Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20180425a' into staging

Migration pull for 2.13

Alexey Perevalov postcopy blocktime statistics
Xiao Guangrong's compression performance improvements

# gpg: Signature made Wed 25 Apr 2018 20:21:13 BST
# gpg:                using RSA key 0516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>"
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20180425a:
  migration: remove ram_save_compressed_page()
  migration: introduce save_normal_page()
  migration: move calling save_zero_page to the common place
  migration: move calling control_save_page to the common place
  migration: move some code to ram_save_host_page
  migration: introduce control_save_page()
  migration: detect compression and decompression errors
  migration: stop decompression to allocate and free memory frequently
  migration: stop compression to allocate and free memory frequently
  migration: stop compressing page in migration thread
  migration: add postcopy total blocktime into query-migrate
  migration: add blocktime calculation into migration-test
  migration: postcopy_blocktime documentation
  migration: calculate vCPU blocktime on dst side
  migration: add postcopy blocktime ctx into MigrationIncomingState
  migration: introduce postcopy-blocktime capability

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

1 files changed, 34 insertions, 9 deletions

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index bb63c779cc..0463f4c321 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -658,8 +658,32 @@ uint64_t qemu_get_be64(QEMUFile *f)
     return v;
 }
 
-/* Compress size bytes of data start at p with specific compression
- * level and store the compressed data to the buffer of f.
+/* return the size after compression, or negative value on error */
+static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
+                              const uint8_t *source, size_t source_len)
+{
+    int err;
+
+    err = deflateReset(stream);
+    if (err != Z_OK) {
+        return -1;
+    }
+
+    stream->avail_in = source_len;
+    stream->next_in = (uint8_t *)source;
+    stream->avail_out = dest_len;
+    stream->next_out = dest;
+
+    err = deflate(stream, Z_FINISH);
+    if (err != Z_STREAM_END) {
+        return -1;
+    }
+
+    return stream->next_out - dest;
+}
+
+/* Compress size bytes of data start at p and store the compressed
+ * data to the buffer of f.
  *
  * When f is not writable, return -1 if f has no space to save the
  * compressed data.
@@ -667,9 +691,8 @@ uint64_t qemu_get_be64(QEMUFile *f)
  * do fflush first, if f still has no space to save the compressed
  * data, return -1.
  */
-
-ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
-                                  int level)
+ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
+                                  const uint8_t *p, size_t size)
 {
     ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
 
@@ -683,11 +706,13 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
             return -1;
         }
     }
-    if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen,
-                  (Bytef *)p, size, level) != Z_OK) {
-        error_report("Compress Failed!");
-        return 0;
+
+    blen = qemu_compress_data(stream, f->buf + f->buf_index + sizeof(int32_t),
+                              blen, p, size);
+    if (blen < 0) {
+        return -1;
     }
+
     qemu_put_be32(f, blen);
     if (f->ops->writev_buffer) {
         add_to_iovec(f, f->buf + f->buf_index, blen, false);