userfaultfd: UFFDIO_COPY|UFFDIO_ZEROPAGE uAPI

This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 41 insertions, 1 deletions

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index a5f8825381ef..df0e09bb7dd5 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -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 */