[Qemu-devel] Re: [PATCH 3/4] qed: Report error for unsupported features

[Kevin Wolf <kwolf@redhat.com>]

Am 09.02.2011 12:21, schrieb Anthony Liguori:
> On 02/09/2011 04:32 AM, Kevin Wolf wrote:
>> Instead of just returning -ENOTSUP, generate a more detailed error.
>>
>> Unfortunately we don't have a helpful text for features that we don't know yet,
>> so just print the feature mask. It might be useful at least if someone asks for
>> help.
>>
>> Signed-off-by: Kevin Wolf<kwolf@redhat.com>
>>    
> 
> We can use a compatible feature to create a feature name table.

If you want to introduce something like this in a 0.14-rc2...? I'm not
going to write the code, but if someone sends a patch, we can consider it.

>> ---
>>   block/qed.c |    8 +++++++-
>>   1 files changed, 7 insertions(+), 1 deletions(-)
>>
>> diff --git a/block/qed.c b/block/qed.c
>> index 3273448..8b0a975 100644
>> --- a/block/qed.c
>> +++ b/block/qed.c
>> @@ -14,6 +14,7 @@
>>
>>   #include "trace.h"
>>   #include "qed.h"
>> +#include "qerror.h"
>>
>>   static void qed_aio_cancel(BlockDriverAIOCB *blockacb)
>>   {
>> @@ -311,7 +312,12 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
>>           return -EINVAL;
>>       }
>>       if (s->header.features&  ~QED_FEATURE_MASK) {
>> -        return -ENOTSUP; /* image uses unsupported feature bits */
>> +        /* image uses unsupported feature bits */
>> +        char version[64];
>> +        snprintf(version, sizeof(version), "%" PRIx64, s->header.features);
>>    
> 
> It would be useful to do s->header.features & QED_FEATURE_MASK here as a 
> management tool doesn't know what features this version of QED supports.

Makes sense. I'll change this for v2.

Kevin