Re: [Qemu-block] [Qemu-devel] [PATCH] scsi: turn "is this a SCSI device?" into a conditional hint

[Laurent Vivier]

On 21/03/2018 11:58, Paolo Bonzini wrote:
> If the user does not have permissions to send ioctls to the device (due to
> SELinux or cgroups, for example), the output can look like
> 
> qemu-kvm: -device scsi-block,drive=disk: cannot get SG_IO version number:
>   Operation not permitted.  Is this a SCSI device?
> 
> but this is confusing because the ioctl was blocked _before_ the device
> even received the SG_GET_VERSION_NUM ioctl.  Therefore, for EPERM errors
> the suggestion should be eliminated.  To make that simpler, change the
> code to use error_append_hint.
> 
> Reported-by: Ala Hino <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  hw/scsi/scsi-disk.c    | 7 ++++---
>  hw/scsi/scsi-generic.c | 7 ++++---
>  2 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index 94043ed024..ccc245589a 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -2637,9 +2637,10 @@ static void scsi_block_realize(SCSIDevice *dev, Error 
> **errp)
>      /* check we are using a driver managing SG_IO (version 3 and after) */
>      rc = blk_ioctl(s->qdev.conf.blk, SG_GET_VERSION_NUM, &sg_version);
>      if (rc < 0) {
> -        error_setg(errp, "cannot get SG_IO version number: %s.  "
> -                     "Is this a SCSI device?",
> -                     strerror(-rc));
> +        error_setg(errp, "cannot get SG_IO version number: %s", 
> strerror(-rc));


You could use:

  error_setg_errno(errp, -rc, "cannot get SG_IO version number");

Thanks,
Laurent