Re: [PATCH 01/10] scsi: xen: Drop use of internal host codes.

[Mike Christie <michael.christie@oracle.com>]

On 8/4/22 1:18 AM, Juergen Gross wrote:
> On 04.08.22 05:40, Mike Christie wrote:
>> The error codes:
>>
>> DID_TARGET_FAILURE
>> DID_NEXUS_FAILURE
>> DID_ALLOC_FAILURE
>> DID_MEDIUM_ERROR
>>
>> are internal to the SCSI layer. Drivers must not use them because:
>>
>> 1. They are not propagated upwards, so SG IO/passthrough users will not
>> see an error and think a command was successful.
>>
>> xen-scsiback will never see this error and should not try to send it.
>>
>> 2. There is no handling for them in scsi_decide_disposition so if
>> xen-scsifront were to return the error to scsi-ml then it kicks off the
>> error handler which is definitely not what we want.
>>
>> This patch remove the use from xen-scsifront/back.
>>
>> Signed-off-by: Mike Christie <michael.christie@oracle.com>
>> ---
>>   drivers/scsi/xen-scsifront.c       |  8 --------
>>   drivers/xen/xen-scsiback.c         | 12 ------------
>>   include/xen/interface/io/vscsiif.h | 10 +---------
>>   3 files changed, 1 insertion(+), 29 deletions(-)
>>
> 
> ...
> 
>> diff --git a/include/xen/interface/io/vscsiif.h b/include/xen/interface/io/vscsiif.h
>> index 7ea4dc9611c4..44eb1f34f1a0 100644
>> --- a/include/xen/interface/io/vscsiif.h
>> +++ b/include/xen/interface/io/vscsiif.h
>> @@ -316,16 +316,8 @@ struct vscsiif_response {
>>   #define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED 14
>>   /* Transport class fastfailed */
>>   #define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST  15
>> -/* Permanent target failure */
>> -#define XEN_VSCSIIF_RSLT_HOST_TARGET_FAILURE      16
>> -/* Permanent nexus failure on path */
>> -#define XEN_VSCSIIF_RSLT_HOST_NEXUS_FAILURE       17
>> -/* Space allocation on device failed */
>> -#define XEN_VSCSIIF_RSLT_HOST_ALLOC_FAILURE       18
>> -/* Medium error */
>> -#define XEN_VSCSIIF_RSLT_HOST_MEDIUM_ERROR        19
>>   /* Transport marginal errors */
>> -#define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL  20
>> +#define XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL  16
> 
> Please drop the modifications of this header.
> 
> This is a copy of the master from the Xen repository. It might be used
> in multiple OS'es across many releases, so it needs to be regarded as ABI.
> 

How do you want to handle scsifront_host_byte?

xen-scsiback.c will never return those error codes, but can some other
implementation? Do you want me to add translation from the XEN_VSCSIIF
to some other DID codes?