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

[Paolo Bonzini]

On 21/03/2018 13:17, Laurent Vivier wrote:
> 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");

Nice, thanks.  Will do.

Paolo