[Qemu-devel] [PATCH v2 14/16] postcopy: Update userfaultfd.h header

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

We use a new userfaultfd define, so update the header.
(Not needed if someone just runs the update script once it's
gone into the main kernel).

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
---
 linux-headers/linux/userfaultfd.h | 81 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 71 insertions(+), 10 deletions(-)

diff --git a/linux-headers/linux/userfaultfd.h 
b/linux-headers/linux/userfaultfd.h
index 19e8453..a7c1a62 100644
--- a/linux-headers/linux/userfaultfd.h
+++ b/linux-headers/linux/userfaultfd.h
@@ -11,13 +11,19 @@
 
 #include <linux/types.h>
 
-#define UFFD_API ((__u64)0xAA)
 /*
- * After implementing the respective features it will become:
- * #define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP | \
- *                           UFFD_FEATURE_EVENT_FORK)
+ * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and
+ * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR.  In
+ * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ
+ * means the userland is reading).
  */
-#define UFFD_API_FEATURES (0)
+#define UFFD_API ((__u64)0xAA)
+#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP |    \
+                          UFFD_FEATURE_EVENT_FORK |            \
+                          UFFD_FEATURE_EVENT_REMAP |           \
+                          UFFD_FEATURE_EVENT_MADVDONTNEED |    \
+                          UFFD_FEATURE_MISSING_HUGETLBFS |     \
+                          UFFD_FEATURE_MISSING_SHMEM)
 #define UFFD_API_IOCTLS                                \
        ((__u64)1 << _UFFDIO_REGISTER |         \
         (__u64)1 << _UFFDIO_UNREGISTER |       \
@@ -25,7 +31,11 @@
 #define UFFD_API_RANGE_IOCTLS                  \
        ((__u64)1 << _UFFDIO_WAKE |             \
         (__u64)1 << _UFFDIO_COPY |             \
-        (__u64)1 << _UFFDIO_ZEROPAGE)
+        (__u64)1 << _UFFDIO_ZEROPAGE |         \
+        (__u64)1 << _UFFDIO_WRITEPROTECT)
+#define UFFD_API_RANGE_IOCTLS_BASIC            \
+       ((__u64)1 << _UFFDIO_WAKE |             \
+        (__u64)1 << _UFFDIO_COPY)
 
 /*
  * Valid ioctl command number range with this API is from 0x00 to
@@ -40,6 +50,7 @@
 #define _UFFDIO_WAKE                   (0x02)
 #define _UFFDIO_COPY                   (0x03)
 #define _UFFDIO_ZEROPAGE               (0x04)
+#define _UFFDIO_WRITEPROTECT           (0x05)
 #define _UFFDIO_API                    (0x3F)
 
 /* userfaultfd ioctl ids */
@@ -56,6 +67,8 @@
                                      struct uffdio_copy)
 #define UFFDIO_ZEROPAGE                _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \
                                      struct uffdio_zeropage)
+#define UFFDIO_WRITEPROTECT    _IOWR(UFFDIO, _UFFDIO_WRITEPROTECT, \
+                                     struct uffdio_writeprotect)
 
 /* read() structure */
 struct uffd_msg {
@@ -72,6 +85,21 @@ struct uffd_msg {
                } pagefault;
 
                struct {
+                       __u32   ufd;
+               } fork;
+
+               struct {
+                       __u64   from;
+                       __u64   to;
+                       __u64   len;
+               } remap;
+
+               struct {
+                       __u64   start;
+                       __u64   end;
+               } madv_dn;
+
+               struct {
                        /* unused reserved fields */
                        __u64   reserved1;
                        __u64   reserved2;
@@ -84,9 +112,9 @@ struct uffd_msg {
  * Start at 0x12 and not at 0 to be more strict against bugs.
  */
 #define UFFD_EVENT_PAGEFAULT   0x12
-#if 0 /* not available yet */
 #define UFFD_EVENT_FORK                0x13
-#endif
+#define UFFD_EVENT_REMAP       0x14
+#define UFFD_EVENT_MADVDONTNEED        0x15
 
 /* flags for UFFD_EVENT_PAGEFAULT */
 #define UFFD_PAGEFAULT_FLAG_WRITE      (1<<0)  /* If this was a write fault */
@@ -104,11 +132,37 @@ struct uffdio_api {
         * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE
         * are to be considered implicitly always enabled in all kernels as
         * long as the uffdio_api.api requested matches UFFD_API.
+        *
+        * UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER
+        * with UFFDIO_REGISTER_MODE_MISSING mode will succeed on
+        * hugetlbfs virtual memory ranges. Adding or not adding
+        * UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has
+        * no real functional effect after UFFDIO_API returns, but
+        * it's only useful for an initial feature set probe at
+        * UFFDIO_API time. There are two ways to use it:
+        *
+        * 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the
+        *    uffdio_api.features before calling UFFDIO_API, an error
+        *    will be returned by UFFDIO_API on a kernel without
+        *    hugetlbfs missing support
+        *
+        * 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in
+        *    uffdio_api.features and instead it will be set by the
+        *    kernel in the uffdio_api.features if the kernel supports
+        *    it, so userland can later check if the feature flag is
+        *    present in uffdio_api.features after UFFDIO_API
+        *    succeeded.
+        *
+        * UFFD_FEATURE_MISSING_SHMEM works the same as
+        * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem
+        * (i.e. tmpfs and other shmem based APIs).
         */
-#if 0 /* not available yet */
 #define UFFD_FEATURE_PAGEFAULT_FLAG_WP         (1<<0)
 #define UFFD_FEATURE_EVENT_FORK                        (1<<1)
-#endif
+#define UFFD_FEATURE_EVENT_REMAP               (1<<2)
+#define UFFD_FEATURE_EVENT_MADVDONTNEED                (1<<3)
+#define UFFD_FEATURE_MISSING_HUGETLBFS         (1<<4)
+#define UFFD_FEATURE_MISSING_SHMEM             (1<<5)
        __u64 features;
 
        __u64 ioctls;
@@ -164,4 +218,11 @@ struct uffdio_zeropage {
        __s64 zeropage;
 };
 
+struct uffdio_writeprotect {
+       struct uffdio_range range;
+       /* !WP means undo writeprotect. DONTWAKE is valid only with !WP */
+#define UFFDIO_WRITEPROTECT_MODE_WP            ((__u64)1<<0)
+#define UFFDIO_WRITEPROTECT_MODE_DONTWAKE      ((__u64)1<<1)
+       __u64 mode;
+};
 #endif /* _LINUX_USERFAULTFD_H */
-- 
2.9.3