Re: [Qemu-devel] [PATCH 2/2] scsi-generic: Merge block max xfer len in INQUIRY response

[Paolo Bonzini <pbonzini@redhat.com>]

On 26/05/2016 08:15, Fam Zheng wrote:
> The rationale is similar to the above mode sense response interception:
> this is practically the only channel to communicate restraints from
> elsewhere such as host and block driver.
> 
> The scsi bus we attach onto can have a larger max xfer len than what is
> accepted by the host file system (guarding between the host scsi LUN and
> QEMU), in which case the SG_IO we generate would get -EINVAL.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>

The two patches are pretty much separate, so I'm queuing this myself.

Thanks,

Paolo

> ---
>  hw/scsi/scsi-generic.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
> index 7459465..71372a8 100644
> --- a/hw/scsi/scsi-generic.c
> +++ b/hw/scsi/scsi-generic.c
> @@ -222,6 +222,18 @@ static void scsi_read_complete(void * opaque, int ret)
>              r->buf[3] |= 0x80;
>          }
>      }
> +    if (s->type == TYPE_DISK &&
> +        r->req.cmd.buf[0] == INQUIRY &&
> +        r->req.cmd.buf[2] == 0xb0) {
> +        uint32_t max_xfer_len = blk_get_max_transfer_length(s->conf.blk);
> +        if (max_xfer_len) {
> +            stl_be_p(&r->buf[8], max_xfer_len);
> +            /* Also take care of the opt xfer len. */
> +            if (ldl_be_p(&r->buf[12]) > max_xfer_len) {
> +                stl_be_p(&r->buf[12], max_xfer_len);
> +            }
> +        }
> +    }
>      scsi_req_data(&r->req, len);
>      scsi_req_unref(&r->req);
>  }
>