[mirror_qemu.git] / linux-headers / linux / userfaultfd.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 *  include/linux/userfaultfd.h
 *
 *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
 *  Copyright (C) 2015  Red Hat, Inc.
 *
 */

#ifndef _LINUX_USERFAULTFD_H
#define _LINUX_USERFAULTFD_H

#include <linux/types.h>

/*
 * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and
 * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR.  In
 * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ
 * means the userland is reading).
 */
#define UFFD_API ((__u64)0xAA)
#define UFFD_API_REGISTER_MODES (UFFDIO_REGISTER_MODE_MISSING |	\
				 UFFDIO_REGISTER_MODE_WP |	\
				 UFFDIO_REGISTER_MODE_MINOR)
#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP |	\
			   UFFD_FEATURE_EVENT_FORK |		\
			   UFFD_FEATURE_EVENT_REMAP |		\
			   UFFD_FEATURE_EVENT_REMOVE |		\
			   UFFD_FEATURE_EVENT_UNMAP |		\
			   UFFD_FEATURE_MISSING_HUGETLBFS |	\
			   UFFD_FEATURE_MISSING_SHMEM |		\
			   UFFD_FEATURE_SIGBUS |		\
			   UFFD_FEATURE_THREAD_ID |		\
			   UFFD_FEATURE_MINOR_HUGETLBFS)
#define UFFD_API_IOCTLS				\
	((__u64)1 << _UFFDIO_REGISTER |		\
	 (__u64)1 << _UFFDIO_UNREGISTER |	\
	 (__u64)1 << _UFFDIO_API)
#define UFFD_API_RANGE_IOCTLS			\
	((__u64)1 << _UFFDIO_WAKE |		\
	 (__u64)1 << _UFFDIO_COPY |		\
	 (__u64)1 << _UFFDIO_ZEROPAGE |		\
	 (__u64)1 << _UFFDIO_WRITEPROTECT |	\
	 (__u64)1 << _UFFDIO_CONTINUE)
#define UFFD_API_RANGE_IOCTLS_BASIC		\
	((__u64)1 << _UFFDIO_WAKE |		\
	 (__u64)1 << _UFFDIO_COPY |		\
	 (__u64)1 << _UFFDIO_CONTINUE)

/*
 * Valid ioctl command number range with this API is from 0x00 to
 * 0x3F.  UFFDIO_API is the fixed number, everything else can be
 * changed by implementing a different UFFD_API. If sticking to the
 * same UFFD_API more ioctl can be added and userland will be aware of
 * which ioctl the running kernel implements through the ioctl command
 * bitmask written by the UFFDIO_API.
 */
#define _UFFDIO_REGISTER		(0x00)
#define _UFFDIO_UNREGISTER		(0x01)
#define _UFFDIO_WAKE			(0x02)
#define _UFFDIO_COPY			(0x03)
#define _UFFDIO_ZEROPAGE		(0x04)
#define _UFFDIO_WRITEPROTECT		(0x06)
#define _UFFDIO_CONTINUE		(0x07)
#define _UFFDIO_API			(0x3F)

/* userfaultfd ioctl ids */
#define UFFDIO 0xAA
#define UFFDIO_API		_IOWR(UFFDIO, _UFFDIO_API,	\
				      struct uffdio_api)
#define UFFDIO_REGISTER		_IOWR(UFFDIO, _UFFDIO_REGISTER, \
				      struct uffdio_register)
#define UFFDIO_UNREGISTER	_IOR(UFFDIO, _UFFDIO_UNREGISTER,	\
				     struct uffdio_range)
#define UFFDIO_WAKE		_IOR(UFFDIO, _UFFDIO_WAKE,	\
				     struct uffdio_range)
#define UFFDIO_COPY		_IOWR(UFFDIO, _UFFDIO_COPY,	\
				      struct uffdio_copy)
#define UFFDIO_ZEROPAGE		_IOWR(UFFDIO, _UFFDIO_ZEROPAGE,	\
				      struct uffdio_zeropage)
#define UFFDIO_WRITEPROTECT	_IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
				      struct uffdio_writeprotect)
#define UFFDIO_CONTINUE		_IOR(UFFDIO, _UFFDIO_CONTINUE,	\
				     struct uffdio_continue)

