[kvm-unit-tests PATCH v3 7/9] s390x: css: msch, enable test

Pierre Morel
2019-12-06T16:26:40Z

A second step when testing the channel subsystem is to prepare a channel
for use.
This includes:
- Get the current SubCHannel Information Block (SCHIB) using STSCH
- Update it in memory to set the ENABLE bit
- Tell the CSS that the SCHIB has been modified using MSCH
- Get the SCHIB from the CSS again to verify that the subchannel is
enabled.

This tests the success of the MSCH instruction by enabling a channel.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
s390x/css.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/s390x/css.c b/s390x/css.c
index 3d4a986..4c0031c 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -58,11 +58,50 @@ static void test_enumerate(void)
report("Tested %d devices, %d found", 1, scn, found);
}

+static void test_enable(void)
+{
+ struct pmcw *pmcw = &schib.pmcw;
+ int cc;
+
+ if (!test_device_sid) {
+ report_skip("No device");
+ return;
+ }
+ /* Read the SCIB for this subchannel */
+ cc = stsch(test_device_sid, &schib);
+ if (cc) {
+ report("stsch cc=%d", 0, cc);
+ return;
+ }
+ /* Update the SCHIB to enable the channel */
+ pmcw->flags |= PMCW_ENABLE;
+
+ /* Tell the CSS we want to modify the subchannel */
+ cc = msch(test_device_sid, &schib);
+ if (cc) {
+ report("msch cc=%d", 0, cc);
+ return;
+ }
+
+ /* Read the SCHIB again to verify the enablement */
+ cc = stsch(test_device_sid, &schib);
+ if (cc) {
+ report("stsch cc=%d", 0, cc);
+ return;
+ }
+ if (!(pmcw->flags & PMCW_ENABLE)) {
+ report("Enable failed. pmcw: %x", 0, pmcw->flags);
+ return;
+ }
+ report("Tested", 1);
+}
+
static struct {
const char *name;
void (*func)(void);
} tests[] = {
{ "enumerate (stsch)", test_enumerate },
+ { "enable (msch)", test_enable },
{ NULL, NULL }
};

--
2.17.0