[Qemu-devel] [PATCH v10 21/24] migration: Transmit initial package through the multifd channels

[Juan Quintela <quintela@redhat.com>]

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 45 insertions(+), 5 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 1aab96bd5e..4efac0c20c 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -52,6 +52,8 @@
 #include "qemu/rcu_queue.h"
 #include "migration/colo.h"
 #include "migration/block.h"
+#include "sysemu/sysemu.h"
+#include "qemu/uuid.h"
 
 /***********************************************************/
 /* ram save/restore */
@@ -491,12 +493,30 @@ static void multifd_send_sync_main(void)
     trace_multifd_send_sync_main();
 }
 
+typedef struct {
+    uint32_t version;
+    unsigned char uuid[16]; /* QemuUUID */
+    uint8_t id;
+} __attribute__((packed)) MultiFDInit_t;
+
 static void *multifd_send_thread(void *opaque)
 {
     MultiFDSendParams *p = opaque;
+    MultiFDInit_t msg;
+    Error *local_err = NULL;
+    size_t ret;
 
     trace_multifd_send_thread_start(p->id);
 
+    msg.version = 1;
+    msg.id = p->id;
+    memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid));
+    ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), &local_err);
+    if (ret != 0) {
+        terminate_multifd_send_threads(local_err);
+        return NULL;
+    }
+
     while (true) {
         qemu_sem_wait(&p->sem);
         qemu_mutex_lock(&p->mutex);
@@ -730,12 +750,32 @@ bool multifd_recv_all_channels_created(void)
 void multifd_recv_new_channel(QIOChannel *ioc)
 {
     MultiFDRecvParams *p;
-    /* we need to invent channels id's until we transmit */
-    /* we will remove this on a later patch */
-    static int i = 0;
+    MultiFDInit_t msg;
+    Error *local_err = NULL;
+    size_t ret;
 
-    p = &multifd_recv_state->params[i];
-    i++;
+    ret = qio_channel_read_all(ioc, (char *)&msg, sizeof(msg), &local_err);
+    if (ret != 0) {
+        terminate_multifd_recv_threads(local_err);
+        return;
+    }
+
+    if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) {
+        char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid);
+        error_setg(&local_err, "multifd: received uuid '%s' and expected "
+                   "uuid '%s' for channel %hhd", msg.uuid, uuid, msg.id);
+        g_free(uuid);
+        terminate_multifd_recv_threads(local_err);
+        return;
+    }
+
+    p = &multifd_recv_state->params[msg.id];
+    if (p->c != NULL) {
+        error_setg(&local_err, "multifd: received id '%d' already setup'",
+                   msg.id);
+        terminate_multifd_recv_threads(local_err);
+        return;
+    }
     p->c = ioc;
     socket_recv_channel_ref(ioc);
 
-- 
2.14.3