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

[Hailiang Zhang]

On 2016/7/14 0:12, Dr. David Alan Gilbert wrote:
> * zhanghailiang (address@hidden) wrote:
> > Usage:
> > (qemu) migrate file:/path/to/vm_statefile
> >
> > Signed-off-by: zhanghailiang <address@hidden>
> > Signed-off-by: Benoit Canet <address@hidden>
> > ---
> > - 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 / address@hidden / Manchester, UK
>
> .