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

[Andrea Arcangeli]

This implements the uABI of UFFDIO_COPY and UFFDIO_ZEROPAGE.

Signed-off-by: Andrea Arcangeli <address@hidden>
---
 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 */