[Qemu-devel] [PATCH v2 7/8] multifd: Add zlib compression support

[Juan Quintela <quintela@redhat.com>]

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/migration.c  |  9 ++++++++
 migration/migration.h  |  1 +
 migration/ram.c        | 47 ++++++++++++++++++++++++++++++++++++++++++
 qapi/common.json       |  4 +++-
 tests/migration-test.c |  6 ++++++
 5 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/migration/migration.c b/migration/migration.c
index d6f8ef342a..69d85cbe5e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2141,6 +2141,15 @@ bool migrate_use_multifd(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
 }
 
+bool migrate_use_multifd_zlib(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters.multifd_compress == MULTIFD_COMPRESS_ZLIB;
+}
+
 bool migrate_pause_before_switchover(void)
 {
     MigrationState *s;
diff --git a/migration/migration.h b/migration/migration.h
index 438f17edad..fc4fb841d4 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -269,6 +269,7 @@ bool migrate_ignore_shared(void);
 
 bool migrate_auto_converge(void);
 bool migrate_use_multifd(void);
+bool migrate_use_multifd_zlib(void);
 bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
 
diff --git a/migration/ram.c b/migration/ram.c
index d7f8fe45a8..06b25ac66d 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -582,6 +582,7 @@ exit:
 #define MULTIFD_VERSION 1
 
 #define MULTIFD_FLAG_SYNC (1 << 0)
+#define MULTIFD_FLAG_ZLIB (1 << 1)
 
 /* This value needs to be a multiple of qemu_target_page_size() */
 #define MULTIFD_PACKET_SIZE (512 * 1024)
@@ -663,6 +664,12 @@ typedef struct {
     uint64_t num_pages;
     /* syncs main thread and channels */
     QemuSemaphore sem_sync;
+    /* stream for compression */
+    z_stream zs;
+    /* compressed buffer */
+    uint8_t *zbuff;
+    /* size of compressed buffer */
+    uint32_t zbuff_len;
 }  MultiFDSendParams;
 
 typedef struct {
@@ -698,6 +705,12 @@ typedef struct {
     uint64_t num_pages;
     /* syncs main thread and channels */
     QemuSemaphore sem_sync;
+    /* stream for compression */
+    z_stream zs;
+    /* compressed buffer */
+    uint8_t *zbuff;
+    /* size of compressed buffer */
+    uint32_t zbuff_len;
 } MultiFDRecvParams;
 
 static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
@@ -1035,6 +1048,9 @@ void multifd_save_cleanup(void)
         p->packet_len = 0;
         g_free(p->packet);
         p->packet = NULL;
+        deflateEnd(&p->zs);
+        g_free(p->zbuff);
+        p->zbuff = NULL;
     }
     qemu_sem_destroy(&multifd_send_state->channels_ready);
     qemu_sem_destroy(&multifd_send_state->sem_sync);
@@ -1198,6 +1214,7 @@ int multifd_save_setup(void)
 
     for (i = 0; i < thread_count; i++) {
         MultiFDSendParams *p = &multifd_send_state->params[i];
+        z_stream *zs = &p->zs;
 
         qemu_mutex_init(&p->mutex);
         qemu_sem_init(&p->sem, 0);
@@ -1211,6 +1228,17 @@ int multifd_save_setup(void)
         p->packet = g_malloc0(p->packet_len);
         p->name = g_strdup_printf("multifdsend_%d", i);
         socket_send_channel_create(multifd_new_send_channel_async, p);
+        zs->zalloc = Z_NULL;
+        zs->zfree = Z_NULL;
+        zs->opaque = Z_NULL;
+        if (deflateInit(zs, migrate_compress_level()) != Z_OK) {
+            printf("deflate init failed\n");
+            return -1;
+        }
+        /* We will never have more than page_count pages */
+        p->zbuff_len = page_count * qemu_target_page_size();
+        p->zbuff_len *= 2;
+        p->zbuff = g_malloc0(p->zbuff_len);
     }
     return 0;
 }
@@ -1278,6 +1306,9 @@ int multifd_load_cleanup(Error **errp)
         p->packet_len = 0;
         g_free(p->packet);
         p->packet = NULL;
+        inflateEnd(&p->zs);
+        g_free(p->zbuff);
+        p->zbuff = NULL;
     }
     qemu_sem_destroy(&multifd_recv_state->sem_sync);
     g_free(multifd_recv_state->params);
@@ -1396,6 +1427,7 @@ int multifd_load_setup(void)
 
     for (i = 0; i < thread_count; i++) {
         MultiFDRecvParams *p = &multifd_recv_state->params[i];
+        z_stream *zs = &p->zs;
 
         qemu_mutex_init(&p->mutex);
         qemu_sem_init(&p->sem_sync, 0);
@@ -1405,6 +1437,21 @@ int multifd_load_setup(void)
                       + sizeof(ram_addr_t) * page_count;
         p->packet = g_malloc0(p->packet_len);
         p->name = g_strdup_printf("multifdrecv_%d", i);
+
+        zs->zalloc = Z_NULL;
+        zs->zfree = Z_NULL;
+        zs->opaque = Z_NULL;
+        zs->avail_in = 0;
+        zs->next_in = Z_NULL;
+        if (inflateInit(zs) != Z_OK) {
+            printf("inflate init failed\n");
+            return -1;
+        }
+        /* We will never have more than page_count pages */
+        p->zbuff_len = page_count * qemu_target_page_size();
+        /* We know compression "could" use more space */
+        p->zbuff_len *= 2;
+        p->zbuff = g_malloc0(p->zbuff_len);
     }
     return 0;
 }
diff --git a/qapi/common.json b/qapi/common.json
index 7248172792..89df6854cb 100644
--- a/qapi/common.json
+++ b/qapi/common.json
@@ -201,8 +201,10 @@
 #
 # @none: no compression.
 #
+# @zlib: Compress using zlib.
+#
 # Since: 4.1
 #
 ##
 { 'enum': 'MultifdCompress',
-  'data': [ 'none' ] }
+  'data': [ 'none', 'zlib' ] }
diff --git a/tests/migration-test.c b/tests/migration-test.c
index 8a1ccc2516..2dd4d4c5b4 100644
--- a/tests/migration-test.c
+++ b/tests/migration-test.c
@@ -1119,6 +1119,11 @@ static void test_multifd_tcp_none(void)
     test_multifd_tcp("none");
 }
 
+static void test_multifd_tcp_zlib(void)
+{
+    test_multifd_tcp("zlib");
+}
+
 int main(int argc, char **argv)
 {
     char template[] = "/tmp/migration-test-XXXXXX";
@@ -1174,6 +1179,7 @@ int main(int argc, char **argv)
     /* qtest_add_func("/migration/ignore_shared", test_ignore_shared); */
     qtest_add_func("/migration/xbzrle/unix", test_xbzrle_unix);
     qtest_add_func("/migration/multifd/tcp/none", test_multifd_tcp_none);
+    qtest_add_func("/migration/multifd/tcp/zlib", test_multifd_tcp_zlib);
 
     ret = g_test_run();
 
-- 
2.20.1