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[Qemu-devel] [PATCH 18/21] userfaultfd: UFFDIO_REMAP uABI
From: |
Andrea Arcangeli |
Subject: |
[Qemu-devel] [PATCH 18/21] userfaultfd: UFFDIO_REMAP uABI |
Date: |
Thu, 5 Mar 2015 18:18:01 +0100 |
This implements the uABI of UFFDIO_REMAP.
Notably one mode bitflag is also forwarded (and in turn known) by the
lowlevel remap_pages method.
Signed-off-by: Andrea Arcangeli <address@hidden>
---
include/uapi/linux/userfaultfd.h | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
index 61251e6..db6e99a 100644
--- a/include/uapi/linux/userfaultfd.h
+++ b/include/uapi/linux/userfaultfd.h
@@ -19,7 +19,8 @@
#define UFFD_API_RANGE_IOCTLS \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
- (__u64)1 << _UFFDIO_ZEROPAGE)
+ (__u64)1 << _UFFDIO_ZEROPAGE | \
+ (__u64)1 << _UFFDIO_REMAP)
/*
* Valid ioctl command number range with this API is from 0x00 to
@@ -34,6 +35,7 @@
#define _UFFDIO_WAKE (0x02)
#define _UFFDIO_COPY (0x03)
#define _UFFDIO_ZEROPAGE (0x04)
+#define _UFFDIO_REMAP (0x05)
#define _UFFDIO_API (0x3F)
/* userfaultfd ioctl ids */
@@ -50,6 +52,8 @@
struct uffdio_copy)
#define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
struct uffdio_zeropage)
+#define UFFDIO_REMAP _IOWR(UFFDIO, _UFFDIO_REMAP, \
+ struct uffdio_remap)
/*
* Valid bits below PAGE_SHIFT in the userfault address read through
@@ -122,4 +126,25 @@ struct uffdio_zeropage {
__s64 wake;
};
+struct uffdio_remap {
+ __u64 dst;
+ __u64 src;
+ __u64 len;
+ /*
+ * Especially if used to atomically remove memory from the
+ * address space the wake on the dst range is not needed.
+ */
+#define UFFDIO_REMAP_MODE_DONTWAKE ((__u64)1<<0)
+#define UFFDIO_REMAP_MODE_ALLOW_SRC_HOLES ((__u64)1<<1)
+ __u64 mode;
+
+ /*
+ * "remap" 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 remap;
+ __s64 wake;
+};
+
#endif /* _LINUX_USERFAULTFD_H */
- Re: [Qemu-devel] [PATCH 19/21] userfaultfd: remap_pages: UFFDIO_REMAP preparation, (continued)
- [Qemu-devel] [PATCH 04/21] userfaultfd: linux/userfaultfd_k.h, Andrea Arcangeli, 2015/03/05
- [Qemu-devel] [PATCH 14/21] userfaultfd: mcopy_atomic|mfill_zeropage: UFFDIO_COPY|UFFDIO_ZEROPAGE preparation, Andrea Arcangeli, 2015/03/05
- [Qemu-devel] [PATCH 03/21] userfaultfd: uAPI, Andrea Arcangeli, 2015/03/05
- [Qemu-devel] [PATCH 05/21] userfaultfd: add vm_userfaultfd_ctx to the vm_area_struct, Andrea Arcangeli, 2015/03/05
- Re: [Qemu-devel] [PATCH 00/21] RFC: userfaultfd v3, Pavel Emelyanov, 2015/03/05
- [Qemu-devel] [PATCH 09/21] userfaultfd: prevent khugepaged to merge if userfaultfd is armed, Andrea Arcangeli, 2015/03/05
- [Qemu-devel] [PATCH 18/21] userfaultfd: UFFDIO_REMAP uABI,
Andrea Arcangeli <=