Re: [Qemu-devel] [PATCH 4/7] migration-local: implementation of outgoing part

[Lei Li]

On 06/17/2013 12:07 AM, Anthony Liguori wrote:
> Lei Li <address@hidden> writes:
>
> > Signed-off-by: Lei Li <address@hidden>
> > ---
> >   Makefile.objs                 |    1 +
> >   include/migration/migration.h |   15 +++++
> >   migration-local.c             |  116 +++++++++++++++++++++++++++++++++++++++++
> >   migration-unix.c              |   13 +++++
> >   qapi-schema.json              |   14 +++++
> >   qmp-commands.hx               |   22 ++++++++
> >   6 files changed, 181 insertions(+), 0 deletions(-)
> >   create mode 100644 migration-local.c
> >
> > diff --git a/Makefile.objs b/Makefile.objs
> > index 5b288ba..2a3d9a5 100644
> > --- a/Makefile.objs
> > +++ b/Makefile.objs
> > @@ -53,6 +53,7 @@ common-obj-$(CONFIG_LINUX) += fsdev/
> >   common-obj-y += migration.o migration-tcp.o
> >   common-obj-y += qemu-char.o #aio.o
> >   common-obj-y += block-migration.o
> > +common-obj-y += migration-local.o
> >   common-obj-y += page_cache.o xbzrle.o
> >   
> >   common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
> > diff --git a/include/migration/migration.h b/include/migration/migration.h
> > index 9cc5285..12c75cf 100644
> > --- a/include/migration/migration.h
> > +++ b/include/migration/migration.h
> > @@ -58,6 +58,17 @@ struct MigrationState
> >       int64_t xbzrle_cache_size;
> >   };
> >   
> > +
> > +typedef struct LocalMigState LocalMigState;
> > +
> > +struct LocalMigState
> > +{
> > +    int fd;
> > +    int state;
> > +    QEMUFile *file;
> > +    QemuThread thread;
> > +};
> > +
> >   void process_incoming_migration(QEMUFile *f);
> >   
> >   void qemu_start_incoming_migration(const char *uri, Error **errp);
> > @@ -80,6 +91,8 @@ void unix_start_incoming_migration(const char *path, Error 
> > **errp);
> >   
> >   void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp);
> >   
> > +void unix_start_local_outgoing_migration(LocalMigState *s, const char *path, Error **errp);
> > +
> >   void fd_start_incoming_migration(const char *path, Error **errp);
> >   
> >   void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp);
> > @@ -90,6 +103,8 @@ void migrate_fd_connect(MigrationState *s);
> >   
> >   int migrate_fd_close(MigrationState *s);
> >   
> > +void migrate_fd_connect_local(LocalMigState *s);
> > +
> >   void add_migration_state_change_notifier(Notifier *notify);
> >   void remove_migration_state_change_notifier(Notifier *notify);
> >   bool migration_is_active(MigrationState *);
> > diff --git a/migration-local.c b/migration-local.c
> > new file mode 100644
> > index 0000000..a97dd3a
> > --- /dev/null
> > +++ b/migration-local.c
> > @@ -0,0 +1,116 @@
> > +/*
> > + * QEMU localhost live migration
> > + *
> > + * Copyright IBM, Corp. 2013
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2.  See
> > + * the COPYING file in the top-level directory.
> > + *
> > + * Contributions are licensed under the terms of the GNU GPL, version 2
> > + * or (at your option) any later version.
> You can just add the "or later" clause to the first paragraph.

Sure.

