[PATCH v5 5/8] multifd: Add zlib compression multifd support

[Juan Quintela <quintela@redhat.com>]

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 hw/core/qdev-properties.c    |   2 +-
 migration/Makefile.objs      |   1 +
 migration/migration.c        |   9 +
 migration/migration.h        |   1 +
 migration/multifd-zlib.c     | 325 +++++++++++++++++++++++++++++++++++
 migration/multifd.c          |   6 +
 migration/multifd.h          |   4 +
 qapi/migration.json          |   3 +-
 tests/qtest/migration-test.c |   6 +
 9 files changed, 355 insertions(+), 2 deletions(-)
 create mode 100644 migration/multifd-zlib.c

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 4442844d37..bf88a50cdf 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -645,7 +645,7 @@ const PropertyInfo qdev_prop_fdc_drive_type = {
 const PropertyInfo qdev_prop_multifd_method = {
     .name = "MultiFDMethod",
     .description = "multifd_method values, "
-                   "none",
+                   "none/zlib",
     .enum_table = &MultiFDMethod_lookup,
     .get = get_enum,
     .set = set_enum,
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index d3623d5f9b..0308caa5c5 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -8,6 +8,7 @@ common-obj-y += xbzrle.o postcopy-ram.o
 common-obj-y += qjson.o
 common-obj-y += block-dirty-bitmap.o
 common-obj-y += multifd.o
+common-obj-y += multifd-zlib.o
 
 common-obj-$(CONFIG_RDMA) += rdma.o
 
diff --git a/migration/migration.c b/migration/migration.c
index 4f88f8e958..3b081e8147 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2265,6 +2265,15 @@ MultiFDMethod migrate_multifd_method(void)
     return s->parameters.multifd_method;
 }
 
+int migrate_multifd_zlib_level(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters.multifd_zlib_level;
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;
diff --git a/migration/migration.h b/migration/migration.h
index 3d23a0852e..95e9c196ff 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -301,6 +301,7 @@ bool migrate_use_multifd(void);
 bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
 MultiFDMethod migrate_multifd_method(void);
+int migrate_multifd_zlib_level(void);
 
