO_COPY | \
50 (__u64)1 << _UFFDIO_CONTINUE)
51
52 /*
53 * Valid ioctl command number range with this API is from 0x00 to
54 * 0x3F. UFFDIO_API is the fixed number, everything else can be
55 * changed by implementing a different UFFD_API. If sticking to the
56 * same UFFD_API more ioctl can be added and userland will be aware of
57 * which ioctl the running kernel implements through the ioctl command
58 * bitmask written by the UFFDIO_API.
59 */
60 #define _UFFDIO_REGISTER (0x00)
61 #define _UFFDIO_UNREGISTER (0x01)
62 #define _UFFDIO_WAKE (0x02)
63 #define _UFFDIO_COPY (0x03)
64 #define _UFFDIO_ZEROPAGE (0x04)
65 #define _UFFDIO_WRITEPROTECT (0x06)
66 #define _UFFDIO_CONTINUE (0x07)
67 #define _UFFDIO_API (0x3F)
68
69 /* userfaultfd ioctl ids */
70 #define UFFDIO 0xAA
71 #define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \
72 struct uffdio_api)
73 #define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \
74 struct uffdio_register)
75 #define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \
76 struct uffdio_range)
77 #define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \
78 struct uffdio_range)
79 #define UFFDIO_COPY _IOWR(UFFDIO, _UFFDIO_COPY, \
80 struct uffdio_copy)
81 #define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
82 struct uffdio_zeropage)
83 #define UFFDIO_WRITEPROTECT _IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
84 struct uffdio_writeprotect)
85 #define UFFDIO_CONTINUE _IOWR(UFFDIO, _UFFDIO_CONTINUE, \
86 struct uffdio_continue)
87
88 /* read() structure */
89 struct uffd_msg {
90 __u8 event;
91
92 __u8 reserved1;
93 __u16 reserved2;
94 __u32 reserved3;
95
96 union {
97 struct {
98 __u64 flags;
99 __u64 address;
100 union {
101 __u32 ptid;
102 } feat;
103 } pagefault;
104
105 struct {
106 __u32 ufd;
107 } fork;
108
109 struct {
110 __u64 from;
111 __u64 to;
112 __u64 len;
113 } remap;
114
115 struct {
116 __u64 start;
117 __u64 end;
118 } remove;
119
120 struct {
121 /* unused reserved fields */
122 __u64 reserved1;
123 __u64 reserved2;
124 __u64 reserved3;
125 } reserved;
126 } arg;
127 } __attribute__((packed));
128
129 /*
130 * Start at 0x12 and not at 0 to be more strict against bugs.
131 */
132 #define UFFD_EVENT_PAGEFAULT 0x12
133 #define UFFD_EVENT_FORK 0x13
134 #define UFFD_EVENT_REMAP 0x14
135 #define UFFD_EVENT_REMOVE 0x15
136 #define UFFD_EVENT_UNMAP 0x16
137
138 /* flags for UFFD_EVENT_PAGEFAULT */
139 #define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */
140 #define UFFD_PAGEFAULT_FLAG_WP (1<<1) /* If reason is VM_UFFD_WP */
141 #define UFFD_PAGEFAULT_FLAG_MINOR (1<<2) /* If reason is VM_UFFD_MINOR */
142
143 struct uffdio_api {
144 /* userland asks for an API number and the features to enable */
145 __u64 api;
146 /*
147 * Kernel answers below with the all available features for
148 * the API, this notifies userland of which events and/or
149 * which flags for each event are enabled in the current
150 * kernel.
151 *
152 * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
153 * are to be considered implicitly always enabled in all kernels as
154 * long as the uffdio_api.api requested matches UFFD_API.
155 *
156 * UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER
157 * with UFFDIO_REGISTER_MODE_MISSING mode will succeed on
158 * hugetlbfs virtual memory ranges. Adding or not adding
159 * UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has
160 * no real functional effect after UFFDIO_API returns, but
161 * it's only useful for an initial feature set probe at
162 * UFFDIO_API time. There are two ways to use it:
163 *
164 * 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the
165 * uffdio_api.features before calling UFFDIO_API, an error
166 * will be returned by UFFDIO_API on a kernel without
167 * hugetlbfs missing support
168 *
169 * 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in
170 * uffdio_api.features and instead it will be set by the
171 * kernel in the uffdio_api.features if the kernel supports
172 * it, so userland can later check if the feature flag is
173 * present in uffdio_api.features after UFFDIO_API
174 * succeeded.
175 *
176 * UFFD_FEATURE_MISSING_SHMEM works the same as
177 * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem
178 * (i.e. tmpfs and other shmem based APIs).
179 *
180 * UFFD_FEATURE_SIGBUS feature means no page-fault
181 * (UFFD_EVENT_PAGEFAULT) event will be delivered, instead
182 * a SIGBUS signal will be sent to the faulting process.