/* read() structure */
struct uffd_msg {
	__u8	event;

	__u8	reserved1;
	__u16	reserved2;
	__u32	reserved3;

	union {
		struct {
			__u64	flags;
			__u64	address;
			union {
				__u32 ptid;
			} feat;
		} pagefault;

		struct {
			__u32	ufd;
		} fork;

		struct {
			__u64	from;
			__u64	to;
			__u64	len;
		} remap;

		struct {
			__u64	start;
			__u64	end;
		} remove;

		struct {
			/* unused reserved fields */
			__u64	reserved1;
			__u64	reserved2;
			__u64	reserved3;
		} reserved;
	} arg;
} __attribute__((packed));

/*
 * Start at 0x12 and not at 0 to be more strict against bugs.
 */
#define UFFD_EVENT_PAGEFAULT	0x12
#define UFFD_EVENT_FORK		0x13
#define UFFD_EVENT_REMAP	0x14
#define UFFD_EVENT_REMOVE	0x15
#define UFFD_EVENT_UNMAP	0x16

/* flags for UFFD_EVENT_PAGEFAULT */
#define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */
#define UFFD_PAGEFAULT_FLAG_WP		(1<<1)	/* If reason is VM_UFFD_WP */
#define UFFD_PAGEFAULT_FLAG_MINOR	(1<<2)	/* If reason is VM_UFFD_MINOR */

struct uffdio_api {
	/* userland asks for an API number and the features to enable */
	__u64 api;
	/*
	 * Kernel answers below with the all available features for
	 * the API, this notifies userland of which events and/or
	 * which flags for each event are enabled in the current
	 * kernel.
	 *
	 * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
	 * are to be considered implicitly always enabled in all kernels as
	 * long as the uffdio_api.api requested matches UFFD_API.
	 *
	 * UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER
	 * with UFFDIO_REGISTER_MODE_MISSING mode will succeed on
	 * hugetlbfs virtual memory ranges. Adding or not adding
	 * UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has
	 * no real functional effect after UFFDIO_API returns, but
	 * it's only useful for an initial feature set probe at
	 * UFFDIO_API time. There are two ways to use it:
	 *
	 * 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the
	 *    uffdio_api.features before calling UFFDIO_API, an error
	 *    will be returned by UFFDIO_API on a kernel without
	 *    hugetlbfs missing support
	 *
	 * 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in
	 *    uffdio_api.features and instead it will be set by the
	 *    kernel in the uffdio_api.features if the kernel supports
	 *    it, so userland can later check if the feature flag is
	 *    present in uffdio_api.features after UFFDIO_API
	 *    succeeded.
	 *
	 * UFFD_FEATURE_MISSING_SHMEM works the same as
	 * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem
	 * (i.e. tmpfs and other shmem based APIs).
	 *
	 * UFFD_FEATURE_SIGBUS feature means no page-fault
	 * (UFFD_EVENT_PAGEFAULT) event will be delivered, instead
	 * a SIGBUS signal will be sent to the faulting process.
	 *
	 * UFFD_FEATURE_THREAD_ID pid of the page faulted task_struct will
	 * be returned, if feature is not requested 0 will be returned.
	 *
	 * UFFD_FEATURE_MINOR_HUGETLBFS indicates that minor faults
	 * can be intercepted (via REGISTER_MODE_MINOR) for
	 * hugetlbfs-backed pages.
	 */
#define UFFD_FEATURE_PAGEFAULT_FLAG_WP		(1<<0)
#define UFFD_FEATURE_EVENT_FORK			(1<<1)
#define UFFD_FEATURE_EVENT_REMAP		(1<<2)
#define UFFD_FEATURE_EVENT_REMOVE		(1<<3)
#define UFFD_FEATURE_MISSING_HUGETLBFS		(1<<4)
#define UFFD_FEATURE_MISSING_SHMEM		(1<<5)
#define UFFD_FEATURE_EVENT_UNMAP		(1<<6)
#define UFFD_FEATURE_SIGBUS			(1<<7)
#define UFFD_FEATURE_THREAD_ID			(1<<8)
#define UFFD_FEATURE_MINOR_HUGETLBFS		(1<<9)
	__u64 features;

