Question on VRING_DESC_F_WRITE flag

Hi,

 

I have a question on VRING_DESC_F_WRITE flag.  As per the specifications, if this flag is set, then the corresponding buffer pointed by the descriptor is Write only, otherwise Read Only.  I am trying to understand why there is no READ_AND_WRITE
 option, i.e. a buffer could be Read by device emulation and written back into. 

 

Is there any issue or concern because of which it was not considered? 

 

If this is not the right mailing list to raise this question,  any pointers would help.

 

Thanks,

Subha