Re: [Qemu-block] [Qemu-devel] [PATCH 3/3] ide: abort TRIM operation for invalid range

[John Snow]

On 12/08/2017 07:10 AM, Anton Nefedov wrote:
> ATA8-ACS3, 7.9 DATA SET MANAGEMENT - 06h, DMA
> 
>     7.9.5 Error Outputs
>     If the Trim bit is set to one and:
>       a) the device detects an invalid LBA Range Entry; or
>       b) count is greater than IDENTIFY DEVICE data word 105
>          (see 7.16.7.55),
>     then the device shall return command aborted.
>     A device may trim one or more LBA Range Entries before it returns
>     command aborted. See table 209.
> 
> This check is not in the common ide_dma_cb() as the range for TRIM
> is harder to reach: it is not in LBA/count registers and the buffer has
> to be parsed first.
> 
> Signed-off-by: Anton Nefedov <address@hidden>
> ---
>  hw/ide/core.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index 23c71fa..3d1494f 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -401,6 +401,7 @@ typedef struct TrimAIOCB {
>      QEMUIOVector *qiov;
>      BlockAIOCB *aiocb;
>      int i, j;
> +    bool is_invalid;
>  } TrimAIOCB;
>  
>  static void trim_aio_cancel(BlockAIOCB *acb)
> @@ -428,8 +429,11 @@ static void ide_trim_bh_cb(void *opaque)
>  {
>      TrimAIOCB *iocb = opaque;
>  
> -    iocb->common.cb(iocb->common.opaque, iocb->ret);
> -
> +    if (iocb->is_invalid) {
> +        ide_dma_error(iocb->s);
> +    } else {
> +        iocb->common.cb(iocb->common.opaque, iocb->ret);
> +    }
>      qemu_bh_delete(iocb->bh);
>      iocb->bh = NULL;
>      qemu_aio_unref(iocb);
> @@ -456,6 +460,11 @@ static void ide_issue_trim_cb(void *opaque, int ret)
>                      continue;
>                  }
>  
> +                if (!ide_sect_range_ok(s, sector, count)) {
> +                    iocb->is_invalid = true;
> +                    goto done;
> +                }
> +
>                  /* Got an entry! Submit and exit.  */
>                  iocb->aiocb = blk_aio_pdiscard(s->blk,
>                                                 sector << BDRV_SECTOR_BITS,
> @@ -471,6 +480,7 @@ static void ide_issue_trim_cb(void *opaque, int ret)
>          iocb->ret = ret;
>      }
>  
> +done:
>      iocb->aiocb = NULL;
>      if (iocb->bh) {
>          qemu_bh_schedule(iocb->bh);
> @@ -491,6 +501,7 @@ BlockAIOCB *ide_issue_trim(
>      iocb->qiov = qiov;
>      iocb->i = -1;
>      iocb->j = 0;
> +    iocb->is_invalid = false;
>      ide_issue_trim_cb(iocb, 0);
>      return &iocb->common;
>  }>

Looks about right, just remember that this flow won't call
block_acct_invalid because you're bypassing the return to ide_dma_cb. I
assume you'll get to that in your next series.

For now, this should properly reject bogus TRIM commands. When you send
your next series, may I ask for a simple test case if possible?

1-3:
Reviewed-by: John Snow <address@hidden>