> > + */
> > +
> > +#include "qemu-common.h"
> > +#include "migration/migration.h"
> > +#include "monitor/monitor.h"
> > +#include "migration/qemu-file.h"
> > +#include "sysemu/sysemu.h"
> > +#include "block/block.h"
> > +#include "qemu/sockets.h"
> > +#include "migration/block.h"
> > +#include "qemu/thread.h"
> > +#include "qmp-commands.h"
> > +#include "exec/memory.h"
> > +#include "trace.h"
> > +#include "qemu/osdep.h"
> > +
> > +//#define DEBUG_MIGRATION_LOCAL
> > +
> > +#ifdef DEBUG_MIGRATION_LOCAL
> > +#define DPRINTF(fmt, ...) \
> > +    do { printf("migration-local: " fmt, ## __VA_ARGS__); } while (0)
> > +#else
> > +#define DPRINTF(fmt, ...) \
> > +    do { } while (0)
> > +#endif
> > +
> > +
> > +/************************************************************************
> > + * Outgoing part
> > + */
> > +
> > +static void *migration_local_thread(void *opaque)
> > +{
> > +    LocalMigState *s = opaque;
> > +    int ret;
> > +    ram_addr_t size;
> > +
> > +    DPRINTF("Beginning savevm\n");
> > +
> > +    /* This will be replaced by new function qemu_save_local_state(). */
> > +    ret = qemu_save_device_state(s->file);
> > +    qemu_fclose(s->file);
> > +
> > +    if (ret < 0) {
> > +        s->state = MIG_STATE_ERROR;
> > +        return NULL;
> > +    } else {
> > +        /* XXX: The logic will be changed, need more work here. */
> > +        s->state = MIG_STATE_COMPLETED;
> > +
> > +        size = ram_bytes_total();
> > +        ram_madvise_free(size);
> > +    }
> > +
> > +    return NULL;
> > +}
> > +
> > +void migrate_fd_connect_local(LocalMigState *s)
> > +{
> > +    s->state = MIG_STATE_ACTIVE;
> > +    trace_migrate_set_state(MIG_STATE_ACTIVE);
> > +
> > +    qemu_thread_create(&s->thread, migration_local_thread, s,
> > +                       QEMU_THREAD_JOINABLE);
> > +}
> > +
> > +void qmp_localhost_migrate(const char *uri, Error **errp)
> > +{
> > +    const char *path;
> > +    Error *local_err = NULL;
> > +    int is_vm_running;
> > +    LocalMigState *s;
> > +
> > +    is_vm_running = runstate_is_running();
> > +
> > +    /* Stop the VM first */
> > +    if (is_vm_running) {
> > +        vm_stop(RUN_STATE_SAVE_VM);
> > +    }
> > +
> > +    bdrv_flush_all();
> > +
> > +    s = g_malloc0(sizeof(LocalMigState));
> > +
> > +    /* Start outgoing migration by unix socket. */
> > +    if (strstart(uri, "unix:", &path)) {
> > +        /* XXX. Creat a new unix_start_outgoing_migration_* is not necessary,
> > +         * just for the first step. This will be replaced by vmsplice
> > +         * mechanism. */
> > +        unix_start_local_outgoing_migration(s, path, &local_err);
> > +    } else {
> > +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "uri", "a valid migration 
> > protocol");
> > +        goto fail;
> > +    }
> > +
> > +    if (local_err) {
> > +        s->state = MIG_STATE_ERROR;
> > +        error_propagate(errp, local_err);
> > +        goto fail;
> > +    }
> > +
> > +fail:
> > +    if (!is_vm_running) {
> > +        vm_start();
> > +    }
> > +}
> > diff --git a/migration-unix.c b/migration-unix.c
> > index 94b7022..a21262a 100644
> > --- a/migration-unix.c
> > +++ b/migration-unix.c
> > @@ -49,6 +49,19 @@ void unix_start_outgoing_migration(MigrationState *s, const 
> > char *path, Error **
> >       unix_nonblocking_connect(path, unix_wait_for_connect, s, errp);
> >   }
> >   
> > +void unix_start_local_outgoing_migration(LocalMigState *s, const char *path, Error **errp)
> > +{
> > +    s->fd = unix_connect(path, errp);
> > +    if (s->fd < 0) {
> > +        s->file = NULL;
> > +        /* There should be a fd_error_set function */
> > +        s->state = MIG_STATE_ERROR;
> > +    } else {
> > +        s->file = qemu_fopen_socket(s->fd, "wb");
> > +        migrate_fd_connect_local(s);
> > +    }
> > +}
> > +
> Skipping most of the above as it's a work-in-progress.
>
> >   static void unix_accept_incoming_migration(void *opaque)
> >   {
> >       struct sockaddr_un addr;
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 5ad6894..2890f70 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -648,6 +648,20 @@
> >   { 'command': 'query-migrate-capabilities', 'returns':   
> > ['MigrationCapabilityStatus']}
> >   
> >   ##
> > +# @localhost-migrate
> > +#
> > +# Migrates the current running guest to another localhost VM.
> > +#
> > +# @uri: the Uniform Resource Identifier of the destination VM
> > +#
> > +# Returns: nothing on success
> > +#
> > +# Since: 1.7
> > +##
> > +{ 'command': 'localhost-migrate',
> > +  'data': {'uri': 'str'} }
> I suspect we should just do this as a flag to the existing migration
> command.  Perhaps we could even just use a capability.

Yeah, I had thought about this by adding a flag to the existing migration 
command like:

migrate -l for localhost migration.

This is just for a easy start.

> Regards,
>
> Anthony Liguori
>
> > +
> > +##
> >   # @MouseInfo:
> >   #
> >   # Information about a mouse device.
> > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > index 8cea5e5..bf6d042 100644
> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -787,6 +787,28 @@ Example:
> >   EQMP
> >   
> >       {
> > +        .name      = "localhost-migrate",
> > +        .args_type = "uri:s",
> > +        .mhandler.cmd_new = qmp_marshal_input_localhost_migrate,
> > +    },
> > +
> > +SQMP
> > +localhost-migrate
> > +
> > +Migrate VM in localhost.
> > +
> > +Arguments:
> > +
> > +- "uri": Destination URI (json-string)
> > +
> > +Example:
> > +
> > +-> { "execute": "localhost-migrate", "arguments": { "uri": "/tmp/foo" }
> > +<- { "return": {} }
> > +
> > +EQMP
> > +
> > +    {
> >           .name       = "dump-guest-memory",
> >           .args_type  = "paging:b,protocol:s,begin:i?,end:i?",
> >           .params     = "-p protocol [begin] [length]",
> > --
> > 1.7.7.6


--
Lei