[PATCH 13/21] userfaultfd: UFFDIO_COPY|UFFDIO_ZEROPAGE uAPI

Andrea Arcangeli
2015-03-05T17:17:56Z

This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
---
include/uapi/linux/userfaultfd.h | 46 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 9a8cd56..61251e6 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -17,7 +17,9 @@
(__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
@@ -30,6 +32,8 @@
#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 */
@@ -42,6 +46,10 @@
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)

/*
* Valid bits below PAGE_SHIFT in the userfault address read through
@@ -78,4 +86,40 @@ 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" and "wake" are written by the ioctl and must be at
+ * the end: the copy_from_user will not read the last 16
+ * bytes.
+ */
+ __s64 copy;
+ __s64 wake;
+};
+
+struct uffdio_zeropage {
+ struct uffdio_range range;
+#define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0)
+ __u64 mode;
+
+ /*
+ * "zeropage" and "wake" are written by the ioctl and must be
+ * at the end: the copy_from_user will not read the last 16
+ * bytes.
+ */
+ __s64 zeropage;
+ __s64 wake;
+};
+
#endif /* _LINUX_USERFAULTFD_H */