2010/6/2 Anthony Liguori <aligu...@linux.vnet.ibm.com>:
> On 06/01/2010 11:23 AM, Yoshiaki Tamura wrote:
>>
>> 2010/6/2 Anthony Liguori<aligu...@linux.vnet.ibm.com>:
>>
>>>
>>> On 06/01/2010 10:40 AM, Yoshiaki Tamura wrote:
>>>
>>>>
>>>> Create a thread to handle tcp incoming migration when CONFIG_IOTHREAD
>>>> is enabled. Spawned thread writes it's return status to th_fds[1]
>>>> before exit, and main thread joins and reads it. In
>>>> tcp_start_incoming_migration(), allocate FdMigrationState and return
>>>> MigrationState to let migration to print incoming migration info.
>>>>
>>>>
>>>
>>> In the absence of any locking, I can't see how this is safe.
>>>
>>
>> Right. If we use threading here, we need to prevent commands from
>> monitor that affects incoming thread.
>>
>
> There's a huge number of calls that can get made during live migration that
> can also be triggered by the monitor.
>
> Even the basic things likes qemu_set_fd_handler2 can cause havoc.
>
> Just preventing certain monitor commands is not sufficient.
Ah, that was my concern. Sorry for not understanding well.
Thanks for your advice.
Yoshi
>
> Regards,
>
> Anthony Liguori
>
>> Thanks,
>>
>> Yoshi
>>
>>
>>>
>>> Regards,
>>>
>>> Anthony Liguori
>>>
>>>
>>>>
>>>> Signed-off-by: Yoshiaki Tamura<tamura.yoshi...@lab.ntt.co.jp>
>>>> ---
>>>> migration-tcp.c | 86
>>>> ++++++++++++++++++++++++++++++++++++++++++++++---------
>>>> migration.h | 2 +-
>>>> 2 files changed, 73 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/migration-tcp.c b/migration-tcp.c
>>>> index 95ce722..f20e5fe 100644
>>>> --- a/migration-tcp.c
>>>> +++ b/migration-tcp.c
>>>> @@ -18,6 +18,7 @@
>>>> #include "sysemu.h"
>>>> #include "buffered_file.h"
>>>> #include "block.h"
>>>> +#include "qemu-thread.h"
>>>>
>>>> //#define DEBUG_MIGRATION_TCP
>>>>
>>>> @@ -29,6 +30,11 @@
>>>> do { } while (0)
>>>> #endif
>>>>
>>>> +#ifdef CONFIG_IOTHREAD
>>>> +static QemuThread migration_thread;
>>>> +static int th_fds[2];
>>>> +#endif
>>>> +
>>>> static int socket_errno(FdMigrationState *s)
>>>> {
>>>> return socket_error();
>>>> @@ -176,41 +182,93 @@ static void tcp_accept_incoming_migration(void
>>>> *opaque)
>>>> out_fopen:
>>>> qemu_fclose(f);
>>>> out:
>>>> +#ifndef CONFIG_IOTHREAD
>>>> qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
>>>> +#endif
>>>> close(s);
>>>> close(c);
>>>> +#ifdef CONFIG_IOTHREAD
>>>> + write(th_fds[1],&ret, sizeof(ret));
>>>> + qemu_thread_exit(NULL);
>>>> +#endif
>>>> +}
>>>> +
>>>> +#ifdef CONFIG_IOTHREAD
>>>> +static void tcp_incoming_migration_complete(void *opaque)
>>>> +{
>>>> + int ret, state = 0;
>>>> + FdMigrationState *s = opaque;
>>>> +
>>>> + qemu_thread_join(&migration_thread, NULL);
>>>> +
>>>> + ret = read(th_fds[0],&state, sizeof(state));
>>>> + if (ret == -1) {
>>>> + fprintf(stderr, "failed to read from pipe\n");
>>>> + goto err;
>>>> + }
>>>> +
>>>> + s->state = state< 0 ? MIG_STATE_ERROR : MIG_STATE_COMPLETED;
>>>> +
>>>> +err:
>>>> + qemu_set_fd_handler2(th_fds[0], NULL, NULL, NULL, NULL);
>>>> + close(th_fds[0]);
>>>> + close(th_fds[1]);
>>>> }
>>>> +#endif
>>>>
>>>> -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->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);
>>>> +#ifdef CONFIG_IOTHREAD
>>>> + if (qemu_pipe(th_fds) == -1) {
>>>> + fprintf(stderr, "failed to create pipe\n");
>>>> + goto err;
>>>> + }
>>>>
>>>> - return 0;
>>>> + qemu_thread_create(&migration_thread, (void
>>>> *)tcp_accept_incoming_migration,
>>>> + (void *)(unsigned long)s->fd);
>>>> + qemu_set_fd_handler2(th_fds[0], NULL,
>>>> tcp_incoming_migration_complete, NULL,
>>>> + (void *)s);
>>>> +#else
>>>> + qemu_set_fd_handler2(s->fd, NULL, tcp_accept_incoming_migration,
>>>> NULL,
>>>> + (void *)(unsigned long)s->fd);
>>>> +#endif
>>>> +
>>>> + return&s->mig_state;
>>>>
>>>> err:
>>>> - close(s);
>>>> - return -socket_error();
>>>> + close(s->fd);
>>>> + 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,
>>>>
>>>>
>>>
>>>
>>>
>
>
>
