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

[Lei Li <lilei@linux.vnet.ibm.com>]

On 06/17/2013 12:07 AM, Anthony Liguori wrote:
> Lei Li <lilei@linux.vnet.ibm.com> writes:
>
>> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
>> ---
>>   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