Re: [Qemu-devel] [RFC 02/13] migration: Allow the migrate command to work on file: urls

[Hailiang Zhang <zhang.zhanghailiang@huawei.com>]

On 2016/7/14 0:12, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
>> Usage:
>> (qemu) migrate file:/path/to/vm_statefile
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
>> ---
>> - With this patch, we can easily test memory snapshot
>> - Rebase on qemu 2.5
>> ---
>>   include/migration/migration.h |  6 +++++-
>>   migration/fd.c                | 19 +++++++++++++++++--
>>   migration/migration.c         |  4 +++-
>>   3 files changed, 25 insertions(+), 4 deletions(-)
>
> Even if the rest of this series takes some time to finish; it might be
> best to post this patch separately - it just a nice bit of simplification.
> Of course now you have to rewrite using qio_channel_file_new_path
> but I guess it's simple.
>
> (I've tended to use migrate "exec:cat > file" but a file:  would be nice)
>

OK, if you need this, i will send it as a single patch.

Thanks.

> Dave
>
>> diff --git a/include/migration/migration.h b/include/migration/migration.h
>> index 4c80939..bf4f8e9 100644
>> --- a/include/migration/migration.h
>> +++ b/include/migration/migration.h
>> @@ -193,7 +193,11 @@ void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **
>>
>>   void fd_start_incoming_migration(const char *path, Error **errp);
>>
>> -void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
>> +void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
>> +                                 int outfd, Error **errp);
>> +
>> +void file_start_outgoing_migration(MigrationState *s, const char *filename,
>> +                                   Error **errp);
>>
>>   void rdma_start_outgoing_migration(void *opaque, const char *host_port, Error **errp);
>>
>> diff --git a/migration/fd.c b/migration/fd.c
>> index 3e4bed0..b62161f 100644
>> --- a/migration/fd.c
>> +++ b/migration/fd.c
>> @@ -42,9 +42,10 @@ static bool fd_is_socket(int fd)
>>       return S_ISSOCK(stat.st_mode);
>>   }
>>
>> -void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
>> +void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
>> +                                 int outfd, Error **errp)
>>   {
>> -    int fd = monitor_get_fd(cur_mon, fdname, errp);
>> +    int fd = fdname ? monitor_get_fd(cur_mon, fdname, errp) : outfd;
>>       if (fd == -1) {
>>           return;
>>       }
>> @@ -58,6 +59,20 @@ void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **
>>       migrate_fd_connect(s);
>>   }
>>
>> +void file_start_outgoing_migration(MigrationState *s, const char *filename,
>> +                                   Error **errp)
>> +{
>> +    int fd;
>> +
>> +    fd = qemu_open(filename, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
>> +    if (fd < 0) {
>> +        error_setg_errno(errp, errno, "Failed to open file: %s", filename);
>> +        return;
>> +    }
>> +    fd_start_outgoing_migration(s, NULL, fd, errp);
>> +}
>> +
>> +
>>   static void fd_accept_incoming_migration(void *opaque)
>>   {
>>       QEMUFile *f = opaque;
>> diff --git a/migration/migration.c b/migration/migration.c
>> index c842499..3ec3b85 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -1021,7 +1021,9 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>>       } else if (strstart(uri, "unix:", &p)) {
>>           unix_start_outgoing_migration(s, p, &local_err);
>>       } else if (strstart(uri, "fd:", &p)) {
>> -        fd_start_outgoing_migration(s, p, &local_err);
>> +        fd_start_outgoing_migration(s, p, -1, &local_err);
>> +    } else if (strstart(uri, "file:", &p)) {
>> +        file_start_outgoing_migration(s, p,  &local_err);
>>   #endif
>>       } else {
>>           error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
>> --
>> 1.8.3.1
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
> .
>