Re: [Qemu-devel] [PULL 32/35] ahci: ncq migration

[Paolo Bonzini <pbonzini@redhat.com>]

On 04/07/2015 08:07, John Snow wrote:
> Migrate the NCQ queue. This is solely for the benefit of halted commands,
> since anything else should have completed and had any relevant status
> flushed to the HBA registers already.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Message-id: 1435767578-32743-13-git-send-email-jsnow@redhat.com
> ---
>  hw/ide/ahci.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
> index 13b0157..a2620f6 100644
> --- a/hw/ide/ahci.c
> +++ b/hw/ide/ahci.c
> @@ -1521,6 +1521,21 @@ void ahci_reset(AHCIState *s)
>      }
>  }
>  
> +static const VMStateDescription vmstate_ncq_tfs = {
> +    .name = "ncq state",
> +    .version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_UINT32(sector_count, NCQTransferState),
> +        VMSTATE_UINT64(lba, NCQTransferState),
> +        VMSTATE_UINT8(tag, NCQTransferState),
> +        VMSTATE_UINT8(cmd, NCQTransferState),
> +        VMSTATE_UINT8(slot, NCQTransferState),
> +        VMSTATE_BOOL(used, NCQTransferState),
> +        VMSTATE_BOOL(halt, NCQTransferState),
> +        VMSTATE_END_OF_LIST()
> +    },
> +};
> +
>  static const VMStateDescription vmstate_ahci_device = {
>      .name = "ahci port",
>      .version_id = 1,
> @@ -1546,14 +1561,17 @@ static const VMStateDescription vmstate_ahci_device = {
>          VMSTATE_BOOL(done_atapi_packet, AHCIDevice),
>          VMSTATE_INT32(busy_slot, AHCIDevice),
>          VMSTATE_BOOL(init_d2h_sent, AHCIDevice),
> +        VMSTATE_STRUCT_ARRAY(ncq_tfs, AHCIDevice, AHCI_MAX_CMDS,
> +                             1, vmstate_ncq_tfs, NCQTransferState),
>          VMSTATE_END_OF_LIST()
>      },
>  };
>  
>  static int ahci_state_post_load(void *opaque, int version_id)
>  {
> -    int i;
> +    int i, j;
>      struct AHCIDevice *ad;
> +    NCQTransferState *ncq_tfs;
>      AHCIState *s = opaque;
>  
>      for (i = 0; i < s->ports; i++) {
> @@ -1565,6 +1583,37 @@ static int ahci_state_post_load(void *opaque, int version_id)
>              return -1;
>          }
>  
> +        for (j = 0; j < AHCI_MAX_CMDS; j++) {
> +            ncq_tfs = &ad->ncq_tfs[j];
> +            ncq_tfs->drive = ad;
> +
> +            if (ncq_tfs->used != ncq_tfs->halt) {
> +                return -1;
> +            }
> +            if (!ncq_tfs->halt) {
> +                continue;
> +            }
> +            if (!is_ncq(ncq_tfs->cmd)) {
> +                return -1;
> +            }
> +            if (ncq_tfs->slot != ncq_tfs->tag) {
> +                return -1;
> +            }
> +            /* If ncq_tfs->halt is justly set, the engine should be engaged,
> +             * and the command list buffer should be mapped. */
> +            ncq_tfs->cmdh = get_cmd_header(s, i, ncq_tfs->slot);
> +            if (!ncq_tfs->cmdh) {
> +                return -1;
> +            }
> +            ahci_populate_sglist(ncq_tfs->drive, &ncq_tfs->sglist,
> +                                 ncq_tfs->cmdh, ncq_tfs->sector_count * 512,

sector_count should be cast to a 64-bit type before multiplying it.

Paolo

> +                                 0);
> +            if (ncq_tfs->sector_count != ncq_tfs->sglist.size >> 9) {
> +                return -1;
> +            }
> +        }
> +
> +
>          /*
>           * If an error is present, ad->busy_slot will be valid and not -1.
>           * In this case, an operation is waiting to resume and will re-check
>