[Qemu-devel] [PATCH 2/4] migration-tcp: add support for asynchronous incoming migration.

[Yoshiaki Tamura]

Introduce tcp_incoming_migration_async(), and register it handle
incoming migration asynchronously.  MigrateInocming is used to pass
argument to tcp_incoming_migration_async().
tcp_start_incoming_migration() allocates FdMigrationState, and returns
MigrationState to print incoming migration info.

Signed-off-by: Yoshiaki Tamura <address@hidden>
---
 migration-tcp.c |  109 ++++++++++++++++++++++++++++++++++++++++---------------
 migration.h     |    2 +-
 2 files changed, 80 insertions(+), 31 deletions(-)

diff --git a/migration-tcp.c b/migration-tcp.c
index 95ce722..b55e891 100644
--- a/migration-tcp.c
+++ b/migration-tcp.c
@@ -137,16 +137,54 @@ MigrationState *tcp_start_outgoing_migration(Monitor *mon,
     return &s->mig_state;
 }
 
+typedef struct MigrateIncoming {
+    FdMigrationState *s;
+    int c;
+} MigrateIncoming;
+
+static void tcp_incoming_migration_async(void *opaque)
+{
+    MigrateIncoming *p = opaque;
+    FdMigrationState *s = p->s;
+    QEMUFile *f = s->file;
+    int ret;
+
+    ret = qemu_loadvm_state_async(f);
+    if (ret < 0) {
+        s->state = MIG_STATE_ERROR;
+        fprintf(stderr, "load of migration failed\n");
+        goto out;
+    } else if (ret == 0) {
+        qemu_announce_self();
+        s->state = MIG_STATE_COMPLETED;
+        DPRINTF("successfully loaded vm state\n");
+
+        if (autostart) {
+            vm_start();
+        }
+
+        goto out;
+    }
+
+    return;
+
+out:
+    qemu_set_fd_handler2(p->c, NULL, NULL, NULL, NULL);
+    close(p->c);
+    migrate_fd_cleanup(s);
+    qemu_free(p);
+}
+
 static void tcp_accept_incoming_migration(void *opaque)
 {
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
-    int s = (unsigned long)opaque;
-    QEMUFile *f;
+    FdMigrationState *s = opaque;
+    MigrateIncoming *p;
     int c, ret;
 
     do {
-        c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
+        c = qemu_accept(s->fd, (struct sockaddr *)&addr, &addrlen);
     } while (c == -1 && socket_error() == EINTR);
 
     DPRINTF("accepted migration\n");
@@ -156,61 +194,72 @@ static void tcp_accept_incoming_migration(void *opaque)
         return;
     }
 
-    f = qemu_fopen_socket(c);
-    if (f == NULL) {
+    p = qemu_mallocz(sizeof(MigrateIncoming));
+    p->s = s;
+    p->c = c;    
+
+    s->file = qemu_fopen_socket(c);
+    if (s->file == NULL) {
         fprintf(stderr, "could not qemu_fopen socket\n");
         goto out;
     }
 
-    ret = qemu_loadvm_state(f);
+    ret = qemu_loadvm_state_begin(s->file);
     if (ret < 0) {
-        fprintf(stderr, "load of migration failed\n");
-        goto out_fopen;
+        goto out;
     }
-    qemu_announce_self();
-    DPRINTF("successfully loaded vm state\n");
 
-    if (autostart)
-        vm_start();
+    qemu_set_fd_handler2(c, NULL, tcp_incoming_migration_async, NULL, p);
+
+    return;
 
-out_fopen:
-    qemu_fclose(f);
 out:
-    qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
-    close(s);
     close(c);
+    migrate_fd_release(&s->mig_state);
+    qemu_free(p);
 }
 
-int tcp_start_incoming_migration(const char *host_port)
+MigrationState *tcp_start_incoming_migration(const char *host_port)
 {
     struct sockaddr_in addr;
+    FdMigrationState *s;
     int val;
-    int s;
 
     if (parse_host_port(&addr, host_port) < 0) {
         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
-        return -EINVAL;
+        return NULL;
     }
 
-    s = qemu_socket(PF_INET, SOCK_STREAM, 0);
-    if (s == -1)
-        return -socket_error();
+    s = qemu_mallocz(sizeof(*s));
+
+    s->get_error = socket_errno;
+    s->close = tcp_close;
+    s->mig_state.cancel = migrate_fd_cancel;
+    s->mig_state.get_status = migrate_fd_get_status;
+    s->mig_state.release = migrate_fd_release;
+    s->state = MIG_STATE_ACTIVE;
+
+    s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
+    if (s->fd == -1) {
+        qemu_free(s);
+        return NULL;
+    }
 
     val = 1;
-    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
+    setsockopt(s->fd, SOL_SOCKET, SO_REUSEADDR, (const char *)&val,
+               sizeof(val));
 
-    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
+    if (bind(s->fd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
         goto err;
 
-    if (listen(s, 1) == -1)
+    if (listen(s->fd, 1) == -1)
         goto err;
 
-    qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
-                         (void *)(unsigned long)s);
+    qemu_set_fd_handler2(s->fd, NULL, tcp_accept_incoming_migration, NULL, s);
 
-    return 0;
+    return &s->mig_state;
 
 err:
-    close(s);
-    return -socket_error();
+    migrate_fd_release(&s->mig_state);
+    return NULL;
 }
diff --git a/migration.h b/migration.h
index 385423f..c11e6db 100644
--- a/migration.h
+++ b/migration.h
@@ -76,7 +76,7 @@ MigrationState *exec_start_outgoing_migration(Monitor *mon,
                                              int blk,
                                              int inc);
 
-int tcp_start_incoming_migration(const char *host_port);
+MigrationState *tcp_start_incoming_migration(const char *host_port);
 
 MigrationState *tcp_start_outgoing_migration(Monitor *mon,
                                              const char *host_port,
-- 
1.7.0.31.g1df487