	__u64 ioctls;
};

struct uffdio_range {
	__u64 start;
	__u64 len;
};

struct uffdio_register {
	struct uffdio_range range;
#define UFFDIO_REGISTER_MODE_MISSING	((__u64)1<<0)
#define UFFDIO_REGISTER_MODE_WP		((__u64)1<<1)
#define UFFDIO_REGISTER_MODE_MINOR	((__u64)1<<2)
	__u64 mode;

	/*
	 * kernel answers which ioctl commands are available for the
	 * range, keep at the end as the last 8 bytes aren't read.
	 */
	__u64 ioctls;
};

struct uffdio_copy {
	__u64 dst;
	__u64 src;
	__u64 len;
#define UFFDIO_COPY_MODE_DONTWAKE		((__u64)1<<0)
	/*
	 * UFFDIO_COPY_MODE_WP will map the page write protected on
	 * the fly.  UFFDIO_COPY_MODE_WP is available only if the
	 * write protected ioctl is implemented for the range
	 * according to the uffdio_register.ioctls.
	 */
#define UFFDIO_COPY_MODE_WP			((__u64)1<<1)
	__u64 mode;

	/*
	 * "copy" is written by the ioctl and must be at the end: the
	 * copy_from_user will not read the last 8 bytes.
	 */
	__s64 copy;
};

struct uffdio_zeropage {
	struct uffdio_range range;
#define UFFDIO_ZEROPAGE_MODE_DONTWAKE		((__u64)1<<0)
	__u64 mode;

	/*
	 * "zeropage" is written by the ioctl and must be at the end:
	 * the copy_from_user will not read the last 8 bytes.
	 */
	__s64 zeropage;
};

struct uffdio_writeprotect {
	struct uffdio_range range;
/*
 * UFFDIO_WRITEPROTECT_MODE_WP: set the flag to write protect a range,
 * unset the flag to undo protection of a range which was previously
 * write protected.
 *
 * UFFDIO_WRITEPROTECT_MODE_DONTWAKE: set the flag to avoid waking up
 * any wait thread after the operation succeeds.
 *
 * NOTE: Write protecting a region (WP=1) is unrelated to page faults,
 * therefore DONTWAKE flag is meaningless with WP=1.  Removing write
 * protection (WP=0) in response to a page fault wakes the faulting
 * task unless DONTWAKE is set.
 */
#define UFFDIO_WRITEPROTECT_MODE_WP		((__u64)1<<0)
#define UFFDIO_WRITEPROTECT_MODE_DONTWAKE	((__u64)1<<1)
	__u64 mode;
};

struct uffdio_continue {
	struct uffdio_range range;
#define UFFDIO_CONTINUE_MODE_DONTWAKE		((__u64)1<<0)
	__u64 mode;

	/*
	 * Fields below here are written by the ioctl and must be at the end:
	 * the copy_from_user will not read past here.
	 */
	__s64 mapped;
};

/*
 * Flags for the userfaultfd(2) system call itself.
 */

/*
 * Create a userfaultfd that can handle page faults only in user mode.
 */
#define UFFD_USER_MODE_ONLY 1

