[Qemu-devel] [PATCH 20/23] 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 | 42 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 8e42bc3..c8a543f 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -21,7 +21,9 @@
         (__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
@@ -34,6 +36,8 @@
 #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 */
@@ -46,6 +50,10 @@
                                     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 {
@@ -118,4 +126,36 @@ 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 */