[4/4] migration/savevm: wrap into qemu_loadvm_state_header()

On source side, we have qemu_savevm_state_header() to send related data,
while on the receiving side those steps are scattered in
qemu_loadvm_state().

This patch wrap those related steps into qemu_loadvm_state_header() to
make it friendly to read.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/savevm.c | 69 +++++++++++++++++++++++++++-------------------
 1 file changed, 40 insertions(+), 29 deletions(-)

On 4/23/19 9:47 PM, Wei Yang wrote:
> On source side, we have qemu_savevm_state_header() to send related data,
> while on the receiving side those steps are scattered in
> qemu_loadvm_state().
>
> This patch wrap those related steps into qemu_loadvm_state_header() to
> make it friendly to read.
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>


Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>


> ---
>   migration/savevm.c | 69 +++++++++++++++++++++++++++-------------------
>   1 file changed, 40 insertions(+), 29 deletions(-)
>
> diff --git a/migration/savevm.c b/migration/savevm.c
> index a80ae83663..64d23682c6 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -2256,6 +2256,43 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
>       return 0;
>   }
>   
> +static int qemu_loadvm_state_header(QEMUFile *f)
> +{
> +    unsigned int v;
> +    int ret;
> +
> +    v = qemu_get_be32(f);
> +    if (v != QEMU_VM_FILE_MAGIC) {
> +        error_report("Not a migration stream");
> +        return -EINVAL;
> +    }
> +
> +    v = qemu_get_be32(f);
> +    if (v == QEMU_VM_FILE_VERSION_COMPAT) {
> +        error_report("SaveVM v2 format is obsolete and don't work anymore");
> +        return -ENOTSUP;
> +    }
> +    if (v != QEMU_VM_FILE_VERSION) {
> +        error_report("Unsupported migration stream version");
> +        return -ENOTSUP;
> +    }
> +
> +    if (migrate_get_current()->send_configuration) {
> +        if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
> +            error_report("Configuration section missing");
> +            qemu_loadvm_state_cleanup();
> +            return -EINVAL;
> +        }
> +        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
> +
> +        if (ret) {
> +            qemu_loadvm_state_cleanup();
> +            return ret;
> +        }
> +    }
> +    return 0;
> +}
> +
>   static int qemu_loadvm_state_setup(QEMUFile *f)
>   {
>       SaveStateEntry *se;
> @@ -2403,7 +2440,6 @@ int qemu_loadvm_state(QEMUFile *f)
>   {
>       MigrationIncomingState *mis = migration_incoming_get_current();
>       Error *local_err = NULL;
> -    unsigned int v;
>       int ret;
>   
>       if (migration_is_blocked(&local_err)) {
> @@ -2411,34 +2447,9 @@ int qemu_loadvm_state(QEMUFile *f)
>           return -EINVAL;
>       }
>   
> -    v = qemu_get_be32(f);
> -    if (v != QEMU_VM_FILE_MAGIC) {
> -        error_report("Not a migration stream");
> -        return -EINVAL;
> -    }
> -
> -    v = qemu_get_be32(f);
> -    if (v == QEMU_VM_FILE_VERSION_COMPAT) {
> -        error_report("SaveVM v2 format is obsolete and don't work anymore");
> -        return -ENOTSUP;
> -    }
> -    if (v != QEMU_VM_FILE_VERSION) {
> -        error_report("Unsupported migration stream version");
> -        return -ENOTSUP;
> -    }
> -
> -    if (migrate_get_current()->send_configuration) {
> -        if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
> -            error_report("Configuration section missing");
> -            qemu_loadvm_state_cleanup();
> -            return -EINVAL;
> -        }
> -        ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
> -
> -        if (ret) {
> -            qemu_loadvm_state_cleanup();
> -            return ret;
> -        }
> +    ret = qemu_loadvm_state_header(f);
> +    if (ret) {
> +        return ret;
>       }
>   
>       if (qemu_loadvm_state_setup(f) != 0) {