#endif /* _LINUX_USERFAULTFD_H */
Commit	Line	Data
dd873966	1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
c1fcf220 DDAG	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
c1fcf220	15	/*
3a5eb5b4 PB	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).
c1fcf220	20	*/
3a5eb5b4	21	#define UFFD_API ((__u64)0xAA)
278f064e EH	22	#define UFFD_API_REGISTER_MODES (UFFDIO_REGISTER_MODE_MISSING \| \
	23	UFFDIO_REGISTER_MODE_WP \| \
	24	UFFDIO_REGISTER_MODE_MINOR)
dc6f8d45 CH	25	#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP \| \
dc6f8d45 CH	26	UFFD_FEATURE_EVENT_FORK \| \
3a5eb5b4	27	UFFD_FEATURE_EVENT_REMAP \| \
278f064e	28	UFFD_FEATURE_EVENT_REMOVE \| \
74c98e20	29	UFFD_FEATURE_EVENT_UNMAP \| \
3a5eb5b4	30	UFFD_FEATURE_MISSING_HUGETLBFS \| \
d4083f50 AP	31	UFFD_FEATURE_MISSING_SHMEM \| \
d4083f50 AP	32	UFFD_FEATURE_SIGBUS \| \
278f064e EH	33	UFFD_FEATURE_THREAD_ID \| \
278f064e EH	34	UFFD_FEATURE_MINOR_HUGETLBFS)
c1fcf220 DDAG	35	#define UFFD_API_IOCTLS \
	36	((__u64)1 << _UFFDIO_REGISTER \| \
	37	(__u64)1 << _UFFDIO_UNREGISTER \| \
	38	(__u64)1 << _UFFDIO_API)
	39	#define UFFD_API_RANGE_IOCTLS \
	40	((__u64)1 << _UFFDIO_WAKE \| \
	41	(__u64)1 << _UFFDIO_COPY \| \
dc6f8d45	42	(__u64)1 << _UFFDIO_ZEROPAGE \| \
278f064e EH	43	(__u64)1 << _UFFDIO_WRITEPROTECT \| \
278f064e EH	44	(__u64)1 << _UFFDIO_CONTINUE)
3a5eb5b4 PB	45	#define UFFD_API_RANGE_IOCTLS_BASIC \
3a5eb5b4 PB	46	((__u64)1 << _UFFDIO_WAKE \| \
278f064e EH	47	(__u64)1 << _UFFDIO_COPY \| \
278f064e EH	48	(__u64)1 << _UFFDIO_CONTINUE)
c1fcf220 DDAG	49
	50	/*
	51	* Valid ioctl command number range with this API is from 0x00 to
	52	* 0x3F. UFFDIO_API is the fixed number, everything else can be
	53	* changed by implementing a different UFFD_API. If sticking to the
	54	* same UFFD_API more ioctl can be added and userland will be aware of
	55	* which ioctl the running kernel implements through the ioctl command
	56	* bitmask written by the UFFDIO_API.
	57	*/
	58	#define _UFFDIO_REGISTER (0x00)
	59	#define _UFFDIO_UNREGISTER (0x01)
	60	#define _UFFDIO_WAKE (0x02)
	61	#define _UFFDIO_COPY (0x03)
	62	#define _UFFDIO_ZEROPAGE (0x04)
dc6f8d45	63	#define _UFFDIO_WRITEPROTECT (0x06)
278f064e	64	#define _UFFDIO_CONTINUE (0x07)
c1fcf220 DDAG	65	#define _UFFDIO_API (0x3F)
	66
	67	/* userfaultfd ioctl ids */
	68	#define UFFDIO 0xAA
	69	#define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \
	70	struct uffdio_api)
	71	#define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \
	72	struct uffdio_register)
	73	#define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \
	74	struct uffdio_range)
	75	#define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \
	76	struct uffdio_range)
	77	#define UFFDIO_COPY _IOWR(UFFDIO, _UFFDIO_COPY, \
	78	struct uffdio_copy)
	79	#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
	80	struct uffdio_zeropage)
dc6f8d45 CH	81	#define UFFDIO_WRITEPROTECT _IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
dc6f8d45 CH	82	struct uffdio_writeprotect)
278f064e EH	83	#define UFFDIO_CONTINUE _IOR(UFFDIO, _UFFDIO_CONTINUE, \
278f064e EH	84	struct uffdio_continue)
c1fcf220 DDAG	85
	86	/* read() structure */
	87	struct uffd_msg {
	88	__u8 event;
	89
	90	__u8 reserved1;
	91	__u16 reserved2;
	92	__u32 reserved3;
	93
	94	union {
	95	struct {
	96	__u64 flags;
	97	__u64 address;
d4083f50 AP	98	union {
	99	__u32 ptid;
	100	} feat;
c1fcf220 DDAG	101	} pagefault;
c1fcf220 DDAG	102