 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);
diff --git a/migration/multifd-zlib.c b/migration/multifd-zlib.c
new file mode 100644
index 0000000000..91b3128256
--- /dev/null
+++ b/migration/multifd-zlib.c
@@ -0,0 +1,325 @@
+/*
+ * Multifd zlib compression implementation
+ *
+ * Copyright (c) 2020 Red Hat Inc
+ *
+ * Authors:
+ *  Juan Quintela <quintela@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include <zlib.h>
+#include "qemu/rcu.h"
+#include "exec/target_page.h"
+#include "qapi/error.h"
+#include "migration.h"
+#include "trace.h"
+#include "multifd.h"
+
+struct zlib_data {
+    /* stream for compression */
+    z_stream zs;
+    /* compressed buffer */
+    uint8_t *zbuff;
+    /* size of compressed buffer */
+    uint32_t zbuff_len;
+};
+
+/* Multifd zlib compression */
+
+/**
+ * zlib_send_setup: setup send side
+ *
+ * Setup each channel with zlib compression.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int zlib_send_setup(MultiFDSendParams *p, Error **errp)
+{
+    uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
+    struct zlib_data *z = g_malloc0(sizeof(struct zlib_data));
+    z_stream *zs = &z->zs;
+
+    zs->zalloc = Z_NULL;
+    zs->zfree = Z_NULL;
+    zs->opaque = Z_NULL;
+    if (deflateInit(zs, migrate_multifd_zlib_level()) != Z_OK) {
+        g_free(z);
+        error_setg(errp, "multifd %d: deflate init failed", p->id);
+        return -1;
+    }
+    /* We will never have more than page_count pages */
+    z->zbuff_len = page_count * qemu_target_page_size();
+    z->zbuff_len *= 2;
+    z->zbuff = g_try_malloc(z->zbuff_len);
+    if (!z->zbuff) {
+        deflateEnd(&z->zs);
+        g_free(z);
+        error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
+        return -1;
+    }
+    p->data = z;
+    return 0;
+}
+
+/**
+ * zlib_send_cleanup: cleanup send side
+ *
+ * Close the channel and return memory.
+ *
+ * @p: Params for the channel that we are using
+ */
+static void zlib_send_cleanup(MultiFDSendParams *p, Error **errp)
+{
+    struct zlib_data *z = p->data;
+
+    deflateEnd(&z->zs);
+    g_free(z->zbuff);
+    z->zbuff = NULL;
+    g_free(p->data);
+    p->data = NULL;
+}
+
+/**
+ * zlib_send_prepare: prepare date to be able to send
+ *
+ * Create a compressed buffer with all the pages that we are going to
+ * send.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ */
+static int zlib_send_prepare(MultiFDSendParams *p, uint32_t used, Error **errp)
+{
+    struct iovec *iov = p->pages->iov;
+    struct zlib_data *z = p->data;
+    z_stream *zs = &z->zs;
+    uint32_t out_size = 0;
+    int ret;
+    uint32_t i;
+
+    for (i = 0; i < used; i++) {
+        uint32_t available = z->zbuff_len - out_size;
+        int flush = Z_NO_FLUSH;
+
+        if (i == used - 1) {
+            flush = Z_SYNC_FLUSH;
+        }
+
+        zs->avail_in = iov[i].iov_len;
+        zs->next_in = iov[i].iov_base;
+
+        zs->avail_out = available;
+        zs->next_out = z->zbuff + out_size;
+
+        /*
+         * Welcome to deflate semantics
+         *
+         * We need to loop while:
+         * - return is Z_OK
+         * - there are stuff to be compressed
+         * - there are output space free
+         */
+        do {
+            ret = deflate(zs, flush);
+        } while (ret == Z_OK && zs->avail_in && zs->avail_out);
+        if (ret == Z_OK && zs->avail_in) {
+            error_setg(errp, "multifd %d: deflate failed to compress all input",
+                       p->id);
+            return -1;
+        }
+        if (ret != Z_OK) {
+            error_setg(errp, "multifd %d: deflate returned %d instead of Z_OK",
+                       p->id, ret);
+            return -1;
+        }
+        out_size += available - zs->avail_out;
+    }
+    p->next_packet_size = out_size;
+    p->flags |= MULTIFD_FLAG_ZLIB;
+
+    return 0;
+}
+
+/**
+ * zlib_send_write: do the actual write of the data
+ *
+ * Do the actual write of the comprresed buffer.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ * @errp: pointer to an error
+ */
+static int zlib_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
+{
+    struct zlib_data *z = p->data;
+
+    return qio_channel_write_all(p->c, (void *)z->zbuff, p->next_packet_size,
+                                 errp);
+}
+
+/**
+ * zlib_recv_setup: setup receive side
+ *
+ * Create the compressed channel and buffer.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @errp: pointer to an error
+ */
+static int zlib_recv_setup(MultiFDRecvParams *p, Error **errp)
+{
+    uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
+    struct zlib_data *z = g_malloc0(sizeof(struct zlib_data));
+    z_stream *zs = &z->zs;
+
+    p->data = z;
+    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) {
+        error_setg(errp, "multifd %d: inflate init failed", p->id);
+        return -1;
+    }
+    /* We will never have more than page_count pages */
+    z->zbuff_len = page_count * qemu_target_page_size();
+    /* We know compression "could" use more space */
+    z->zbuff_len *= 2;
+    z->zbuff = g_try_malloc(z->zbuff_len);
+    if (!z->zbuff) {
+        inflateEnd(zs);
+        error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
+        return -1;
+    }
+    return 0;
+}
+
+/**
+ * zlib_recv_cleanup: setup receive side
+ *
+ * For no compression this function does nothing.
+ *
+ * @p: Params for the channel that we are using
+ */
+static void zlib_recv_cleanup(MultiFDRecvParams *p)
+{
+    struct zlib_data *z = p->data;
+
+    inflateEnd(&z->zs);
+    g_free(z->zbuff);
+    z->zbuff = NULL;
+    g_free(p->data);
+    p->data = NULL;
+}
+
+/**
+ * zlib_recv_pages: read the data from the channel into actual pages
+ *
+ * Read the compressed buffer, and uncompress it into the actual
+ * pages.
+ *
+ * Returns 0 for success or -1 for error
+ *
+ * @p: Params for the channel that we are using
+ * @used: number of pages used
+ * @errp: pointer to an error
+ */
+static int zlib_recv_pages(MultiFDRecvParams *p, uint32_t used, Error **errp)
+{
+    struct zlib_data *z = p->data;
+    z_stream *zs = &z->zs;
+    uint32_t in_size = p->next_packet_size;
+    /* we measure the change of total_out */
+    uint32_t out_size = zs->total_out;
+    uint32_t expected_size = used * qemu_target_page_size();
+    uint32_t flags = p->flags & MULTIFD_FLAG_METHOD_MASK;
+    int ret;
+    int i;
+
+    if (flags != MULTIFD_FLAG_ZLIB) {
+        error_setg(errp, "multifd %d: flags received %x flags expected %x",
+                   p->id, flags, MULTIFD_FLAG_ZLIB);
+        return -1;
+    }
+    ret = qio_channel_read_all(p->c, (void *)z->zbuff, in_size, errp);
+
+    if (ret != 0) {
+        return ret;
+    }
+
+    zs->avail_in = in_size;
+    zs->next_in = z->zbuff;
+
+    for (i = 0; i < used; i++) {
+        struct iovec *iov = &p->pages->iov[i];
+        int flush = Z_NO_FLUSH;
+        unsigned long start = zs->total_out;
+
+        if (i == used  - 1) {
+            flush = Z_SYNC_FLUSH;
+        }
+
+        zs->avail_out = iov->iov_len;
+        zs->next_out = iov->iov_base;
+
+        /*
+         * Welcome to inflate semantics
+         *
+         * We need to loop while:
+         * - return is Z_OK
+         * - there are input available
+         * - we haven't completed a full page
+         */
+        do {
+            ret = inflate(zs, flush);
+        } while (ret == Z_OK && zs->avail_in
+                             && (zs->total_out - start) < iov->iov_len);
+        if (ret == Z_OK && (zs->total_out - start) < iov->iov_len) {
+            error_setg(errp, "multifd %d: inflate generated too few output",
+                       p->id);
+            return -1;
+        }
+        if (ret != Z_OK) {
+            error_setg(errp, "multifd %d: inflate returned %d instead of Z_OK",
+                       p->id, ret);
+            return -1;
+        }
+    }
+    out_size = zs->total_out - out_size;
+    if (out_size != expected_size) {
+        error_setg(errp, "multifd %d: packet size received %d size expected %d",
+                   p->id, out_size, expected_size);
+        return -1;
+    }
+    return 0;
+}
+
+static MultiFDMethods multifd_zlib_ops = {
+    .send_setup = zlib_send_setup,
+    .send_cleanup = zlib_send_cleanup,
+    .send_prepare = zlib_send_prepare,
+    .send_write = zlib_send_write,
+    .recv_setup = zlib_recv_setup,
+    .recv_cleanup = zlib_recv_cleanup,
+    .recv_pages = zlib_recv_pages
+};
+
+static void multifd_zlib_register(void)
+{
+    multifd_register_ops(MULTIFD_METHOD_ZLIB, &multifd_zlib_ops);
+}
+
+migration_init(multifd_zlib_register);
diff --git a/migration/multifd.c b/migration/multifd.c
index 1c49c2a665..7bb9c3582f 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -166,6 +166,12 @@ static MultiFDMethods *multifd_ops[MULTIFD_METHOD__MAX] = {
     [MULTIFD_METHOD_NONE] = &multifd_nocomp_ops,
 };
 
