Re: [Qemu-devel] [PATCH v2 27/45] scsi-disk: Preserve tray state on migration

[Hannes Reinecke <hare@suse.de>]

On 08/03/2011 03:08 PM, Markus Armbruster wrote:
> Breaks migration of qdevs "scsi-cd" and legacy "scsi-disk" to older
> versions.  We normally use subsections to avoid that.  Not possible
> here, because we don't have a section to begin with.  Too bad.
>
> Signed-off-by: Markus Armbruster<armbru@redhat.com>
> ---
>   hw/scsi-disk.c |   35 +++++++++++++++++++++++++++++++++++
>   1 files changed, 35 insertions(+), 0 deletions(-)
>
> diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
> index f223de6..04e0a77 100644
> --- a/hw/scsi-disk.c
> +++ b/hw/scsi-disk.c
> @@ -1301,6 +1301,39 @@ static int scsi_disk_initfn(SCSIDevice *dev)
>       return scsi_initfn(dev, scsi_type);
>   }
>
> +static int scsi_cd_post_load(void *opaque, int version_id)
> +{
> +    SCSIDiskState *s = opaque;
> +
> +    bdrv_eject(s->bs, s->tray_open);
> +    bdrv_lock_medium(s->bs, s->tray_locked);
> +    return 0;
> +}
> +
> +static const VMStateDescription vmstate_scsi_cd = {
> +    .name = "scsi-cd",
> +    .version_id = 0,
> +    .minimum_version_id = 0,
> +    .post_load = scsi_cd_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_BOOL(tray_open, SCSIDiskState),
> +        VMSTATE_BOOL(tray_locked, SCSIDiskState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static const VMStateDescription vmstate_scsi_disk = {
> +    .name = "scsi-disk",
> +    .version_id = 0,
> +    .minimum_version_id = 0,
> +    .post_load = scsi_cd_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_BOOL(tray_open, SCSIDiskState),
> +        VMSTATE_BOOL(tray_locked, SCSIDiskState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
And again; if we had just one 'flags' value we would have to save 
only one variable. And wouldn't need to touch this one for future 
states.

>   #define DEFINE_SCSI_DISK_PROPERTIES()                           \
>       DEFINE_BLOCK_PROPERTIES(SCSIDiskState, qdev.conf),          \
>       DEFINE_PROP_STRING("ver",  SCSIDiskState, version),         \
> @@ -1333,6 +1366,7 @@ static SCSIDeviceInfo scsi_disk_info[] = {
>           .qdev.fw_name = "disk",
>           .qdev.desc    = "virtual SCSI CD-ROM",
>           .qdev.size    = sizeof(SCSIDiskState),
> +        .qdev.vmsd    =&vmstate_scsi_cd,
>           .qdev.reset   = scsi_disk_reset,
>           .init         = scsi_cd_initfn,
>           .destroy      = scsi_destroy,
> @@ -1353,6 +1387,7 @@ static SCSIDeviceInfo scsi_disk_info[] = {
>           .qdev.fw_name = "disk",
>           .qdev.desc    = "virtual SCSI disk or CD-ROM (legacy)",
>           .qdev.size    = sizeof(SCSIDiskState),
> +        .qdev.vmsd    =&vmstate_scsi_disk,
>           .qdev.reset   = scsi_disk_reset,
>           .init         = scsi_disk_initfn,
>           .destroy      = scsi_destroy,

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)