3a5eb5b4 PB	103	struct {
	104	__u32 ufd;
	105	} fork;
	106
	107	struct {
	108	__u64 from;
	109	__u64 to;
	110	__u64 len;
	111	} remap;
	112
	113	struct {
	114	__u64 start;
	115	__u64 end;
74c98e20	116	} remove;
3a5eb5b4	117
c1fcf220 DDAG	118	struct {
	119	/* unused reserved fields */
	120	__u64 reserved1;
	121	__u64 reserved2;
	122	__u64 reserved3;
	123	} reserved;
	124	} arg;
b89485a5	125	} __attribute__((packed));
c1fcf220 DDAG	126
	127	/*
	128	* Start at 0x12 and not at 0 to be more strict against bugs.
	129	*/
	130	#define UFFD_EVENT_PAGEFAULT 0x12
c1fcf220	131	#define UFFD_EVENT_FORK 0x13
3a5eb5b4	132	#define UFFD_EVENT_REMAP 0x14
74c98e20 CH	133	#define UFFD_EVENT_REMOVE 0x15
74c98e20 CH	134	#define UFFD_EVENT_UNMAP 0x16
c1fcf220 DDAG	135
	136	/* flags for UFFD_EVENT_PAGEFAULT */
	137	#define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */
	138	#define UFFD_PAGEFAULT_FLAG_WP (1<<1) /* If reason is VM_UFFD_WP */
278f064e	139	#define UFFD_PAGEFAULT_FLAG_MINOR (1<<2) /* If reason is VM_UFFD_MINOR */
c1fcf220 DDAG	140
	141	struct uffdio_api {
	142	/* userland asks for an API number and the features to enable */
	143	__u64 api;
	144	/*
	145	* Kernel answers below with the all available features for
	146	* the API, this notifies userland of which events and/or
	147	* which flags for each event are enabled in the current
	148	* kernel.
	149	*
	150	* Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
	151	* are to be considered implicitly always enabled in all kernels as
	152	* long as the uffdio_api.api requested matches UFFD_API.
3a5eb5b4 PB	153	*
	154	* UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER
	155	* with UFFDIO_REGISTER_MODE_MISSING mode will succeed on
	156	* hugetlbfs virtual memory ranges. Adding or not adding
	157	* UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has
	158	* no real functional effect after UFFDIO_API returns, but
	159	* it's only useful for an initial feature set probe at
	160	* UFFDIO_API time. There are two ways to use it:
	161	*
	162	* 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the
	163	* uffdio_api.features before calling UFFDIO_API, an error
	164	* will be returned by UFFDIO_API on a kernel without
	165	* hugetlbfs missing support
	166	*
	167	* 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in
	168	* uffdio_api.features and instead it will be set by the
	169	* kernel in the uffdio_api.features if the kernel supports
	170	* it, so userland can later check if the feature flag is
	171	* present in uffdio_api.features after UFFDIO_API
	172	* succeeded.
	173	*
	174	* UFFD_FEATURE_MISSING_SHMEM works the same as
	175	* UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem
	176	* (i.e. tmpfs and other shmem based APIs).
d4083f50 AP	177	*
	178	* UFFD_FEATURE_SIGBUS feature means no page-fault
	179	* (UFFD_EVENT_PAGEFAULT) event will be delivered, instead
	180	* a SIGBUS signal will be sent to the faulting process.
	181	*
	182	* UFFD_FEATURE_THREAD_ID pid of the page faulted task_struct will
	183	* be returned, if feature is not requested 0 will be returned.
278f064e EH	184	*
	185	* UFFD_FEATURE_MINOR_HUGETLBFS indicates that minor faults
	186	* can be intercepted (via REGISTER_MODE_MINOR) for
	187	* hugetlbfs-backed pages.
c1fcf220	188	*/
c1fcf220 DDAG	189	#define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0)
c1fcf220 DDAG	190	#define UFFD_FEATURE_EVENT_FORK (1<<1)
3a5eb5b4	191	#define UFFD_FEATURE_EVENT_REMAP (1<<2)
