On Wed, Nov 28, 2018 at 05:50:01PM +0200, Liran Alon wrote:
From: Nikita Leshchenko email@example.com
When mpt-scsi receives a SCSI message, it wraps it in a MPT request message and writes it's address to an IO port to be added to the request queue.
This MPT request is allocated on the stack. Previous to this commit, the request is aligned to 4 bytes. However, VirtualBox LSI53c1030 device emulation aligns the request address to 8 bytes. Therefore, this commit change alignment of request to 8 bytes.
VirtualBox source code which handles this is at Devices/Storage/DevLsiLogicSCSI.cpp. lsilogicRegisterWrite() LSILOGIC_REG_REQUEST_QUEUE handler adds the request to the queue (pRequestQueueBase). lsilogicR3Worker() reads request from pRequestQueueBase and aligns it to 8 bytes (u32RequestMessageFrameDesc & ~0x07).
Thanks. Is this change done to match virtualbox, or because it fixes some type of problem?