From: Aboo Valappil <aboo@xxxxxxxx> Subject: SCSITAP, Virtual SCSI HBA and user space SCSI initiators Date: Fri, 13 Oct 2006 03:25:46 +1000 > I have developed a Virtual HBA (Around ~600 lines of code). It is a > kernel module and works very well with 2.6.9 kernel. Basically it > registers a HBA (LLD) to the SCSI Mid layer. It implements a linked list > with all the SCSI commands queued from Mid layer. I registered a > character device driver. I ship out the SCSI commands off to user space > via this character device. There is a user space application monitoring > this character device looking for SCSI commands, process it and sends it > back to the mid layer through this character interface. At the moment, > the interface to the Virtual HBA inside the kernel is through read/write > and ioctls to the character device. I am trying to get rid of reading > and writing of SCSI request_buffer through character device and use > memmap/splice to avoid copying kernel buffer to user space(I am facing > some challenges as the request_buffer is not a linear buffer, but a > scatter gather buffer). As James and Mike said, tgt provides SCSI command processing in user space (target mode). I implemented the virtual HBA driver (initiator mode) for Xen that works with tgt. I guess that it is similar to your virtual HBA driver. You can find the slides in Xen Summit site: http://www.xensource.com/xen/xensummit.html - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
