Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20151110' into staging

migration/next for 20151110

# gpg: Signature made Tue 10 Nov 2015 14:23:26 GMT using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"

* remotes/juanquintela/tags/migration/20151110: (57 commits)
  migration: qemu_savevm_state_cleanup becomes mandatory operation
  Inhibit ballooning during postcopy
  Disable mlock around incoming postcopy
  End of migration for postcopy
  Postcopy: Mark nohugepage before discard
  postcopy: Wire up loadvm_postcopy_handle_ commands
  Start up a postcopy/listener thread ready for incoming page data
  Postcopy; Handle userfault requests
  Round up RAMBlock sizes to host page sizes
  Host page!=target page: Cleanup bitmaps
  Don't iterate on precopy-only devices during postcopy
  Don't sync dirty bitmaps in postcopy
  postcopy: Check order of received target pages
  Postcopy: Use helpers to map pages during migration
  postcopy_ram.c: place_page and helpers
  Page request: Consume pages off the post-copy queue
  Page request: Process incoming page request
  Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
  Postcopy: End of iteration
  Postcopy: Postcopy startup in migration thread
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 167 insertions, 0 deletions

diff --git a/linux-headers/linux/userfaultfd.h b/linux-headers/linux/userfaultfd.h
new file mode 100644
index 0000000000..9057d7af3a
--- /dev/null
+++ b/linux-headers/linux/userfaultfd.h
@@ -0,0 +1,167 @@
+/*
+ *  include/linux/userfaultfd.h
+ *
+ *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
+ *  Copyright (C) 2015  Red Hat, Inc.
+ *
+ */
+
+#ifndef _LINUX_USERFAULTFD_H
+#define _LINUX_USERFAULTFD_H
+
+#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)
+ */
+#define UFFD_API_FEATURES (0)
+#define UFFD_API_IOCTLS				\
+	((__u64)1 << _UFFDIO_REGISTER |		\
+	 (__u64)1 << _UFFDIO_UNREGISTER |	\
+	 (__u64)1 << _UFFDIO_API)
+#define UFFD_API_RANGE_IOCTLS			\
+	((__u64)1 << _UFFDIO_WAKE |		\
+	 (__u64)1 << _UFFDIO_COPY |		\
+	 (__u64)1 << _UFFDIO_ZEROPAGE)
+
+/*
+ * Valid ioctl command number range with this API is from 0x00 to
+ * 0x3F.  UFFDIO_API is the fixed number, everything else can be
+ * changed by implementing a different UFFD_API. If sticking to the
+ * same UFFD_API more ioctl can be added and userland will be aware of
+ * which ioctl the running kernel implements through the ioctl command
+ * bitmask written by the UFFDIO_API.
+ */
+#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 */
+#define UFFDIO 0xAA
+#define UFFDIO_API		_IOWR(UFFDIO, _UFFDIO_API,	\
+				      struct uffdio_api)
+#define UFFDIO_REGISTER		_IOWR(UFFDIO, _UFFDIO_REGISTER, \
+				      struct uffdio_register)
+#define UFFDIO_UNREGISTER	_IOR(UFFDIO, _UFFDIO_UNREGISTER,	\
+				     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 {
+	__u8	event;
+
+	__u8	reserved1;
+	__u16	reserved2;
+	__u32	reserved3;
+
+	union {
+		struct {
+			__u64	flags;
+			__u64	address;
+		} pagefault;
+
+		struct {
+			/* unused reserved fields */
+			__u64	reserved1;
+			__u64	reserved2;
+			__u64	reserved3;
+		} reserved;
+	} arg;
+} __packed;
+
+/*
+ * 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
+
+/* flags for UFFD_EVENT_PAGEFAULT */
+#define UFFD_PAGEFAULT_FLAG_WRITE	(1<<0)	/* If this was a write fault */
+#define UFFD_PAGEFAULT_FLAG_WP		(1<<1)	/* If reason is VM_UFFD_WP */
+
+struct uffdio_api {
+	/* userland asks for an API number and the features to enable */
+	__u64 api;
+	/*
+	 * Kernel answers below with the all available features for
+	 * the API, this notifies userland of which events and/or
+	 * which flags for each event are enabled in the current
+	 * kernel.
+	 *
+	 * 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.
+	 */
+#if 0 /* not available yet */
+#define UFFD_FEATURE_PAGEFAULT_FLAG_WP		(1<<0)
+#define UFFD_FEATURE_EVENT_FORK			(1<<1)
+#endif
+	__u64 features;
+
+	__u64 ioctls;
+};
+
+struct uffdio_range {
+	__u64 start;
+	__u64 len;
+};
+
+struct uffdio_register {
+	struct uffdio_range range;
+#define UFFDIO_REGISTER_MODE_MISSING	((__u64)1<<0)
+#define UFFDIO_REGISTER_MODE_WP		((__u64)1<<1)
+	__u64 mode;
+
+	/*
+	 * kernel answers which ioctl commands are available for the
+	 * range, keep at the end as the last 8 bytes aren't read.
+	 */
+	__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 */