[PATCH v2 3/5] migration: Introduce unimplemented 'qatzip' compression method

[Bryan Zhang <bryan.zhang@bytedance.com>]

Adds support for 'qatzip' as an option for the multifd compression
method parameter, but copy-pastes the no-op logic to leave the actual
methods effectively unimplemented. This is in preparation of a subsequent
commit that will implement actually using QAT for compression and
decompression.

Signed-off-by: Bryan Zhang <bryan.zhang@bytedance.com>
Signed-off-by: Hao Xiang <hao.xiang@linux.dev>
---
 hw/core/qdev-properties-system.c |   6 +-
 migration/meson.build            |   1 +
 migration/multifd-qatzip.c       | 117 +++++++++++++++++++++++++++++++
 migration/multifd.h              |   1 +
 qapi/migration.json              |   5 +-
 tests/qtest/meson.build          |   4 ++
 6 files changed, 132 insertions(+), 2 deletions(-)
 create mode 100644 migration/multifd-qatzip.c

diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index 1a396521d5..d8e48dcb0e 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -658,7 +658,11 @@ const PropertyInfo qdev_prop_fdc_drive_type = {
 const PropertyInfo qdev_prop_multifd_compression = {
     .name = "MultiFDCompression",
     .description = "multifd_compression values, "
-                   "none/zlib/zstd",
+                   "none/zlib/zstd"
+#ifdef CONFIG_QATZIP
+                   "/qatzip"
+#endif
+                   ,
     .enum_table = &MultiFDCompression_lookup,
     .get = qdev_propinfo_get_enum,
     .set = qdev_propinfo_set_enum,
diff --git a/migration/meson.build b/migration/meson.build
index 92b1cc4297..e20f318379 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -40,6 +40,7 @@ if get_option('live_block_migration').allowed()
   system_ss.add(files('block.c'))
 endif
 system_ss.add(when: zstd, if_true: files('multifd-zstd.c'))
+system_ss.add(when: qatzip, if_true: files('multifd-qatzip.c'))
 
 specific_ss.add(when: 'CONFIG_SYSTEM_ONLY',
                 if_true: files('ram.c',
diff --git a/migration/multifd-qatzip.c b/migration/multifd-qatzip.c
new file mode 100644
index 0000000000..f66336a4a7
--- /dev/null
+++ b/migration/multifd-qatzip.c
@@ -0,0 +1,117 @@
+/*
+ * Multifd QATzip compression implementation
+ *
+ * Copyright (c) Bytedance
+ *
+ * Authors:
+ *  Bryan Zhang <bryan.zhang@bytedance.com>
+ *  Hao Xiang   <hao.xiang@bytedance.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 "exec/ramblock.h"
+#include "exec/target_page.h"
+#include "qapi/error.h"
+#include "migration.h"
+#include "options.h"
+#include "multifd.h"
+
+/*
+ * This is an intermediary file to introduce 'qatzip' as an option for multifd
+ * compression. The actual method implementations are no-ops.
+ */
+
+static int qatzip_send_setup(MultiFDSendParams *p, Error **errp)
+{
+    if (migrate_zero_copy_send()) {
+        p->write_flags |= QIO_CHANNEL_WRITE_FLAG_ZERO_COPY;
+    }
+
+    return 0;
+}
+
+static void qatzip_send_cleanup(MultiFDSendParams *p, Error **errp)
+{
+    return;
+}
+
+static int qatzip_send_prepare(MultiFDSendParams *p, Error **errp)
+{
+    bool use_zero_copy_send = migrate_zero_copy_send();
+    MultiFDPages_t *pages = p->pages;
+    int ret;
+
+    if (!use_zero_copy_send) {
+        /*
+         * Only !zerocopy needs the header in IOV; zerocopy will
+         * send it separately.
+         */
+        multifd_send_prepare_header(p);
+    }
+
+    for (int i = 0; i < pages->num; i++) {
+        p->iov[p->iovs_num].iov_base = pages->block->host + pages->offset[i];
+        p->iov[p->iovs_num].iov_len = p->page_size;
+        p->iovs_num++;
+    }
+
+    p->next_packet_size = pages->num * p->page_size;
+    p->flags |= MULTIFD_FLAG_NOCOMP;
+
+    multifd_send_fill_packet(p);
+
+    if (use_zero_copy_send) {
+        /* Send header first, without zerocopy */
+        ret = qio_channel_write_all(p->c, (void *)p->packet,
+                                    p->packet_len, errp);
+        if (ret != 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+static int qatzip_recv_setup(MultiFDRecvParams *p, Error **errp)
+{
+    return 0;
+}
+
+static void qatzip_recv_cleanup(MultiFDRecvParams *p)
+{
+}
+
+static int qatzip_recv_pages(MultiFDRecvParams *p, Error **errp)
+{
+    uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
+
+    if (flags != MULTIFD_FLAG_NOCOMP) {
+        error_setg(errp, "multifd %u: flags received %x flags expected %x",
+                   p->id, flags, MULTIFD_FLAG_NOCOMP);
+        return -1;
+    }
+    for (int i = 0; i < p->normal_num; i++) {
+        p->iov[i].iov_base = p->host + p->normal[i];
+        p->iov[i].iov_len = p->page_size;
+    }
+    return qio_channel_readv_all(p->c, p->iov, p->normal_num, errp);
+}
+
+static MultiFDMethods multifd_qatzip_ops = {
+    .send_setup = qatzip_send_setup,
+    .send_cleanup = qatzip_send_cleanup,
+    .send_prepare = qatzip_send_prepare,
+    .recv_setup = qatzip_recv_setup,
+    .recv_cleanup = qatzip_recv_cleanup,
+    .recv_pages = qatzip_recv_pages
+};
+
+static void multifd_qatzip_register(void)
+{
+    multifd_register_ops(MULTIFD_COMPRESSION_QATZIP, &multifd_qatzip_ops);
+}
+
+migration_init(multifd_qatzip_register);
diff --git a/migration/multifd.h b/migration/multifd.h
index b3fe27ae93..ae73f1713c 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -33,6 +33,7 @@ bool multifd_queue_page(RAMBlock *block, ram_addr_t offset);
 #define MULTIFD_FLAG_NOCOMP (0 << 1)
 #define MULTIFD_FLAG_ZLIB (1 << 1)
 #define MULTIFD_FLAG_ZSTD (2 << 1)
+#define MULTIFD_FLAG_QATZIP (3 << 1)
 
 /* This value needs to be a multiple of qemu_target_page_size() */
 #define MULTIFD_PACKET_SIZE (512 * 1024)
diff --git a/qapi/migration.json b/qapi/migration.json
index 66ea6d32fc..9018166ac8 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -625,11 +625,14 @@
 #
 # @zstd: use zstd compression method.
 #
+# @qatzip: use qatzip compression method.
+#
 # Since: 5.0
 ##
 { 'enum': 'MultiFDCompression',
   'data': [ 'none', 'zlib',
-            { 'name': 'zstd', 'if': 'CONFIG_ZSTD' } ] }
+            { 'name': 'zstd', 'if': 'CONFIG_ZSTD' },
+            { 'name': 'qatzip', 'if': 'CONFIG_QATZIP'} ] }
 
 ##
 # @MigMode:
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 6ea77893f5..539104c06d 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -315,6 +315,10 @@ if gnutls.found()
   endif
 endif
 
+if qatzip.found()
+  migration_files += [qatzip]
+endif
+
 qtests = {
   'bios-tables-test': [io, 'boot-sector.c', 'acpi-utils.c', 'tpm-emu.c'],
   'cdrom-test': files('boot-sector.c'),
-- 
2.30.2