+void multifd_register_ops(int method, MultiFDMethods *ops)
+{
+    assert(0 < method && method < MULTIFD_METHOD__MAX);
+    multifd_ops[method] = ops;
+}
+
 static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
 {
     MultiFDInit_t msg = {};
diff --git a/migration/multifd.h b/migration/multifd.h
index c7fea4914c..3fa5132f1d 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -23,11 +23,13 @@ void multifd_recv_sync_main(void);
 void multifd_send_sync_main(QEMUFile *f);
 int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset);
 
+/* Multifd Compression flags */
 #define MULTIFD_FLAG_SYNC (1 << 0)
 
 /* We reserve 3 bits for METHODS */
 #define MULTIFD_FLAG_METHOD_MASK (7 << 1)
 #define MULTIFD_FLAG_NOCOMP (1 << 1)
+#define MULTIFD_FLAG_ZLIB (2 << 1)
 
 /* This value needs to be a multiple of qemu_target_page_size() */
 #define MULTIFD_PACKET_SIZE (512 * 1024)
@@ -160,5 +162,7 @@ typedef struct {
     int (*recv_pages)(MultiFDRecvParams *p, uint32_t used, Error **errp);
 } MultiFDMethods;
 
+void multifd_register_ops(int method, MultiFDMethods *ops);
+
 #endif
 
diff --git a/qapi/migration.json b/qapi/migration.json
index 289dce0da7..032ee7d3e6 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -494,12 +494,13 @@
 # An enumeration of multifd compression.
 #
 # @none: no compression.
+# @zlib: use zlib compression method.
 #
 # Since: 5.0
 #
 ##
 { 'enum': 'MultiFDMethod',
-  'data': [ 'none' ] }
+  'data': [ 'none', 'zlib' ] }
 
 ##
 # @MigrationParameter:
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index d2f9ef38f5..8effed205d 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -1313,6 +1313,11 @@ static void test_multifd_tcp_none(void)
     test_multifd_tcp("none");
 }
 
+static void test_multifd_tcp_zlib(void)
+{
+    test_multifd_tcp("zlib");
+}
+
 /*
  * This test does:
  *  source               target
@@ -1475,6 +1480,7 @@ int main(int argc, char **argv)
     qtest_add_func("/migration/auto_converge", test_migrate_auto_converge);
     qtest_add_func("/migration/multifd/tcp/none", test_multifd_tcp_none);
     qtest_add_func("/migration/multifd/tcp/cancel", test_multifd_tcp_cancel);
+    qtest_add_func("/migration/multifd/tcp/zlib", test_multifd_tcp_zlib);
 
     ret = g_test_run();
 
-- 
2.24.1