74c98e20	192	#define UFFD_FEATURE_EVENT_REMOVE (1<<3)
3a5eb5b4 PB	193	#define UFFD_FEATURE_MISSING_HUGETLBFS (1<<4)
3a5eb5b4 PB	194	#define UFFD_FEATURE_MISSING_SHMEM (1<<5)
74c98e20	195	#define UFFD_FEATURE_EVENT_UNMAP (1<<6)
d4083f50 AP	196	#define UFFD_FEATURE_SIGBUS (1<<7)
d4083f50 AP	197	#define UFFD_FEATURE_THREAD_ID (1<<8)
278f064e	198	#define UFFD_FEATURE_MINOR_HUGETLBFS (1<<9)
c1fcf220 DDAG	199	__u64 features;
	200
	201	__u64 ioctls;
	202	};
	203
	204	struct uffdio_range {
	205	__u64 start;
	206	__u64 len;
	207	};
	208
	209	struct uffdio_register {
	210	struct uffdio_range range;
	211	#define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0)
	212	#define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1)
278f064e	213	#define UFFDIO_REGISTER_MODE_MINOR ((__u64)1<<2)
c1fcf220 DDAG	214	__u64 mode;
	215
	216	/*
	217	* kernel answers which ioctl commands are available for the
	218	* range, keep at the end as the last 8 bytes aren't read.
	219	*/
	220	__u64 ioctls;
	221	};
	222
	223	struct uffdio_copy {
	224	__u64 dst;
	225	__u64 src;
	226	__u64 len;
dc6f8d45	227	#define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0)
c1fcf220	228	/*
dc6f8d45 CH	229	* UFFDIO_COPY_MODE_WP will map the page write protected on
	230	* the fly. UFFDIO_COPY_MODE_WP is available only if the
	231	* write protected ioctl is implemented for the range
	232	* according to the uffdio_register.ioctls.
c1fcf220	233	*/
dc6f8d45	234	#define UFFDIO_COPY_MODE_WP ((__u64)1<<1)
c1fcf220 DDAG	235	__u64 mode;
	236
	237	/*
	238	* "copy" is written by the ioctl and must be at the end: the
	239	* copy_from_user will not read the last 8 bytes.
	240	*/
	241	__s64 copy;
	242	};
	243
	244	struct uffdio_zeropage {
	245	struct uffdio_range range;
	246	#define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0)
	247	__u64 mode;
	248
	249	/*
	250	* "zeropage" is written by the ioctl and must be at the end:
	251	* the copy_from_user will not read the last 8 bytes.
	252	*/
	253	__s64 zeropage;
	254	};
	255
dc6f8d45 CH	256	struct uffdio_writeprotect {
	257	struct uffdio_range range;
	258	/*
	259	* UFFDIO_WRITEPROTECT_MODE_WP: set the flag to write protect a range,
	260	* unset the flag to undo protection of a range which was previously
	261	* write protected.
	262	*
	263	* UFFDIO_WRITEPROTECT_MODE_DONTWAKE: set the flag to avoid waking up
	264	* any wait thread after the operation succeeds.
	265	*
	266	* NOTE: Write protecting a region (WP=1) is unrelated to page faults,
	267	* therefore DONTWAKE flag is meaningless with WP=1. Removing write
	268	* protection (WP=0) in response to a page fault wakes the faulting
	269	* task unless DONTWAKE is set.
	270	*/
	271	#define UFFDIO_WRITEPROTECT_MODE_WP ((__u64)1<<0)
	272	#define UFFDIO_WRITEPROTECT_MODE_DONTWAKE ((__u64)1<<1)
	273	__u64 mode;
	274	};
	275
278f064e EH	276	struct uffdio_continue {
	277	struct uffdio_range range;
	278	#define UFFDIO_CONTINUE_MODE_DONTWAKE ((__u64)1<<0)
	279	__u64 mode;
	280
	281	/*
	282	* Fields below here are written by the ioctl and must be at the end:
	283	* the copy_from_user will not read past here.
	284	*/
	285	__s64 mapped;
	286	};
	287
b3c818a4 EF	288	/*
	289	* Flags for the userfaultfd(2) system call itself.
	290	*/
	291
	292	/*
	293	* Create a userfaultfd that can handle page faults only in user mode.
	294	*/
	295	#define UFFD_USER_MODE_ONLY 1
	296
c1fcf220	297	#endif /* _LINUX_USERFAULTFD_H */