[PATCH v1 04/16] vfio/ccw: move where IDA flag is set in ORB

Eric Farman
2022-11-21T21:41:52Z

The output of vfio_ccw is always a Format-2 IDAL, but the code that
explicitly sets this is buried in cp_init().

In fact the input is often already a Format-2 IDAL, and would be
rejected (via the check in ccwchain_calc_length()) if it weren't,
so explicitly setting it doesn't do much. Setting it way down here
only makes it impossible to make decisions in support of other
IDAL formats.

Let's move that to where the rest of the ORB is set up, so that the
CCW processing in cp_prefetch() is performed according to the
contents of the unmodified guest ORB.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
drivers/s390/cio/vfio_ccw_cp.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 268a90252521..3a11132b1685 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -707,15 +707,9 @@ int cp_init(struct channel_program *cp, union orb *orb)
/* Build a ccwchain for the first CCW segment */
ret = ccwchain_handle_ccw(orb->cmd.cpa, cp);

- if (!ret) {
+ if (!ret)
cp->initialized = true;

- /* It is safe to force: if it was not set but idals used
- * ccwchain_calc_length would have returned an error.
- */
- cp->orb.cmd.c64 = 1;
- }
-
return ret;
}

@@ -837,6 +831,11 @@ union orb *cp_get_orb(struct channel_program *cp, struct subchannel *sch)
orb->cmd.intparm = (u32)virt_to_phys(sch);
orb->cmd.fmt = 1;

+ /*
+ * Everything built by vfio-ccw is a Format-2 IDAL.
+ */
+ orb->cmd.c64 = 1;
+
if (orb->cmd.lpm == 0)
orb->cmd.lpm = sch->lpm;

--
2.34.1