Merge tag 'migration-next-pull-request' of https://gitlab.com/peterx/qemu into staging

Migartion pull request for 20240304

- Bryan's fix on multifd compression level API
- Fabiano's mapped-ram series (base + multifd only)
- Steve's amend on cpr document in qapi/

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* tag 'migration-next-pull-request' of https://gitlab.com/peterx/qemu: (27 commits)
  migration/multifd: Document two places for mapped-ram
  tests/qtest/migration: Add a multifd + mapped-ram migration test
  migration/multifd: Add mapped-ram support to fd: URI
  migration/multifd: Support incoming mapped-ram stream format
  migration/multifd: Support outgoing mapped-ram stream format
  migration/multifd: Prepare multifd sync for mapped-ram migration
  migration/multifd: Add incoming QIOChannelFile support
  migration/multifd: Add outgoing QIOChannelFile support
  migration/multifd: Add a wrapper for channels_created
  migration/multifd: Allow receiving pages without packets
  migration/multifd: Allow multifd without packets
  migration/multifd: Decouple recv method from pages
  migration/multifd: Rename MultiFDSend|RecvParams::data to compress_data
  tests/qtest/migration: Add tests for mapped-ram file-based migration
  migration/ram: Add incoming 'mapped-ram' migration
  migration/ram: Add outgoing 'mapped-ram' migration
  migration: Add mapped-ram URI compatibility check
  migration/ram: Introduce 'mapped-ram' migration capability
  migration/qemu-file: add utility methods for working with seekable channels
  io: fsync before closing a file channel
  ...

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

# Conflicts:
#	migration/ram.c

4 files changed, 111 insertions, 0 deletions

diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
index 3eb79723c6..848915ea5b 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -44,6 +44,19 @@ struct RAMBlock {
     size_t page_size;
     /* dirty bitmap used during migration */
     unsigned long *bmap;
+
+    /*
+     * Below fields are only used by mapped-ram migration
+     */
+    /* bitmap of pages present in the migration file */
+    unsigned long *file_bmap;
+    /*
+     * offset in the file pages belonging to this ramblock are saved,
+     * used only during migration to a file.
+     */
+    off_t bitmap_offset;
+    uint64_t pages_offset;
+
     /* bitmap of already received pages in postcopy */
     unsigned long *receivedmap;
 
diff --git a/include/io/channel.h b/include/io/channel.h
index 5f9dbaab65..7986c49c71 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -44,6 +44,7 @@ enum QIOChannelFeature {
     QIO_CHANNEL_FEATURE_LISTEN,
     QIO_CHANNEL_FEATURE_WRITE_ZERO_COPY,
     QIO_CHANNEL_FEATURE_READ_MSG_PEEK,
+    QIO_CHANNEL_FEATURE_SEEKABLE,
 };
 
 
@@ -130,6 +131,16 @@ struct QIOChannelClass {
                            Error **errp);
 
     /* Optional callbacks */
+    ssize_t (*io_pwritev)(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          off_t offset,
+                          Error **errp);
+    ssize_t (*io_preadv)(QIOChannel *ioc,
+                         const struct iovec *iov,
+                         size_t niov,
+                         off_t offset,
+                         Error **errp);
     int (*io_shutdown)(QIOChannel *ioc,
                        QIOChannelShutdown how,
                        Error **errp);
@@ -529,6 +540,78 @@ int qio_channel_close(QIOChannel *ioc,
                       Error **errp);
 
 /**
+ * qio_channel_pwritev
+ * @ioc: the channel object
+ * @iov: the array of memory regions to write data from
+ * @niov: the length of the @iov array
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error. To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ * Behaves as qio_channel_writev_full, apart from not supporting
+ * sending of file handles as well as beginning the write at the
+ * passed @offset
+ *
+ */
+ssize_t qio_channel_pwritev(QIOChannel *ioc, const struct iovec *iov,
+                            size_t niov, off_t offset, Error **errp);
+
+/**
+ * qio_channel_pwrite
+ * @ioc: the channel object
+ * @buf: the memory region to write data into
+ * @buflen: the number of bytes to @buf
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error. To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ */
+ssize_t qio_channel_pwrite(QIOChannel *ioc, char *buf, size_t buflen,
+                           off_t offset, Error **errp);
+
+/**
+ * qio_channel_preadv
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data into
+ * @niov: the length of the @iov array
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error.  To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ * Behaves as qio_channel_readv_full, apart from not supporting
+ * receiving of file handles as well as beginning the read at the
+ * passed @offset
+ *
+ */
+ssize_t qio_channel_preadv(QIOChannel *ioc, const struct iovec *iov,
+                           size_t niov, off_t offset, Error **errp);
+
+/**
+ * qio_channel_pread
+ * @ioc: the channel object
+ * @buf: the memory region to write data into
+ * @buflen: the number of bytes to @buf
+ * @offset: offset in the channel where writes should begin
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Not all implementations will support this facility, so may report
+ * an error.  To avoid errors, the caller may check for the feature
+ * flag QIO_CHANNEL_FEATURE_SEEKABLE prior to calling this method.
+ *
+ */
+ssize_t qio_channel_pread(QIOChannel *ioc, char *buf, size_t buflen,
+                          off_t offset, Error **errp);
+
+/**
  * qio_channel_shutdown:
  * @ioc: the channel object
  * @how: the direction to shutdown
diff --git a/include/migration/qemu-file-types.h b/include/migration/qemu-file-types.h
index 9ba163f333..adec5abc07 100644
--- a/include/migration/qemu-file-types.h
+++ b/include/migration/qemu-file-types.h
@@ -50,6 +50,8 @@ unsigned int qemu_get_be16(QEMUFile *f);
 unsigned int qemu_get_be32(QEMUFile *f);
 uint64_t qemu_get_be64(QEMUFile *f);
 
+bool qemu_file_is_seekable(QEMUFile *f);
+
 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 {
     qemu_put_be64(f, *pv);
diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
index cb3526d1f4..2c0a2fe751 100644
--- a/include/qemu/bitops.h
+++ b/include/qemu/bitops.h
@@ -68,6 +68,19 @@ static inline void clear_bit(long nr, unsigned long *addr)
 }
 
 /**
+ * clear_bit_atomic - Clears a bit in memory atomically
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ */
+static inline void clear_bit_atomic(long nr, unsigned long *addr)
+{
+    unsigned long mask = BIT_MASK(nr);
+    unsigned long *p = addr + BIT_WORD(nr);
+
+    return qatomic_and(p, ~mask);
+}
+
+/**
  * change_bit - Toggle a bit in memory
  * @nr: Bit to change
  * @addr: Address to start counting from