183 *
184 * UFFD_FEATURE_THREAD_ID pid of the page faulted task_struct will
185 * be returned, if feature is not requested 0 will be returned.
186 *
187 * UFFD_FEATURE_MINOR_HUGETLBFS indicates that minor faults
188 * can be intercepted (via REGISTER_MODE_MINOR) for
189 * hugetlbfs-backed pages.
190 *
191 * UFFD_FEATURE_MINOR_SHMEM indicates the same support as
192 * UFFD_FEATURE_MINOR_HUGETLBFS, but for shmem-backed pages instead.
193 *
194 * UFFD_FEATURE_EXACT_ADDRESS indicates that the exact address of page
195 * faults would be provided and the offset within the page would not be
196 * masked.
197 */
198 #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0)
199 #define UFFD_FEATURE_EVENT_FORK (1<<1)
200 #define UFFD_FEATURE_EVENT_REMAP (1<<2)
201 #define UFFD_FEATURE_EVENT_REMOVE (1<<3)
202 #define UFFD_FEATURE_MISSING_HUGETLBFS (1<<4)
203 #define UFFD_FEATURE_MISSING_SHMEM (1<<5)
204 #define UFFD_FEATURE_EVENT_UNMAP (1<<6)
205 #define UFFD_FEATURE_SIGBUS (1<<7)
206 #define UFFD_FEATURE_THREAD_ID (1<<8)
207 #define UFFD_FEATURE_MINOR_HUGETLBFS (1<<9)
208 #define UFFD_FEATURE_MINOR_SHMEM (1<<10)
209 #define UFFD_FEATURE_EXACT_ADDRESS (1<<11)
210 __u64 features;
211
212 __u64 ioctls;
213 };
214
215 struct uffdio_range {
216 __u64 start;
217 __u64 len;
218 };
219
220 struct uffdio_register {
221 struct uffdio_range range;
222 #define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0)
223 #define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1)
224 #define UFFDIO_REGISTER_MODE_MINOR ((__u64)1<<2)
225 __u64 mode;
226
227 /*
228 * kernel answers which ioctl commands are available for the
229 * range, keep at the end as the last 8 bytes aren't read.
230 */
231 __u64 ioctls;
232 };
233
234 struct uffdio_copy {
235 __u64 dst;
236 __u64 src;
237 __u64 len;
238 #define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
239 /*
240 * UFFDIO_COPY_MODE_WP will map the page write protected on
241 * the fly. UFFDIO_COPY_MODE_WP is available only if the
242 * write protected ioctl is implemented for the range
243 * according to the uffdio_register.ioctls.
244 */
245 #define UFFDIO_COPY_MODE_WP ((__u64)1<<1)
246 __u64 mode;
247
248 /*
249 * "copy" is written by the ioctl and must be at the end: the
250 * copy_from_user will not read the last 8 bytes.
251 */
252 __s64 copy;
253 };
254
255 struct uffdio_zeropage {
256 struct uffdio_range range;
257 #define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0)
258 __u64 mode;
259
260 /*
261 * "zeropage" is written by the ioctl and must be at the end:
262 * the copy_from_user will not read the last 8 bytes.
263 */
264 __s64 zeropage;
265 };
266
267 struct uffdio_writeprotect {
268 struct uffdio_range range;
269 /*
270 * UFFDIO_WRITEPROTECT_MODE_WP: set the flag to write protect a range,
271 * unset the flag to undo protection of a range which was previously
272 * write protected.
273 *
274 * UFFDIO_WRITEPROTECT_MODE_DONTWAKE: set the flag to avoid waking up
275 * any wait thread after the operation succeeds.
276 *
277 * NOTE: Write protecting a region (WP=1) is unrelated to page faults,
278 * therefore DONTWAKE flag is meaningless with WP=1. Removing write
279 * protection (WP=0) in response to a page fault wakes the faulting
280 * task unless DONTWAKE is set.
281 */
282 #define UFFDIO_WRITEPROTECT_MODE_WP ((__u64)1<<0)
283 #define UFFDIO_WRITEPROTECT_MODE_DONTWAKE ((__u64)1<<1)
284 __u64 mode;
285 };
286
287 struct uffdio_continue {
288 struct uffdio_range range;
289 #define UFFDIO_CONTINUE_MODE_DONTWAKE ((__u64)1<<0)
290 __u64 mode;
291
292 /*
293 * Fields below here are written by the ioctl and must be at the end:
294 * the copy_from_user will not read past here.
295 */
296 __s64 mapped;
297 };
298
299 /*
300 * Flags for the userfaultfd(2) system call itself.
301 */
302
303 /*
304 * Create a userfaultfd that can handle page faults only in user mode.
305 */
306 #define UFFD_USER_MODE_ONLY 1
307
308 #endif /* _LINUX_USERFAULTFD_H */