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Commit 1f1c6f07 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

userfaultfd: UFFDIO_COPY|UFFDIO_ZEROPAGE uAPI 



This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.

Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1380fca0

include/uapi/linux/userfaultfd.h

+41 −1
Original line number Diff line number Diff line
@@ -25,7 +25,9 @@ 
	 (__u64)1 << _UFFDIO_UNREGISTER |	\

	 (__u64)1 << _UFFDIO_API)

#define UFFD_API_RANGE_IOCTLS			\

	((__u64)1 << _UFFDIO_WAKE)

	((__u64)1 << _UFFDIO_WAKE |		\

	 (__u64)1 << _UFFDIO_COPY |		\

	 (__u64)1 << _UFFDIO_ZEROPAGE)



/*

 * Valid ioctl command number range with this API is from 0x00 to
@@ -38,6 +40,8 @@ 
#define _UFFDIO_REGISTER		(0x00)

#define _UFFDIO_UNREGISTER		(0x01)

#define _UFFDIO_WAKE			(0x02)

#define _UFFDIO_COPY			(0x03)

#define _UFFDIO_ZEROPAGE		(0x04)

#define _UFFDIO_API			(0x3F)



/* userfaultfd ioctl ids */
@@ -50,6 +54,10 @@ 
				     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)



/* read() structure */

struct uffd_msg {
@@ -126,4 +134,36 @@ struct uffdio_register { 
	__u64 ioctls;

};



struct uffdio_copy {

	__u64 dst;

	__u64 src;

	__u64 len;

	/*

	 * There will be a wrprotection flag later that allows to map

	 * pages wrprotected on the fly. And such a flag will be

	 * available if the wrprotection ioctl are implemented for the

	 * range according to the uffdio_register.ioctls.

	 */

#define UFFDIO_COPY_MODE_DONTWAKE		((__u64)1<<0)

	__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;

};



#endif /* _LINUX_USERFAULTFD_H */