Re: [Qemu-devel] [PATCH] scsi: Fix migration of scsi sense data

[Paolo Bonzini <pbonzini@redhat.com>]

Il 06/03/2014 09:26, Fam Zheng ha scritto:
> c5f52875 changed the size of sense array in vmstate_scsi_device by
> mistake. This patch restores the old size, and add a subsection for the
> remaining part of the buffer size. So that migration is not broken.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  hw/scsi/scsi-bus.c          | 30 +++++++++++++++++++++++++++++-
>  include/hw/scsi/scsi.h      |  1 +
>  include/migration/vmstate.h |  3 +++
>  3 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
> index 50a0acf..eaad925 100644
> --- a/hw/scsi/scsi-bus.c
> +++ b/hw/scsi/scsi-bus.c
> @@ -1905,6 +1905,26 @@ static const VMStateInfo vmstate_info_scsi_requests = {
>      .put  = put_scsi_requests,
>  };
>
> +static bool scsi_sense_state_needed(void *opaque)
> +{
> +    SCSIDevice *s = opaque;
> +
> +    return s->sense_len > SCSI_SENSE_BUF_SIZE_OLD;
> +}
> +
> +static const VMStateDescription vmstate_scsi_sense_state = {
> +    .name = "SCSIDevice/sense",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .minimum_version_id_old = 1,
> +    .fields      = (VMStateField []) {
> +        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
> +                                SCSI_SENSE_BUF_SIZE_OLD,
> +                                SCSI_SENSE_BUF_SIZE - SCSI_SENSE_BUF_SIZE_OLD),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  const VMStateDescription vmstate_scsi_device = {
>      .name = "SCSIDevice",
>      .version_id = 1,
> @@ -1915,7 +1935,7 @@ const VMStateDescription vmstate_scsi_device = {
>          VMSTATE_UINT8(unit_attention.asc, SCSIDevice),
>          VMSTATE_UINT8(unit_attention.ascq, SCSIDevice),
>          VMSTATE_BOOL(sense_is_ua, SCSIDevice),
> -        VMSTATE_UINT8_ARRAY(sense, SCSIDevice, SCSI_SENSE_BUF_SIZE),
> +        VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice, 0, SCSI_SENSE_BUF_SIZE_OLD),
>          VMSTATE_UINT32(sense_len, SCSIDevice),
>          {
>              .name         = "requests",
> @@ -1927,6 +1947,14 @@ const VMStateDescription vmstate_scsi_device = {
>              .offset       = 0,
>          },
>          VMSTATE_END_OF_LIST()
> +    },
> +    .subsections = (VMStateSubsection []) {
> +        {
> +            .vmsd = &vmstate_scsi_sense_state,
> +            .needed = scsi_sense_state_needed,
> +        }, {
> +            /* empty */
> +        }
>      }
>  };
>
> diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
> index e5fc39d..1adb549 100644
> --- a/include/hw/scsi/scsi.h
> +++ b/include/hw/scsi/scsi.h
> @@ -31,6 +31,7 @@ typedef struct SCSISense {
>      uint8_t ascq;
>  } SCSISense;
>
> +#define SCSI_SENSE_BUF_SIZE_OLD 96
>  #define SCSI_SENSE_BUF_SIZE 252
>
>  struct SCSICommand {
> diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
> index ded8e23..e7e1705 100644
> --- a/include/migration/vmstate.h
> +++ b/include/migration/vmstate.h
> @@ -650,6 +650,9 @@ extern const VMStateInfo vmstate_info_bitmap;
>  #define VMSTATE_UINT8_ARRAY(_f, _s, _n)                               \
>      VMSTATE_UINT8_ARRAY_V(_f, _s, _n, 0)
>
> +#define VMSTATE_UINT8_SUB_ARRAY(_f, _s, _start, _num)                \
> +    VMSTATE_SUB_ARRAY(_f, _s, _start, _num, 0, vmstate_info_uint8, uint8_t)
> +
>  #define VMSTATE_UINT8_2DARRAY(_f, _s, _n1, _n2)                       \
>      VMSTATE_UINT8_2DARRAY_V(_f, _s, _n1, _n2, 0)
>
>

Looks good, thanks!  I'll apply to scsi-next after a little more testing.

Paolo