Quoting Eric Farman (2022-11-09 21:21:56) > From: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> > > The ORB is a construct that is sent to the real hardware, > so should contain a physical address in its interrupt > parameter field. Let's clarify that. Maybe I don't get it, but I think the commit description is inaccurate. The PoP says (p. 15-25): > Bits 0-31 of word 0 are > preserved unmodified in the subchannel until > replaced by a subsequent START SUBCHANNEL or > MODIFY SUBCHANNEL instruction. These bits are > placed in word 1 of the interruption code when an I/O > interruption occurs and when an interruption request > is cleared by the execution of TEST PENDING > INTERRUPTION. So the hardware actually doesn't care what kind of address this is. Rather, the CIO driver expects the intparam to be a physical address - probably so it fits 32 bits -, see do_cio_interrupt.